When a mammogram detected a lump in Barbara Laufer's breast, the fear was paralyzing.

"You think you're going to die," says Laufer, 40, of Burbank, Calif.

Laufer was diagnosed with a perplexing condition called ductal carcinoma in situ, or DCIS, a growth of malignant cells inside the milk ducts of the breast. Though some doctors describe the condition to patients as a very early breast cancer, others compare it to a precancer.

Although the disease is almost never life-threatening, Laufer says the diagnosis put her life on hold.

She has had three surgeries, including two lumpectomies that disfigured her right breast. She spent seven weeks in daily radiation treatment. And she has had to delay trying to have children for five years while she takes a hormonal treatment called tamoxifen, which can cause birth defects.

"The huge effect from DCIS is that my life has to stop," says Laufer, who was diagnosed at 37 and recently began taking the drug. "I can't have babies. I'm going to have to wait until I'm 44 1/2 until I can even find out if I can. It's just really poor timing for me."

The advent of mammograms

More than 60,000 American women are diagnosed with DCIS each year. Doctors would like to spare these women from the rigors of cancer therapy, says breast oncologist Patricia Ganz, a professor at UCLA's Jonsson Comprehensive Cancer Center. But doctors today don't know enough about DCIS to tell a harmless tumor from one that could turn lethal. As a result, they tend to treat all women the same, regardless of the tumor's size.

"We're asking women to make decisions that are crucial to their lives, without a lot of hard evidence," says Susan Reed, an obstetrician-gynecologist at Seattle's Fred Hutchinson Cancer Research Center, who served on an expert panel on DCIS last month at the National Institutes of Health. "We're giving them a lot of uncertainty."

If doctors know so little, it's partly because DCIS is so new.

"When I started my career, this disease did not exist," says Ganz, who has been in practice for 30 years.

The incidence of DCIS has grown seven-fold since the early '70s, when doctors began using mammograms, says the University of Florida's Carmen Allegra, a cancer specialist and chairman of the NIH panel.

Mammograms, which take X-rays of the breast, can find tumors that are too small to be felt by hand.

Doctors, who had never seen such tiny tumors, assumed that they should treat them like the large, lethal masses they were used to finding. They piled on additional treatments over the years as studies showed that radiation and hormonal therapies further reduced the risk of relapse.

After so much therapy, the cure rate is now strikingly high. After 10 to 15 years, only about 10% of women with "low-grade" lesions -- the least aggressive kind -- have relapses. And these relapses are usually curable. Ninety-six percent to 98% of women are alive 10 years later, Ganz says.

"We don't need more effective treatments," says Eric Winer of Boston's Dana-Farber Cancer Institute. "We need to talk about eliminating some of these treatments for women who might do well without them. The real question is, who could do well with less?"

Doctors need to answer these questions with more research, says Barbara Brenner of Breast Cancer Action, an advocacy group.

But because virtually all women get aggressive therapy, doctors don't know what would happen if women opted to scale back, say H. Gilbert Welch, Lisa Schwartz and Steve Woloshin of Dartmouth Medical School, who published an editorial on the subject last year.

"It's time to figure out whether they really need surgery or whether all they really need is repeat mammography" or an MRI, they wrote in the Journal of the National Cancer Institute. "Should they be treated for breast cancer or should they be managed as individuals with an elevated risk?"

A study presented last week may begin to offer some guidance about which women are at greatest risk from DCIS. In a study of 8,203 women, researchers at the 2009 Breast Cancer Symposium in San Francisco said they found that patients 45 to 50 had half the risk of relapse after having surgery and radiation, compared with those 44 and under.

'Waiting for other shoe to drop'

Yet few women are comfortable living with DCIS -- or opting to watch and wait, Ganz says.

"They told me I had a precancer, and that it could lead to cancer, but I thought, 'Let's just get rid of this,' " Laufer says. "At the same time, you also think, 'My life is going so well, why do I need to stop for something that I may not need to be treated for until later, if at all?' "

Sharon Ezersky, 49, opted for an even more aggressive approach.

When Ezersky had her first screening mammogram, at age 40, doctors found a 3-millimeter tumor. Although it was similar in size to DCIS and had begun in the ducts, the cancer had just begun to push its way out of the ducts to invade the rest of the breast.

"They said I was a poster child for mammograms because it picked up such a tiny tumor," Ezersky says.

At the time, she opted for a lumpectomy, radiation and hormonal therapy. But that didn't ease her anxiety.

"You're always waiting for the other shoe to drop," Ezersky says.

Seven years later, a mammogram detected DCIS. This time, she opted for a double mastectomy.

"I almost felt grateful to get it a second time, so I could just be done with it, to have the mastectomy and be finished," Ezersky says. "I didn't want to worry anymore."