WEDNESDAY, July 18, 2001 (HealthDayNews) -- Surgically removing both breasts is a good preventative for women carrying a gene that creates a high risk for breast cancer, a Dutch study shows.
The decision to take the drastic step must be made by the woman herself, after a full explanation of her risk and alternative measures, says Dr. Jan G. M. Klijn, chairman of the Rotterdam Family Cancer Clinic and leader of a group reporting the experiences of 139 women who carried the gene.
"We give all the information on risk assessment and different strategies and leave the choice to the women themselves. We don't like to force women in any direction," says Klijn.
All the women described in the new issue of the New England Journal of Medicine carried mutant versions of either the BRCA1 or BRCA2 genes. A woman with one of the genes has a 55 percent to 85 percent risk of getting breast cancer and a 15 percent to 65 percent risk of ovarian cancer. In all the cases, the mutations were detected by genetic tests of women from families with a high incidence of breast and/or ovarian cancer.
Of the 139 women, 76 chose a bilateral mastectomy, surgical removal of both breasts. The other 63 chose a regimen of watchful surveillance, with monthly breast self-examinations, professional breast examinations every six months and mammograms every year.
In a follow-up that averaged three years, eight women in the surveillance group were diagnosed with breast cancer, one of whom died of the disease. None of the women who had surgery developed breast cancer.
There is an obvious need to follow all the women for many more years, the researchers say. But statistics indicate that 25 percent of the women carrying a mutated gene will develop breast cancer within 10 years, and half of those women will die of the disease, the researchers say.
"Our data
indicate that prophylactic bilateral mastectomy substantially reduces the incidence of breast cancer in women with a BRCA1 or BRCA2 mutation," the researchers say.
Alternatives include surgery to remove the ovaries, which reduces the risk of both ovarian and breast cancer. Ovaries produce estrogen, a hormone that can exacerbate certain cancers. And women can take tamoxifen, a drug known to reduce the risk of breast cancer. "But the use of tamoxifen as a preventive agent has been questioned in view of its long-term side effects, the researchers say.
Since about 7 percent of all breast cancer patients have genetic alterations, thousands of American women may face the issue each year, says Dr. LaMar McGinnis, senior medical consultant to the American Cancer Society.
The new study is important because it shows a clear benefit of mastectomy for high-risk women, McGinnis says. But the follow-up period of the study is short, and "it will be 20 years before we know the long-term effects," he says. "It shows that mastectomy can prevent breast cancer in the short run, but we don't know whether it will reduce mortality over the long run."
Several studies have shown that the psychological effects of mastectomy are not as great as many people fear, since virtually all the women have reconstructive surgery, McGinnis says. "They are pleased with their appearance and mental outlook," he says.
Breast cancer is the most common cancer among American women and is second only to lung cancer as a cause of death. About 192,200 women will be told this year that they have a new invasive case of breast cancer, and about 40,600 will die of the disease, says the American Cancer Society.
What To Do
Genetic counseling should be considered by a woman with two first-degree relatives who have developed breast cancer before menopause or one first-degree relative who has had premenopausal cancer in both breasts, McGinnis says. Counseling will help a woman decide whether to have a test to detect a mutated cancer gene. "It is a good, accurate test that can be performed in a short period of time," McGinnis says, at a cost of $2,000 or more.
For an overview of breast cancer, including genetic issues, go to the National Cancer Institute or the American Cancer Society.
Curious to see where the BRCA1 gene is? Take a look at this government site.
