Should I get prophylactic mastectomy if I have ovarian cancer and BRCA gene mutations?

About 10-15% of patients with ovarian cancers may have genetic mutation of BRCA1 and BRAC2 genes.  Mutations in these genes predispose women for breast cancer as well.  However, the most appropriate management of breast cancer risk in these patients has not been defined.     

A 2013 study evaluated164 patients had BRCA-ovarian cancer (115 with BRCA1; 49 with BRCA2). Of these 164 patients, 152 developed ovarian cancer prior to BRCA testing (median time to testing, 2.4 years [0.01-55 years]). There were 46 deaths, but none were due to breast cancer. The 5- and 10-year overall survival were 85% (95% confidence interval [CI]= 0.78, 0.90) and 68% (95% CI = 0.59, 0.76), respectively. There were 18 metachronous breast cancer diagnoses.

The conclusion of the study was for women with a BRCA-associated epithelial ovarian cancer, the greatest risk of death was from ovarian cancer and not breast cancer.  Thus,  breast cancer surveillance with mammography and breast-clinical exam are a reasonable alternative to prophylactic bilateral mastectomy.

Reference: Domchek SM, Jhaveri K, Patil S, Stopfer JE, Hudis C, Powers J, Stadler Z, Goldstein L, Kauff N, Khasraw M, Offit K, Nathanson KL, Robson M.  Risk of metachronous breast cancer after BRCA mutation-associated ovarian cancer.  Cancer. 2013 Apr;119(7):1344-8.