TUESDAY, March 15, 2005 (HealthDay News) -- In the 1980s and 1990s, many women with a strong family history of breast cancer had a double mastectomy to try to eliminate their chances of being struck by the devastating disease.
Now a new study provides good news for these women, suggesting those surgeries lowered their long-term risk for malignancies by 95 percent.
"It's very reassuring," said study co-author Ann Geiger, a cancer researcher with the Kaiser Permanente Southern California, in Pasadena.
Genetic tests developed over the past decade have made it easier for doctors to predict which high-risk women will develop breast cancer, so double mastectomy has become less favored as a preventive approach for those who haven't developed the disease. But in past decades, the disfiguring procedure was a more commonly accepted option for women without breast cancer who developed precancerous lesions in the breast, had already lost relatives to the disease, or both.
Attitudes about mastectomies also contributed to their use as a preventive procedure. "When I started practice in mid-1970s, there were surgeons who had the attitude that doing a mastectomy was no big deal," said Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society. "It was incredibly insensitive."
Mastectomies don't prevent breast cancer in all cases, because some breast tissue can remain after the procedure. To determine how well the surgery prevented breast cancer in women who had the procedure, Geiger and her colleagues examined the medical records of nearly 500 women aged 18-80 who were identified between 1979-1998 as having at least one risk factor for breast cancer.
They then compared the long-term outcomes of 276 women who underwent preventive double mastectomies to another 196 women who did not.
The women in the former group underwent either traditional mastectomy or so-called subcutaneous mastectomies, which preserved the nipples and some skin tissue.
Geiger's team reported their findings in the March 14 issue of the Archives of Internal Medicine.
Just one of the 276 women (0.4 percent) who had double mastectomies went on to develop breast cancer, while 4 percent of at-risk women who did not undergo the procedure went on to develop the disease.
That 4 percent was expected, the researchers note, since being in a high-risk group doubles breast cancer rates over 10 years to between 4 percent and 9 percent, depending on a woman's age.
In all, mastectomies reduced the risk of disease for the women who had them by 95 percent, the researchers found.
The study results may appear to support the use of mastectomy as a preventive procedure, but Geiger cautioned that most women in the study had their procedure many years ago, and hardly any underwent genetic testing.
Now, such tests give doctors and their patients more perspective about the prospects for women in high-risk groups, Geiger said. Also, genetic counselors can provide expert guidance about the pros and cons of taking surgical action.
"Most of us have trouble understanding risk," she said. "When you say your risk is 5 percent, that may be high to some people, and it may be lower to other people. Genetic counselors can help you understand and place your risk in context."
She added that there are now a variety of alternatives for women at high risk for breast cancer, including removal of the ovaries, which reduces the risk by 30 percent to 50 percent, and the use of tamoxifen, which lowers the risk by half. Regular monitoring, including new, highly sensitive MRI tests, is also used, she said.
Double mastectomies are still an option for women who haven't developed breast cancer, but the procedure is usually only performed on women at extreme risk, said Lichtenfeld. On the preventive front, "this is a pretty radical operation," he said.
To learn more about breast cancer treatment, try breastcancer.org.