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 (removal of the fallopian tubes and ovaries) had an associated decreased risk of breast cancer and ovarian cancer, according to a study in the September 1 issue of JAMA.
“Women who have inherited mutations in the BRCA1 or BRCA2 genes have substantially elevated risks of breast cancer and ovarian cancer, with a lifetime risk of breast cancer of 56 to 84 percent,” the authors write. “Women who are mutation carriers have cancer risk-management options that include salpingo-oophorectomy, 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 mutation carriers to determine cancer reduction estimates following risk-reducing salpingo-oophorectomy and mastectomy, incorporating mutation type and cancer history.
The study 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 three years of prospective follow-up.
“In contrast, seven percent of women without risk-reducing mastectomy over a similar follow-up period were diagnosed with breast cancer,” the researchers write. Risk-reducing salpingo-oophorectomy was associated with a decreased risk of ovarian cancer, with no ovarian cancer events seen during the six years of prospective follow-up in BRCA2 mutation carriers without prior breast cancer who underwent the procedure.
Three percent of women without salpingo-oophorectomy over a similar follow-up period were diagnosed with ovarian cancer. No cases of ovarian cancer were diagnosed in BRCA2 mutation carriers after salpingo-oophorectomy, which was also associated with a decreased risk of breast cancer in both BRCA1 and BRCA2 mutation carriers without prior diagnosis of breast cancer.
“Compared with women who did not undergo risk-reducing salpingo-oophorectomy, undergoing salpingo-oophorectomy was associated with lower all-cause mortality, breast cancer-specific mortality and ovarian cancer-specific mortality,” according to the authors.