Preventive Surgeries Linked to Lower Risk of Breast Cancer

Women with the inherited mutations of the breast cancer (BRCA) genes who had prophylactic mastectomy or the removal of the fallopian tubes and ovaries (salpingo-oophorectomy) were found to have a significantly lower risk of developing ovarian and breast cancers, according to a new study.

Researchers at the University of Pennsylvania School of Medicine (Philadelphia, USA) conducted a prospective, multicenter cohort study of 2,482 women with BRCA1 or BRCA2 mutations ascertained between 1974 and 2008, at 22 clinical and research genetics centers in Europe and North America, to assess the relationship of risk-reducing mastectomy or salpingo-oophorectomy with cancer outcomes. The women were followed up until the end of 2009. The main outcome measures were breast and ovarian cancer risk, cancer-specific mortality, and overall mortality.

The results showed that no breast cancers were diagnosed in the 247 women with risk-reducing mastectomy, compared with 98 women of 1,372 diagnosed with breast cancer who did not have risk-reducing mastectomy. The researchers found no cases of ovarian cancer among women with the BRCA1 mutation after salpingo-oophorectomy, which was likewise linked to a lower risk of breast cancer in BRCA1 and BRCA2 mutation carriers without prior diagnosis of breast cancer. Additionally, undergoing salpingo-oophorectomy was associated with lower all-cause mortality (10% vs. 3%), breast cancer-specific mortality (6% vs. 2%), and ovarian cancer-specific mortality (3% vs. 0.4%). The study was published in the September 1, 2010, issue of the Journal of the American Medical Association (JAMA).

"Females who carry the inherited mutations of the BRCA1 or BRCA2 genes have a considerably higher chance of developing breast or ovarian cancer; there is a 56% lifetime risk of breast cancer and 84% lifetime risk of ovarian cancer,” concluded lead author Susan Domchek, M.D. "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.”

Hundreds of BRCA mutations have been identified. Some of them cause increased risk of breast cancer, ovarian cancer, and other cancers. Instead of a 12% lifetime risk of breast cancer, women with high risk BRCA1 or BRCA2 gene mutations may have a risk of up to 60% risk of developing breast cancer. The increased risk of developing ovarian cancer is about 55% for women with high-risk BRCA1 mutations and about 25% for women with high-risk BRCA2 mutations. Women who are mutation carriers have cancer risk-management options that include risk-reducing salpingo-oophorectomy, risk-reducing mastectomy, annual cancer screening, and chemoprevention.

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University of Pennsylvania School of Medicine