A study in the September 1 issue of JAMA says that women at increased risk of breast and ovarian cancer because of inherited mutations of the BRCA1 or BRCA2 genes who had prophylactic mastectomy or salpingo-oophorectomy had an associated decreased risk of breast cancer and ovarian cancer.
"Women who have inherited mutations in the BRCA1 or BRCA2 (BRCA1/2) genes have substantially elevated risks of breast cancer and ovarian cancer, with a lifetime risk of breast cancer of 56 percent to 84 percent," the authors write. "Women who are mutation carriers have cancer risk-management options that include risk-reducing salpingo-oophorectomy, risk-reducing mastectomy, annual cancer screening, and chemoprevention."
Susan M. Domchek, M.D., of the University of Pennsylvania School of Medicine, Philadelphia, and colleagues conducted a study that included a large group of BRCA1/2 mutation carriers to determine cancer reduction estimates following risk-reducing salpingo-oophorectomy and mastectomy, incorporating mutation type (BRCA1 vs. BRCA2), and cancer history (prior history of breast cancer vs. none). The study, which included 2,482 women with BRCA1 or BRCA2 mutations (determined between 1974 and 2008), was conducted at 22 clinical and research genetics centers in Europe and North America. The women were followed up until the end of 2009.
The researchers found that risk-reducing mastectomy was associated with a decreased risk of breast cancer in BRCA1/2 mutation carriers, with no breast cancer events occurring in women who underwent risk-reducing mastectomy during 3 years of prospective follow-up. "In contrast, 7 percent of women without risk-reducing mastectomy over a similar follow-up period were diagnosed with breast cancer," the researchers write.
