A WOMAN'S DILEMMA; REMOVAL OF HEALTHY BREASTS REDUCES CANCER RISK 90%.

Byline: Denise Grady The New York Times

For women with a high risk of breast cancer, a study being published today offers hope, but at a cruel price: Removing both breasts while they are still healthy reduces the risk of getting breast cancer by 90 percent.

The new findings, from a study of 639 women who had their breasts removed between 1960 and 1993, are widely regarded as the most reliable information to date on the long-term effectiveness of the operation. The women in the study were considered high-risk because of a strong family history of breast cancer or a personal history of breast lumps needing biopsies. Tests developed in the 1990s to detect genetic mutations also provide an indication of women who might be at risk.

Surgeons had been performing the breast-removal procedure, known as bilateral prophylactic mastectomy on such women, since the 1960s, assuming that it would reduce a woman's cancer risk. But they did not know whether it really did, or by how much.

One way that high-risk women can try to protect themselves is by having regular mammograms and breast examinations in hopes of detecting the disease early enough to cure it with surgery, chemotherapy and radiation. The only other way that high-risk women can protect themselves against breast cancer is by taking the drug tamoxifen, which in a large study last year was shown to reduce the risk of the disease by about 45 percent.

But women are supposed to take the drug for only five years, and it is not known how long the benefit lasts once they stop. In addition, tamoxifen might cause blood clots or uterine cancer in some women, and although it reduces the risk of breast cancer, studies have not shown that it lowers the death rate from the disease, as mastectomy does.

The new study of the surgery, by researchers at the Mayo Clinic in Rochester, Minn., is being published today in the New England Journal of Medicine.

``This is a very important paper,'' said Dr. Patrick Borgen, chief of breast surgery at Memorial Sloan Kettering Cancer Center in New York, who was not involved in the study. ``It's the first credible calculation.''

But Borgen and other cancer experts, including the authors of the paper, cautioned that the findings should not be used to pressure women into having their breasts removed.

``The study doesn't mean we should sell the surgery to more women,'' Borgen said. ``But women who are considering it now have a hard-core fact to use as they're making their calculation.''

The data only reflect rates of illness and death for the participants as a group. Individual women involved in the study, and others who have undergone the procedure, have no way of knowing whether it spared them from cancer that might have killed them, or cost them their breasts to protect them from a disease they would never have contracted.

Dr. Lynn Hartmann, a medical oncologist who directed the study of breast removal, said, ``This report is not meant as a universal recommendation for this procedure. It's meant to provide data for a tough and controversial area. I think that to date only a minority of high-risk women are interested in this procedure.''

Dr. Patricia Ganz, director of the division for cancer prevention and control research at the Jonsson Cancer Center at the University of California at Los Angeles, said that despite the warnings, ``A lot of physicians and surgeons scare women, and there is fear in the medical community that they will say to women, You ought to have your breasts removed.''

Among the 214 women at high risk and 425 at moderate risk, the probably was for at least 20 and as many as 40 deaths. But after the women had their breasts removed, there were only two deaths, both in the high-risk group.

Dr. Barbara Weber, an expert on breast cancer genetics at the University of Pennsylvania, and co-author of an editorial that accompanied the study, pointed out that although the procedure theoretically saved 18 lives, 621 other women who had their breasts removed probably would have survived without the drastic operation. She also noted that it was ironic to find evidence supporting breast removal in healthy women, when treatments for women who already have cancer are aimed at saving the breast whenever possible.

By contrast, she and other researchers said, many women with strong family histories of breast and ovarian cancer are urged strongly to have their ovaries removed, and many do so. But that decision is less agonizing, because the surgery is not disfiguring, and ovarian cancer, unlike breast cancer, is difficult to detect early enough to save a woman's life.

Dr. Larry Norton, director of the Lauder Breast Center at Memorial Sloan Kettering Cancer Center, said the study was convincing and important. But the surgery ``is not for everybody,'' he said, adding, ``I would like very much to make this not an option, to have better ways of preventing breast cancer in ways that do not involve surgery.'' He said he hoped studies that would be starting soon, combining a tamoxifen-like drug and other drugs that manipulate hormone levels, ultimately would provide a risk reduction equal to that shown for the surgery.

The number of women in the United States who have had their breasts removed in the hope of preventing cancer is not known, but could be in the thousands. There is no registry of cases. ``This is not a commonly performed procedure,'' Hartmann said. She and other researchers said women who want it tend to be those who have seen mothers, aunts and sisters die young from breast cancer, in their 30s, 40s and 50s.