Double mastectomy markedly reduces cancer risk in BRCA1/2 carriers

Findings from a new study indicate that bilateral prophylactic mastectomy reduces the risk of breast cancer by about 90% in women with germline BRCA1 or BRCA2 mutations.

If double mastectomy is combined with bilateral oophorectomy, a widely recommended procedure, then the risk reduction is 95%, according to the report published in the March 15th issue of the Journal of Clinical Oncology.After any kind of mastectomy, there is still a chance of cancer due to the breast tissue that remains, lead author Dr. Timothy R. Rebbeck, from the University of Pennsylvania in Philadelphia, said in a statement. By quantifying the benefits of bilateral mastectomy, the new findings should help high-risk women make better informed treatment decisions, he added.The findings stem from a study of 483 women with BRCA mutations who were followed a mean of 6.4 years to assess breast cancer occurrence. The subjects included 105 who elected to undergo bilateral prophylactic mastectomy and 378 matched controls who did not. In the control group, 48.7% of the women developed breast cancer, the researchers note. In contrast, only 1.9% of women in the mastectomy group developed this malignancy. “The goal of future research is to refine these estimates for women in specific situations,” based on the specific BRCA mutation, mastectomy type, and age and timing of surgery, Dr. Rebbeck said. (Source: J Clin Oncol 2004: Reuters Health: February 23, 2004: Oncolink)