Labrie F, Cusan L, Gomez JL, Diamond P, Candas B
Prostate Cancer Research Unit, CHUL Research Center, Le Centre Hospitalier de l'Universite Laval, Quebec, Canada.
J Clin Endocrinol Metab 1995 Jul;80(7):2002-13

Prostate cancer is the second cause of cancer death in men in the Western world; its medical and social impact is comparable to that of breast cancer in women. Although it is well recognized that early treatment is the only possibility for reducing the high rate of death from prostate cancer, screening and even early treatment are controversial issues due mainly to arguments based upon old literature and lack of awareness of the significant advances recently made in this field. As it is well known that surgical removal of organ-confined prostate cancer cures the disease, and it has been demonstrated that annual screening with prostate-specific antigen coupled with digital rectal examination followed, when indicated, by transrectal ultrasonography of the prostate more than doubles the proportion of organ-confined disease, screening alone offers the possibility of at least doubling the number of patients curable from prostate cancer or the potential for a cure to an estimated 45% of prostate cancer patients compared to a maximum of 20% in the absence of screening. It is important to mention that screening does not detect small and insignificant cancers, especially when random biopsies are not performed routinely. The critical volume of prostate cancer is estimated at 0.3 cm or a tumor 7.5 mm in diameter, if spherical. Such a tumor should increase serum prostate-specific antigen by 0.5 ng/mL. Contrary to the belief that screening detects cancers that are too small, the fact is that screening detects prostate cancer too late or nonorgan- or nonspecimen-confined cancer in 35-50% of cases. There is, thus, a narrow window when prostate cancer can be detected at a curable stage, and even the best available screening techniques cannot succeed in all cases. It should be mentioned that the recent improvements of the technique of radical prostatectomy have markedly improved the acceptability of surgery. Concerning the recent publicity related to watchful waiting, it is essential to indicate that all such reports support the notion that prostate cancer grows slowly, but steadily and irremediably, with increasing malignancy and risk of distant metastases and death if sufficient time is allowed. Another serious limitation of watchful waiting is that the available prognostic factors have a large margin of error and cannot predict with certainty the rate of progression of the tumor.

Labrie F, Candas B, Cusan L, Gomez JL, Diamond P, Suburu R, Lemay M
Prostate Cancer Clinical Research Unit, CHUL Research Center, Quebec, Canada.
Urology 1996 Feb;47(2):212-7

OBJECTIVES: To determine the percentage of localized and potentially curable prostate cancers diagnosed at follow-up screening visits compared with the first screening visit.

METHODS: Within the context of a prospective screening study performed in randomly chosen men aged between 45 and 80 years, up to 6-year follow-up screening visits have been performed with serum prostate-specific antigen (PSA) measurement and digital rectal examination (DRE) followed by transrectal ultrasonography of the prostate when PSA or DRE is abnormal.

RESULTS: Of the 117 prostate cancers diagnosed at 14,554 annual follow-up visits, only 1 cancer (0.9%) was metastatic compared with 8% (26/322) at 8029 first visits. Moreover, 97% of the cancers detected at follow-up visits could be identified by PSA alone compared with 86% at first visit. The incidence of 0.8% per year during 15 years of screening between the ages of 55 and 70 years would diagnose localized prostate cancer in 12% of the population, a value not too different from the 10% diagnosed with prostate cancer during life-time in the absence of screening.

CONCLUSIONS: The present data show that annual screening with PSA diagnoses clinically localized prostate cancer in more than 95% of cases, thus almost completely eliminating the diagnosis of metastatic prostate cancer. Moreover, the number of prostate cancers diagnosed is not significantly increased by screening.

Babaian RJ, Fritsche HA, Zhang Z, Zhang KH, Madyastha KR, Barnhill SD
Department of Urology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Urology 1998 Jan;51(1):132-136

OBJECTIVES: Although prostate-specific antigen (PSA) has revolutionized the detection of prostate cancer, it has definite limitations with respect to its clinical sensitivity and specificity. Because a substantial number (20% to 40%) of men undergoing radical prostatectomy have a PSA level of 4.0 ng/mL or less, any new test offering diagnostic improvement must perform well in patients whose PSA level is less than or equal to 4.0 ng/mL, as well as in patients whose PSA is greater than 4.0 ng/mL. The performances of two tests, the ProstAsure index and the percent free PSA test, were evaluated in detecting cancer.

METHODS: We retrospectively analyzed serum samples from 225 men who were grouped into three categories: 94 men who had a normal digital rectal examination and a serum PSA level of 4.0 ng/mL or less, 77 men who were clinically suspected of having benign prostatic hyperplasia (BPH) with a serum PSA level of 4.0 ng/mL or less, and 54 men with localized prostate cancer. The PSA assays were performed using the Hybritech and Tosoh assays and the ProstAsure index was determined by Global Health Net, Savannah, Ga. Receiver operator characteristic (ROC) curves were constructed to evaluate the performance of these two tests, and the areas under the curve were compared for significance.

RESULTS: The sensitivity and specificity of detecting prostate cancer using ProstAsure were 93% and 81%, respectively. Using a cutoff value of 15%, the sensitivity and specificity of detecting cancer for percent free PSA were 80% and 74%, respectively (sensitivity increased to 93% and specificity to 59% for free PSA at 19%). In men with a total serum PSA level of 4.0 ng/mL or less, ProstAsure had a lower false-positive rate compared to free PSA level at 19% for men with or without clinical BPH as well as for men without clinical BPH using a 15% free PSA threshold. ProstAsure left fewer cancers undetected (7%) compared to free PSA at the 15% cutoff (20%).

CONCLUSIONS: In this study of selected men, ROC curve analysis shows a statistically significant advantage in performance (P = 0.0023) for the ProstAsure index compared to free PSA in detecting prostate cancer.

Catalona WJ, Smith DS, Ornstein DK
Division of Urologic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, Mo 63110, USA.
JAMA 1997 May 14;277(18):1452-5

OBJECTIVE: To determine the detection rate of prostate cancer in a screening population of men with prostate-specific antigen (PSA) concentrations of 2.6 to 4.0 ng/mL and a benign prostate examination, to assess the clinicopathological features of the cancers detected, and to assess the usefulness of measuring the ratio of free to total PSA to reduce the number of prostatic biopsies.

DESIGN: A community-based study of serial screening for prostate cancer with serum PSA measurements and prostate examinations.

SETTING: University medical center.

SUBJECTS: A total of 914 consecutive screening volunteers aged 50 years or older with serum PSA levels of 2.6 to 4.0 ng/mL who had a benign prostate examination and no prior screening tests suspicious for prostate cancer, 332 (36%) of whom underwent biopsy of the prostate.

MAIN OUTCOME MEASURES: Cancer detection rate, clinical and pathological features of cancers detected, and specificity for cancer detection using measurements of percentage of free PSA.

RESULTS: Cancer was detected in 22% (73/332) of men who underwent biopsy. All cancers detected were clinically localized, and 81% (42/52) that were surgically staged were pathologically organ confined. Ten percent of the cancers were clinically low-volume and low-grade tumors, and 17% of those surgically staged were low-volume and low-grade or moderately low-grade tumors (possibly harmless). Using a percentage of free PSA cutoff of 27% or less as a criterion for performing prostatic biopsy would have detected 90% of cancers, avoided 18% of benign biopsies, and yielded a positive predictive value of 24% in men who underwent biopsy.

CONCLUSIONS: There is an appreciable rate of detectable prostate cancer in men with serum PSA levels of 2.6 to 4.0 ng/mL. The great majority of cancers detected have the features of medically important tumors. Free serum PSA measurements may reduce the number of additional biopsies required by the lower PSA cutoff.

Harris CH, Dalkin BL, Martin E, Marx PC, Ahmann FR
Section of Urology, University of Arizona College of Medicine and Tucson Veterans Affairs Medical Center, USA.
J Urol 1997 May;157(5):1740-3

PURPOSE: We evaluated the 3-year longitudinal changes in serial serum prostate specific antigen (PSA) levels in men with an initial PSA of 4.0 ng./ml. or less and no suspicion of prostate cancer.

MATERIALS AND METHODS: A total of 760 men with an initial PSA of 4.0 ng./ml. or less plus a normal or suspicious digital rectal examination and a benign prostate biopsy was enrolled into an every 4-month PSA monitoring study.

RESULTS: Of the 559 men with an initial PSA of 2.0 ng./ml. or less only 3 (0.5%) had a persistently abnormal PSA for 3 years and 1 cancer (0.2%) was detected, and 48 men had a PSA velocity of 0.8 ng./ml. per year or more at year 1 but only 1 (2%) had a persistent rate of increase (2.4 ng./ml. per year) at 3 years. Of the 201 men with a PSA of 2.1 to 4.0 ng./ml. 85 had an abnormal PSA but only 37 (43%) met the criteria for biopsy. Only 8 of 23 biopsies (35%) revealed cancer. Of the 201 men 24 had a PSA velocity of 0.8 ng./ml. Per year or more at year 1 but only 4 had persistence for 3 years. All 4 men had cancer but they were identified as at high risk by PSA criteria.

CONCLUSIONS: Men with a PSA of 2.0 ng./ml. or less are at low risk for an abnormal PSA or cancer within 3 years and annual monitoring may not be necessary. However, annual monitoring is clinically useful in men with an initial PSA of 2.1 to 4.0 ng./ml. Also, serial monitoring with interval testing in men whose PSA becomes greater than 4.0 ng./ml. is beneficial in identifying a high risk group requiring biopsy. Finally, PSA velocity did not add further to cancer detection in this population.

Eskew LA, Bare RL, McCullough DL
Department of Urology, Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, North Carolina, USA.
J Urol 1997 Jan;157(1):199-202; discussion 202-3

PURPOSE: The number of patients undergoing prostate biopsy has dramatically increased due to prostate specific antigen screening. The low specificity of this screening tool requires prostate biopsy for diagnosis of prostate cancer. The sextant biopsy technique has been used widely with success in diagnosing carcinoma of the prostate. However, concern has arisen that the original sextant method may not include an adequate sampling of the prostate. For many years we have used a method of prostate biopsy that, in addition to sextant biopsies, takes additional biopsies in a systematic fashion, which we call the 5 region prostate biopsy. We conducted a prospective study to determine if our 5 region prostate biopsy technique significantly increases the chances of finding carcinoma of the prostate compared to the sextant biopsy technique.

MATERIALS AND METHODS: A total of 119 patients underwent transrectal ultrasound guided needle biopsy of the prostate. In addition to sextant biopsies, cores were taken from the far lateral and mid regions of the gland. Pathological findings of the additional regions were compared to those of the sextant regions.

RESULTS: Of the 48 patients with prostate cancer 17 (35%) had carcinomas only in the additional regions, which would have remained undetected had the sextant biopsy technique been used alone (p < 0.05). Of these additional cancers 83% had Gleason scores of 6 or more.

CONCLUSIONS: We introduce the 5 region technique of prostate biopsy as a means of significantly increasing the diagnostic yield of prostate biopsy in finding carcinoma of the prostate. We have found this technique to be safe, efficacious and superior to the sextant method of biopsy in identifying prostate cancer at an early but significant stage. The greatest use of the 5 region biopsy technique is in patients who have prostate specific antigen levels between 4 and 10 ng./ml.

Aihara M, Wheeler TM, Ohori M and Scardino PT
Urology 43:60-4, 1994.

OBJECTIVE. To understand the morphologic and spatial relationships of the various grades of prostate cancer, we investigated whether poorly differentiated cancer usually arises within the center of a large, well-differentiated tumor or more often forms the periphery or leading edge of the tumor.

METHODS. In a series of one hundred and one completely sectioned whole-mount radical prostatectomy specimens removed from patients with clinical Stage T2 prostate cancer, we mapped the distribution of each of the five Gleason grades and assessed their frequency, proportion, and spatial distribution.

RESULTS. The average number of different grades present in our patients was 2.7 (range 1-5). Over 50 percent of the prostates contained at least three different grades of cancer. The number of different Gleason grades present increased significantly with increasing tumor volume (p < 0.0001). Only 10 percent of the index cancers (largest tumor present) were composed of a single grade and these cancers were small (0.02-1.7 cm3). Among cancers with multiple grades, the most common finding (53%) was a high-grade cancer present within the core of a larger, more well-differentiated tumor; however, the opposite pattern, low-grade cancer present within a larger poorly differentiated cancer, was also common (30%) and predominated in very large cancers (> 10 cm3).

CONCLUSION. Small prostate cancers are often composed of a single grade, usually Gleason grade 2 or 3. But most palpable cancers contain multiple grades which are arranged in heterogeneous and unpredictable geographic interrelationships.

Brawn PN
Cancer 1983 Jul 15;52(2):246-51

Fifty-four patients with prostate carcinoma, each having 2 TURP (transurethral resection of the prostate) procedures separated by 3 to 11 years, were studied to determine whether the histologic appearance of prostate carcinoma remains the same for the life of the host or whether the histological appearance changes with time. Using the M. D. Anderson (MDAH) method of grading prostate carcinoma, 19 of 26 (73%) Grade 1 lesions, 9 of 12 (75%) Grade 2 lesions, and 7 of 8 (88%) Grade 3 lesions dedifferentiated into another grade at the time of the 2nd TURP. Eight cases that were Grade 4 at the time of the 1st TURP, remained Grade 4 lesions at the time of the 2nd TURP. Although 10 Grade 1, Grade 2, and Grade 3 lesions did not change grades, 8 of these 10 cases were less differentiated at the time of the second TURP than they were at the time of the first TURP. Furthermore, no Grade 1 lesions demonstrated evidence of metastases, but 19% of Grade 2 lesions, 55% of Grade 3 lesions, and 80% of Grade 4 lesions demonstrated evidence of metastases. This study suggests that the usual course of prostate carcinoma is dedifferentiation and that with dedifferentiation, the likelihood of metastases increases.

Lehr JE, Pienta KJ, Yamazaki K, Pilat MJ
University of Michigan Comprehensive Cancer Center, Ann Arbor 48109-0946, USA.
Cell Mol Biol (Noisy-le-grand) 1998 Sep;44(6):949-59

Normal rat prostate epithelial cells (EPYP-1) were isolated and immortalized with the Simian Virus-40 (SV40) large T-antigen, and transfected with the v-H-ras (EPYP-1-ras) and the c-myc oncogenes (EPYP-1-myc; EPYP-1-ras-myc) to serially create a step-wise model of tumor development in the rat prostate. Pronounced morphological differences were observed between EPYP-1 and the transfected sublines. The immortal epithelial cells (EPYP-1) maintained a cuboidal shape with orderly, contact mediated inhibition of growth. Oncogene transfected clones displayed a spindle shaped structure with multiple overlapping pseudopodia. Transfected cells also exhibited a greater degree of dysplasia, loss of contact inhibition growth and the upregulation of an epithelial tumor marker, cytokeratin-18. All cells exhibited anchorage independent and androgen independent growth. In vivo, EPYP-1 cells and EPYP-1-myc and formed slowly growing non-metastatic, benign tumors in immune compromised mice, while EPYP-1-ras and EPYP-1-ras-myc transfected cells produced rapidly growing, malignant tumors in similar animals. This model augments the hypothesis that tumor initiation and progression can be caused by as few as two discrete genetic events. In addition, the "normal" rat prostate epithelium and transfected daughter cell lines represent a tumor model system with distinct, well understood genetic alterations: activation of ras and myc. This model will be a valuable addition to the current cell lines used in the investigation of prostate cancer carcinogenesis.

Yamazaki H, Sinha BK
Proc Annu Meet Am Assoc Cancer Res 34:A2309, 1993.

No abstract.

McDonnell TJ, Troncoso P, Brisbay SM, Logothetis C, Chung LW, Hsieh JT, Tu SM, Campbell ML
Department of Molecular Pathology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Cancer Res 1992 Dec 15;52(24):6940-4

The significance of apoptosis in relation to the development and progression of prostate cancer remains largely undefined. bcl-2 is an oncogene that functions by overriding apoptosis. bcl-2 expression was localized to the basal epithelial cells in the normal human prostate with the use of immunohistochemistry. Androgen-dependent and androgen-independent prostate carcinomas were evaluated immunohistochemically for bcl-2 expression. bcl-2 was undetectable in 13 of 19 cases of androgen-dependent cancers. In contrast, androgen-independent cancers displayed diffuse, high levels of bcl-2 staining (P < 0.01). In rats, steady-state levels of bcl-2 mRNA, assessed by S1 assays, reached maximum levels 10 days following castration. Addition of exogenous testosterone with, or without, flutamide demonstrated that the increased bcl-2 Mrna resulted from androgen ablation. Our findings indicate that bcl-2 expression is augmented following androgen ablation and is correlated with the progression of prostate cancer from androgen dependence to androgen independence.

Bookstein R, MacGrogan D, Hilsenbeck SG, Sharkey F, Allred DC
Department of Molecular Biology, Canji, Inc., San Diego, California 92121.
Cancer Res 1993 Jul 15;53(14):3369-73

Inactivation of p53, a tumor suppressor gene, contributes to the genesis and/or progression of a substantial fraction of all human cancers, including > or = 50% of breast, lung, and colon carcinomas. Mutated p53 alleles typically contain missense single-base substitutions within exons 5-8 and encode abnormally stable p53 proteins that accumulate to high levels in tumor cell nuclei. To evaluate the frequency, type, and clinical significance of p53 mutation in human prostate cancer, archival tumor material from 150 prostate cancer patients was examined by immunohistochemistry (IHC) with anti-p53 antibodies. Abnormal nuclear p53 accumulation (IHC) was observed in 19 tumors (12.7%) and was strongly related to disease stage (23% of 69 stage III or IV tumors were IHC+ versus 4% of 74 stage 0-II tumors; P < 0.001, Fisher's exact test). The methods of polymerase chain reaction, single-strand conformational polymorphism, and direct sequencing were used to identify mutations, predominantly missense single-base substitutions in exons 5, 7, or 8 in 9 of 14 IHC+ cases but in none of 20 IHC- cases; 5 of these mutations were G:C-->A:T transitions at CpG dinucleotides. These data indicate that mutated p53 alleles are quite uncommon in early prostate cancers but are found in 20-25% of advanced cancers, suggesting a role for p53 mutation in the progression of at least a subset of prostate cancers.

Veldscholte J, Ris-Stalpers C, Kuiper GG, Jenster G, Berrevoets C, Claassen E, van Rooij HC, Trapman J, Brinkmann AO, Mulder E
Department of Biochemistry II, Erasmus University Rotterdam, The Netherlands.
Biochem Biophys Res Commun 1990 Dec 14;173(2):534-40

LNCaP prostate tumor cells contain an abnormal androgen receptor system. Progestagens, estradiol and anti-androgens can compete with androgens for binding to the androgen receptor and can stimulate both cell growth and excretion of prostate specific acid phosphatase. We have discovered in the LNCaP androgen receptor a single point mutation changing the sense of codon 868 (Thr to Ala) in the ligand binding domain. Expression vectors containing the normal or mutated androgen receptor sequence were transfected into COS or Hela cells. Androgens, progestagens, estrogens and anti-androgens bind the mutated androgen receptor protein and activate the expression of an androgen-regulated reporter gene construct (GRE-tk-CAT). The mutation therefore influences both binding and the induction of gene expression by different steroids and antisteroids.

Sciarra F, Sorcini G, Di Silverio F, et al:
Clin Endocrinol 2:101-109, 1973.

Instituo di Patologia Speciale Medica e Metodologia Clinica II, and *Clinica Urologica, University of Rome, Italy

Orchiectomy is often used in the management of metastatic adenocarcinoma of the prostate, an androgen dependent tumour, since it markedly reduces the concentrations of plasma testosterone (to a mean level of 28 ± 16 (SD) ng/100 ml) and temporarily inhibits the growth of the neoplasm.

In some orchiectomized patients, however, the values of plasma testosterone and androstenedione do not drop to these levels, but remain higher, around 137 ± 23 ng/100 ml and 213 ± 39 ng/100 ml respectively.

In these patients, treatment with dexamethasone significantly decreased the levels of testosterone and androstenedione to 22 ± 20 ng/100 ml (P<0.0005) and 43 ± 11 ng/100 ml (P<0.0005) respectively.

It can therefore be assumed that in orchiectomized patients these compounds are produced in the adrenal cortex, which in some cases is stimulated to produce a larger amount of strong androgens such as testosterone and weaker androgens such as androstenedione.

It has also been observed that those patients with an inadequate lowering of plasma testosterone levels after orchiectomy, did not show clinical improvement.

Further studies in a larger number of patients are needed in order to support this finding.

Herrada J, Hossan B, Amato R, et al:
Proc Am Soc Clin Oncol 13:237, 1994.

No abstract.

Scher HI, Kelly WK
Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY 10021.
J Clin Oncol 1993 Aug;11(8):1566-72

PURPOSE: To evaluate the effect of discontinuation of the antiandrogen, flutamide, in patients with metastatic prostate cancer who are progressing on hormonal therapy.

PATIENTS AND METHODS: Thirty-six patients with progressive disease on hormonal treatment that included flutamide had discontinuation of the antiandrogen. Thirty-five (95%) had progressive increases in prostate-specific antigen (PSA) levels, despite castrate levels of testosterone. Twenty-five patients (69%) were treated with combined androgen blockade (orchiectomy or gonadotropin-releasing hormone [GnRH] analog plus flutamide) as initial therapy and 11 (31%) were started on monotherapy alone. Patients who had not undergone a previous orchiectomy were continued on the GnRH analog. Patients were monitored clinically and with serial PSA measurements, radionuclide scans, and radiographs as indicated to assess response.

RESULTS: Considering the 35 patients with increasing PSA values, 10 (29%) showed a significant decline (> or = 80% in seven, and > or = 50% in three) in PSA from baseline. All 10 had received combined androgen blockade as initial therapy. The duration of decline was short (median, 5+ months; range, 2 to 10+), but was associated with improvement in clinical symptoms, while one patient had a partial response in an epidural mass with parallel decline in PSA. None of the patients started on single hormone therapies responded.

CONCLUSION: Discontinuation of flutamide was associated with a significant decrease in PSA values in 10 of 25 patients (40%; 95% confidence interval, 21% to 59%) and clinical improvement in a subset of patients who had an initial response, but later progressive disease on combined androgen blockade. A trial of flutamide withdrawal should be considered in patients progressing on total androgen blockade before the initiation of more toxic therapies. It is likely that flutamide withdrawal has contributed to the observed responses in phase II trials of both second-line hormonal therapies and new cytotoxic agents. Future phase II trials in hormone-refractory prostatic cancer must control for this observation, and insure that progression off flutamide is documented before initiation of alternative treatment.

Figg WD, Sartor O, Cooper MR, et al:
Pharmacology Branch, National Cancer Institute, Bethesda, Maryland, USA.
Am J Med 98:412-14, 1995.

No abstract.

Small EJ, Srinivas S
Department of Medicine, University of California, San Francisco, Mt Zion/UCSF Cancer Center 94115, USA.
Cancer 1995 Oct 15;76(8):1428-34

BACKGROUND. Flutamide withdrawal has been reported to be therapeutically efficacious for patients with hormone-refractory prostate cancer, with a reported prostate specific antigen (PSA) response rate of 29%.

METHODS. To evaluate the results of flutamide withdrawal in a large group of unselected patients, the medical records of 107 consecutive patients with metastatic prostate cancer who developed progressive disease while receiving flutamide therapy were reviewed retrospectively. Flutamide withdrawal was undertaken at the time of disease progression.

RESULTS. Eighty-two patients were evaluable. Of these, three had a > 80% fall in PSA value, and another nine had a > 50% decrease, for a response proportion of 14.6% (95% confidence interval 7.8%-24.2%). The median response duration was 3.5 months (range, 1-12+ months). Eight of patients treated with combined androgen blockade at the time of diagnosis of metastatic disease had a response (14%), whereas 4/25 responses (16%) were noted in patients in whom flutamide was added later, at the time of first progression. When patients who responded were compared with patients who did not respond, there was not a significant difference in age, pretreatment PSA level, type of gonadal androgen deprivation, or the likelihood of prior combined androgen blockade versus late addition of flutamide. The duration of prior therapy with flutamide was longer in patients who responded (21.5 vs. 12.0 months).

CONCLUSIONS. These findings confirm the flutamide withdrawal phenomenon in a large group of unselected patients, although its frequency is not as high as previously reported. In contrast to earlier reports, whether patients have had initial hormonal therapy with combined androgen blockade or monotherapy does not appear to be predictive of the likelihood of response to antiandrogen withdrawal.

Small EJ, Carroll PR
Department of Medicine, University of California, San Francisco.
Urology 1994 Mar;43(3):408-10

OBJECTIVE. To evaluate the relationship between antiandrogen withdrawal and change in prostate-specific antigen (PSA) when the antiandrogen in question is other than flutamide.

METHODS. Presented is a case of a patient in whom the antiandrogen casodex was discontinued after clinical progression despite combined androgen blockade.

RESULTS. A transient decline in serum PSA was observed after casodex withdrawal.

CONCLUSIONS. The relationship between antiandrogen withdrawal and a change in PSA may be a general phenomenon, not unique to flutamide.

Small EJ, Schelhammer P, Venner P, et al:
Proc Am Soc Clin Oncol 15:255A, 1996.

No abstract.

Dawson NA and McLeod DG
J Urol 153:1956-7, 1995.

No abstract.

Bissada NK, Kaczmarek AT
Department of Urology, Medical University of South Carolina, Charleston, USA.
J Urol 1995 Jun;153(6):1944-5

The phenomenon of regression of adenocarcinoma of the prostate after the withdrawal of antiandrogens is well documented. However, to our knowledge we report the first case of durable complete remission of hormone refractory prostate cancer after cessation of diethylstilbestrol. The drug was discontinued because the patient had disease progression while on diethylstilbestrol and withdrawal resulted in durable remission. In more than 3 years of followup since discontinuing diethylstilbes trol there has been no evidence of clinical or biochemical recurrence.

Culig Z, Hobisch A, Cronauer MV, Cato AC, Hittmair A, Radmayr C, Eberle J, Bartsch G, Klocker H
Department of Urology, University of Innsbruck, Austria.
Mol Endocrinol 1993 Dec;7(12):1541-50

Structural changes of the androgen receptor (AR) may contribute to the development of resistance to endocrine therapy in prostatic carcinoma. We have isolated AR cDNA fragments from seven tumor specimens derived from patients with advanced metastatic prostatic tumors. In one specimen obtained from a patient who failed to respond to endocrine and cytotoxic therapy we have detected a point mutation in the hormone-binding domain of the receptor. This AR mutation is a guanine-to-adenine transition at nucleotide 2671 that leads to substitution of methionine for the wild type valine at position 715. It is a somatic mutation because it was not present in the AR genomic DNA fragments isolated from prostatic and testicular tissues of the same patient. The mutant AR was recreated in an expression vector and transiently expressed in COS-7 and CV-1 cells. Hormone-binding assays revealed that the mutant receptor does not differ from the wild type receptor in its ability to bind androgen. The dissociation constant for the synthetic androgen mibolerone was 3 nM for both receptors. There was also no significant difference in binding of other steroids and nonsteroidal antiandrogens as revealed by competition binding assays. However, transfection experiments to determine the trans-activation potential of the mutant receptor produced differences in the action of this receptor compared to the wild type receptor. Dihydrotestosterone and the synthetic androgens methyltrienolone (R1881) and mibolerone were equally proficient in conferring trans-activation activity to both the mutant and wild type receptors. Adrenal androgens such as dehydroepiandrosterone and androstenedione, as well as progesterone mediated a higher trans-activation through the mutant than through the wild type receptor. These data demonstrate that the exchange of a single valine into methionine at position 715 in the AR promoters trans-activation not only by testicular but also by adrenal androgens and progesterone. This pattern of ligand-dependent trans-activation may have significance in the process controlling the progression of prostatic carcinoma.

Taplin ME, Bubley GJ, Shuster TD, Frantz ME, Spooner AE, Ogata GK, Keer HN, Balk SP
Department of Medicine, University of Massachusetts Medical Center, Worcester, USA.
N Engl J Med 1995 May 25;332(21):1393-8

BACKGROUND. Metastatic prostate cancer is a leading cause of cancer-related death in men. The rate of response to androgen ablation is high, but most patients relapse as a result of the outgrowth of androgen-independent tumor cells. The androgen receptor, which binds testosterone and stimulates the transcription of androgen-responsive genes, regulates the growth of prostate cells. We analyzed the androgen-receptor genes from samples of metastatic androgen-independent prostate cancers to determine whether mutations in the gene have a role in androgen independence.

METHODS. Complementary DNA was synthesized from metastatic prostate cancers in 10 patients with androgen-independent prostate cancer, and the expression of the androgen-receptor gene was estimated by amplification with the polymerase chain reaction. Exons B through H of the gene were cloned, and mutations were identified by DNA sequencing. The functional effects of the mutations were assessed in cells transfected with mutant genes.

RESULTS. All androgen-independent tumors expressed high levels of androgen-receptor gene transcripts, relative to the levels expressed by an androgen-independent prostate-cancer cell line (LNCaP). Point mutations in the androgen-receptor gene were identified in metastatic cells from 5 of the 10 patients examined. One mutation was in the same codon as the mutation found previously in the androgen-independent prostate-cancer cell line. The mutations were not detected in the primary tumors from of the two patients. Functional studies of two of the mutant androgen receptors demonstrated that they could be activated by progesterone and estrogen.

CONCLUSIONS. Most metastatic androgen-independent prostate cancers express high levels of androgen-receptor gene transcripts. Mutations in androgen-receptor genes are not uncommon and may provide a selective growth advantage after androgen ablation.

Fenton M-A, Shuster TD, Feris A, Taplin M-E, Kolvenbag G, Bubley GJ and Balk SP:
Clin Cancer Res 3:1383, 1997.

No abstract.

Olea N, Sakabe K, Soto AM, Sonnenschein C
Tufts University Health Science Schools, Department of Anatomy and Cellular Biology, Boston, Massachusetts 02111.
Endocrinology 1990 Mar;126(3):1457-63

The effect of steroidal and nonsteroidal "anti-androgens" on the proliferative capacity of androgen-sensitive LNCaP-FGC human prostate tumor cells in culture was studied using charcoal-dextran stripped human serum-supplemented media. Cyproterone and medroxyprogesterone acetates, flutamide, hydroxyflutamide, and anandron (R23908) were administered alone at concentrations between 3 X 10(-12) and 3 X 10(-6) M. Results indicated that although medroxyprogesterone induced maximal proliferation at 3 X 10(-9) M, the other "anti-androgens" (with the exception of flutamide that was ineffective) were effective at 3 X 10(-8) M and higher concentrations; the amplitude of the proliferative response by these compounds was comparable to that elicited by estradiol-17 beta (3 to 5-fold over control). None of the anti-androgens tested triggered the shutoff effect characteristic of androgen action. When 3 X 10(-10) M DHT and the above mentioned anti-androgens were administered simultaneously, a synergistic pattern was seen; on the contrary, 3 X 10(-8) M DHT cancelled the proliferative effect of each of the anti-androgens when administered simultaneously. The relative binding affinity of these anti-androgens to androgen receptors present in LNCaP-FGC cells did not correlate well with their proliferative efficiency. The data collected were interpreted within the premises of the negative control hypotheses for the regulation of cell proliferation in metazoans. Within those premises, results became compatible with the notion that first, "anti-androgens" elicited the proliferation of androgen-sensitive cells by neutralizing the effect of a serum-borne inhibitor (androcolyone-I); this event seems not to be mediated by androgens receptors. Second, anti-androgens did not trigger a proliferative shutoff response like androgens do, i.e. the proliferative pattern induced by anti-androgens was comparable to that elicited by estrogens and progestins. Third, when administered simultaneously with 3 X 10(-10) M DHT, anti-androgens behaved synergistically. Fourth, the DHT-induced shutoff effect consistently overrode the proliferative effect generated by anti-androgens and estrogens when added alone. Finally, taken together these results raise important questions regarding the therapeutic role of anti-androgens in prostate cancer.

Joyce R, Fenton MA, Rode P, Constantine M, Gaynes L, Kolvenbag G, DeWolf W, Balk S, Taplin ME, Bubley GJ
Department of Medicine, Harvard Medical School, Boston, Massachusetts, USA.
J Urol 1998 Jan;159(1):149-53

PURPOSE: A pilot study of the antiandrogen bicalutamide at 150 mg. a day for androgen independent prostate cancer was performed. This study was based on the possibility that androgen independent cases might display responses to additional hormonal agents.

MATERIALS AND METHODS: The study included 31 androgen independent cases with an increasing prostate specific antigen (PSA) and progressive disease. PSA measurements were used as the primary method of assessing response. However, PSA decline was also correlated with clinical status.

RESULTS: Seven patients demonstrated PSA declines of greater than 50% for 2 months or more, for an overall response rate of 22.5%. Responses were observed almost exclusively in patients treated with long-term flutamide as part of a complete androgen blockade regimen (43% response rate) in contrast to patients treated with androgen deprivation without flutamide (6% response rate). Of the 7 PSA responding patients bicalutamide resulted in a significant improvement in performance status and a decrease in analgesic requirement in 4 and 3 remained asymptomatic. Bicalutamide at 150 mg. a day was well tolerated, with the most frequent side effect being mild exacerbation of hot flashes.

CONCLUSIONS: Bicalutamide at this dose is modestly effective for some patients with androgen independent prostate cancer, particularly for those previously treated with long-term flutamide. This study indicates that previous antiandrogen therapy alters the response to subsequent hormonal agents.

Trachtenberg J, Halpern N, Pont A
J Urol 1983 Jul;130(1):152-3

Ketoconazole is an orally administered broad-spectrum antifungal agent that acts through the inhibition of the steroid synthetic pathways. At high doses in humans ketoconazole can lower rapidly serum testosterone and maintain it in the castrate range with frequent administration. This property suggested that ketoconazole might be useful in the treatment of prostatic cancer. We report a case of prostatic cancer in which ketoconazole resulted in rapid and sustained reduction in serum androgens as well as rapid induction of a clinical remission. Ketoconazole may be a valuable agent in the treatment of prostatic cancer.

Eichenberger T, Trachtenberg J, Chronis P, Keating A
Division of Urology, Toronto General Hospital, Ontario.
Clin Invest Med 1989 Dec;12(6):363-6

Ketoconazole has been recently used in the primary treatment of patients with metastatic cancer of the prostate and is identified as a potent inhibitor of cytochrome P450-dependent adrenal and testicular androgen production. The drug has also shown activity in patients failing conventional hormonal manipulation. We subsequently showed that ketoconazole in vitro has a direct cytotoxic effect on human androgen-independent prostatic cancer cell lines. In order to better define the possible role of ketoconazole on hormone-independent prostatic cancer, we incubated the cells from human androgen-independent prostatic cancer lines in a methylcellulose tumour colony assay with different doses of the drug and increasing doses of conventional cytotoxic agents (etoposide, bleomycin, vinblastine, methotrexate, and teniposide). We demonstrated synergistic suppression of prostate cancer clonogenic cell growth by ketoconazole in the presence of vinblastine or etoposide. This observation may assign a new and important role for ketoconazole as part of combination chemotherapy in the treatment of patients with advanced prostatic cancer.

Continued on the next page...

Eichenberger T, Trachtenberg J, Toor P, Keating A
Division of Urology, Toronto General Hospital, Ontario, Canada.
J Urol 1989 Jan;141(1):190-1

Ketoconazole has been recently used in the treatment of advanced prostatic cancer and is believed to exert its effect by inhibition of androgen production. In order to determine whether ketoconazole exerts an additional direct cytotoxic effect on prostate cancer cells, we studied its effect on human hormone-independent prostate cancer cell lines (PC-3 and DU-145) in an in vitro clonogenic tumor assay. We showed that clinically achievable doses of ketoconazole caused greater than 90% suppression of tumor colony growth.

Siegsmund MJ, Cardarelli C, Aksentijevich I, Sugimoto Y, Pastan I, Gottesman MM
Laboratory of Molecular Biology, DCBDC, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
J Urol 1994 Feb;151(2):485-91

The antifungal agent ketoconazole was found to overcome resistance to vinblastine and doxorubicin in multidrug resistant KB-V1 cells in vitro. These cells are several hundred-fold more resistant than the parental cell line KB-3-1. Ketoconazole had little or no effect on the parental KB-3-1 cells. The concentrations used to overcome drug resistance in vitro have already been safely used in vivo for treatment of fungal infections and in the monotherapy of hormone independent prostate carcinomas to block adrenal androgen production. Because of a possible beneficial effect of a combination of ketoconazole and a chemotherapeutic drug in multidrug resistant cancers, we examined a panel of 11 prostate carcinoma tissues for the expression of the MDR1 gene by an RNA-PCR assay. MDR1 expression was detectable, albeit at low levels, in 8 of the 11 tumors, suggesting a possible role of this gene in the drug resistance of prostate carcinomas. Our data suggest that ketoconazole might be useful in overcoming multidrug resistance in concentrations that are achievable in humans.

Pont A
J Urol 1987 May;137(5):902-4

The antifungal drug ketoconazole has been shown to block testosterone synthesis. High dose ketoconazole therapy was given to 17 patients with previously untreated stage D2 prostatic cancer. Rapid relief of pain occurred in 15 patients with significant pain. Prostatic acid phosphatase levels normalized or decreased in all patients. Bone scan scores were stable or improved. Two patients remain on therapy for more than 30 months. The remainder have ceased treatment owing to subsequent progressive disease (5 patients), side effects (6) or noncompliance. Eleven patients who had relapse after previous endocrine ablative therapy were treated with ketoconazole. Subjective responses were frequent but long-term objective responses were rare. There was a high incidence of side effects, particularly nausea. Ketoconazole may have limited usefulness as initial therapy in patients with endocrine responsive advanced prostatic cancer. The drug can be palliative in some patients who have failed previous therapeutic modalities. Analogues of the drug should prove to have better efficacy and fewer side effects.

Muscato JJ, Ahmann TA, Johnson KM, et al
Proc Am Soc Clin Oncol 13:229A, 1994.

No abstract.

Small EJ, Baron AD, Fippin L, Apodaca D
Department of Medicine, University of California, San Francisco Cancer Center 94115, USA.
J Urol 1997 Apr;157(4):1204-7

PURPOSE: We tested the hypothesis that certain patients with hormone refractory prostate cancer retain hormonal sensitivity even after progression following antiandrogen withdrawal. The efficacy of ketoconazole and hydrocortisone in this patient population was evaluated.

MATERIALS AND METHODS: A total of 50 consecutive patients with advanced prostate cancer received ketoconazole and hydrocortisone at progression after antiandrogen withdrawal. Prostate specific antigen (PSA) response was defined as greater than a 50% decrease in PSA from baseline that was maintained for at least 8 weeks.

RESULTS: Overall, of 48 evaluable patients 30 (62.5%, 95% confidence interval 47.3 to 76.1%) had greater than a 50% decrease in PSA, while 23 (48%) had greater than an 80% decrease. The median duration of response was 3.5 months but 23 of 48 patients continue to exhibit a response, ranging from 3.25 to 12.75 or more months. The ketoconazole response rate in patients with no response to prior antiandrogen withdrawal was not different from that in patients with such a response (65 versus 40%, p = 0.35). Toxicity was mild. Grade 1 or 2 nausea, fatigue, edema, hepatotoxicity and rash occurred in 10.4 (5 of 48), 6.25, 6.25, 4.2 and 4.2% of patients, respectively, and anorexia occurred in 2%.

CONCLUSIONS: Failure to respond to antiandrogen withdrawal does not identify patients with truly hormone refractory disease. Ketoconazole retains significant activity in this setting and is extremely well tolerated.

Small EJ, Baron A, Bok R
University of California-San Francisco Cancer Center, University of California 94115, USA.
Cancer 1997 Nov 1;80(9):1755-9

BACKGROUND: Although antiandrogen withdrawal has moderate efficacy in patients with hormone refractory prostate carcinoma (HRPC), the effect of the simultaneous suppression of adrenal androgens with ketoconazole at the time of antiandrogen withdrawal is not known.

METHODS: Twenty consecutive patients with HRPC who had developed progressive disease despite combined androgen blockade were treated with antiandrogen withdrawal and simultaneous ketoconazole as a means of inhibiting adrenal steroid production. Prostate specific antigen (PSA) response was defined as a > 50% fall in PSA from baseline that was maintained for at least 8 weeks.

RESULTS: Ten patients had established metastatic disease, 2 had high PSAs and no imaging studies (PSA of 70 and 160 ng/mL, respectively), 3 had microscopically positive lymph nodes and serologic progression, and 5 had serologic progression alone. Overall, of 20 evaluable patients, 11 (55%) had a > 50% fall in PSA (95% confidence interval [CI], 31.5-76.9%). The median PSA response duration was 8.5 months (95% CI, 7-17 months). The median survival was 19 months. Toxicity was mild, with Grade 1 and 2 nausea and emesis in 15% of patients, Grade 1 fatigue in 10% of patients, and reversible Grade 1 or 2 hepatotoxicity in 10% of patients. Mild skin toxicity was observed in 20% of patients.

CONCLUSIONS: The addition of ketoconazole and hydrocortisone to antiandrogen withdrawal appears to increase the PSA response proportion observed with antiandrogen withdrawal alone. Toxicity is mild.

Sella A, Kilbourn R, Amato R, Bui C, Zukiwski AA, Ellerhorst J, Logothetis CJ
Department of Genitourinary Medical Oncology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
J Clin Oncol 1994 Apr;12(4):683-8

PURPOSE: A phase II clinical trial was performed to assess the antitumor activity and toxicity of ketoconazole in combination with doxorubicin (Adriamycin; Adria Laboratories, Columbus, OH) in patients with androgen-independent prostate cancer (AI PCa).

PATIENTS AND METHODS: Thirty-nine consecutive patients whose disease progressed following castration were treated with oral ketoconazole (1,200 mg) daily and Adriamycin (20 mg/m2 in a 24-hour infusion) once weekly. Antitumor activity was assessed by the level of prostatic-specific antigen (PSA) decline.

RESULTS: PSA levels decreased > or = 50% from baseline in 21 (55%; 95% confidence interval, 38% to 71%) of 38 assessable patients. We observed partial responses (PRs) in seven (58%) of 12 patients with measurable soft tissue disease (in the lung, lymph nodes, and liver). Two patients with history of atherosclerotic heart disease had a sudden cardiac death. Serious toxic reactions included grade III to V stomatitis and grade III to IV acral erythema in 11 patients (29%), and grade III to IV anal and urethral mucositis in five patients (13%). Grade III to IV neutropenia occurred in 11 patients (29%). Seventeen patients (45%) required hospitalization for complications. Fifteen patients (39%) developed hypokalemia, and 24 patients (63%) developed clinical adrenal insufficiency.

CONCLUSION: The combination of ketoconazole and Adriamycin has a 55% PSA response rate in patients with AI PCa and is worthy of additional study. This treatment results in frequent adrenal insufficiency. Therefore, future studies should incorporate routine corticosteroid replacement. The cardiac complications caused by this combination should be studied further before it is widely used.

Ellerhorst JA, Tu SM, Amato RJ, Finn L, Millikan RE, Pagliaro LC, Jackson A, Logothetis CJ
Department of Genitourinary Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Clin Cancer Res 1997 Dec;3(12 Pt 1):2371-2376

Two distinct regimens of weekly chemotherapy for hormone-refractory prostate cancer were combined in an alternating schedule and tested in a Phase II trial to determine efficacy and toxic effects. Forty-six patients with hormone-refractory prostate cancer and rising prostate-specific antigen (PSA) levels entered the trial. Therapy consisted of doxorubicin (20 mg/m2/week) plus oral ketoconazole (400 mg three times a day) given at weeks 1, 3, and 5 and vinblastine (5 mg/m2/week) plus oral estramustine (140 mg three times a day) given at weeks 2, 4, and 6. No therapy was given at weeks 7 and 8. Replacement doses of hydrocortisone were administered throughout treatment to counteract potential adrenal insufficiency secondary to the ketoconazole. In 67% of patients (31 of 46), the PSA declined by 50% or greater for a minimum duration of 8 weeks (95% confidence interval, 52-80%). Among the 16 patients with measurable soft tissue disease, there were 12 responses (75%; 95% confidence interval, 47-92%). The median duration of response was 8. 4 months (1.8-14.9). The median survival for the entire group was 19 months. The median survival of PSA responders has not been reached, whereas that of nonresponders was 13 months (P = 0.010). Seventy-six percent of symptomatic patients noted improvement. Hematological toxicity was modest and was managed without growth factors. Peripheral edema (49%) and deep venous thrombosis (18%) were the most common nonhematological toxicities. The alternating weekly regimen of chemohormonal therapy is active for hormone-refractory prostate cancer, providing a high rate of symptom control, soft tissue response, and PSA decline.

Chin TW, Loeb M, Fong IW
Department of Pharmacy, St. Michael's Hospital, Toronto, Canada.
Antimicrob Agents Chemother 1995 Aug;39(8):1671-5

Absorption of ketoconazole is impaired in patients with achlorhydria. The purpose of this study was to determine the effectiveness of a palatable acidic beverage (Coca-Cola Classic, pH 2.5) in improving the absorption of ketoconazole in the presence of drug-induced achlorhydria. A prospective, randomized, three-way crossover design with a 1-week wash-out period between each treatment was employed. Nine healthy nonsmoking, nonobese volunteers between 22 and 41 years old were studied. Each subject was randomized to receive three treatments: (A) ketoconazole 200-mg tablet with water (control), (B) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with water, and (C) omeprazole (60 mg) followed by ketoconazole (200 mg) taken with 240 ml of Coca-Cola Classic. The pH values of gastric aspirates were checked after omeprazole was administered to confirm attainment of a pH of > 6. Multiple serum samples were obtained for measurements of ketoconazole concentrations by high-pressure liquid chromatography. The mean area under the ketoconazole concentration-time curve from zero to infinity for the control treatment (17.9 +/- 13.1 mg.h/liter) was significantly greater than that for treatment B (3.5 +/- 5.1 mg.h/liter; 16.6% +/- 15.0% of control).

Tannock I, Gospodarowicz M, Meakin W, Panzarella T, Stewart L, Rider W
Princess Margaret Hospital, Toronto, Ontario, Canada.
J Clin Oncol 1989 May;7(5):590-7

Thirty-seven men with symptomatic bone metastases from prostate cancer that had progressed following earlier treatment with estrogens and/or orchidectomy were treated with low-dose prednisone (7.5 to 10 mg daily). The rationale for this treatment was that some patients might still have hormone-sensitive disease that was stimulated by weak androgens of adrenal origin, and that these androgens could be suppressed by prednisone through its negative feedback on secretion of adrenocorticotrophic hormone (ACTH). Response to treatment was assessed by requirement for analgesics, by the McGill-Melzack pain questionnaire, and by a series of 17 linear analog self-assessment (LASA) scales relating to pain and to various aspects of quality of life. Fourteen patients (38%) had improvement in indices used to assess pain at 1 month after starting prednisone, and seven patients (19%) maintained this improvement for 3 to 30 months (median, 4 months). Reduction in pain was associated with improvement in other dimensions of quality of life, and in the scale for overall well-being. Prednisone treatment led to a decrease in the concentration of serum testosterone in seven of nine patients where it was not initially suppressed below 2 nmol/L, and caused a decrease in serum levels of androstenedione and dehydroepiandrosterone sulfate in more than 50% of patients. Symptomatic response was associated with a decrease in serum concentration of adrenal androgens. We conclude that (1) low-dose prednisone may cause useful relief of pain in some patients with advanced prostatic cancer; (2) relief of pain was associated with suppression of adrenal androgens; and (3) measures of pain and quality of life can be used to assess possible benefits of systemic therapy in patients with metastatic prostate cancer.

Tannock IF, Osoba D, Stockler MR, Ernst DS, Neville AJ, Moore MJ, Armitage GR, Wilson JJ, Venner PM, Coppin CM, Murphy KC
Department of Medicine, Princess Margaret Hospital, Toronto, Canada.
ian-tannock@pmh.toronto.on.ca
J Clin Oncol 1996 Jun;14(6):1756-64

PURPOSE: To investigate the benefit of chemotherapy in patients with symptomatic hormone-resistant prostate cancer using relevant end points of palliation in a randomized controlled trial.

PATIENTS AND METHODS: We randomized 161 hormone-refractory patients with pain to receive mitoxantrone plus prednisone or prednisone alone (10 mg daily). Nonresponding patients on prednisone could receive mitoxantrone subsequently. The primary end point was a palliative response defined as a 2-point decrease in pain as assessed by a 6-point pain scale completed by patients (or complete loss of pain if initially 1 +) without an increase in analgesic medication and maintained for two consecutive evaluations at least 3 weeks apart. Secondary end points were a decrease of > or = 50% in use of analgesic medication without an increase in pain, duration of response, and survival. Health-related quality of life was evaluated with a series of linear analog self-assessment scales (LASA and the Prostate Cancer-Specific Quality-of-Life Instrument [PROSQOLI]), the core questionnaire of the European Organization for Research and Treatment of Cancer (EORTC), and a disease-specific module.

RESULTS: Palliative response was observed in 23 of 80 patients (29%; 95% confidence interval, 19% to 40%) who received mitoxantrone plus prednisone, and in 10 of 81 patients (12%; 95% confidence interval, 6% to 22%) who received prednisone alone (P = .01). An additional seven patients in each group reduced analgesic medication > or = 50% without an increase in pain. The duration of palliation was longer in patients who received chemotherapy (median, 43 and 18 weeks; P < .0001, log-rank). Eleven of 50 patients randomized to prednisone treatment responded after addition of mitoxantrone. There was no difference in overall survival. Treatment was well tolerated, except for five episodes of possible cardiac toxicity in 130 patients who received mitoxantrone. Most responding patients had an improvement in quality-of-life scales and a decrease in serum prostate-specific antigen (PSA) level.

CONCLUSION: Chemotherapy with mitoxantrone and prednisone provides palliation for some patients with symptomatic hormone-resistant prostate cancer.

Harvey, WH and Bretton PR
Proc Am Soc Clin Oncol 13:255A, 1994.

No abstract.

Storlie JA, Buckner JC, Wiseman GA, Burch PA, Hartmann LC, Richardson RL
Department of Family Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
Cancer 1995 Jul 1;76(1):96-100

BACKGROUND. It has been suggested that suppression of adrenal androgens may provide benefit to patients with metastatic prostate cancer refractory to initial hormonal therapy (e.g., orchiectomy).

METHODS. The records of 38 patients with metastatic prostate cancer that had progressed after orchiectomy who were placed subsequently on low dose dexamethasone (DXM) with no other concurrent therapy (36 patients received 0.75 mg twice daily and two received 0.75 mg three times daily) were reviewed. Symptomatic status, prostate specific antigen (PSA) measurements, and available radiographic assessments were recorded. Bone scans were reviewed by an independent, blinded evaluator.

RESULTS. Symptomatic improvement was experienced by 24 patients (63%), 20 (83%) of whom also had decreases in PSA. Prostate specific antigen values decreased in 30 patients (79%) with decreases 50% or greater and 80% or greater in 23 (61%) and 13 (34%) patients, respectively. Of the 23 patients with PSA decreases 50% or greater, 8 (35%) had radiographic evidence of disease regression, 5 (22%) were stable, 7 (30%) had disease progression, and 3 (13%) did not have serial radiographic exams. Flutamide was discontinued shortly before DXM treatment for 2 of the 23 patients.

CONCLUSIONS. Low dose DXM may produce important symptomatic improvement and decreased PSA levels in the majority of patients with hormone-refractory prostate cancer. In addition, a substantial percentage of those patients with decreases in PSA also will have radiographic evidence of disease regression. These results suggest the need for additional prospective controlled studies of DXM as a therapy for hormone-refractory prostate cancer.

Kelly WK, Scher H, Bajorin D, et al
Proc Am Soc Clin Oncol 13:A710, 1994.

No abstract.

Sinha AA, Blackard CE, Doe RP, et al:
Cancer 31:682-8, 1973.

No abstract.

Davies P, Griffiths K
J Endocrinol 59:367-368, 1973.

No abstract.

Lasnitzki I
J Steroid Biochem 11:625-630, 1979.

No abstract.

Byer DP
Cancer 32:1126-30, 1973.

No abstract.

Blackard CE
Cancer Chemother Rep 59(Part 1):225-7, 1975.

No abstract.

Pavone-Macaluso M, de Voogt HJ, Viggiano G, Barasolo E, Lardennois B, de Pauw M, Sylvester R
J Urol 1986 Sep;136(3):624-31

Patients with previously untreated category T3 to T4 Mo or Ml prostatic cancer were allocated randomly to receive 250 mg. cyproterone acetate per day, a loading dose of 500 mg. medroxyprogesterone acetate intramuscularly 3 times weekly for 8 weeks followed by 100 mg. orally twice daily, or 1 mg. diethylstilbestrol 3 times daily in a phase III trial (protocol 30761) performed by the genitourinary tract cooperative group of the European Organization for Research on the Treatment of Cancer. Of 236 patients entered 210 were eligible: 75 received cyproterone acetate, 71 medroxyprogesterone acetate and 64 diethylstilbestrol. Local and distant tumor response, time to progression, survival and toxicity were assessed. Patients treated with medroxyprogesterone acetate had a less favorable course with a shorter duration of survival and time to progression than those treated with the other 2 drugs. There was no significant difference between diethylstilbestrol and cyproterone acetate. Cardiovascular side effects were reported more often in patients treated with diethylstilbestrol than in those treated with cyproterone acetate but severe and lethal cardiovascular toxicity was relatively low in all groups. Other side effects were negligible. Further studies are required to establish the influence of effective hormonal treatment upon survival.

Emtage LA, George J, Boughton BJ, Trethowan C, Blackledge GR
West Midlands Cancer Research Campaign Clinical Trials Unit, Department of Medicine, Queen Elizabeth Hospital, Birmingham, U.K.
Eur J Cancer 1990 Mar;26(3):315-9

Two hundred and fifty patients were entered into a randomized clinical study to compare the effectiveness of goserelin (Zoladex) in depot formulation with diethyl stilboestrol in locally advanced or metastatic prostate cancer. In 22 patients from the two arms of the study regular assessments were made of the effect of these hormone treatments on the haemostatic system. Selection of those patients with no recent surgical intervention and those on no drugs liable to interfere with the haemostatic mechanism was done at entry, in order to remove bias and achieve comparable groups. Baseline comparison of the two treatment groups showed no difference in clinical or biochemical measures of disease extent or activity, including serum prostate specific antigen (PSA) levels. There was a significant fall in plasma antithrombin-III (AT-III) activity in the DES treated group both from baseline and compared with the goserelin group. This effect commenced within 1 month and was maintained until monitoring ceased at 12 months. There was also a significant increase of fibrinolytic activity in the DES treated patients compared with those on goserelin. No divergence between the two treatment groups was seen in any other haematological parameters at baseline or on follow-up. A single AT-III estimation was also performed on a larger group of 74 patients at median follow-up time of 17 months (range 3-24). This confirmed the difference noted in the original study group. In the main study thrombotic episodes were noted in 13/126 patients treated with DES and 0/124 treated with goserelin (P less than 0.001). These findings suggest that lowered AT-III is the major factor through which DES affects the coagulation mechanism, and that no such effect is seen with goserelin treatment despite an equivalent therapeutic efficacy.

Byer DP and Corle DK
NCI Monogr 7:165-70, 1988.

No abstract.

Scott WW, Menon M and Walsh PC
Cancer 47(7 suppl):1929-36, 1980.

No abstract.

Jazieh AR, Munshi NC, Muirhead M and Ross SW
Proc Am Assoc Cancer Res 35:233A, 1994.

No abstract.

Smith DC, Redman BG, Flaherty LE, Li L, Strawderman M, Pienta KJ
University of Michigan Comprehensive Cancer Center, Division of Hematology/Oncology, University of Michigan School of Medicine, Ann Arbor, USA.
Urology 1998 Aug;52(2):257-60

OBJECTIVES: To test the use of 1 mg/day of oral diethylstilbesterol (DES) as a treatment for patients with advanced prostate cancer who had failed primary hormonal therapy. Approximately 40,000 men this year will experience first-line hormonal therapy failure for their metastatic prostate cancer. At this time there is no standard therapy for men whose first-line hormonal manipulation has failed. This clinical problem has been exacerbated by the use of prostate-specific antigen (PSA) as a proved biomarker to follow disease progression. Patients who are experiencing hormonal therapy failure now present with a rising PSA, and virtually all are asymptomatic. The dilemma of how to treat these patients represents a new clinical problem for the medical oncologist and urologist that needs to be answered.

METHODS: We conducted a Phase II trial of oral DES in 21 patients. Patients were followed for response by PSA criteria and toxicity. A decrease in two serial measurements of PSA of greater than 50% from baseline was judged to be a partial response.

RESULTS: Nine of 21 patients achieved a PSA response (43% response rate with 95% confidence intervals of 22% to 64%) leading to early cessation of this Phase II trial. Eight of 13 patients (62%) who had only one prior hormone manipulation that failed demonstrated a PSA response, whereas only 1 of 8 patients (13%) who had received two or more hormone treatments responded (P = 0.07). The median follow-up is 82 weeks (range 8 to 122) among 16 surviving patients. The survival rate at 2 years is 63% (95% confidence interval 41% to 99%).

CONCLUSIONS: DES appears to be an active agent for second-line hormone therapy for metastatic prostate cancer. Because it has been taken off the market for economic reasons, DES should be considered for development under the orphan drug strategy.

Colapinto V and Aberhart C
Br J Urol 33:171, 1961.

No abstract.

Ferro MA, Heinemann D, Smith PJ, Symes MO
Department of Urology, University of Bristol, Royal Infirmary.
Br J Urol 1988 Aug;62(2):166-72

Controversy still exists as to whether oestrogens exert a direct effect on the prostatic cell. Incorporation of 75Selenomethionine (SeM) was used as a measure of protein synthesis by prostatic carcinoma cells in vitro to investigate the action of hormones on prostatic carcinoma cells in tissue culture. Stilboestrol (DES) and stilboestrol diphosphate (Honvan) inhibited protein synthesis in a proportion of patients, while testosterone was stimulatory. A similar effect was noted in cells from patients with benign hyperplasia (BPH). This work confirms that oestrogens have a direct inhibitory effect on prostatic cells at high concentrations which can be attained in patients given intravenous stilboestrol diphosphate.

Abramson FP, Miller HC Jr
J Urol 1982 Dec;128(6):1336-9

The kinetic behavior of diethylstilbestrol (DES) produced from stilphostrol has been studied in man, dog and rat. A sensitive and selective assay for DES in plasma and tissues has been developed with the use of gas chromatographic separation and mass spectrometric detection. In patients with prostate cancer, the plasma concentrations of DES produced by 1,000-mg. infusions of stilphostrol are 1,500 times the DES concentrations produced by conventional oral DES doses. The pharmacokinetics of DES show 2 separate phases; 1 with a t1/2 of approximately 1 hour, another with a t1/2 of approximately a day. In rats, stilphostrol does not selectively liberate DES in the prostate compared to dosing with DES itself. In dogs, a 50-mg. tablet of stilphostrol was bioequivalent to 40 mg. of DES taken orally. Some of these data support the idea that the high DES concentrations produced by stilphostrol infusions underlie in its ability to produce objective responses in patients refractory to conventional oral DES therapy.

Ferro MA, Gillatt D, Symes MO, Smith PJ
Department of Urology, Bristol Royal Infirmary, United Kingdom.
Urology 1989 Sep;34(3):134-8

High-dose intravenous estrogen therapy was shown to be effective in relieving bone pain due to metastatic disease in 22 of 29 (75.9%) men with advanced hormone-resistant prostate cancer. This clinical response was accompanied by significant falls in serum prostate-specific antigen (PSA) levels in 13 (44.8%) patients. It is suggested that this clinical benefit is due to a direct inhibitory effect of estrogen on prostate cancer cells.

Droz JP, Kattan J, Bonnay M, Chraibi Y, Bekradda M, Culine S
Department of Medicine, Institut Gustave-Roussy, Villejuif, France.
Cancer 1993 Feb 1;71(3 Suppl):1123-30

BACKGROUND. The initial treatment of advanced-stage prostate cancer is total androgen deprivation. Autonomous proliferation of primarily or secondarily hormonal unresponsive cells may explain the development of hormone-refractory status. The median survival of patients with hormone-resistant disease is short; there is no standard regimen of chemotherapy.

METHODS. Fosfestrol or diethylstilbestrol diphosphate and its metabolites have cytotoxic activity in hormone-refractory prostatic cell lines. Pharmacokinetic studies have shown that fosfestrol metabolites have a short half-life that supports the use of long-term infusion in the clinic.

RESULTS. A review of the literature shows that high-dose fosfestrol induces no objective response, a greater than 50% tumor marker decrease in 50% of patients, a subjective improvement in 75% of patients, and cardiovascular complications in 5% of patients. The median survival time of patients is 5 months after the onset of treatment.

CONCLUSIONS. An exact evaluation of the role of high-dose estrogens requires additional investigation.

Ferro MA
Huddersfield Royal Infirmary, West Yorkshire, England.
Urol Clin North Am 1991 Feb;18(1):139-43

The patient presenting with severe bone pain after primary hormonal therapy, with vertebral collapse, or with uremia resulting from ureteric obstruction should be considered for intravenous stilbestrol diphosphate therapy. The urologist can expect early marked improvement in the patients' mobility and pain, with a reduction in analgesic requirements, from a single 7-day course of treatment. In addition, the drug is inexpensive and free of the side effects commonly associated with cytotoxic therapy. Accurate monitoring of the response is possible with serum prostate-specific antigen measurements, which also enable further therapy to be planned efficiently.

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Effects of protein kinase and phosphatase inhibitors on the growth of human prostatic cancer cells

Konno S.; Cherry J.; Tazaki H.; Mallouh C.; Chiao J.W.
Dr. S. Konno, New York Medical College, Department of Urology, Valhalla, NY 10595 USA
Medical Science Research (United Kingdom), 1997, 25/5 (353-354)

The effects of protein kinase and phosphatase inhibitors on cell growth were investigated in human prostatic cancer, JCA-1, PC-3, and LNCaP cells. All four inhibitors showed a significant growth inhibitory effect, as determined by the (3H)thymidine incorporation method. The IC50 (50% inhibitory concentration) of each inhibitor was then calculated from the respective growth curves. Among the three cell lines, JCA-1 cells were relatively more susceptible to the inhibitors, while PC-3 cells were least sensitive. The IC50 data revealed that calphostin C and okadaic acid were more potent growth inhibitors than genistein and sodium orthovanadate. These results suggest that cell growth appears to be more effectively inhibited by the inhibitors of Ser/Thr-kinases/phosphatases (i.e. calphostin C and okadaic acid). Thus the family of Ser/Thr-kinases/phosphatases may be critically involved in regulating the growth of prostatic cancer cells.

Phyto-oestrogens and Western diseases

Adlercreutz H.; Mazur W.
Prof. H. Adlercreutz, Department of Clinical Chemistry, University of Helsinki, Meilahti Hospital, Haartmaninkatu 4, FIN-00290 Helsinki Finland
Annals of Medicine (United Kingdom), 1997, 29/2 (95-120)

Incidences of breast, colorectal and prostate cancer are high in the Western world compared to countries in Asia. We have postulated that the Western diet compared to the semivegetarian diet in some Asian countries may alter hormone production, metabolism or action at the cellular level by some biochemical mechanisms. Our interest has been focused on two groups of hormone-like diphenolic phyto-oestrogens of dietary origin, the lignans and isoflavonoids abundant in plasma of subjects living in areas with low cancer incidence. The precursors of the biologically active compounds detected in man are found in soybean products, whole-grain cereal food, seeds, and berries. The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormone-like compounds. The weakly oestrogenic diphenols formed influence sex-hormone production, metabolism and biological activity, intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation, cell adhesion and angiogenesis in such a way as to make them strong candidates for a role as natural cancer-protective compounds. Their effect on some of the most important steroid biosynthetic enzymes may result in benes and action in the ce lls preventing development of cancer. Owing to their oestrogenic activity they reduce hot flushes and vaginal dryness in postmenopausal women and may to some degree inhibit osteoporosis, but alone they may be insufficient for complete protection. Soy intake prevents oxidation of the low-density lipoproteins in vitro when isolated from soy-treated individuals and affect favourably plasma lipid concentrations. Animal experiments provide evidence suggesting that both lignans and isoflavonoids may prevent the development of cancer as well as atherosclerosis. However, in some of these experiments it has not been possible to separate the phyto-oestrogen effect from the effect of other components in the food. The isoflavonoids and lignans may play a significant inhibitory role in cancer development particularly in the promotional phase of the disease, but recent evidence points also to a role in the initiation stage of carcinogenesis. At present, however, no definite recommendations can be made as to the dietary amounts needed for prevention of disease. This review deals with all the above-mentioned aspects of phyto-oestrogens.

Genistein inhibits proliferation and in vitro invasive potential of human prostatic cancer cell lines

Santibanez J.F.; Navarro A.; Martinez J.
Dr. J. Martinez, Unidad de Biologia Celular, INTA, Universidad de Chile, Casilla 138-11, Santiago Chile
Anticancer Research (Greece), 1997, 17/2 A (1199-1204)

Genistein -a natural flavone compound with antitumor activity- has been proposed as an effective agent to prevent the expression of metastasic capacity in hormone-dependent cancers. The present study represethe prolife ration and expression of the in vitro invasive capacity of tumoral prostatic cells with different invasive potential. In a cell culture system, genistein appeared to be cytotoxic and inhibitory of miaration through a Matriael barrier to PC-3 cells. the more aggressive invasive cell-line studied. DU-145 and LNCalphaP cells, which are less invasive than PC-3, are less affected by Genistein both with respect to proliferation rate and inhibition of u-PA and 72 kDa Gelatinase secretion. Measurement of the level of tyrosine-phosphoproteins in the three cell lines studied also showed that PC-3 cells are the most sensitive cells, with a possible molecular target in a membrane-bound protein of 130 kDa.

Soy and rye diets inhibit the development of Dunning R3327 prostatic adenocarcinoma in rats

Zhang J.-X.; Hallmans G.; Landstrom M.; Bergh A.; Damber J.-E.; Aman P.; Adlercreutz H.
Sweden
Cancer Letters (Ireland), 1997, 114/1-2 (313-314)

Two experiments were conducted to investigate the effect of soy and rye on the development of Dunning R3327 prostatic adenocarcinoma in rats.

Measurement and metabolism of isoflavonoids and lignans in the human male

Morton M.S.; Matos-Ferreira A.; Abranches-Monteiro L.; Correia R.; Blacklock N.; Chan P.S.F.; Cheng C.; Lloyd S.; Chieh-Ping W.; Griffiths K.
United Kingdom
Cancer Letters (Ireland), 1997, 114/1-2 (145-151):

Asian men, who consume a low fat/high fibre soya-based diet, have very much lower incidence of prostate cancer than men from North America and Europe. The soya bean is a rich source of the isoflavonic phyto-oestrogens, daidzein, genistein and equol, compounds which may be cancer-protective in Asian populations. The lignans, enterolactone and enterodiol, plant oestrogens derived from cereals and vegetables, may act in a similar manner in vegetarian men. We report here on the measurement of isoflavonoids and lignans, by gas chromatography-mass spectrometry, in prostatic fluid of men from Asia and Europe and also on the metabolism of these compounds in Western men following dietary supplementation.

Inhibition of N-methyl-N-nitrosourea-induced mammary tumors in rats by the soybean isoflavones

Constantinou A.I.; Mehta R.G.; Vaughan A.
Dr. A.I. Constantinou, University of Illinois, Department of Surgical Oncology, College of Medicine, 840 South Wood Street, Chicago, IL 60612 USA
Anticancer Research (Greece), 1996, 16/6 A (3293-3298)

Soy-based diets, rich in the isoflavones genistein and daidzein, are thought to protect against breast and prostate cancer. Soy-based diets, rich in the isoflavones genistein and daidzein, are thought to protect against breast and prostate cancer. We used the N-methyl-N-nitrosourea (MNU)-induced mammary carcinogenesis animal model to test the effectiveness of these two isoflavones as chemopreventive agents. Each isoflavone was injected daily into 35-day-old rats for six months while we monitored the animals' body weight and mammary tumor appearance. Genistein was effective in reducing tumor multiplicity, but it reduced tumor incidence only marginally. Daidzein was less effective in reducing both tumor incidence and multiplicity. To investigate genistein's mechanism of action we determined the topoisomerase II (topo II) activity and detected the phosphotyrosine-containing peptides in the extracts of mammary tissues isolated from control and isoflavone-treated animals. tumors contained over 60-fold higher topo II enzymatic activity than the mammary glands. Similarly, more tyrosine phosphopeptides were detectable in mammary tumors than in mammary glands. Tissue samples from genistein treated animals contained similar topo II and protein tyrosine kinase (PTK) activities as the control group. These data suggest that mammary tumorigenesis is accompanied by an extensive increase in topo II and PTK activities. The mechanism of chemoprevention by genistein, however, is independent of topo II or PTK inhibition.

Genistein-induced apoptosis of prostate cancer cells is preceded by a specific decrease in focal adhesion kinase activity

Kyle E.; Neckers L.; Takimoto C.; Curt G.; Bergan R.
USA
Molecular Pharmacology (USA), 1997, 51/2 (193-200)

Genistein (5,7,4'-trihydroxyisoflavone), an isoflavinoid found in soy beans, has been identified as potentially causal for the low incidence of metastatic prostate cancer (PCa) in certain countries. Although genistein- induced PCa cell adhesion has been identified as a possible causative mechanism, direct growth inhibition by genistein has been reported and also could be causal. If in vivo growth inhibition was significant, then growth inhibition should occur at concentrations attained with dietary consumption, the mechanism of growth inhibition should be relevant to PCa, and genistein (a broad-spectrum in vitro protein-tyrosine kinase inhibitor) should have relatively specific kinase inhibitory effects in vivo. These considerations were investigated by measuring growth inhibitory activity in a variety of PCa cell lines. Growth inhibitory effects were shown not to occur with concentrations below the low micromolar range (i.e., 3 logs above that attained in serum). In-depth mechanistic studies with the PC3-M metastatic variant cell line demonstrated that growth inhibition was in was shown to decrease the viability of nonadherent cells, suggesting a lack of dependence on cell adhesion for growth inhibition. However, important molecular and kinetic differences between genistein's effects on growth in adherent versus nonadherent cells were identified. Specific suppression of focal adhesion kinase activity (without global decreases in phosphotyrosine) was shown to precede induction of apoptosis, which was responsible for growth inhibition in adherent cells. These findings do not support an in vivo growth inhibitory role by genistein consumed in quantities associated with a soy-based diet. They do, however, identify genistein as a potential therapeutic agent for PCa and as a tool with which to study the control of apoptosis in PCa.

Genistein-stimulated adherence of prostate cancer cells is associated with the binding of focal adhesion kinase to beta-1-integrin

Bergan R.; Kyle E.; Nguyen P.; Trepel J.; Ingui C.; Neckers L.
Clinical Pharmacology, Building 10, National Cancer Institute, NIH, Bethesda, MD 20892 USA
Clinical and Experimental Metastasis (United Kingdom), 1996, 14/4 (389-398)

The isoflavinoid genistein is a protein-tyrosine kinase inhibitor which has been identified as a putative cancer prevention agent. Its consumption is associated with a low incidence of clinical metastatic prostate cancer in the face of a sustained high incidence of organ-confined prostate cancer. We therefore undertook studies to examine genistein's effect upon cell adhesion as one possible mechanism by which it could be acting as an antimetastatic agent. A morphogenic analysis revealed that genistein caused cell flattening in a variety of cell lines: PC3-M, PC3, and DU-145 prostate carcinoma cells, as well as MCF-7 breast carcinoma cells. Mechanistic studies focused on the highly metastatic PC3-M cell line, and revealed that cell flattening was accompanied by an increase in cell adhesion. Further investigations demonstrated that focal adhesion kinase (FAK) accumulated in areas of focal cell attachment, and that this accumulation occurred only when cells were actively undergoing genistein-mediated morphologic change. Concurrent formation of a complex between the cell attachment molecule, beta-1-integrin, and FAK was shown to occur, and to correlate with transient activation of FAK activity. Genistein is presented as a novel investigative tool for use in the study of molecular events involved in the process of cell adhesion.

Quantification of genistein and genistin in soybeans and soybean products

Fukutake M.; Takahashi M.; Ishida K.; Kawamura H.; Sugimura T.; Wakabayashi K.
Biochemistry Division, Natl Cancer Ctr Research Institute, 1-1 Tsukiji, 5-chome, Chuo-ku, Tokyo 104 Japan
Food and Chemical Toxicology (United Kingdom), 1996, 34/5 (457-461)

It has been suggested that the isoflavone, may have some role as a chemopreventive agent against cancer in humans. Levels of genistein and its beta-glucoside conjugate, genistin, ingested in soybeans and related bean products by the Japanese were quantified by HPLC, to estimate daily intake of these compounds. Amounts of genistein and genistin in soybeans, soy nuts and soy powder were in the range of 4.6 to 18.2 and 200.6 to 968.1 microg/g food, respectively. The values for soy milk and tofu (bean curd) were 1.9 to 13.9 and 94.8 to 137.7 microg/g food, respectively. Levels of isoflavones in fermented soybean products, miso (bean paste) and natto (fermented soybeans), were 38.5 to 229.1 microg/food for genistein and 71.7 to 492.8 microg/g food for genistin. Thus, the level of genistein in the fermented soybean products was higher than in soy beans and soybean products such as soy milk and tofu. From these observations, it is suggested that the beta-glycosyl bond of genistin is cleaved to produce genistein by microbes during fermentation to yield mise and natto. Soy sauce was also found to contain both isoflavones, but at levels lower than in miso and natto. On the basiual consumption of soybeans and related products, daily intake of genistein and genistin by the Japanese is calculated to be 1.5-4.1 and 6.3-8.3 mg/person, respectively. These levels are much higher than those for Americans or Western Europeans, whose mortality rates for breast, colon and prostate cancers are greater than the Japanese.

Molecular effects of genistein on estrogen receptor mediated pathways

Wang T.T.Y.; Sathyamoorthy N.; Phang J.M.
Lab Nutritional Molecular Regulation, NCI-Frederick Cancer Res Dev Ctr, NIH, Frederick, MD 21702-1201 USA
Carcinogenesis (United Kingdom), 1996, 17/2 (271-275)

Genistein, a component of soy products, may play a role in the prevention of breast and prostate cancer. However, little is known about the molecular mechanisms involved. In the present study, we examined the effects of genistein on the estrogen receptor positive human breast cancer cell line MCF-7. We observed that genistein stimulated estrogen-responsive pS2 mRNA expression at concentrations as low as 10-8 M and these effects can be inhibited by tamoxifen. We also showed that genistein competed with (3H)estradiol binding to the estrogen receptor with 50% inhibition at 5 X 10-7 M. Thus, the estrogenic effect of genistein would appear to be a result of an interaction with the estrogen receptor. The effect of genistein on growth of MCF-7 cells was also examined. Genistein produced a concentration-dependent effect on the growth of MCF-7 cells. At lower concentrations (10-8-10-6 M) genistein stimulated growth, but at higher concentrations (>10-5 M) genistein inhibited growth. The effects of genistein on growth at lower concentrations appeared to be via the estrogen receptor pathway, while the effects at higher concentrations were independent of the estrogen receptor. We also found that genistein, though estrogenic, can interfere with the effects of estradiol. In addition, prolonged exposure to genistein resulted in a decrease in estrogen receptor mRNA level as well as a decreased response to stimulation by estradiol.

Effects of soya consumption for one month on steroid hormones in premenopausal women: Implications for breast cancer risk reduction

Lu L.-J.W.; Anderson K.E.; Grady J.J.; Nagamani M.
Preventive Med./Commun. Health Dept., 2.102 Ewing Hall, University of Texas Medical Branch, Galveston, TX 77555-1110 USA
Cancer Epidemiology Biomarkers and Prevention (USA), 1996, 5/1 (63-70)

Soybean consumption is associated with reduced rates of breast, prostate, and colon cancer, which is possibly related to the presence of isoflavones that are weakly estrogenic and anticarcinogenic. We examined the effects of soya consumption on circulating steroid hormones in six healthy females 22- 29 years of age. Starting within 6 days after the onset of menses, the subjects ingested a 12-oz portion of soymilk with each of three meals daily for 1 month on a metabolic unit. Daily isoflavone intakes were similar100 mg of daidzein (mostly as daidzin) and similar100 mg of genistein (mostly as genistin). Serum 17beta-estradiol levels on cycle days 5-7, 12-14, and 20-22 decreased by 31% (P = 0.09), 81% (P = 0.03), and 49% (P = 0.02), respectively, during soya feeding. Decreases persisted for two to three menstrual cycles after withdrawal from soya feeding. The luteal phase progesterone levels decreased by 35% during soya feeding (P = 0.002). Dehydroepiandrosterone sulfate levels decreased progressively during soya feeding by 14-30% (P = 0.03). Menstrual cycle length was 28.3 plus or minus 1.9 days before soymilk feeding, increased to 31.8 plus or minus 5.1 days during the month of soymilk feeding (P = 0.06), remained increased at 32.7 plus or minus 8.4 days (P = 0. 11) at one cycle after termination of soymilk feeding, and returned to pre-soya diet levels five to six cycles later. These results suggest that consumption of soya diets containing phytoestrogens may reduce circulating ovarian steroids and adrenal androgens and increase menstrual cycle length. Such effects may account at least in part for the decreased risk of breast cancer that has been associated with legume consumption.

Early di. An update

D'Amico A.; Motta L.; Ficarra V.; Pianon R.; Malossini G.; Tallarigo C.; Comunale L.; Mobilio G.
Italy
Medecine Biologie Environnement (Italy), 1996, 24/2 (139-152)

The main disagreements concerning the early diagnosis and the screening of prostate carcinoma are due to the lack of clinical evidence that the discovery of an early stage tumor, followed by a radical surgical treatment, does induce a prolonged survival of the patients and/or an improvement of the quality of life. However, many clinical studies on the epidemiology and the natural history of the disease suggested the efficacy of the early diagnosis. Moreover, the volume of neoplasia diagnosed by screening programs and surgically treated is generally higher than 0.5 ml and this is certainly an important clinical value. The dosage of serum PSA was particularly be reliable to detect an early diagnosis, according to its higher diagnostic accuracy if compared with digital rectal examination and transrectal ultrasonography. The combination of these diagnostic methods increased the accuracy of the whole clinical picture. In order to increase total PSA specificity by reducing its false positive values, especially when marker's values are only slightly augmented (ranged between 4.1 and 10 ng/ml), many approaches may be adopted, such as the evaluation of PSA velocity (PSAV), the assessment of PSA density (PSAD), the appropriate use of specific PSA values according to the different age of the patients and, especially, the comparison between free and complexed PSA dosages to total PSA values. In particular, it has been, recently observed that free PSA and total PSA ratio shows a more marked specificity than total PSA at the same degree of sensitivity. However, it is necessary to assess for international standard parameters concerning both total PSA and its molecular forms, since clinical observations were generally carried out through many different laboratory tools and according to different reference values. Finally, the research on prognostic factors which might foresee the developing power of the single tumor detected into the prostate, may provide useful information in order to select the patients who may benefit from a radical surgical treatment.

Prostate-specific antigen as a screening test for prostate cancer: The United States experience

Arcangeli C.G.; Ornstein D.K.; Keetch D.W.; Andriole G.L.
USA
Urologic Clinics of North America (USA), 1997, 24/2 (299-306)

Serum PSA-based early detection for prostate cancer has been studied fairly extensively for the past several years. It appears that we can state fairly categorically what the relative performances of total serum PSA, DRE, and TRUS are in detecting early-stage prostate cancer; that initial screening is effective in detecting histologically significant and pathologically organ-confined prostate cancer; that annual, serial, repetitive screening, at least over a 4- to 5-year horizon, does not overdetect prostate cancer, and that the results of early detection will improve as our ability to use certain PSA transformations such as PSA density, PSA slope, age-specific PSA adjustment, and knowledge of free versus total serum PSA is better characterized. These advances in our ability to diagnose early-stage prostate cancer likely will be coupled with an increased ability to predict the behavior, curability, and significance of individual tumors. It is hoped that information soon will be available to allow physicians to categorize an individual tumor as insignificant, significant and surgically curable, or significant and incurable by standard approaches. This ability, coupled with the demon strated ability to detect prostate cancer, will make an even more compelling argument for widespread PSA-based screening. At present, annual DRE and total serum PSA measurements are recommended for men older than 50 and among younger men at high risk for prostate cancer. All suspicious DRE findings should be evaluated with prostatic biopsy. Among younger men, PSA levels over 2.5 ng/mL should be considered worrisome and further evaluated. For men older than 65, serum PSA levels above 4 ng/mL should be considered abnormal and warrant biopsy. Men with persistent serum PSA elevation and a negative biopsy should undergo repeat biopsy at least once, and perhaps more often if PSA slope exceeds 0.75 per year, if density is greater than 0.10, or if PSA is less than 20%.

Prostate cancer screening: The controversy

Assaf G.J.
Lebanon
Revue Medicale Libanaise (Lebanon), 1996, 8/3 (152-154)

As of 1993, prostate cancer is the most common cancer among men in the USA and Canada, and the second leading cause of cancer deaths in males. In 1980, of patients in whom the diagnosis of prostate cancer was made clinically, 40% had disease beyond the prostate gland, for the most part an incurable condition. One should always bear in mind that localized prostate cancer is asymptomatic. The obstructive voiding symptoms rarely occur with localized organ confined prostate cancer. Few years ago, the PSA (prostate specific antigen) serologic test was developed, as a methodology for screening patients for prostate cancer, seeking the detection of this disease at an early stage. We will discuss the natural history of prostate cancer, early detection of this disease and the limitations of the PSA determination.

Clinical utility of measurements of free and total prostate-specific antigen (PSA): A review

Catalona W.J.
Division of Urologic Surgery, Washington Univ. Sch. of Medicine, 4960 Childrens' Place, St. Louis, MO 63110 USA
Prostate (USA), 1996, 29/Suppl. 7 (64-69)

BACKGROUND. Prostate-specific antigen (PSA) is a widely-used tumor marker to aid in the early detection of prostate cancer. PSA testing has appreciable false-positive and false-negative results, particularly in the 2.5-10.0 ng/ml range. Measurements of the percentage of nonprotein-bound (free) PSA in serum, which is lower in patients with prostate cancer, has been evaluated as a method for increasing the accuracy of PSA testing.

METHODS. The literature on forms of PSA in serum, as it relates to issues of clinical utility for prostate cancer screening, was reviewed and summarized through May 1996.

RESULTS. Measurements of the percentage of free PSA in serum increases the accuracy of PSA testing for prostate cancer in men whose total PSA levels are 2.5-10.0 ng/ml. Cutoffs for screening are affected by prostate volume and total PSA levels. One study also demonstrated a correlation between percentage of free PSA and pathologic features of cancer aggressiveness.

CONCLUSIONS. Measurement of free PSA in serum has potential clinical utility for increasing the sensitivity and specificity of PSA screening. Insufficient data are available to establish cutoffs to be used in clinical practice. Cutoffs are affected by total PSA level and prostate volume. The prevalence rate of cancer in the screened population (age, race, previous biopsy history, etc.) will also influence screening cutoffs. Percentage of free PSA may also correlate with the potential aggressiveness of early-stage prostate cancer.

Detection of human papillomavirus DNA and p53 gene mutations in human prostate cancer

Suzuki H.; Komiya A.; Aida S.; Ito H.; Yatani R.; Shimazaki J.
Department of Urology, School of Medicine, Chiba University, Inohana 1-8-1, Chuo-ku, Chiba-shi, Chiba 260 Japan
Prostate (USA), 1996, 28/5 (318-324)

The relationship between integration with human papillomavirus (HPV) and p53 gene mutations in tissues of prostate cancer was examined. Tissue samples analyzed were obtained by tofrom autopsy (22 endocrine therapy-resist ant metastatic disease cases). HPV DNA was detected in 8 of 51 (16%, 5 in stage B and 3 in autopsy cases) by polymerase chain reaction (PCR) using consensus primers on L1 region. Genotypes of HPV were entirely type 16. Structural abnormalities of p53 gene were detected in 7 of the 22 autopsy cases (32%) by PCR-single-strand conformation polymorphism analysis and direct sequencing. No p53 gene mutation was found in stage B cancer cases. Analysis of mutation spectra revealed clear differences between Japanese and Westerners. There was a significant difference in the mutation frequency between stage B and autopsy cases (P < 0.01, Fisher's exact test). One case showed both integration of HPV and p53 gene mutation in different cancer foci. However, the other cases revealed an inverse correlation between the presence of HPV DNA and p53 gene mutations. These data show that p53 genetic alteration is correlated with the progression of prostate cancer, in contrast to the integration of HPV that may occur in a relatively early stage. In conclusion, this study may indicate that either p53 gene mutation or the presence of HPV's oncogenic protein E6 is involved in the development of prostate cancer.

Effects of potent vitamin D3 analogs on clonal proliferation of human prostate cancer cell lines

De Vos S.; Holden S.; Heber D.; Elstner E.; Binderup L.; Uskokovic M.; Rude B.; Chen D.L.; Le J.; Cho S.K.; Koeffler H.P.
Dr. S. De Vos, Cedars-Sinai Medical Center, Davis Bldg. 5034, UCLA School of Medicine, 8700 Beverly Blvd., Los Angeles, CA 90048 USA
Prostate (USA), 1997, 31/2 (77-83)

BACKGROUND. Management of prostate cancer that has spread outside of the prostate capsule is a difficult problem. Innovative, non-toxic approaches to the disease are required. New, relatively non-toxic vitamin D3 analogs have recently been synthesized. We report that several of these compounds have marked antiproliferative effects on prostate cells.

METHODS. The clonal antiproliferative activity of five novel analogs of 1,25 dihydroxyvitamin D3 (1,25(OH)2D3, (cmpd C)) as well as 1,25(OH)2D3 itself was tested on three human prostate cancer cell lines (PC-3, LNCaP, and DU-145). The analogs were 20-epi-22oxa-24a,26a,27a-tri-homo- 1alpha,25(OH)2D3 (code name: KH 1060); 24a26a27a-tri-homo-22,24-diene- 1alpha,25(OH)2D3 (code name: EB 1089); 1,25(OH)2-16ene-D3 (code name: HM); 1,25(OH)2-16ene-23yne-D3 (code name: V); 1,25(OH)2-20-epi-D3 (code name: MC 1288)).

RESULTS. With the parent compound (1,25(OH)2D3), the effective dose that inhibited 50% clonogenic growth of PC-3 and LNCaP was 10-8M and 7 x 10-9 M, respectively. For these prostate cancer cell lines, KH 1060 was the most potent analog by an order of 25- to 35-fold as compared to cmpd C. The second and third most potent analogs were HM and MC 1288. DU-145 was resistant to all the vitamin D3 analogs. The major side-effect of 1,25(OH)2D3 is the production of hypercalcemia. The relative inhibitory index (RII) was determined by comparing the antiproliferative activity of the analog to its ability to produce hypercalcemia in mice injected intraperitoneally every other day. The KH 1060 had the best RTI: 50- to 70- fold greater than 1,25(OH)2D3 for PC-3 and LNCaP, respectively.

CONCLUSIONS. A trial of one or more of theatment of minimal residual disease of prostate cancer.

1,25-Dihydroxyvitamin D3 and 9-cis-retinoic acid act synergistically to inhibit the growthcause accumulation of cells in G1

Blutt S.E.; Allegretto E.A.; Pike J.W.; Weigel N.L.
USA
Endocrinology (USA), 1997, 138/4 (1491-1497)

Recent studies have suggested that the active metabolite of vitamin D3, 1,25-dihydroxyvitamin D3, can inhibit the growth and/or induce the differentiation of a variety of cell types and that these characteristics might be useful in the treatment of some cancers. Retinoids also promote the differentiation and inhibit the growth of some cells. That the vitamin D receptor acts as a heterodimer with the retinoid X receptor (RXR) suggests that there may be functional interactions between 1,25-dihydroxyvitamin D3 and retinoids. In this study, we show that the combination of 1,25- dihydroxyvitamin D3 and 9-cis retinoic acid synergistically inhibits the growth of LNCaP prostate cancer cells. That this effect is mediated by RXR rather than retinoic acid receptors was shown using RXR- and retinoic acid receptor-specific ligands. The vitamin D3 analog, EB1089, inhibited growth more effectively than 1,25-dihydroxyvitamin D3 and also acted synergistically with 9-cis-retinoic acid. These treatments caused cells to accumulate in the G1 phase of the cell cycle, suggesting that 1,25- dihydroxyvitamin D3 can regulate one or more factors critical for the G1/S transition.

Vitamin D receptor content and transcriptional activity do not fully predict antiproliferative effects of vitamin D in human prostate cancer cell lines

Zhuang S.-H.; Schwartz G.G.; Cameron D.; Burnstein K.L.
USA
Molecular and Cellular Endocrinology (Ireland), 1997, 126/1 (83-90)

Prostate cancer cell lines exhibit variable growth suppression by the hormonal form molecular basis for this differential sensitivity to 1,25 D3, we compared growth response to 1,25 D3, vitamin D receptor (VDR) content and VDR transcriptional activity in four well-characterized human prostate cancer cell lines: LNCaP, DU145, PC-3 and ALVA-31. In PC-3 and DU145 cells, relative lack of growth inhibition by 1,25 D3 (< 10% inhibition) correlates with very low levels of VDR (9-15 fmol/mg protein) compared to classical vitamin D3 target tissues (similar 75-200 fmol/mg protein). Transfection of DU145 and PC-3 cells with a VDR cDNA expression vector is sufficient to establish growth sensitivity to 1,25 D3, suggesting that low VDR levels are responsible for the failure of these cell lines to respond to 1,25 D3. LNCaP cells are highly sensitive to growth inhibition by 1,25 D3 (similar 55% inhibition) and contain similar 2-3-fold more VDR (25 fmol/mg) than the relatively 1,25 D3-insensitive PC-3 and DU145 cell lines. However, ALVA-31 cells display less than 20% growth inhibition to 1,25 D3 although they contain the highest levels of VDR (45 fmol/mg) of the four cell lines. Thus, sensitivity to growth inhibition by 1,25 D3 does not correlate with VDR content in ALVA-31 and LNCaP cells. This lack of correlation between VDR density and growth responses to 1,25 D3 led us to investigate VDR-mediated gene transcription in these cell lines. We employed two different naturally-occurring vitamin D response elements (VDREs) linked to a reporter gene. Reporter gene activation by 1,25 D3 correlated well with VDR content in all four cell lines. Therefore, compared to LNCaP cells, decreased sensitivity of ALVA-31 to growth inhibition by 1,25 D3 is not due to a decrease in the general transcriptional activity of VDR. We conclude that growth inhibition by 1,25 D3 in prostate cancer cells requires VDR but that this response is modulated by non-receptor factors that are cell line-specific.

A preliminary report on the use of transfer factor for treating stage D3 hormone-unr metastatic prostate cancer

Pizza G.; De Vinci C.; Cuzzocrea D.; Menniti D.; Aiello E.; Maver P.; Corrado G.; Romagnoli P.; Dragoni E.; LoConte G.; Riolo U.; Palareti A.; Zucchelli P.; Fornarola V.; Viza D.
Dr. G. Pizza, Immunodiagnosis/Immunotherapy Unit, 1st Division of Urology, Sant'Orsola-Malpighi Hospital, Via P. Palagi 9, 40138 Bologna Italy
Biotherapy (Netherlands), 1996, 9/1-3 (123-132)

As conventional treatments are unsuccessful, the survival rate of stage D3 prostate cancer patients is poor. Reports have suggested the existence of humoral and cell-mediated immunity (CMI) against prostate cancer tumour-associated antigens (TAA). These observations prompted us to treat stage D3 prostate cancer patients with an in vitro produced transfer factor (TF) able to transfer, in vitro and in vivo, CMI against bladder and prostate TAA. Fifty patients entered this study and received one intramuscular injection of 2-5 units of specific TF monthly. Follow-up, ranging from 1 to 9 years, showed that complete remission was achieved in 2 patients, partial remission in 6, and no progression of metastatic disease in 14. The median survival was 126 weeks, higher than the survival rates reported in the literature for patients of the same stage.

The role of vitamin D in normal prostate growth and differentiation

Konety B.R.; Schwartz G.G.; Acierno J.S. Jr.; Becich M.J.; Getzenberg R.H.
University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213 USA
Cell Growth and Differentiation (USA), 1996, 7/11 (1563-1570)

Although increasing data indicate a role for vitamin D in prostate cancer, littlis hormone in the noncancerous prostate. We examined the effect of 1,25-dihydroxyvitamin D3 (1,25 D) on the growth of noncancerous rat prostates in vivo. Rats were castrated and treated with vehicle (controls), 1,25 D, testosterone, or a combination of both hormones for 2 weeks. Histological examination of the harvested prostates revealed that 1,25 D had a selective regressive effect on epithelial cells in treated rats compared to untreated castrated rats and to normal uncastrated rats. However, 1,25 D stimulated stromal growth in the prostate. The mean prostatic weight of the vitamin D-treated rats was twice that of the untreated rats (0.13 plus or minus SEM 0.005 g versus 0.06 plus or minus SEM 0.006 g). The histological differences were less marked in the testosterone-supplemented animals. A greater degree of cellular differentiation was observed in the rats treated with testosterone and vitamin D compared to rats that received testosterone supplementation alone. Studies of the nuclear matrix composition revealed differences between the testosterone-supplemented and the testosterone and 1,25 D-treated rat prostates. We conclude that in the absence of testosterone, 1,25 D may exert a growth-promoting effect on the prostatic stroma in vivo. In concert with testosterone, it may play an important role in the growth and differentiation of the normal rat prostate.

Effects of 1,25 dihydroxyvitamin D3 and its analogues on induction of apoptosis in breast cancer cells

James S.Y.; Mackay A.G.; Colston K.W.
Department of Clinical Biochemistry, St George's Hospital, Medical School, London SW17 ORE United Kingdom
Journal of Steroid Biochemistry and Molecular Biology (United Kingdom), 1996, 58/4 (395-401)

Vitamin D derivatives have been shown both to inhibit the proliferation of cultured breast cancer cells and totumours in vivo. We have investig ated the ability of several vitamin D analogues to promote the regression of experimental rat mammary tumours. Our results revealed that one vitamin D compound in particular, EB1089 (1(S),3(R)-dihydroxy-20(R)-5'-ethyl-5'-hydroxy-hepta- 1',3'(E)-dien- 1'-yl)-9,10-secopregna-5(Z),7(E), 10(19)-triene), was highly effective at inhibiting tumour progression, without causing a significant rise in serum calcium concentration. Tumour regression occurs when the rate of cell. death is greater than the rate of cell proliferation. Apoptosis (programmed or active cell death) is an active, energy-dependent process in which a distinct series of biochemical and molecular events leads to the death of cells by specific signals. We have examined effects of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) and the synthetic vitamin D analogue EB1089 on indices of apoptosis in cultured human breast cancer cells. The effects of the vitamin D compounds on the expression of two oncoproteins which may regulate apoptosis, bcl-2 and p53 were examined by Western analysis. In MCF-7 cell cultures treated for six days with 1,25(OH)2D3 or EB1089 (1 x 10-8 M), bcl-2 protein was reduced in comparison to control levels, whereas p53 protein was increased. In addition, the p21 protein, whose gene WAF-1 is induced by wild type p53, was also increased by both vitamin D compounds. Using Northern analysis, it was observed that 24-h treatment of MCF-7 cells with 1 x 10-8 M 1,25(OH)2D3 or EB1089 resulted in an induction of TRPM-2 (clusterin) mRNA, a gene associated with onset of apoptosis in the involuting prostate. Fragmentation of genomic DNA is a characteristic feature of apoptosis. With the terminal deoxynucleotidyl transferase (TdT) assay, 3'-OH DNA breaks indicative of DNA fragmentation were detected histochemically in MCF-7 cells treated with 1 x 10-8 M 1,25(OH)2D3 or EB1089 for four days prior to fixation and TdT reaction. Further evidence of apoptosis was obtained following six days treatment of MCF-7 cell cultures with 5 x 10-8 M 1,25(OH)2D3 or EB1089, utilizing a cell death ELISA assay, which measures the presence of histone-associated oligonucleosome complexes generated from DNA fragmentation. Taken together our findings indicate that vitamin D derivatives may play a role in regulating the expression of genes and protein products implicated in apoptosis.

Vitamin D receptor expression is required for growth modulation by 1alpha,25-dihydroxyvitamin D3 in the human prostatic carcinoma cell line ALVA-31

Hedlund T.E.; Moffatt K.A.; Miller G.J.
Department of Pathology, Box B-216, Univ. of Colorado Hlth Sciences Ctr, 4200 East Ninth Ave., Denver, CO 80262 USA
Journal of Steroid Biochemistry and Molecular Biology (United Kingdom), 1996, 58/3 (277-288)

Epidemiological data suggest that vitamin D3, obtained from dietary sources and sunlight exposure, protects against mortality from prostate cancer (PC). In agreement with this, the most active vitamin D metabolite 1alpha,25-dihydroxyvitamin D3 (1,25(OH)2 D3) regulates the growth and differentiation of several human PC cell lines. Both genomic and non-genomic signalling pathways for 1,25(OH)2 D3 have been reported, although the mechanism of action in PC cells has not been defined. We now provide data supporting an active role for the nuclear vitamin D receptor (VDe growth-inhibitory effects of 1,25(OH)2 D3 on these cells. In the VDR-rich cell line ALVA-31, the observed changes in growth by 1,25(OH)2 D3 are preceded by significant changes in VDR mRNA expression, In contrast, the cell line JCA-1, containing few VDRs, fails to show both early changes in VDR gene expression and later changes in growth with 1,25(OH)2 D3. To assess the role of the VDR more directly, transfection studies were pursued. ALVA-31 cells were stably transfected with an antisense VDR cDNA construct in an attempt to reduce VDR expression. Antisense mRNA expression among clones was associated with: (a) reduced or abolished sensitivity to the effects of 1,25(OH)2 D3 on growth; (b) decreased numbers of VDRs per cell, as measured by radiolabelled-ligand binding; and (c) a lack of induction of the VDR-regulated enzyme 24-hydroxylase in response to 1,25(OH)2 D3. From these studies we conclude that the antiproliferative effects of 1,25(OH)2 D3 require expression of the nuclear VDR in this system.

Induction of transforming growth factor-beta autocrine activity by all-trans-retinoic acid and 1alpha,25-dihydroxyvitamin D3 in NRP-152 rat prostatic epithelial cells

Danielpour D.
Laboratory of Chemoprevention, National Cancer Institute, Building 41, Bethesda, MD 20892 USA
Journal of Cellular Physiology (USA), 1996, 166/1 (231-239)

Retinoids and vitamin D analogues are known to inhibit the proliferation of a variety of cells in culture and prevent the formation of certain tumors in mammals. Although it is well established that these hormones control the transcription of many genes upon binding to and activating specific nuclear receptors, the mechanisms by which they prevent cancer are as yet poorly understood. In this study the role of the transforming growth factor-p (TGF-beta) growth inhibitors, in promoting the biological activities of all-trans-retinoic acid (RA) and 1alpha,25-dihydroxyvitamin D3 (1,25-(OH)2D3) was studied in NRP-152 cells, a nontumorigenic epithelial line derived from rat dorsal-lateral prostate. Inhibition of growth by nanomolar concentrations of RA was associated with an increase in both mRNA and protein for all three TGF-beta isoforms, with greater and much earlier increases for TGF-betas 2 and 3 (5.5 h) than for TGF-beta1 (24 h). A monoclonal antibody against TGF-beta and TGF-beta1 latency associated peptide (LAP), both of which neutralize all three TGF-beta isoforms, each block the ability of RA to inhibit growth of NRP-152 cells by >95%. Neutralization of growth inhibition by isoform-specific antibodies suggested that all three TGF-betas are involved in this effect. The ability of RA to upregulate fibronectin and thrombospondin expression in NRP-152 cells was also blocked by the monoclonal antibody. 1,25-(OH)2D3, which also induced TCF-betas 2 and 3 but not TGF-beta1, and their respective mRNAs, also induced fibronectin and thrombospondin through induction of TGF-beta. Thus, autocrine production of TGF-betas may be a significant part of the mechanisms by which RA and 1,25-(OH)2D3 promote cellular differentiation.

Biologically active acylglycerides from the berries of saw-palmetto (Serenoa repens)

Shimada H.; Tyler V.E.; McLaughlin J.L.
J.L. McLaughlin, DMCMP, Sch. of Pharmacy/Pharmacal Sciences, Purdue University, West Lafayette, IN 47907 USA
Journal of Natural Products (USA), 1997, 60/4 (417-418)

Brine shrimp lethality-directed fractionation of the 95% EtOH extract of the powdered, dried berries of Serenoa repens (Bart.) Small (saw-palmetto) (Palmae) led to the isolation of two monoacylglycerides, 1-monolaurin (1) and 1-monomyristin (2). Compounds 1 and 2 showed moderate biological activities in the brine shrimp lethality test and against renal (A-498) and pancreatic (PACA-2) human tumor cells; borderline cytotoxicity was exhibited against human prostatic (PC-3) cells. The fruits and extracts of saw-palmetto are taken orally as an herbal medicine to prevent prostatic hyperplasias.

Effects of the lipidosterolic extract of Serenoa repens (Permixon (R)) on human prostatic cell lines

Ravenna L.; Di Silverio F.; Russo M.A.; Salvatori L.; Morgante E.; Morrone S.; Cardillo M.R.; Russo A.; Frati L.; Gulino A.; Petrangeli E.
Istituto Tecnologie Biomediche, via G. B. Morgagni 30/E, 00161 Roma Italy
Prostate (USA), 1996, 29/4 (219-230)

BACKGROUND. Permixon (R) is a drug used in the treatment of benign prostatic hyperplasia. We studied its androgenic and antiandrogenic effects in the prostatic cell line LNCaP and PC3, respectively responsive and unresponsive to androgen stimulation.

METHODS. We performed FACScan analysis to investigate toxicity, 3H thymidine and 35S methionine incorporation to determine antiproliferative and metabolic effects, electron microscopy to study ultrastructural changes and cotransfection experiments to elucidate the role of wild type androgeor.

RESULTS. In LNCaP cell line, Permixon (R) induced a double proliferative/differentiative effect, not observed in PC3 cells. In PC3 cells cotransfected with wild-type androgen receptors and CAT reporter genes under the control of a androgen responsive element, the drug inhibited androgen-induced CAT transcription.

CONCLUSIONS. Our data indicate a role of the androgen receptor in mediating the effects of Permixon (R) in LNCaP cells. Cotransfection experiments in PC3 cells support a clear antiandrogenic action of the drug.

Comparison of in vitro effects of the pure antiandrogens OH-flutamide, casodex, and nilutamide on androgen-sensitive parameters

Simard J.; Singh S.M.; Labrie F.; Schellhammer P.F.; Candas B.
Canada
Urology (USA), 1997, 49/4 (580-589)

Objectives. A combination of flutamide (Eulexin) or nilutamide (Anandron) with a luteinizing hormone-releasing hormone (LHRH) agonist or orchiectomy is the only therapy demonstrated to prolong life in prostate cancer. Recently, the low 50-mg daily dose of Casodex, an analogue of the pure antiandrogen flutamide, was chosen for clinical studies on the basis that the compound was 5 to 10 times more potent than flutamide, as suggested by data obtained in the inappropriate intact rat model. The present study was designed to compare the in vitro antiandrogenic activity of OH-flutamide (OH- FLU), the active metabolite of flutamide, Casodex, and nilutamide.

Methods. The effect of the antiandrogens was tested on two androgen-sensitive parameters, namely proliferation of the SEM-107 clone of Shionogi mouse mammary tumor ceils and secretion of the GCDFP-15 (gross cystic disease fluid protein 15 kDa) in T-47D and ZR-75-1 human breast cancer cells.

Results. The twofold stimulation of Shionogi cell proliferation caused by a 10-day exposure to 1 nM testosterone was competitively reversed by incubation with OH-FLU, Casodex, or nilutamide, at the respective IC50 values of 72, 243, and 412 nM. Moreover, the marked increase in GCDFP-15 release induced by 1 nM testosterone was blocked by OH-FLU, Casodex, or nilutamide at respective IC50 values of 29, 180, and 87 nM in T-47D cells and at 35, 142, and 75 nM in ZR-75-1 cells. Similar data were detected in 4-androstenedione-induced Shionogi cell proliferation and in dihydrotestosterone-induced GCDFP-15 secretion in T-47D cells.

Conclusions. OH-FLU is 3.1 - to 7.8-fold more potent than Casodex, as measured on two in vitro androgen-sensitive parameters, in agreement with our recent in vivo data obtained in the model of castrated rats supplemented with 4-androstenedione implants, in which threefold greater potency of flutamide was observed. The present data, as well as other data from the literature, strongly indicate the need to choose a more appropriate dose of Casodex for the treatment of prostate cancerlexin/USA scheri ng plough; anadron/FRA roussel uclaf; ru 23908/FRA roussel uclaf; casodex

Casodex ^(R) (Bicalutamide): Overview of a new antiandrogen developed for the treatment of prostate cancer

Blackledge G.R.P.; Cockshott I.D.; Furr B.J.A.
Dr. G.R.P. Blackledge, Medical Affairs Department, Zeneca Pharmaceuticals, Mereside, Alderley Park, Macclesfield SK10 4TG United Kingdom
European Urology (Switzerland), 1997, 31/SUPPL. 2 (30-39)

Casodex ^(R) (bicalutamide, Zeneca Ltd), has been developed for prostate cancer therapy. Its preclinical, pharmacokinetic, pharmacodynamic, clinical efficacy and tolerability data are described, Casodex is a potent and specific nonsteroidal antiandrogen. Clinical studies indicated that Casodex is orally bioavailable and well absorbed, with a plasma hallife of around 1 week. A Casodex dose of 50 mg daily decreased prostatic acid phosphatase comparable with castration. This dose was, therefore, evaluated initially as monotherapy and later as a component of maximal androgen blockade. Using prostate specific antigen as an end point, Casodex 150 mg daily was well-tolerated with demonstrable evidence of activity. Casodex 150 mg monotherapy was less effective than castration in terms of efficacy in patients with metastatic disease at entry. However, in patients non-metastatic at entry, Casodex 150 mg monotherapy appeared to be equivalent to castration in terms of time to death (data immature). Casodex was well-tolerated. In combination treatment, Casodex at 50 mg daily was at least as effective as 750 mg flutamide (Eulexin (R), Schering-Plough International) with respect to time to treatment failure, equivalent in terms of survival, and better tolerated with respect to diarrhoea. In conclusion, Casodex is a good option for the antiandrogen component of maximal androgen blockade.

Recommended dose of flutamide with LH-RH agonist therapy in patients with advanced prostate cancer

Akaza H.; Isaka S.; Usami M.; Kanetake H.; Kotake T.; Koiso K.; Aso Y.
H. Akaza, Department of Urology, Institute of Clinical Medicine, University of Tsukuba, 1-1 Tennodai, Tsukuba City, Ibaraki 305 Japan
International Journal of Urology (Japan), 1996, 3/6 (468-471)

Background: in a recent study by the Casodex Combination Study Group, USA, patients in a flutamide (750 mg/day) plus LH-RH agonist group showed a high treatment failure rate, mainly due to flutamide-induced diarrhea and hepatotoxicity. Our current study was conducted to determine the optimal dose of flutamide for use in this type of combination therapy.

Methods: In a randomized, multicenter study, 30 patients (hormone untreated; stage C or D) were divided into 2 groups: flutamide 250 mg (125 mg x 2; 14 patients) and flutamide 375 mg (125 mg x 3; 16 patients), and each dose combined with either goserelin acetate (3.6 mg every 4 weeks) or leuprolide acetate (3.75 mg every 4 weeks). Goserelin and leuprolide were administered to patients in a 1:1 ratio. Flutamide monotherapjapan in our previous phase II study. The endpoints of this pilot study were the objective response and adverse events during the 12-week treatment.

Results: The objective response rate was 83.3% in the flutamide 250 mg group and 85.7% in the flutamide 375 mg group according to the Japanese response criteria for prostate cancer. Elevated PSA levels fell to within the normal range in 83.3% of the patients in the former group and in 93.3% of the patients in the latter group. One patient administered 250 mg of flutamide experienced diarrhea, while the serum COT and/or GPT were elevated in 3 patients administered 250 mg of flutamide acid 4 patients administered 375 mg of flutamide.

Conclusions: Based on the findings of this pilot study of maximal androgen-depletion therapy for advanced prostate cancer, 375 mg/day of flutamide is recommended in combination with an CH-RH agonist. Assessment of the effects of our recommended regimen on longer term survival, quality of life and antiandrogen withdrawal syndrome of patients treated requires additional patients and time for follow-up.

Bicalutamide (Casodex^(TM))

Schellhammer P.
USA
Expert Opinion on Investigational Drugs (United Kingdom), 1996, 5/12 (1707-1722)

Bicalutamide (Casodex^(TM)) is a relatively new non-steroidal anti-androgen indicated for use in combination therapy with castration for the treatment of advanced prostate cancer. Developed from a series of non-steroidal compounds related to flutamide, bicalutamide is a potent, orally active, well tolerated anti-androgen with a hallife compatible with once-daily administration. In the clinical programme in prostatic cancer, patients were exposed to bicalutamide in doses ranging from 10 - 600 mg. Doses of 10 - 200 mg have been shown to have intrinsic activity in terms of producing subjective improvement and objective responses, and daily doses of up to 600 mg are currently being evaluated. Results of monotherapy studies reveal that 50 mg of bicalutamide is less effective than castration in patients with advanced disease; Phase III monotherapy studies are ongoing to compare 150 mg of bicalutamide with castration. In monotherapy studies, both 50 mg and 150 mg of bicalutamide have an advantage over castration in allowing patients to maintain libido and sexual potency. As combination therapy, 50 mg bicalutamide and a luteinising hormone-releasing hormone (LHRH) analogue is at least as effective as 750 mg of flutamide and an LHRH analogue and is better tolerated. The overall safety and tolerability profile of bicalutamide is indicative of a well tolerated therapy that has a relatively low incidence of treatment-related withdrawals. Because of its efficacy in combination with medical castration, its excellent safety profile, and its convenient once-daily oral formulation, bicalutamide represents a valid choice for anti-androgen therapy when used in combination with castration for patients with advanced prostate cancer.

U.S. Drug and biologic approvals in 1994-1995

Beary III J.F.; Duchaine C.M.; Rhein R.W. Jr.
Div. Regulatory/Scientific Affairs, Pharmaceutical Research, Manufacturers of America, 1100 Fifteenth Street NW, Washington, DC 20005 USA
Drug Development Research (USA), 1996, 37/4 (197-207)

Since the introduction of the Prescription Drug User Fee in 1992, the mean approval time for new drugs has decreased from 29.9 months (1992) to 19.2 months (1995). In 1994, 22 new drugs and 1 biological were approved. In 1995, 28 drugs and 2 biologicals were approved.

Cryosurgery of prostate cancer. Use of adjuvant hormonal therapy and temperature monitoring - A one year follow-up

Lee F.; Bahn D.K.; McHugh T.A.; Kumar A.A.; Badalament R.A.
Dr. F. Lee, Prostate Center, Crittenton Hospital, 1101 W University Drive, Rochester, MI 48307 USA
Anticancer Research (Greece), 1997, 17/3 A (1511-1515)

Objective: To determine the clinical outcomes at one year of Stages T2-T3 prostate cancer by cryosurgery utilizing pretreatment with total androgen ablation therapy and temperature monitoring to control the freez347 pat ients have had 356 cryosurgical procedures. 280 have reached one year post treatment. Of these, 131 had re-evalation with prostatic biopsy and serum PSA.

Methods: Transrectal ultrasound (TRUS) measurement of tumor size and biopsy of extraprostatic space was used to stage patients into two main groups: confined (66.6%) versus non-confined (19.3%). Radiation failures (14.1%) formed a separate group. Failure rates for the 131 men include all cancer diagnosed during the one year period following cryosurgery.

Results: The one year failure rate for the study group was 19.8% (26/131). For stages T2a, T2b C, T3 and radiation failures, the rates of positive biopsies were 13.9%, 12.9%, 33.3% and 35%, respectively. For those with local control of cancer (negative biopsy), 80% had prostate specific antigen (PSA) levels of < 0.5 ng/ml. The statistical variables for persistent cancer with prostate specific antigen > 0.5 ng/ml were: sensitivity of 66.7%, PPV of 16.7%, NPV of 98% and specificity of 83.7%. A statistically significant difference exists between stages T2 vs T3 and radiation failures (p = < 0.5). Major complications of rectal fistula and total incontinence for previously non-treated cancer versus radiation failures were 0.33% and 8.7% respectively, a 26 times greater risk.

Conclusion: Results of cryosurgery for all stages of prostate cancer at one year are encouraging, being 80% free of disease (biopsy and prostate specific antigen). The morbidity of the previously non-treated cancers from this procedure for us was minimal with high patient acceptance. For radiation failures a local control rate of 65% was achieved. However, early in our experience significant morbidity did occur and our enthusiasm for attempted salvage was initially tempered.

The potential role of lycopene for human health

Gerster H.
H. Gerster, Vitamin Research Department, F. Hoffmann-LaRoche Ltd, Bldg 73/30A, CH-4070 Basel Switzerland
Journal of the American College of Nutrition (USA), 1997, 16/2 (109-126)

Lycopene is one of the major carotenoids in Western diets and is found almost exclusively in tomatoes and tomato products. It accounts for about 50% of carotenoids in human serum. Among the common dietary carotenoids lycopene has the highest singlet oxygen quenching capacity in vitro. Other outstanding features are its high concentration in testes, adrenal gland and prostate. In contrast to other carotenoids its serum values are not regularly reduced by smoking or alcohol consumption but by increasing age. Remarkable inverse relation ships between lycopene intake or serum values and risk have been observed in particular for cancers of the prostate, pancreas and to a certain extent of the stomach. In some of the studies lycopene was the only carotenoid associated with risk reduction. Its role in cancer risk reduction still needs to be clarified. Patients with HIV infection, inflammatory diseases and hyperlipidemia with and without lipid lowering treatment may have depleted lycopene serum concentrations. Before embarking on large-scale human trials the distribution of lycopene and its biological functions need to be further evaluated.

Lycopene: A biologically important carotenoid for humans?

Stahl W.; Sies H.
Germany
Archives of Biochemistry and Biophysics (USA), 1996, 336/1 (1-9)

Lycopene is a carotenoid present in human blood (similar0.5 micromol/liter plasma), and the tissue levels vary from 1 nmol/g wet wt in adipose tissue to up to 20 nmol/g wet wt in adrenals and testes. Its biological activities include antioxidant activity (singlet oxygen quenching and peroxyl radical scavenging), induction of cell-cell communication, and growth control, but no provitamin A activity. Epidemiological studies suggest protective effects of lycopene on some types of cancer, e.g., prostate cancer. In vitro and in vivo studies on growth of tumor cells support this conclusion. The major sources of lycopene for the human are tomatoes and tomato products, and bioavailability from different food items varies considerably. Lycopene oxidation products have recently been identified in human serum. Suggested health effects of lycopene require further investigation.

cis-trans lycopene isomers, carotenoids, and retinol in the human prostate

Clinton S.K.; Emenhiser C.; Schwartz S.J.; Bostwick D.G.; Williams A.W.; Moore B.J.; Erdman J.W. Jr.
Dana-Farber Cancer Institute, Dana Building, 44 Binney Street, Boston, MA 02115-6084 USA
Cancer Epidemiology Biomarkers and Prevention (USA), 1996, 5/10 (823-833)

An evaluation of the Health Professionals Follow-Up Study has detected a lower prostate cancer risk associated with the greater consumption of tomatoes and related food products. Tomatoes are the primary dietary source of lycopene, a non-provitamin A carotenoid with potent antioxidant activity. Our goal was to define the concentrations of lycopene, other carotenoids, and retinol in paired benign and malignant prostate tissue from 25 men, ages 53 to 74, undergoing prostatectomy for localized prostate cancer. The concentrations of specific carotenoids in the benign and malignant prostate tissue from the same subject are highly correlated. Lycopene and all-trans beta-carotene are the predominant carotenoids observed, with means plus or minus SE of 0.80 plus or minus 0.08 nmol/g and 0.54 plus or minus 0.09, respectively. Lycopene concentrations range from 0 to 2.58 nmol/g, and all-trans beta-carotene concentrations range from 0.09 to 1.70 nmol/g. The 9-cis beta-carotene isomer, alpha-carotene, lutein, alpha-cryptoxanthin, zeaxanthin, and beta-cryptoxanthin are consistently detectable in prostate tissue. No significant correlations between the concentration of lycopene and the concentrations of any other carotenoid are observed. In contrast, strong correlations between prostate beta-carotene and alpha-carotene are noted (correlation coefficient, 0.88; P < 0.0001), as are correlations between several other carotenoid pairs, which reflects their similar dietary origins. Mean vitamin A concentration in the prostate is 1.52 nmol/g, with a range of 0.71 to 3.30 nmol/g. We further evaluated tomato- based food products, serum, and prostate tissue for the presence of geometric lycopene isomers using high-performance liquid chromatography with a polymeric C30 reversed phase column. All-trans lycopene accounts for 79 to 91% and cis lycopene isomers for 9 to 21% of total lycopene in tomatoes, tomato paste, and tomato soup. Lycopene concentrations in the serum of men range between 0.60 and 1.9 nmol/ml, with 27 to 42% all-trans lycopene and 58 to 73% cis-isomers distributed among 12 to 13 peaks, depending upon their chromatographic resolution. In striking contrast with foods, all-trans lycopene accounts for only 12 to 21% and cis isomers for 79 to 88% of total lycopene in benign or malignant prostate tissues. cis Isomers of lycopene within the prostate are distributed among 14 to 18 peaks. We conclude that a diverse array of carotenoids are found in the human prostate with significant intra-individual variation. The presence of lycopene in the prostate at concentrations that are biologically active in laboratory studies supports the hypothesis that lycopene may have direct effects within the prostate and contribute to the reduced prostate cancer risk associated with the consumption of tomato-based foods. The future identification and characterization of geometric lycopene isomers may lead to the development of novel agents for chemoprevention studies.

How is individual risk for prostate cancer assessed?

Giovannucci E.
Channing Laboratory, 180 Longwood Avenue, Boston, MA 02115 USA
Hematology/Oncology Clinics of North America (USA), 1996, 10/3 (537-548)

A man's risk of developing prostate cancer is influenced by both genetic and nongenetic factors. Genetic factors are particularly important at younger ages, and the attributable risk of strong genetic factors could be as high as 43% among men less than 55 years of age; however, only about 9%, of all cases may be directly attributable to a family history of prostate cancer. Race appears to be an important determinant of risk; African-American men are at high risk, whereas men of oriental ancestry are at lower risk. The bases of these racial differences remain obscure but may be related to hormonal differences. Modifiable risk factors are most important from a public health perspective. Diet or closely related factors appear to hold the most promise for prevention, although the precise factors are unknown. The strongest evidence indicates that some component of animal fat intake appears to act as a promoter of prostate cancer. Other dietary factors, including vitamin D, vitamin E, and beta-carotene and lycopene, may confer protection, but these require more study. Many but not all studies that have examined long-term effects of vasectomy suggest that this procedure may increase risk of prostate cancer, but whether this association is causal is not established. Occupational factors, smoking, and physical activity level do not appear to be major determinants of prostate cancer risk.

A tomato a day for preventing prostate cancer? Diet may be key

No author listed
Geriatrics (USA), 1996, 51/2 (21)

No abstract.

Intake of carotenoids and retinol in relation to risk of prostate cancer

Giovannucci E.; Ascherio A.; Rimm E.B.; Stampfer M.J.; Colditz G.A.; Willett W.C.
Channing Laboratory, 180 Longwood Ave., Boston, MA 02115 USA
Journal of the National Cancer Institute (USA), 1995, 87/23 (1767-1776)

Background: Several human studies have observed a direct association between retinol (vitamin A) intake and risk of prostate cancer; other studies have found either an inverse association or no association of intake of beta- carotene (the major provitamin A) with risk of prostate cancer. Data regarding carotenoids other than beta-carotene in relation to prostate cancer risk are sparse.

Purpose: We conducted a prospective cohort study to examine the relationship between the intake of various carotenoids, retinol, fruits, and vegetables and the risk of prostate cancer.

Methods: Using responses to a validated, semiquantitative food-frequency questionnaire mailed to participants in the Health Professionals Follow-up Study in 1986, we assessed dietary intake for a 1-year period for a cohort of 47 894 eligible subjects initially free of diagnosed cancer. Follow-up questionnaires were sent to the entire cohort in 1988, 1990, and 1992. We calculated the relative risk (RR) for each of the upper categories of intake of a specific food or nutrient by dividing the incidence rate of prostate cancer among men in each of these categories by the rate among men in the lowest intake level. All P values resulted from two-sided tests.

Results: Between 1986 and 1992, 812 new cases of prostate cancer, including 773 non-stage A1 cases, were documented. Intakes of the carotenoids beta-carotene, alpha-carotene, lutein, and beta- cryptoxanthin were not associated with risk of non-stage A1 prostate cancer; only lycopene intake was related to lower risk (age- and energy-adjusted RR = 0.79; 95% confidence interval (CI) = 0.64-0.99 for high versus low quintile of intake; P for trend = .04). Of 46 vegetables and fruits or related products, four were significantly associated with lower prostate cancer risk; of the four-tomato sauce (P for trend = .001), tomatoes (P for trend = .03), and pizza (P for trend = .05), but not strawberries-were primary sources of lycopene. Combined intake of tomatoes, tomato sauce, tomato juice, and pizza (which accounted for 82% of lycopene intake) was inversely associated with risk of prostate cancer (multivariate RR = 0.65; 95% CI = 0.44-0.95, for consumption frequency greater than 10 versus less than 1.5 servings per week; P for trend = .01) and advanced (stages C and D) prostate cancers (multivariate RR = 0.47; 95% CI = 0.22-1.00; P for trend = .03). No consistent association was observed for dietary retinol and risk of prostate cancer.

Conclusions: These findings suggest that intake of lycopene or other compounds in tomatoes may reduce prostate cancer risk, but other measured carotenoids are unrelated to risk. Implications: Our findings support recommendations to increase vegetable and fruit consumption to reduce cancer incidence but suggest that tomato-based foods may be especially beneficial regarding prostate cancer risk.

Whatever happened to beta carotene?

Holzman D.
Journal of the National Cancer Institute (USA), 1995, 87/23 (1739-1741)

No abstract.

Vegetable and fruit consumption in relation to prostate cancer risk in Hawaii: A reevaluation of the effect of dietary beta-carotene

Le Marchand L.; Hankin J.H.; Kolonel L.N.; Wilkens L.R.
Epidemiology Program, Cancer Research Center of Hawaii, University of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813 USA
Am. J. Epidemiol. (USA), 1991, 133/3 (215-219)

This is a further analysis of a case-control study of 452 prostate cancer cases and 899 population controls that was conducted in 1970-1983 among the multiethnic population of Hawaii. Because a previous analysis had shown a positive association with intake of beta-carotene, a nutrient presently being tested for chemoprevention, the authors reexamined the data for consistency among the main food sources of beta-carotene. Vegetables and fruits containing other phytochemicals suspected to be cancer inhibitors were also examined. With the exception of papaya, which was positively associated with risk among men aged 70 years and older, consumption of other yellow-orange fruits and vegetables, tomatoes, dark green vegetables, and cruciferous vegetables was not associated with prostate cancer risk. These results suggest that: 1) the positive association with beta-carotene intake among older men that the authors previously reported was essentially due to the greater papaya consumption of cases compared with controls; and 2) intake of beta-carotene, lycopene, lutein, indoles, phenols, or other phytochemicals is not associated with prostate cancer risk.

Serologic precursors of cancer. Retinol, carotenoids, and tocopherol and risk of prostate cancer

Hsing A.W.; Comstock G.W.; Abbey H.; Polk B.F.
Training Center for Public Health Research, Box 2067, Hagerstown, MD 21742-2067 USA
J. Natl. Cancer Inst. (USA), 1990, 82/11 (941-946)

We investigated the associations of serum retinol, the carotenoids beta-carotene and lycopene, and tocopherol (vitamin E) with the risk of prostate cancer in a nested case-control study. For the study, serum obtained in 1974 from 25,802 persons in Washington County, MD, was used. Serum levels of the nutrients in 103 men who developed prostate cancer during the subsequent 13 years were compared with levels in 103 control subjects matched for age and race. Although no significant associations were observed with beta-carotene, lycopene, or tocopherol, the data suggested an inverse relationship between serum retinol and risk of prostate cancer. We analyzed data on the distribution of serum retinol by quartiles, using the lowest quartile as the reference value. Odds ratios were 0.67, 0.39, and 0.40 for the second, third, and highest quartiles, respectively.

Carcinogenicity of oral cadmium in the male Wistar (WF/NCr) rat: Effect of chronic dietary zinc deficiency

Waalkes M.P.; Rehm S.
Lab. of Comparative Carcinogenesis, NCI-FCRDC, Frederick, MD 21702-1201 USA
Fundam. Appl. Toxicol. (USA), 1992, 19/4 (512-520)

The effect of chronic dietary zinc deficiency on the carcinogenic potential of dietary cadmium was assessed in male Wistar (WF/NCr) rats. Groups (n = 28) of rats were fed diets adequate (60 ppm) or marginally deficient (7 ppm) in zinc and containing cadmium at various levels (0, 25, 50, 100, or 200 ppm). Lesions were assessed over the following 77 weeks. Zinc deficiency alone had no effect on survival, growth, or food consumption. Cadmium treatment did not reduce survival or food consumption and only at the highest doses of cadmium (100 and 200 ppm) was body weight reduced (maximum 17%). The incidence of prostatic proliferative lesions, both hyperplasias and adenomas, was increased over that seen in controls (1.8%) in both zinc-adequate (20%) and zinc-deficient rats (14%) fed 50 ppm cadmium. The overall incidence for prostatic lesions for all cadmium treatment groups was, however, much lower in zinc-deficient rats, possibly because of a marked increase in prostatic atrophy that was associated with reduced zinc intake. Cadmium treatment resulted in an elevated leukemia incidence (maximum 4.8-fold over control) in both zinc-adequate and zinc-deficient groups, although zinc deficiency reduced the potency of cadmium in this respect. Testicular tumors were significantly elevated only in rats receiving 200 ppm cadmium and diets adequate in zinc. Both zinc-deficient and zinc-adequate groups showed significant positive trends for development of testicular neoplasia with increasing cadmium dosage. Thus, oral cadmium exposure is clearly associated with tumors of the prostate, testes, and hematopoietic system in rats, while dietary zinc deficiency has complex, apparently inhibitory, effects on cadmium carcinogenesis by this route.

Nutrition and prostate cancer: A case-control study

Heshmat M.Y.; Kaul L.; Kovi J.; et al.
Department of Community Health and Family Practice, Howard University College of Medicine, Washington, DC 20059 USA
Prostate (USA), 1985, 6/1 (7-17)

No abstract.

Zinc, vitamin A and prostatic cancer

Whelan P.; Walker B.E.; Kelleher J.
Dep. Urol., St. James's Univ. Hosp., Leeds LS9 7TF United Kingdom
Br. J. Urol. (England), 1983, 55/5 (525-528)

The serum zinc, vitamin A, albumin, copper and retinoid-binding protein content was measured in 27 patients with benign prostatic hyperplasia and 19 patients with carcinoma of the prostate. A significantly lower (P = < 0.05) level of serum zinc was found in the cancer group as well as a significant zinc/vitamin A correlation (P = < 0.05). The possible significance of this in relation to the pathogenesis of carcinoma of the prostate is discussed.

Influence of isoflavones in soy protein isolates on development of induced prostate-related cancers in L-W rats

Pollard M.; Luckert P.H.
M. Pollard, Lobund Lab, University of Notre Dame, Notre Dame, IN 46556 USA
Nutrition and Cancer (USA), 1997, 28/1 (41-45)

Lobund-Wistar (L-W) rats are inherently susceptible to spontaneous and induced metastasizing adenocarcinomas in the prostate-seminal vesicle (P-SV) complex. L-W rats were fed soy protein isolates containing high isoflavones (genistein and daidzein) or low isoflavones to determine their effects on development of induced P-SV tumors in two stages of the tumorigenic process. In rats fed the high-isoflavone-supplemented soy diet before initiation by methylnitrosourea (MNU), the incidence of induced prostate-related cancer was reduced and the disease-free period was prolonged by 27% compared with rats fed the same diet but low in isoflavones. Rats fed the same diets, started after MNU, manifested suggestive but less consistent results than those noted above. The incidence rates were of marginal significance, suggesting that the high intensity of the active induced disease may not represent the character of the slower-growing spontaneous (natural) disease. The delay of disease onset is of clinical significance.

Peptide growth factors: Clinical and therapeutic strategies

Di Silverio F.; Sciarra A.; Di Nicola S.; Di Chiro C.
F. Di Silverio, Dipartimento 'U. Bracci', Universita 'La Sapienza', Viale del Policlinico, 00161 Roma Italy
Minerva Urologica e Nefrologica (Italy), 1997, 49/2 (63-72)

The literature contains many accounts of studies in which tumour growth has been accelerated by administration of a particular mitogen and the response then inhibited by co-administration of the corresponding antagonist. Much effort has been focused on the development of cytokine or growth factor antagonists. Like most other cancer therapies, biological therapies will undoubtedly have undesirable toxicities because the proteins they target may not be unique to malignant cells. We received the clinical and therapeutic potential of growth factor agonists and antagonists in some non urologic and urologic diseases. In a recent report we demonstrated that both androgen and antiandrogen treatments enhance the proliferation rate of the hormone-dependent prostate cancer cell line LNCaP, expressing a mutated androgen receptor. Simultaneous treatment with 1 nM R1881 and 100 nM OH-Flutamide, completely counteracted the androgen-induced increase of Epidermal Growth Factor (EGF) levels. Moreover we found that Testosterone, DHT and EGF are mainly concentrated in the periurethral zone in human BPH and long term treatment with Finasteride and with Flutamide modify the distribution and concentration of these factors. Some authors analyzed whether the addition of aurin tricarboxylic acid (ATA) can reduce the growth rate of basic FGF-dependent cells in a manner similar to suramin.

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Cancer risk factors for selecting cohorts for large-scale chemoprevention trials

Greenwald P.
Dr. P. Greenwald, Dept. of Health and Human Services, National Institutes of Health, National Cancer Institute, Bethesda, MD 20892 USA
Journal of Cellular Biochemistry (USA), 1996, 63/Suppl. 25 (29-36)

Many anticipate that application of findings in molecular genetics will help to achieve greater precision in defining high-risk populations that may benefit from chemopreventive interventions. We must recognize, however, that genetic susceptibility, environmental factors, and complex gene-environment interactions are all likely to be risk determinants for most cancers. Cohort studies of twins and cancer indicate that having 'identical' genes is generally not a very accurate predictor of cancer incidence. Data from twin studies support the suggestion that environmental factors such as tobacco use significantly influence cancer risk. The complexities of the genetic contribution to disease risk are exemplified by the development of Duchenne muscular dystrophy in only one of monozygotic twin girls, hypothesized to be the result of X chromosome inactivation, with the distribution patterns of the X chromosome being skewed to the female X in the manifesting twin and to the male X in the normal twin. Evidence from transgenic and genetic- environmental studies in animals support the possibility of genetic- environmental interactions. Calorie restriction modifies tumor expression in p53 knockout mice; a high-fat, low-calcium, low-vitamin D diet increases prepolyphyperplasia formation in Apc-mutated mice; and calorie restriction early in life influences development of obesity in the genetically obese Zucker rat (fata). Such environmental modulation of gene expression suggests that chemoprevention has the potential to reduce risk for both environmentally and genetically determined cancers. In view of the growing research efforts in chemoprevention, the NCl has developed a Prevention Trials Decision Network (PTDN) to formalize the evaluation and approval process for large scale chemoprevention trials. The PTDN addresses large trial prioritization and the associated issues of minority recruitment and retention; identification and validation of biomarkers as intermediate endpoints for cancer; and chemopreventive agent selection and development. A comprehensive database is being established to support the PTDN's decision making process and will help to determine which agents investigated in preclinical and early phase clinical trials should move to large-scale testing. Cohorts for large-scale chemoprevention trials include individuals who are determined to be at high risk as a result of genetic predisposition, carcinogenic exposure, or the presence of biomarkers indicative of increased risk. Current large scale trials in well-defined, high-risk populations include the Breast Cancer Prevention Trial (tamoxifen), the Prostate Cancer Prevention Trial (finasteride), and the N-(4-hydroxyphenyl) retinamide (4- HPR) breast cancer prevention study being conducted in Milan. Biomarker studies will provide valuable information for refining the design and facilitating the implementation of future large-scale trials. For example, potential biomarkers are being assessed at biopsy in women with ductal carcinoma in situ (DCIS). The women are then randomized to either placebo, tamoxifen, 4-HPR, or tamoxifen plus 4-HPR for 2-4 weeks, at which time surgery is performed and the biomarkers reassessed to determine biomarker modulation by the interventions. For prostate cancer, modulation of prostatic intraepithelial neoplasia (PIN) by 4-HPR and difluoromethylornithine is being investigated; similar studies are being planned for oltipraz, dehydroepiandrosterone, and vitamin E plus selenomethionine. The validation of biomarkers as surrogate endpoints for cancer incidence in high-risk cohorts will allow more agents to be evaluated in shorter studies that use fewer subjects to achieve the desired statistical power.

Inhibition of liposomal lipid peroxidation by isoflavonoid type phyto-oestrogens from soybeans of different countries of origin

Wiseman H.; Lim P.; O'Reilly J.
Department Nutrition and Dietetics, King's College London, Campden Hill Road, London W8 7AH United Kingdom
Biochemical Society Transactions (United Kingdom), 1996, 24/3 (392S)

No abstract.

Phytoestrogens: Epidemiology and a possible role in cancer protection

Adlercreutz H.
Department of Clinical Chemistry, University of Helsinki, Meilahti Hospital, FIN-00290 Helsinki Finland
Environmental Health Perspectives (USA), 1995, 103/Suppl. 7 (103-112)

Because many diseases of the Western Hemisphere are hormone-dependent cancers, we have postulated that the Western diet, compared to a vegetarian or semivegetarian diet, may alter hormone production, metabolism or action at the cellular level by some biochemical mechanisms. Recently, our interest has been mainly focused on the cancer-protective role of some hormonelike diphenolic phytoestrogens of dietary origin, the lignans and the isoflavonoids. The precursors of the biologically active compounds originate in soybean products (mainly isoflavonoids), whole grain cereal food, seeds, and probably berries and nuts (mainly lignans). The plant lignan and isoflavonoid glycosides are converted by intestinal bacteria to hormonelike compounds with weak estrogenic but also antioxidative activity; they have now been shown to influence not only sex hormone metabolism and biological activity but also intracellular enzymes, protein synthesis, growth factor action, malignant cell proliferation, differentiation, and angiogenesis in a way that makes them strong candidates for a role as natural cancer-protective compounds. Epidemiologic investigations strongly support this hypothesis because the highest levels of these compounds in the diet are found in countries or regions with low cancer incidence. This report is a review on recent results suggesting that the diphenolic, isoflavonoids and lignans are natural cancer-protective compounds.

Differential sensitivity of human prostatic cancer cell lines to the effects of protein kinase and phosphatase inhibitors

Rokhlin O.W.; Cohen M.B.
University of Iowa, Department of Pathology, 118 ML, Iowa City, IA 52242 USA
Cancer Letters (Ireland), 1995, 98/1 (103-110)

We investigated the effect of protein kinase and phosphatase inhibitors on the growth of six human prostatic cancer cell lines: DU145, PC3, ND1, LNCaP, ALVA31 and JCA1. We studied okadaic acid and sodium orthovanadate as serine/threonine and tyrosine protein phosphatase inhibitors, respectively, and staurosporin and genistein as a serine/threonine and tyrosine protein kinase inhibitors, respectively. All inhibitors examined exhibited a dose-dependent growth inhibitory effect on prostatic cancer cell lines. Our data indicate that prostatic cancer cell lines express unique biochemical properties since the degree of growth inhibition varied greatly and was dependent on the specific cell line and inhibitor studied. In addition, we found that surface expression of endoglin (CD105) changed by treatment with all inhibitors in most of the cell lines. These data also indicate that endoglin appears to be involved both in protein phosphatase and kinase mediated phosphoprotein turnover.

Genetic damage and the inhibition of 7,12-dimethylbenz(a)anthracene-induced genetic damage by the phytoestrogens, genistein and daidzein, in female ICR mice

Giri A.K.; Lu L.-J.W.
Dept. Prevent. Med. Community Hlth., University of Texas Medical Branch, 700 Strand, Galveston, TX 77555-1110 USA
Cancer Letters (Ireland), 1995, 95/1-2 (125-133)

Populations consuming soybeans have reduced rates of breast, colon and prostate cancer possibly due, in part, to the presence in soybeans of two estrogenic isoflavones, genistein and daidzein. This study investigated the genotoxicity of these soya isoflavones and their interactions with 7,12-dimethylbenz(a)anthracene (DMBA)-induced sister chromatid exchanges (SCE) in bone marrow cells and DNA adduct formations in liver and mammary glands of mice. Groups of female ICR mice were pretreated i.p. with daidzein and/or genistein (10-20 mg/kg per day for 6 days or 50 mg/kg per 12 h for 3 days) or with the solvent, dimethylsulfoxide (DMSO). The mice were implanted with bromodeoxyuridine (BrdU) tablets s.c., and treated with DMBA (50 mg/kg) i.p. and colchicine (4 mg/kg) i.p. 24, 23, and 2 h before sacrifice, respectively. In bone marrow cells, DMBA alone induced 11.73 plus or minus 1.42 SCE/cell compared to 4.35 plus or minus 0.83 SCE/cell in the DMSO treated controls (P = 0.001). DMBA induced 20% fewer SCE (P < 0.05) in mice pretreated with daidzein, genistein or a combination of genistein and daidzein (6 x 20 mg/kg per day for 6 days) when compared to mice that received no pretreatments. Genistein at 50 mg/kg per 12 h for 3 days also inhibited DMBA-induced SCE by 20%. However, treatment for 3 days with 50 mg/kg per 12 h of genistein or daidzein alone, or a combination of daidzein plus genistein (without DMBA treatment) also induced more SCE than treatment with only the solvent (DMSO, P < 0.05). Pretreatment with both the low and the high doses of daidzein plus genistein or the high dose of genistein reduced the replication index of bone marrow cells when compared to pretreatment with DMSO (P < 0.05). Pretreatment with genistein reduced DMBA-induced DNA adduct formation by 34%, but this was only marginally significant (P = 0.08) due to the large inter-individual variability in adduct levels. These results show that genistein and daidzein suppress SCE and possibly DNA adduct formation induced by the known carcinogen, DMBA. This response to a low dose isoflavone exposure may be partly responsible for the protective effect against endocrine cancers of soya consumption.

Rationale for the use of genistein-containing soy matrices in chemoprevention trials for breast and prostate cancer

Barnes S.; Peterson T.G.; Coward L.
Department of Pharmacology, Birmingham Medical Center, University of Alabama, 1670 University Boulevard, Birmingham, AL 35294-0019 USA
Journal of Cellular Biochemistry (USA), 1995, 58/Suppl. 22 (181-187)

Pharmacologists have realized that tyrosine kinase inhibitors (TKI) have potential as anti-cancer agents, both in prevention and therapy protocols. Nonetheless, concern about the risk of toxicity caused by synthetic TKIs restricted their development as chemoprevention agents. However, a naturally occurring TKI (the isoflavone genistein) in soy was discovered in 1987. The concentration of genistein in most soy food materials ranges from 1-2 mg/g. Oriental populations, who have low rates of breast and prostate cancer, consume 20-80 mg of genistein/day, almost entirely derived from soy, whereas the dietary intake of genistein in the US is only 1-3 mg/day. Chronic use of genistein as a chemopreventive agent has an advantage over synthetic TKIs because it is naturally found in soy foods. It could be delivered either in a purified state as a pill (to high-risk, motivated patient groups), or in the form of soy foods or soy-containing foods. Delivery of genistein in soy foods is more economically viable ($1.50 for a daily dose of 50 mg) than purified material ($5/day) and would require no prior approval by the FDA. Accordingly, investigators at several different sites have begun or are planning chemoprevention trials using a soy beverage product based on SUPRO(TM), an isolated soy protein manufactured by Protein Technologies International of St. Louis, MO. These investigators are examining the effect of the soy beverage on surrogate intermediate endpoint biomarkers (SIEBs) in patients at risk for breast and colon cancer, defining potential SIEBs in patients at risk for prostate cancer, and determining whether the soy beverage reduces the incidence of cancer recurrence. These studies will provide the basis for formal Phase I, Phase II and Phase III clinical trials of genistein and soy food products such as SUPRO(TM) for cancer chemoprevention.

A simplified method to quantify isoflavones in commercial soybean diets and human urine after legume consumption

Lu L.-J.W.; Broemeling L.D.; Marshall M.V.; Ramanujam V.M.S.
Prevent. Med./Community Health Dept., 2.102 Ewing Hall, University of Texas, 700 Strand, Galveston, TX 77555-1110 USA
Cancer Epidemiology Biomarkers and Prevention (USA), 1995, 4/5 (497-503)

Reliable and economical quantification of micronutrients in diets and humans is a critical component of successful epidemiological studies to establish relationships between dietary constituents and chronic disease. Legumes are one of the major dietary components consumed by populations worldwide. Consumption of legumes is thought to play a major role in lowering breast and prostate cancer risk. In this study, a simplified method that uses solid-phase extraction and gas chromatography was developed to measure isoflavones at levels down to 10 microg/5 ml. With the use of this method, 12.5 g miso (a soybean paste), 12 ounces Isomil, and 12 ounces soymilk had daidzin/daidzein levels of 2, 5, and 12.4 mg, respectively, and genistin/genistein levels of 3, 6.5, and 13.7 mg, respectively. In these products, most of the isoflavones were present as glucosides. With the same method, urinary levels of isoflavones in six 15-17-year-old subjects were determined after soymilk ingestion. Each subject was placed on unrestricted nonsoya diets, and three 12-ounce portions of soymilk were given at 12-h intervals. Males excreted 15.02 plus or minus 2.74 (SD) mg of daidzein glucuronides/sulfates (mean recovery, 40.4 plus or minus 7.4% (SD)) by 24 h after the third soymilk ingestion, whereas females excreted 25.56 plus or minus 5.10 mg (68.7 plus or minus 13.7%) of daidzein conjugates, which was more than males (P = 0.02). Males and females excreted 7.73 plus or minus 1.95 mg and 9.11 plus or minus 0.84 mg of genistein glucuronides/sulfates (20% recovery of genistin intake), respectively, in the urine. Most of the isoflavones were excreted within 24 h after ingestion. The relative urinary levels of daidzein to genistein excreted were significantly (P < 0.05) higher in females than males after the third ingestion. The observed sex difference requires more study since two of the females are siblings. Thus, the method described can be used to measure isoflavones in soya products and urinary excretion after soya ingestion.

Rapid HPLC analysis of dietary phytoestrogens from legumes and from human urine

Franke A.A.; Custer L.J.; Cerna C.M.; Narala K.
Molecular Carcinogenesis Program, Cancer Research Center of Hawaii, 1236 Lauhala Street, Honolulu, HI 96813 USA
Proc. Soc. Exp. Biol. Med. (USA), 1995, 208/1 (18-26)

Due to growing evidence suggesting that phytoestrogens might protect against various cancers, particularly against breast and prostate cancer, it is important to measure the exposure of populations to these compounds by determining levels in food and in human tissue or body fluids to assess the possible cancer protective properties of these agents. Therefore, we developed a simple and fast procedure to extract and simultaneously hydrolyze phytoestrogens and their conjugates from food items, and present a fast and selective high-performance liquid chromatography (HPLC) method for precise determinations of the most common dietary phytoestrogens genistein, biochanin-A, daidzein, formononetin, and coumestrol using flavone as internal standard. For the first time HPLC was applied to measure these phytoestrogens and their most abundant metabolites equol and O-desmethyl-angotensin from human urine. The proposed methodology has been evaluated for losses due to thermal degradation during extraction and hydrolysis and due to sample handling during the entire work-up including solid phase extraction, and values are given for inter- and intra-assay variability. We present isoflavonoid levels of most common peas and beans used in 'western' and 'eastern' diets and compare isoflavonoid and coumestrol levels of raw, canned, and cooked foods which can be used in future epidemiological studies. We also determined human urinary levels with our methodology comparing values before and after soybean intake.

Soy intake and cancer risk: A review of the in vitro and in vivo data

Messina M.J.; Persky V.; Setchell K.D.R.; Barnes S.
Epidemiology/Biostatistics Program, School of Public Health, University of Illinois, Chicago, IL 60680 USA
Nutr. Cancer (USA), 1994, 21/2 (113-131)

International variations in cancer rates have been attributed, at least in part, to differences in dietary intake. Recently, it has been suggested that consumption of soyfoods may contribute to the relatively low rates of breast, colon, and prostate cancers in countries such as China and Japan. Soybeans contain a number of anticarcinogens, and a recent National Cancer Institute workshop recommended that the role of soyfoods in cancer prevention be investigated. In this review, the hypothesis that soy intake reduces cancer risk is considered by examining relevant in vitro, animal, and epidemiological data. Soybeans are a unique dietary source of the isoflavone genistein, which possesses weak estrogenic activity and has been shown to act in animal models as an antiestrogen. Genistein is also a specific inhibitor of protein tyrosine kinases; it also inhibits DNA topoisomerases and other critical enzymes involved in signal transduction. In vitro, genistein suppresses the growth of a wide range of cancer cells, with IC50 values ranging from 5 to 40 microM (1-10 microg/ml). Of the 26 animal studies of experimental carcinogenesis in which diets containing soy or soybean isoflavones were employed, 17 (65%) reported protective effects. No studies reported soy intake increased tumor development. The epidemiological data are also inconsistent, although consumption of nonfermented soy products, such as soymilk and tofu, tended to be either protective or not associated with cancer risk; however, no consistent pattern was evident with the fermented soy products, such as miso. Protective effects were observed for both hormone- and nonhormone-related cancers. While a definitive statement that soy reduces cancer risk cannot be made at this time, there is sufficient evidence of a protective effect to warrant continued investigation.

Plasma concentrations of phyto-oestrogens in Japanese men

Adlercreutz H.; Markkanen H.; Watanabe S.
Department of Clinical Chemistry, University of Helsinki, Mellahti Hospital, SF-00290 Helsinki Finland
Lancet (United Kingdom), 1993, 342/8881 (1209-1210)

A low mortality from prostatic cancer is found in Japanese men consuming a low-fat diet with high content of soy products, a rich source of isoflavonoids. We therefore assayed four isoflavonoids in plasma of 14 Japanese and 14 Finnish men. The geometric mean plasma total individual isoflavonoid levels were 7 to 110 times higher in the Japanese than in the Finnish men. Genistein, a tyrosine kinase inhibitor, occurred in the highest concentration (geometric mean 276 nmol/L). We hypothesise that these high phyto-oestrogen levels may inhibit the growth of prostatic cancer in Japanese men, which may explain the low mortality from prostatic cancer in that country.

Genistein is an effective stimulator of sex hormone-binding globulin production in hepatocarcinoma human liver cancer cells and suppresses proliferation of these cells in culture

Mousavi Y.; Adlercreutz H.
Department of Clinical Chemistry, University of Helsinki, Meilahti Hospital, SF-00290 Helsinki Finland
Steroids (USA), 1993, 58/7 (301-304)

Studies have indicated a correlation between a high level of urinary lignans and isoflavonoid phytoestrogens, particularly genistein, and a low incidence of hormone-dependent cancers, such as breast and prostate cancer. Previously it has been observed that a vegetarian diet is associated with high plasma levels of sex hormone-binding globulin (SHBG), reducing clearance of sex hormones and probably risk of breast and prostate cancer. In the present study we investigated the in vitro effect of genistein on the production of SHBG by human hepatocarcinoma (Hep-G2) cells in culture and its effect on cell proliferation. We found that genistein not only highly significantly increases the SHBG production by Hep-G2 cells, but also suppresses the proliferation of these cancer cells already at a stage when SHBG production continues to be high. We conclude that, in addition to the lignan enterolactone, the most abundant urinary isoflavonoid genistein stimulates SHBG production and inhibits Hep-G2 cancer cell proliferation.

Genistein and biochanin A inhibit the growth of human prostate cancer cells but not epidermal growth factor receptor tyrosine autophosphorylation

Peterson G.; Barnes S.
Department of Pharmacology, University of Alabama, Birmingham, AL 35294-0019 USA
Prostate (USA), 1993, 22/4 (335-345)

The effect of the isoflavones, genistein, daidzein, and biochanin A on the growth of the LNCaP and DU-145 human prostate cancer cell lines has been examined. Genistein and biochanin A, but not daidzein, inhibit both serum and EGF-stimulated growth of LNCaP and DU-145 cells (IC50 values from 8.0 to 27 microg/ml for serum and 4.3 to 15 microg/ml for EGF), but have no significant effect of the EGF receptor tyrosine autophosphorylation. In contrast, tyrphostin 25, a specific EGF receptor tyrosine kinase inhibitor, inhibits EGF-stimulated growth and EGF receptor tyrosine autophosphorylation in these whole cells, but does not inhibit serum-stimulated growth. These data suggest that the mechanism of action of genistein and biochanin A does not depend on inhibition of EGF receptor tyrosine autophosphorylation, but on a more distal event in the EGF receptor-mediated signal transduction cascade.

Surrogate endpoint biomarkers for phase II cancer chemoprevention trials

Kelloff G.J.; Boone C.W.; Crowell J.A.; Steele V.E.; Lubet R.; Doody L.A.
Chemoprevention Investigat. Studies, Div. of Cancer Prevention/Control, National Cancer Institute, NIH, Bethesda, MD 20892 USA
J. Cell. Biochem. (USA), 1994, 56/Suppl. 19 (1-9)

Three critical aspects govern successful Phase II cancer chemoprevention trials - well-characterized agents, suitable cohorts, and reliable intermediate biomarkers for measuring efficacy. Requirements for the agent are experimental or epidemiological data showing chemopreventive efficacy, safety on chronic administration, and a mechanistic rationale for the chemopreventive activity observed. The cohort should be suitable for measuring the chemopreventive activity of the agent and the intermediate biomarkers chosen. Also, many cohorts proposed for Phase II trials are patients with previous cancers or premalignant lesions. For such patients, the trials should be conducted within the context of standard treatment to avoid unusual risks. The criteria for biomarkers are that they fit expected biological mechanisms (i.e., differential expression in normal and high-risk tissue, on or closely linked to the causal pathway for the cancer, modulated by chemopreventive agents, and short latency compared with cancer), may be assayed reliably and quantitatively, measured easily, and correlate to decreased cancer incidence. They must occur in sufficient incidence to allow their biological and statistical evaluation relevant to cancer. Since carcinogenesis is a multipath process, single biomarkers are difficult to validate as surrogate endpoints, as they may appear on only one or a few of the many possible causal pathways. Panels of biomarkers, particularly those representing the range of carcinogenesis pathways, may prove more useful as surrogate endpoints. It is important to avoid relying solely on biomarkers representing isolated events that may or may not be on the causal pathway or otherwise associated with carcinogenesis. These include markers of normal cellular processes that may be increased or expressed during carcinogenesis, but are nonspecific. Chemoprevention trials should be designed to fully evaluate the two or three biomarkers that appear to be the best models of the cancer. Additional biomarkers should be considered only if they can be analyzed efficiently and the sample size allows the more important biomarkers to be evaluated completely. Two types of biomarkers that stand out in regard to their high correlation to cancer and their ability to be quantified are measures of intraepithelial neoplasia and indicators of cellular proliferation. Measurements made by computer-assisted image analysis that are potentially useful as surrogate endpoint biomarkers include nuclear pleomorphism comprising nuclear size, shape (roundness), and texture (DNA distribution patterns); nucleolar size and number of nucleoli/nucleus; DNA ploidy; and proliferation biomarkers such as S-phase fraction, bromodeoxyuridine uptake, Ki-67, and proliferating cell nuclear antigen. Phase II chemoprevention trials are currently in progress or planned that will evaluate these biomarkers. The cohorts include patients scheduled for surgery for ductal carcinoma in situ in breast or early breast cancer, patients with previously resected colon tumors or adenomas, patients with prostatic intraepithelial neoplasia, and patients scheduled for prostate cancer surgery.

The 16-ene vitamin D analogs

Uskokovic M.R.; Studzinski G.P.; Gardner J.P.; Reddy S.G.; Campbell M.J.; Koeffler H.P.
M.R. Uskokovic, Hoffmann-La Roche, Inc., Nutley, NJ 07110 USA
Current Pharmaceutical Design (Netherlands), 1997, 3/1 (99-123)

Numerous 16-ene vitamin D analogs were investigated as potential anticancer agents. Several structural modifications have been uncovered that contribute to the improvement in the stimulation of HL-60 cells differentiation, the inhibition of HL-60 cells proliferation and the reduction of calcemic properties in vivo. They include the introduction of 16-, 22E-, 23E- and 23Z-double bonds, 23-triple bond or 22R-allene, and substitution of C26 and C27-hydrogens with fluorine or methyl groups. The biggest gains have been achieved by combination of the 16-double bond with 23-double or triple bond and 26-trifluoro or 26,27-hexafluoro substitution patterns. Separately, the combination of the 16-double bond with 22R-allene has produced a highly active analog. In respect to modifications in the ring A, the high activities in cell differentiation and inhibition of cell proliferation with significant reduction of calcemic properties were observed in the 1alpha-fluoro, 3-desoxy, and 19-nor series. It was also shown that the lack of the 1alpha-hydroxy group can be overcome by an optimized modification in the ring D and the side chain; 25(OH)-16,23E-diene-26,27-F6D3 is fully active in HL-60 cell differentiation assay with only mimimal effects on the cellular calcium homeostasis.

Signal transduction inhibitors as modifiers of radiation therapy in human prostate carcinoma xenografts

Teicher B.A.; Bump E.A.; Palayoor S.; Northey D.; Coleman C.N.
USA
Radiation Oncology Investigations (USA), 1996, 4/5 (221-230)

Radiation therapy is very useful in the treatment of prostate cancer; however, local treatment failure still occurs in the majority of patients with locally advanced disease. The growth and progression of tumors involve signaling through protein growth factors and small molecules such as arachidonic acid cascade products. In order to develop novel agents to enhance the efficacy of radiation therapy for patients with prostate cancer, the ability of signal transduction inhibitors including

(1) the antiandrogen, flutamide;

(2) the anti-inflammatory agent, ibuprofen;

(3) the growth factor receptor antagonist, suramin;

(4) the retinoid, all-trans-retinoic acid; and

(5) the calcium pump inhibitor, thapsigargin to enhance the response of the human prostate carcinoma xenografts DU-145 and LN-CaP, was assessed. Flutamide acted as a radiation protector of the androgen independent DU-145 tumor but produced an additive antitumor effect in combination with fractionated radiation therapy in the androgen dependent LNCaP tumor. Administration of suramin or thapsigargin along with radiation therapy provided little or no tumor growth delay compared with radiation therapy alone. Treatment with all-trans-retinoic acid did not alter the response of the DU-145 to radiation therapy but increased the response of LNCaP tumor to radiation therapy. Administration of ibuprofen along with radiation therapy was most effective. The radiation dose modifying factor for ibuprofen in the DU-145 tumor was 1.8 and 1.7 for a 1-week and a 2-week fractionated regimen, respectively. Administration of ibuprofen along with radiation therapy to animals bearing the LNCaP tumor resulted in a 2-fold increase in tumor growth delay compared with radiation therapy alone. Further investigation of inhibitors of the arachidonic acid cascade as radiation modifiers is warranted.

Calcium regulation of androgen receptor expression in the human prostate cancer cell line LNCaP

Gong Y.; Blok L.J.; Perry J.E.; Lindzey J.K.; Tindall D.J.
Department of Urology Research, Mayo Clinic and Foundation, 200 First Street SW, Rochester, MN 55905 USA
Endocrinology (USA), 1995, 136/5 (2172-2178)

Elevation of intracellular calcium levels in the presence of normal androgen levels has been implicated in apoptotic prostate cell death. Since the androgen receptor (AR) plays a critical role in the regulation of growth and differentiation of the prostate, it was of interest to determine whether Ca2+ would affect the expression of androgen receptor messenger RNA (mRNA) and protein, thus affecting the ability of androgens to control prostate function. AR-positive human prostate cancer cells, LNCaP, were incubated with either the calcium ionophore A23187 or the intracellular endoplasmic reticulum Ca2+-ATPase inhibitor thapsigargin. Subsequently, AR mRNA and protein levels were assessed by Northern and Western blot analysis. Both A23187 and thapsigargin were found to down-regulate steady state AR mRNA levels in a time- and dose-dependent manner. AR mRNA began to decrease after 6-8 h of incubation with 10-6 M A23187 or 10-7 M thapsigargin, reaching a nadir at 16 and 10 h of incubation, respectively. In contrast, control mRNA (glyceraldehyde 3-phosphate dehydrogenase) did not change significantly during the treatments with either A23187 or thapsigargin. AR protein levels were found to be decreased after 12 h of incubation with either 10-6 M A23187 or 10-7 M thapsigargin. The decrease in AR mRNA and protein seemed to precede apoptosis, since neither A23187 (24 h) nor thapsigargin (30 h) was found to alter cell morphology within the treatment time. Cycloheximide and actinomycin D were unable to change the calcium-mediated decrease in AR mRNA, ruling out the necessity for de novo protein synthesis or a change in mRNA stability. Moreover, the decrease in AR mRNA induced by calcium does not seem to involve protein kinase C- or calmodulin-dependent pathways, since inhibitors of these cellular components had no effect. Nuclear run-on assays demonstrated little or no effects of either A23187 or thapsigargin treatment on AR gene transcription (8 h and 10 h). In conclusion, these studies show that intracellular calcium seems to be a potent regulator of AR gene expression in LNCaP cells.

The role of calcium, pH, and cell proliferation in the programmed (apoptotic) death of androgen-independent prostatic cancer cells induced by thapsigarin

Furuya Y.; Lundmo P.; Short A.D.; Gill D.L.; Isaacs J.T.
Johns Hopkins Oncology Center, 422 N. Bond Street, Baltimore, MD 21231 USA
Cancer Res. (USA), 1994, 54/23 (6167-6175)

Calcium (Ca2+) accumulates within the endoplasmic reticulum of cells through function of the sarcoplasmic reticulum and endoplasmic reticulum Ca2+-dependent ATPase family of intracellular Ca2+-pumping ATPases. The resulting pools have important signaling functions. Thapsigargin (TG) is a sesquiterpene gamma-lactone which selectively inhibits the sarcoplasmic reticulum and endoplasmic reticulum Ca2+-dependent ATPase pumps with a 50% inhibitory concentration of approximately 30 microM. Treatment of androgen- independent prostate cancer cells of both rat and human origin with TG inhibits their endoplasmic reticulum Ca2+-dependent ATPase activity, resulting in a 3-4-fold elevation in the level of intracellular free Ca2+ (Ca(i)) within minutes of exposure. Due to a secondary influx of extracellular Ca2+, this increase in Ca(i) is sustained, resulting in morphological (cell rounding) and biochemical changes within 6-12 h (enhanced calmodulin, glucose regulated protein, and tissue transglutaminase expression, and decreased expression of the G(i) cyclins). Within 24 h of exposure, androgen-independent prostatic cancer cells stop progression through the cell cycle, arrest out of cycle in G0, and irreversibly lose their ability to proliferate with a median effective concentration value of 31 nM TG. During the next 24-48 h, the genomic DNA of the G0-arrested cells undergoes double-strand fragmentation. This is followed by the loss of plasma membrane integrity and fragmentation of the cell into apoptotic bodies. During this process, there is no acidification in the intracellular pH. Using cells transfected with the avian M(r) 28,000 calbindin D Ca2+-buffering protein, it was demonstrated that the programmed death initiated by TG is critically dependent upon an adequate (i.e., 3-4-fold) sustained (>1 h) elevation in Ca(i) and not depletion of the endoplasmic reticulum pools of Ca2+. These results demonstrate that TG induces programmed cell in androgen-independent prostatic cancer cells in a dose-dependent manner and that this death does not require proliferation or intracellular acidification but is critically dependent upon an adequate, sustained (i.e., >1 h) elevation in Ca(i).

Programmed cell death as a new target for prostatic cancer therapy

Kyprianou N.; Martikainen P.; Davis L.; English H.F.; Isaacs J.T.
Johns Hopkins Oncology Center, Baltimore, MD 21205 USA
Cancer Surv. (USA), 1991, 11/- (265-277)

To increase survival of men with metastatic prostatic cancer, a modality that can effectively eliminate androgen independent cancer cells is desperately needed. By combining such an effective modality with androgen ablation, all of the heterogeneous populations of tumour cells within a prostatic cancer patient can be affected, thus optimizing the chances of cure. Unfortunately, such effective therapy for the androgen independent prostatic cancer cell is not yet available. This therapy will probably require two types of agents, one having antiproliferative activity affecting the small number of dividing androgen independent cells, and the other able to increase the low rate of cell death among the majority of non- proliferating (ie interphase) androgen independent prostatic cancer cells present. Androgen dependent prostatic epithelial cells can be made to undergo programmed death by means of androgen ablation, even if the cells are not in the proliferative cell cycle. Androgen independent prostatic cancer cells retain the major portion of this programmed cell death pathway, only there is a defect in the pathway such that it is no longer activated by androgen ablation. If the intracellular free Ca2+ is sustained at an elevated level for a sufficient time, androgen independent cells can be induced to undergo programmed death. The long term goal is therefore to develop some type of non-androgen ablative method that can be used in vivo to induce a sustained elevation in Ca2+ in androgen independent prostatic cancer cells. To accomplish this task, a more complete understanding of the biochemical pathways involved in programmed cell death is urgently needed. At present, studies are focusing on the mechanism involved in the Ca2+ elevation in the normal and malignant androgen dependent cell induced following androgen ablation and the role of the TRPM-2 protein in this process.

Hyperparathyroidism in metastases of prostatic carcinoma: A biochemical, hormonal and histomorphometric study

Rico H.; Uson A.; Hernandez E.R.; Prados P.; Paramo P.; Cabranes J.A.
Department of Medicine, Medical School, University of Alcala de Henares, E-28871 Madrid Spain
Eur. Urol. (Switzerland), 1990, 17/1 (35-39)

Secondary hyperparathyroidism can develop as a result of bone metastases from prostatic cancer, but this has not been studied from the multiple aspects of biochemistry, hormonal status and histomorphometry. In 20 patients with stage-D prostatic cancer, a transiliac bone biopsy was performed for histomorphometric study. In all of them, molecular parathormone (PTH-M) and osteocalcin were determined by radioimmunoassay together with other parameters considered to be biological markers of bone remodelling. Of these 20 patients, only 2 (10%) had elevated PTH-M (240 plus or minus 20.6 pmol/l), differing significantly from the other 18 (58.6 plus or minus 11.7 pmol/l) and from controls (60.4 plus or minus 7.2 pmol/l). In the high PTH-M patients, corrected calcium was low (7.8 plus or minus 0.4 mg/dl) as compared to normal PTH-M patients (9.2 plus or minus 0.5 mg/dl, p < 0.001), and this was also the case for serum phosphorus (2.2 plus or minus 0.6 vs. 3.2 plus or minus 0.3 and 3.4 plus or minus 0.4 mg/dl, respectively p < 0.001). Alkaline phosphatase was raised in the patient groups as compared to controls (p < 0.001) and was higher in the high PTH-M group (362 plus or minus 58 vs. 224 plus or minus 62 U/l, p < 0.001). The same pattern of higher values in the hyperparathyroid patients was repeated for: hydroxyproline/Cr in fasting urine (3.6 plus or minus 0.2 vs. 2.1 plus or minus 0.4 mg/mg, p < 0.001); Ca/Cr in fasting urine (0.08 plus or minus 0.02 vs. 0.007 plus or minus 0.01 mg/mg, p < 0.001, decreased in both patient groups but more so in the high PTH-M group), and for the 24-hour urinary calcium (128 plus or minus 22 vs. 86 plus or minus 11 mg, p < 0.001) which was only reduced (p < 0.001) in normals. Serum osteocalcin, although raised in both groups, did not differ significantly between patient groups (15.1 plus or minus 2.3 ng/ml for hyperparathyroid patients and 14.4 plus or minus 5.2 ng/ml for normals), but was significantly different between patients and controls (6.8 plus or minus 3.1 ng/ml, p < 0.001). Histomorphometrically, trabecular bone volume was elevated in both groups as compared to controls (p < 0.001), and the resorption surface was increased in hyperparathyroid patients (9.7 plus or minus 1.1 vs. 4.7 plus or minus 2.8%, p < 0.001), as was the osteoid seam thickness index (31.8 plus or minus 6.2 vs. 18.6 plus or minus 5.6, p < 0.001). According to the Pearson test, only effected in the normoparathyroid group, the only significant and positive correlations were between osteocalcin and 24-hour urine calcium and between osteocalcin and Ca/Cr (both p < 0.001). These results demonstrate the existence of a secondary hyperparathyroidism in 10% of patients with blastic bone metastases due to stage-D prostatic cancer and show that osteocalcin is not an adequate biological bone marker in these patients.

In vitro studies of human prostatic epithelial cells: Attempts to identify distinguishing features of malignant cells

Peehl D.M.; Wong S.T.; Bazinet M.; Stamey T.A.
Division of Urology, Stanford Medical Center, Stanford, CA 94305 USA
Growth Factors (United Kingdom), 1989, 1/3 (237-250)

Recent advances in culture techniques have enabled routine establishment and propagation of epithelial cells derived from normal and malignant tissues of the human prostate. Comparative studies of the responses of normal and cancer-derived cell populations to various growth and differentiation factors in vitro were undertaken to examine the possibility that cancer cells might respond differentially. Clonal growth assays in serum-free medium demonstrated that optimal proliferation of normal as well as cancer cell strains was generally dependent on the presence of cholera toxin, epidermal growth factor, pituitary extract, hydrocortisone, insulin and high levels of calcium in the culture medium, and on the use of collagen-coated dishes. Only one cancer strain responded aberrantly to epidermal growth factor and hydrocortisone. Putative differentiation factors (transforming growth factor-beta and vitamin A) inhibited the growth of all normal and cancer strains. The origin of a cancer-derived cell strain that responded similarly to normal strains was verified by positive labeling with a prostate cancer-specific antibody, validating the conclusion from these studies that normal and cancer prostatic epithelial cells are not distinguishable on the basis of responses to the tested factors.

Hypocalcemia associated with estrogen therapy for metastatic adenocarcinoma of the prostate

Vogelgesang S.A.; McMillin J.M.
Research Service, Sioux Falls Veterans Administration Hospital, Sioux Falls, SD USA
J. Urol. (USA), 1988, 140/5 Part I (1025-1027)

We report 2 cases of true hypocalcemia (not caused by decreased binding protein) associated with metastatic prostate cancer and review previously reported cases. Hypocalcemia is a common but frequently unrecognized complication of prostatic cancer. Estrogen therapy often is associated with the hypocalcemia, which may be asymptomatic. The hypocalcemia is always associated with osteoblastic metastases and usually it is associated with increased serum alkaline phosphatase activity, acid phosphatase activity and serum parathyroid hormone concentration. Serum concentrations of magnesium, phosphorus and vitamin D frequently are decreased. Patients are in a positive calcium balance. The osteoblastic metastases seem to act as a calcium sink, creating a 'hungry tumor phenomenon'. The role of estrogens may be to stop the resorption of normal bone resulting in lower serum calcium concentrations.

Hypercalcemia in carcinoma of the prostate: Case report and review of the literature

George A.L. Jr.; Remler R.B.; Heim C.R.; Warner J.J.
Department of Medicine, Vanderbilt University Medical Center, Nashville, TN USA
J. Urol. (Baltimore) (USA), 1987, 137/2 (309-311)

Hypercalcemia developed in a man with recurrent adenocarcinoma of the prostate. Serum calcium became normal soon after bilateral orchiectomy and the patient was free of disease 18 months later. The absence of radiographically detectable bone metastases in this patient suggested a humoral mechanism for the hypercalcemia. Orchiectomy may be an effective treatment for hypercalcemia complicating prostatic carcinoma.

Calcium excretion in metastatic prostatic carcinoma

Grainger R.; Reda M.; Fitzpatrick J.M.
Department of Urology, Meath Hospital, Dublin 8 Ireland
Br. J. Urol. (England), 1984, 56/6 (687-689)

In 64 men with prostatic carcinoma, calcium excretion per litre of glomerular filtrate (Ca(e)) was persistently lower in those with bone secondaries than in those with soft tissue involvement only, despite a normal range of serum calcium in both groups. In three patients who showed an improvement in their bony metastases on bone scan 6 months after starting treatment, the Ca(e) values had increased slightly but still remained in the low range. In a further five who showed no improvement on bone scan, Ca(e) values were lower than before. In patients with prostatic carcinoma, Ca(e) is an indicator of early changes in calcium homeostasis. It may also provide an objective indication of progression of bone secondaries.

Osteomalacia associated with prostatic cancer and osteoblastic metastases

Kabadi U.M.
Dep. Med., Veterans Adm. Med. Cent., Des Moines, IA 50310 USA
Urology (USA), 1983, 21/1 (65-67)

A patient with carcinoma of the prostate, extensive bony metastases, and osteomalacia is reported. The diagnosis of osteomalacia was suspected because of generalized weakness and bone pains, hypocalcemia, hypophosphatemia, and raised alkaline phosphatase. It was documented by low 1,25-hydroxyvitamin D level. Furthermore, it was confirmed by improvement in patient's symptomatology and normalization of serum calcium and phosphorus after treatment with 1,25-hydroxyvitamin Dsub 3 (Rocaltrol).

Carcinoma of the prostate: The treatment of bone metastases by radiophosphorus

Glaser M.G.; Howard N.; Waterfall N.
Dept. Radiother., Charing Cross Hosp., London United Kingdom
Clin. Radiol. (Scotland), 1981, 32/6 (695-697)

Osseous deposits secondary to advanced carcinoma of the prostate are a common feature of the disease. These deposits are most often seen in the lumbar spine and pelvis and cause severe and intractable pain, often requiring large quantities of strong analgesia for alleviation of pain. Relief of pain can be achieved by external irradiation of these deposits, but this relief may not be permanent and the disease may be so widespread that it is impracticable to treat all the deposits by irradiation. Deposits from carcinoma of the prostate are usually multiple and all may cause pain at the same time. A method of delivering the radiation to all the deposits at the same time has been sought. Previous studies have shown that radioactive phosphorus (P32) can be used to obtain this localisation of radioactivity at sites of osseous activity. In this study 24 patients with bone metastases from carcinoma of the prostate were treated with radiophosphorus and methyl testosterone, or radiophosphorus with parathormone and calcium. An overall response rate of 58% shows this to be an effective palliative treatment. The results suggest there is a greater response when P32 is used in conjunction with parathormone and calcium, than with methyl testosterone.

Management of cancer of the prostate

Blackard C.E.
VA Hosp., Minneapolis, Minn. USA
Brit.J.Hosp.Med. (England), 1974, 11/3 (357-372)

In this article the management of prostatic cancer is discussed according to the clinical stage of the tumor. Ordinarily, treatment of prostatic cancer should not be started until a positive histological diagnosis has been made and the patient has been properly staged. Minimal staging studies include a pretreatment prostatic serum acid phosphatase test and a skeletal survey.

Intracavitary irradiation of prostate carcinomas

Dragon V.; Pache G.; Von Niederhausern W.; et al.
Serv. Radiother., CHU Vaudois, Lausanne Switzerland
Rev. Med. Suisse Romande (Switzerland), 1980, 100/9

A method for the intracavitary irradiation of prostate carcinomas, used at the Central University Hospital in Lausanne in 1979 and 1980 on 10 patients is described. The technique, which is the afterloading type, consists of the positioning of a Cs 137 source in the proximal ureter. This is achieved with the aid of a Foley 26 balloon catheter introduced into the bladder after drainage cystostomy. The source remains in place for about 26 hours and delivers a dose of approximately 3800 rads to the prostate to a depth of 4 cm (NSD=2000 ret) and a maximum of 1700 rads to the rectum (NSD=700 ret).

Epidemiology of prostatic cancer: A case-control study

Fincham S.M.; Hill G.B.; Hanson J.; Wijayasinghe C.
Division of Epidemiology and Preventive Oncology, 6th Floor, 9707-110 Street, Edmonton, Alta. T5K 2L9 Canada
Prostate (USA), 1990, 17/3 (189-206)

A population-based case-control study of prostatic cancer in Alberta was undertaken to determine the risk factors associated with the disease. Cases were 382 newly diagnosed prostatic cancer patients and 625 controls, group-matched to the anticipated age distribution of the cases, chosen at random from the health insurance roster. Subjects were interviewed in their homes by using a pre-tested questionnaire including questions related to ethnic group, education, puberty, marital history, family history, residence, water supply, smoking, and diet. Factors significantly related to the risk of developing prostatic cancer included ethnic group (British high, Ukrainian low), education (elementary high, university low), age at first marriage (early high, late low), family history (high risk for those with relatives with prostatic cancer), and increased masculinity among the children of cases. The results with respect to smoking, occupation, medical history, birthplace, residence, water supply, and diet were generally negative.

Demonstration of specifically sensitized lymphocytes in patients treated with an aqueous mistletoe extract (Viscum album L.)

Schultze J.L.; Stettin A.; Berg P.A.
Medizinische Klinik, Abteilung II, Universitat Tubingen, W-7400 Tubingen Germany
Klin. Wochenschr. (Germany), 1991, 69/9 (397-403)

Lymphocytes of 25 patients treated with an aqueous mistletoe extract (Viscum album L.) for up to 6 months (group 1), up to 2 years (group 2), and more than 2 years (group 3) were examined in 3- and 7-day cultures for specifically sensitized lymphocytes. The whole extract (HM), the lectin-polysaccharide fraction (HM-LP), and the 'viscotoxin' fraction (HM-V) were added at concentrations ranging from 0.5 microg to 12.5 mg extract/ml. Lymphocytes from four of the nine group 2 patients and five of the ten group 3 patients reacted specifically with HM and HM-LP at an optimal dose of 5.0 mg/ml, but did not react with HM-V. Stimulation indices varied between 1.6 and 16. In the patients of group 3 this effect was observed only when their lymphocytes were costimulated in the 3-day cultures with phytohemagglutinin (PHA), in contrast to the four patients of group 2 who reacted only in the 7-day cultures with HM-LP without PHA co-stimulation. Patients' lymphocytes had to be protected from mistletoe lectin-induced cytotoxicity by the addition of their own sera containing anti-mistletoe lectin antibodies. Lymphocytes from tumor patients (n = 18) never treated with mistletoe extracts and healthy individuals (n = 18) showed no specific proliferative response when tested in 3- and 7-day cultures. The production of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon-gamma (IFN-gamma) was measured in the supernatants of lymphocytes cultures from all 25 patients and 36 controls exposed to HM, HM-LP, and HM-V in 3- and 7-day cultures.

An urodynamic study of patients with benign prostatic hypertrophy treated conservatively with phytotherapy or testosterone

Flamm J.; Kiesswetter H.; Englisch M.
Urol. Abt., Wilhelminenspit., Wien Austria
Wien. Klin. Wochenschr. (Austria), 1979, 91/18 (622-627)

Conservative therapy of benign prostatic hypertrophy comprises the administration of oestrogens, gestagens, androgens and anti-androgens. Phytodrugs, which contain an extract of Sabal serrulatum or Pygeum Africana as active substance are without side effects and are, therefore, being used increasingly. 74 patients with irritable or obstructive bladder symptoms due to benign prostatic hypertrophy were treated with a phytodrug (Sabal serrulatum) or with testosterone throughout a period of three months. In group one (20 patients given phytodrugs and 10 patients given testosterone) clinical symptoms and measurements of residual urine, residual urine quotient, bladder capacity, micturition pressure and maximum urethral closure pressure were recorded at the beginning and at the end of therapy. In group two 28 patients were treated with the phytodrug in the first and third months with an intervening placebo trial lasting four weeks and 16 patients were given testosterone. Clinical symptoms and uroflow and residual urine only were charted in this group. None of the patients in either group showed an improvement in the urodynamic parameters of obstruction, but all patients felt a subjective alleviation of their symptoms.

Phytoestrogens are partial estrogen agonists in the adult male mouse

Makela S, Santti R, Salo L, McLachlan JA
Institute of Biomedicine and Medicity Research Laboratory, University of Turku, Finland.
Environ Health Perspect 1995 Oct;103 Suppl 7:123-7

The intake, as well as serum and urinary concentrations, of phytoestrogens is high in countries where incidence of prostate cancer is low, suggesting a chemopreventive role for phytoestrogens. Their significance could be explained by the ability to antagonize the action of more potent endogenous estrogens in initiation or promotion of tumor formation. We have studied estrogenicity and antiestrogenicity of dietary soy and two phyloestrogens, coumestrol and daidzein, in our neoDES mouse model for the study of prostatic neoplasia. Soy was chosen because it is rich in phytoestrogens, is widely used in Oriental diets, and has antiestrogenic and anticarcinogenic properties in the neoDES mouse when given from fertilization onward. In short-term tests with adult animals, no evidence for estrogenicity or antiestrogenicity (capability to antagonize the action of 17beta-estradiol) of soy was found when development of epithelial metaplasia and expression of c-fos protooncogene in prostate were used as end points of estrogen action. Estrogenic activity of coumestrol and daidzein on c-fos expression was subtle. Coumestrol, either given alone or in combination with 17beta-estradiol, had no effect on development of epithelial metaplasia. These marginal or missing effects in adult males could be interpreted by assuming that the neonatal period is more critical for estrogenic or antiestrogenic action of soy and phytoestrogens. Once initiated, estrogen-related lesions would develop spontaneously. Alternatively, the chemopreventive action of soy is not due to antiestrogenicity of soy-derived phytoestrogens.

Urinary excretion of lignans and isoflavonoid phytoestrogens in Japanese men and women consuming a traditional Japanese diet

Adlercreutz H, Honjo H, Higashi A, Fotsis T, Hamalainen E, Hasegawa T, Okada H
Department of Clinical Chemistry, University of Helsinki, Meilahti Hospital, Finland.
Am J Clin Nutr 1991 Dec;54(6):1093-100

Epidemiologic studies revealed low mortality in hormone-dependent cancer in Japanese women and men consuming a traditional diet. We previously found that certain diphenolic food components, lignans and isoflavonoids, which are converted to biologically active hormone-like substances by intestinal microflora, may be cancer-protective agents. Therefore, we studied urinary excretion of these compounds (enterolactone, enterodiol, daidzein, equol, and O-desmethylangolensin) in 10 women and 9 men in a rural village south of Kyoto, Japan. The subjects consumed a typical low-fat diet with much rice and soy products, fish, and vegetables. An isotope-dilution gas chromatographic-mass spectrometric method was used for the assays. The urinary excretion of lignans was low but that of the isoflavonoids was very high. The excretion of isoflavonoids correlated with soybean-product intake. The low mortality in breast and prostate cancer of Japanese women and men, respectively, may be due to the high intake of soybean products.

Control of LNCaP proliferation and differentiation: Actions and interactions of androgens, 1alpha,25-dihydroxycholecalciferol, all-trans retinoid acid, 9-cis retinoic acid, and phenylacetate

Esquenet M; Swinnen JV; Heyns W; Verhoeven G
Department of Developmental Biology, Catholic University of Leuven, Belgium.
Prostate (USA), 1996, 28/3 (182-194)

There is increasing evidence that growth and differentiation of prostatic carcinoma cells may be modulated not only by androgens and growth factors but also by vitamin D, retinoids, and phenylacetate (PA). The latter agonists may have a role in the prevention and therapy of prostate cancer but their exact therapeutic potential remains unclear. Since both retinoids and vitamin D act via nuclear receptors, the same way androgens do, we studied the interactions of these compounds with androgen-induced proliferation and differentiation using LNCaP cells as a model of androgen-responsive tumor cells. PA was included because of its suspected different mode of action. (3H)-thymidine incorporation was used as a measure of proliferative activity, secretion of prostate-specific antigen (PSA) as a measure of differentiated function. The present data show that 1alpha,25-dihydroxycholecalciferol (VD3), all-trans retinoic acid (atRA), 9-cis retinoic acid (9cRA), and PA stimulated LNCaP cell-differentiated function in the presence or absence of androgens. The effects on cell growth were more complicated. In the absence of androgens growth stimulatory effects were observed for the retinoids and under some conditions for VD3. These effects were limited, however, and tended to be more pronounced at low cell densities. In the presence of androgens nearly exclusively growth inhibitory effects were observed. On a molar basis VD3 was the most effective antiproliferative agonist (ED50 = 10-9 M). It completely neutralized the stimulatory effects of androgens. Growth inhibition was not due to a decrease in the concentration of androgen receptor: whereas atRA, 9cRA, and PA did not alter androgen receptor levels, VD3 provoked a twofold increase. Neither in the presence nor in the absence of androgens did we observe any cooperativity in the growth stimulatory or inhibitory effects of VD3, atRA, or 9cRA. To test whether treatment with any of the studied agonists resulted in a phenotypic reversion and sustained growth arrest, LNCaP cells were pretreated with VD3, atRA, 9cRA, or PA for 6-12 days and reseeded at equal densities as untreated cells. In all cases tested (3H)-thymidine incorporation was restored within 6 days suggesting that none of these compounds caused irreversible growth inhibition.

1,25-Dihydroxy-16-ene-23-yne-vitamin D3 and prostate cancer cell proliferation in vivo

Schwartz GG; Hill CC; Oeler TA; Becich MJ; Bahnson RR
Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Florida, USA.
Urology (USA), 1995, 46/3 (365-369)

Objectives. 1,25-Dihydroxyvitamin D can inhibit the proliferation of prostate cancer cells, but its clinical use is limited by hypercalcemia. We examined the effects of a 'noncalcemic' vitamin D analogue, 1,25-Dihydroxy- 16-ene-23-yne-cholecalciferol (16-23-D3), on the proliferation of human prostate cancer cells in a mouse model.

Methods. Twenty-four athymic nude mice were inoculated with human prostate carcinoma cells from the PC-3 cell line. Twelve mice (experimental group) received injections of 1.6 microg of 16- 23-D3 on alternate days over a 22-day period. Twelve mice (control group) received sham injections. Tumor volumes, pathologic findings, and terminal serum calcium levels were compared between groups.

Results. The relative increase in tumor volume was significantly lower in the experimental than in the control group in the first interval following treatment (P < 0.01). Mean tumor volumes in the experimental group were approximately 15% smaller than in the control group. Serum calcium levels did not differ between groups.

Conclusions. 16-23-D3 showed modest antiproliferative effects on prostate cancer cells in this model without evidence of drug-induced hypercalcemia. These findings support the concept that vitamin D analogues can inhibit the proliferation of human prostate cancer cells in vivo.

Recent advances in hormonal therapy for cancer

Traynor A
Northwestern University Medical School, Lurie Cancer Center, Division of Hematology-Oncology, Chicago, IL 60611-3008, USA.
Curr Opin Oncol 1995 Nov;7(6):572-81

Hormonal manipulation of cancer is no longer confined to the use of effective antiestrogen therapy for breast cancer or surgical or hormonal castration for prostate cancer. A broader acknowledgment of the potential of different hormonal ligands to evoke cell cycle arrest to prevent the progress of neoplastic transformation, and even to elicit active cell death, has expanded the concept of hormonal therapy. The use of retinoids and deltanoids in conjunction with antiestrogens and antiandrogens is progressing into clinical trials. The use of glucocorticoids in conjunction with cyclic AMP may enhance apotosis induction. The use of antiandrogens in conjunction with cytotoxic therapy may diminish the risk of bcl-2 mediated resistance in prostate cancer. Innovative use of sequential and synergistic hormonal manipulations based on an expanding understanding of transcriptional regulation promises to advance this science.

Endocrine control of prostate cancer

Wilding G
University of Wisconsin Comprehensive Cancer Center, Madison 53792 USA.
Cancer Surveys (USA), 1995, 23/- (43-62)

Steroid hormones play an important part in prostate biology. Androgens are crucial for the normal development of the prostate gland and in maintaining its functional state in the adult. It seems that the prolonged presence of androgens might also be an important factor in the development of prostate cancer. In addition, androgens and oestrogens appear to play a part in the development of benign prostatic hypertrophy, although the exact nature of their role has not been clearly defined. Stimulation of prostate cancer growth by androgens is well established with androgen withdrawal therapy being the most effective therapy in men with prostate cancer. Additive steroid therapy of metastatic prostate cancer with oestrogens or progestogens has also proved effective. The effects of androgens on prostate cancer cell growth might be mediated through modulation of growth factor expression and alteration of growth factor receptor levels. Androgen response can be modulated by the expression of mutated oncogenes such as ras. Androgen independence can occur through a loss of AR expression or mutation of the AR; however, the patterns of AR expression in normal prostatic tissue from development to adulthood and in cancer are now just beginning to be described. Other steroids, such as the retinoids, show promise as preventive agents, possibly through the modulation of growth factors. Vitamin D compounds modulate prostate cancer cell growth, but their role in prevention and therapy is unclear.

Vitamin D and prostate cancer

Feldman D; Skowronski RJ; Peehl DM
Department of Medicine, Stanford University School of Medicine, California 94305-5103 USA.
Adv Exp Med Biol 1995;375:53-63

Our findings demonstrate the presence of VDR in various human prostate cancer cell lines and in primary cultures derived from normal, BPH and prostate cancer. In addition, 1,25-D induced several bioresponses in these cells including growth inhibition and PSA stimulation. Based on examples in many different malignant cells as well as our data in prostate cells, that vitamin D is anti proliferative and promotes cellular maturation, it seem clear that vitamin D must be viewed as an important cellular modulator of growth and differentiation in addition to its classical role as regulator of calcium homeostasis. In this respect, vitamin D has the potential to have beneficial actions on various malignancies including prostate cancer. Its ultimate role in prostate cancer remains to be determined, but 1,25-D may prove useful in chemoprevention and/or differentiation therapy. We believe the data currently available provide the basis for an optimistic view on the possible use of vitamin D to treat prostate cancer in patients and that further investigation is clearly warranted to belief define its potential therapeutic utility.

Actions of vitamin D3 analogs on human prostate cancer cell lines: Comparison with 1,25-dihydroxyvitamin D3

Skowronski RJ; Peehl DM; Feldman D
Department of Medicine, Stanford University School of Medicine, California 94305.
Endocrinology (USA), 1995, 136/1 (20-26)

Data from epidemiological studies has suggested that vitamin D deficiency may promote prostate cancer, although the mechanism is not understood. We have previously demonstrated the presence of vitamin D receptors (VDR) in three human prostate carcinoma cell lines (LNCaP, PC-3, and DU-145) as well as in primary cultures of stromal and epithelial cells derived from normal and malignant prostate tissues. We have also shown that 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) can elicit an antiproliferative action in these cells. In the present study we compared the biological actions of 1,25-(OH)2D3 to those of a series of natural vitamin D3 metabolites and several synthetic analogs of vitamin D3 known to exhibit less hypercalcemic activity in vivo. In ligand binding competition experiments, we demonstrated the following order of potency in displacing (3H)1,25(OH)2D3 from VDR: EB-1089 > 1,25- (OH)2D3 > MC-903 > 1,24,25(OH)3D3 > 22-oxacalcitriol (OCT) > 1alpha,25- dihydroxy-16-ene-cholecalc iferol (Ro24-2637) > 25-hydroxyvitamin D3, with EB-1089 being similar2-fold more potent than the native hormone. No competitive activity was found for 25-hydroxy-16,23-diene-cholecalciferol. When compared for ability to inhibit proliferation of LNCaP cells, MC-903, EB-1089, OCT, and Ro24-2637 exhibited 4-, 3-, 3-, and 2-fold greater inhibitory activity than 1,25-(OH)2D3. Interestingly, although OCT and Ro24-2637 exhibit, respectively, 10 and 14 times lower affinity for VDR than 1,25-(OH)2D3, both compounds inhibited the proliferation of LNCaP cells with a potency greater than that of the native hormone. The relative potency of vitamin D2 metabolites and analogs to inhibit cell proliferation correlated well with the ability of these compounds to stimulate prostate-specific antigen secretion by LNCaP cells as well as with their potency to induce the 25- hydroxyvitamin D3-24-hydroxylase messenger RNA transcript in PC-3 cells. In conclusion, these results demonstrate that synthetic analogs of vitamin D3, known to exhibit reduced calcemic activity, can elicit antiproliferative effects and other biological actions in LNCaP and PC-3 cell lines. It is noteworthy that although binding to VDR is critical for 1,25-(OH)2D3 action, the analog data indicate that additional factors significantly contribute to the magnitude of the biological response. Finally, the strong antiproliferative effects of several synthetic analogs known to exhibit less calcemic activity than 1,25(OH)2D3 suggest that these compounds potentially may be useful as an additional therapeutic option for the treatment of prostate cancer.

Vitamin D and cancer

Verstuyf A.; Mathieu C.; Verlinden L.; Bouillon R.
Legendo, Onderwijs en Navorsing, Universite Catholique, Leuven Belgium
Rev. Fr. Endocrinol. Clin. Nutr. Metab. (France), 1994, 35/4-5

Receptors for 1alpha,25-(OH)2-D3 have been detected not only in the classical target organs, the intestine, kidney and bone but also in other sites such as the skin, pancreas and certain cells of the immune system. A wide variety of human cancer cell lines (including breast, prostatic cancer and leukemia) also have these receptors. In vitro studies have shown that the biologically active metabolite of vitamin D, 1alpha,25-(OH)2-D3 inhibits cell proliferation and stimulates the differentiation of many cell types. Such studies prompted the suggestion of the use of conventional vitamin D compounds in the treatment of certain malignancies. It is shown in vivo that 1alpha,25-(OH)2-D3 may inhibit the growth of mammary carcinomas but at the risk of hypercalcemia and hypercalciuria. For this reason synthetic analogues have been developed which retain the ability to inhibit cell proliferation and promote cell differentiation but have reduced their calcemic activity. Modifications of the side chain of 1alpha,25-(OH)2-D3 can create superanalogues with enhanced non-calcemic activity (10 to 100-fold) and decreased calcemic potency. These analogues have been successfully used in animal models of leukemia and breast cancer.

Human prostate cancer cells: Inhibition of proliferation by vitamin D analogs

Schwartz G.G.; Oeler T.A.; Uskokovic M.R.; Bahnson R.R.
Department of Clinical Epidemiology, Univ Pittsburgh School of Medicine, M-200 Scaife Hall, Pittsburgh, PA 15261 USA
Anticancer Res. (Greece), 1994, 14/3 A (1077-1081)

1,25-Dihydroxyvitamin D (1,25(0H)2D3, calcitriol) can inhibit the proliferation of some human prostate cancer cells but its clinical use is limited by hypercalcemia. We therefore explored the bioactivity of less calcemic vitamin D analogs. We studied the effects of calcitriol and 3 synthetic analogs at concentrations of 10-6 to 10-12 M on the in vitro proliferation of 3 human prostate carcinoma cell lines: DU 145, PC-3, and LNCaP. Calcitriol and analogs showed significant antiproliferative activity on PC-3 and LNCaP cells. DU 145 cells were inhibited by the analogs only. We conclude that vitamin D analogs warrant further investigation as therapeutic agents in prostate cancer.

Vitamin D and prostate cancer: 1,25 Dihydroxyvitamin D3 receptors and actions in human prostate cancer cell lines

Skowronski R.J.; Peehl D.M.; Feldman D.
Stanford Univ. School of Medicine, Stanford, CA 94305 USA
Endocrinology (USA), 1993, 132/5 (1952-1960)

It has been suggested that vitamin D deficiency may promote prostate cancer, although the mechanism is not understood. In this study three human prostate carcinoma cell lines, LNCaP, DU-145, and PC-3, were examined both for the presence of specific 1,25 dihydroxyvitamin D3 (1,25(OH)2D3) receptors (VDRs) and also employed to study the effects of hormone on cell proliferation and differentiation. Ligand binding experiments demonstrated classical VDR in all three cell lines examined with an apparent dissociation constant of 7.5, 5.4, and 6.3 x 10-11 M for LNCaP, DU-145, and PC-3 cells, respectively. Corresponding binding capacity for the three prostate carcinoma cell lines were 27, 31, and 78 fmol/mg protein, respectively. The presence of VDR in the three cell lines was also confirmed by immunocytochemistry. In addition, one major 4.6-kilobase messenger RNA transcript hybridizing with a specific human VDR complementary DNA probe was identified in all three cell lines. Interestingly, both DU-145 and PC-3 but not LNCaP cell lines exhibited 1,25(OH)2D3-stimulated induction of 24-hydroxylase messenger RNA employed as a marker of 1,25(OH)2D3 action. Physiological levels of 1,25(OH)2D3 dramatically inhibited proliferation of the LNCaP and PC-3 cell lines. However, in spite of the presence of high affinity VDR, proliferation of DU- 145 cells was not inhibited by 1,25(OH)2D3 at the doses tested. Treatment with 1,25(OH)2D3 caused a dose-dependent stimulation of prostate-specific antigen secretion by LNCaP cells. In conclusion, these results demonstrate that these three human prostate carcinoma cell lines all possess specific VDR and that 1,25(OH)2D3 treatment can elicit both an antiproliferative and a differentiating action on these cancer cells. The findings lend support to the hypothesis that vitamin D might exert beneficial actions on prostate cancer risk.

Is vitamin D deficiency a risk factor for prostate cancer? (hypothesis)

Schwartz GG; Hulka BS
Department of Epidemiology, University of North Carolina, School of Public Health, Chapel Hill NC 27599.USA
Anticancer Res. (Greece), 1990, 10/5 A (1307-1312)

Prostate cancer is a major cause of cancer death among males, yet little is known about its etiology. We hypothesize that Vitamin (Hormone) D deficiency may underlie the major risks for prostate cancer, including age, Black race, and northern latitudes. These factors all are associated with decreased synthesis of Vitamin D. Mortality rates from prostate cancer in the U.S. are inversely correlated with ultraviolet radiation, the principal source of Vitamin D. This hypothesis is consistent with known antitumor properties of Vitamin D, and may suggest new avenues for research in prostate cancer.

The in vitro response of four antisteroid receptor agents on the hormone-responsive prostate cancer cell line LNCaP

Figg W.D.; McCall N.A.; Reed E.; Sartor O.
Clinical Pharmacology Branch, National Cancer Institute, 9000 Rockville Pike, Bethesda, MD 20892, United States
Oncology Reports (Greece), 1995, 2/2 (295-298)

Previous reports indicate that flutamide withdrawal is associated with PSA declines and tumor shrinkage in selected patients with 'hormone-refractory' prostate cancer. Though the mechanisms underlying this effect are not clear, investagators have hypothesized that these effects are mediated by mutant androgen receptors recognizing hydroxy-flutamide as an androgenic agonist. Such receptors have been well described in the human prostate cancer cell line LNCaP. Despite the finding that the androgen receptor of LNCaP aberrantly recognizes a variety of steroids, including estrogen and progesterone, as androgenic agonists, there are no studies which examine the effect of estrogen antagonists and progesterone antagonist on baseline and androgen-stimulated LNCaP growth. In this report, LNCaP cells were cultured in phenol red-free media using charcoal-stripped sera. As previously reported, flutamide enhanced LNCaP growth and bicalutamide inhibited androgen-stimulated LNCaP proliferation. Neither tamoxifen nor RU486 influenced LNCaP growth (either in the presence or absence of exogenous androgens). From these data we conclude that antagonists of estrogen and progesterone action have no anti-proliferative effect on LNCaP cells and that the mutant androgen receptor expressed in these cells is quite restrictive in the recognition of compounds with antagonistic activity. The clinical implications of these findings are discussed.

Combination treatment in M1 prostate cancer

Ferrari P, Castagnetti G, Ferrari G, Pollastri CA, Tavoni F, Dotti A
Department of Urology, University of Modena Policlinico, Italy.
Cancer (USA), 1993, 72/12 Suppl. (3880-3885)

The treatment of advanced prostate cancer is based on hormone manipulation to eliminate the trophic effect of testosterone on sensitive androgen tissue of the tumor. In this study, we evaluated the efficacy of the partial androgen blockage versus the complete androgen blockage. One hundred, twenty- two patients were entered in this study and randomly were treated with buserelin alone or with buserelin and flutamide. The group that received buserelin was given cyproterone acetate (200 mg/day) during first 3 weeks of treatment to avoid 'flare-up'. During the follow-up (range 0-244 plus or minus 1 weeks), we evaluated 59 patients (61.4%) that had positive response and 37 patients (38.6%) that showed progressive disease: There were no statistically significant differences between the two treatment groups, not even in the evaluation of median time to response and of median time to treatment failure. In conclusion, the results emphasize that total androgenic blockage is as effective as a luteinizing hormone-releasing hormone analog used alone.

Antiandrogenic drugs

McLeod DG
Urology Service, Walter Reed Army Medical Center, Washington, DC.
Cancer (USA), 1993, 71/3 Suppl. (1046-1049)

Background. Prostate cancer is the most frequent cancer diagnosed in American men today. Currently, about half of all patients with newly diagnosed prostate cancer present with metastatic diseases.

Methods. Antiandrogenic drugs, or more appropriately androgen-receptor antagonists, represent a group of compounds that currently have played a limited role in the treatment of metastatic prostate cancer. Their method of action is primarily one of blocking androgens at their receptor sites in target tissues. They generally are classified as steroidal or nonsteroidal compounds. Cyproterone acetate and megestrol acetate are synthetic steroidal antiandrogenic drugs that, not only compete with testosterone and dihydrotestosterone for androgen receptors, but also have progestational activity and reduce pituitary luteinizing hormone and subsequently plasma testosterone. Nonsteroidal antiandrogenic agents (flutamide, Casodex (ICI Pharmaceuticals, England), and nilutamide) block cellular binding of androgens only, and there is no reduction of testosterone levels.

Results. Antiandrogenics have been used in numerous trials both in Europe and the United States. This group of compounds have been used as monotherapy and in combination therapy, ie, with orchiectomy or with LHRH agonists.

Conclusions. Currently, antiandrogens are used primarily in conjunction with conventional medical or surgical castration to achieve maximal androgen deprivation; however, ongoing clinical studies are comparing these compounds alone against standard hormonal therapy. It seems probable that antiandrogens will play an expanding role in the treatment of metastatic prostate cancer as well as having a role in the treatment of prostate cancer.

The effects of flutamide on total DHT and nuclear DHT levels in the human prostate

Geller J, Albert J, Nachtsheim DA, Loza D, Geller S
Prostate (USA), 1981, 2/3 (309-314)

The effects of flutamide, an antiandrogen, on prostate tissue concentrations of total DHT, DHT present in both crude and purified nuclear fractions, prostatic acid phosphatase (PAP) and plasma testosterone were studied and compared to similar parameters in untreated benign prostatic hypertrophy (BPH). Flutamide was given to patients with BPH in a dosage of 750 mg per day by mouth for 10-14 days prior to transurethral resection of the prostate. Total prostate DHT was significantly decreased to 3.95 ng/g in 12 flutamide-treated patients compared to values of 6.61 ng/g in 12 patients with untreated BPH. However, no significant difference was noted in the concentration of DHT present in the crude nuclear fraction of flutamide-treated patients (646 pg/mg DNA, N = 5) and untreated BPH (882 pg/mg DNA, N = 10); nor was DHT in the purified nuclear fraction significantly different in drug versus untreated patients (251 pg/mg DNA for flutamide versus 353 pg/mg DNA for untreated controls). PAP concentration in BPH prostates was 7.11 S.U./mg wet weight and was significantly higher than 2.98 S.U. per mg wet weight noted in flutamide-treated patients. Plasma testosterone tended to rise in the flutamide-treated patients compared to the untreated BPH but this was not statistically significant. The decrease in total prostate DHT without changes in nuclear DHT was unexpected and difficult to explain in terms of current tenets regarding the mechanism of androgen action. The following hypotheses are offered: Flutamide may decrease transport of testosterone into cells, thereby decreasing total prostate DHT. Inhibitory effects of flutamide on receptor-bound DHT translocation to nuclei may be difficult to detect since 95% or more of nuclear DHT may not be bound to a salt extractable receptor. The binding of DHT directly to putative nuclear matrix receptor sites may dilute the effects of flutamide on blocking translocation of receptor bound DHT, resulting in very small differences in DHT present in purified nuclei difficult to detect with current methodology.

Endocrine profiles during administration of the new non-steroidal anti-androgen Casodex in prostate cancer

Verhelst J, Denis L, Van Vliet P, Van Poppel H, Braeckman J, Van Cangh P, Mattelaer J, D'Hulster D, Mahler C
Department of Endocrinology, A. Z. Middleheim, Antwerp, Belgium.
Clin. Endocrinol. (United Kingdom), 1994, 41/4 (525-530)

Objective - Casodex (Zeneca) is a new potent, long-acting non-steroidal anti-androgen, which produces androgen deprivation by blocking the androgen receptor. We evaluated the endocrine effects of Casodex 150 mg daily given in monotherapy as primary treatment for patients with prostate cancer.

Design - As part of a large, multicentre study comparing the therapeutic effects of surgical castration with 150 mg/ day Casodex in monotherapy for patients with prostate cancer, a subgroup of 23 patients on Casodex were studied in detail for changes in endocrine parameters. Serum levels of LH, FSH, testosterone, DHT, oestradiol, prolactin, sex hormone binding globulin and free testosterone were measured at the start of therapy and after 1, 4, 8, 12 and 24 weeks. Effects on libido, sexual activity and the appearance of hot flushes, breast pain and gynaecomastia were recorded.

Results - Administration of Casodex resulted in a rise in LH levels in all patients with a mean increase after 24 weeks of 102% (P < 0.001). Mean FSH levels showed a limited increase (7%) after 24 weeks, which was significant only after 1 week (P < 0.001). As a result of the high LH levels, total testosterone levels increased after 24 weeks by 66% (P < 0.001), free testosterone by 57% (P < 0.001) and dihydrotestosterone by 24% (P = 0.0112). Parallel to testosterone, oestradiol levels rose by a mean of 66% (P < 0.001). Mean sex hormone binding globulin and prolactin levels rose by respectively 8% (P = NS) and 65% (P < 0.01). Despite an increase in testosterone levels, excellent androgen blockade was obtained, as shown by a decrease in prostate specific antigen levels in 22/23 patients. Libido was maintained in 8/11 patients, and sexual activity in 5/6. No patient complained of hot flushes. However, mild gynaecomastia and/or breast tenderness were seen in 48 and 30% of cases respectively.

Conclusion - Casodex 150 mg/day monotherapy resembles surgical castration in achieving androgen deprivation, despite an increase in LH and testosterone levels. In contrast to castration, libido and sexual activity are usually maintained and hot flushes are rare. However, mild gynaecomastia and/or breast tenderness were noted in 48 and 30% of patients.