Diagnosis and Staging
Endometrial cancer is often detected at an early stage since abnormal vaginal bleeding, the most common symptom, prompts women to visit their doctor soon after it begins. If a doctor suspects endometrial cancer, several tests can help confirm the diagnosis, including (Amant 2005; Kawana 2005; Lentz 2012; A.D.A.M. 2012; MayoClinicStaff 2013; NCI 2010; Denschlag 2010):
- A procedure called dilation and curettage (D & C), which involves widening of the cervix and scraping the endometrium to retrieve a sample of cells
- Biopsy of the endometrium
- Examination of endometrial fluids
- Pelvic examination (although results are often normal in early stages of endometrial cancer)
- Transvaginal ultrasound
- Hysteroscopy (a procedure that allows for examination of the inside of the uterus)
Although abnormal test results from a Pap smear may raise the suspicion of endometrial cancer, Pap smear results are not sufficient for a definitive diagnosis of endometrial cancer. Pap smears are not screening tests for endometrial cancer, and when they show abnormal results additional tests are necessary (A.D.A.M. 2012; NCI 2010).
If endometrial cancer is discovered, then other diagnostic tests are used to determine the stage of the disease. Currently, magnetic resonance imaging (MRI) scans of the abdomen are an important non-invasive diagnostic imaging approach to obtain an accurate evaluation of the extent of the disease (Shweel 2012; Tong 2012). The first stage of endometrial cancer refers to cancer that is still confined to the uterus; the second stage involves cancer spreading to the cervix; the third stage involves cancer spreading beyond the uterus but not outside the pelvic area, which may also involve spreading to the local lymph nodes in the pelvis or near the aorta; and the fourth stage of endometrial cancer involves spreading to other organs in the abdominal cavity and beyond, including the bowel and bladder (Wright 2012; Amant 2005; NCI 2013).
Seventy five percent of endometrial cancer cases are diagnosed in stage I, where cure rates as high as 75-90% have been reported. However, 5-year survival rates are only 50% in stage II and up to 30% and less than 10% in stages III and IV, respectively (Emons 2000).
In addition to staging, endometrial cancer is scored by a numerical grading system (grade 1-3). Grade 1 is the least aggressive, while grade 3 is the most aggressive. Higher-grade tumors grow faster and are more likely to spread (metastasize) than low-grade tumors (NCI 2013; A.D.A.M. 2012).