Breast cancer following ovarian cancer in BRCA mutation carriers.

IMPORTANCE BRCA mutation carriers are at increased risk of developing breast cancer. However, the incidence of breast cancer after a diagnosis of epithelial ovarian cancer (EOC), one of the tubal/peritoneal cancers collectively referred to as pelvic serous carcinomas, is not well known. Optimal breast cancer surveillance and detection for these patients have also not been well characterized. OBJECTIVES To determine the incidence of breast cancer after a diagnosis of EOC and to evaluate the need for breast cancer surveillance for these patients. DESIGN, SETTING, AND PARTICIPANTS A retrospective database review of 364 patients who underwent BRCA mutation testing for EOC (stages I-IV) between 1998 and 2012 at an academic medical center with gynecologic and breast cancer centers. MAIN OUTCOMES AND MEASURES Incidence of breast cancer and methods of surveillance. RESULTS Of 364 patients, 135 (37.1%) were found to carry a germline BRCA1 or BRCA2 mutation. The mean age of patients at diagnosis of EOC was 49.5 years (range, 28-89 years). Of the 135 patients, 12 (8.9%) developed breast cancer. The median time from diagnosis of EOC to diagnosis of breast cancer was 50.5 months. Annual mammography was performed for 80 patients (59.3%), with annual magnetic resonance imaging of the breasts performed for 60 patients (44.4%). Thirteen patients (9.6%) underwent a bilateral prophylactic mastectomy at a median of 23 months following EOC diagnosis. Breast cancer was most commonly diagnosed by mammography for 7 of the 12 patients (58.3%), 3 (25.0%) of whom had a palpable mass and 2 (16.7%) of whom had incidental breast cancer detected during a prophylactic mastectomy. Seven patients with breast cancer (58.3%) underwent a bilateral mastectomy. All patients had early-stage breast cancer (stages 0-II). Four patients (33.3%) received adjuvant chemotherapy. At a median follow-up of 6.3 years, 4 of the 12 patients (33.3%) died of recurrent EOC after a diagnosis of breast cancer. The overall 10-year survival rate for the entire cohort of 135 patients was 17.0%. CONCLUSIONS AND RELEVANCE The risk of metachronous breast cancer is low in patients with known BRCA mutations and EOC. A majority of these cases of breast cancer at an early stage are detected by use of mammography. Despite the small number of patients in our study, these results suggest that optimal breast cancer surveillance for patients with BRCA-associated EOC needs to be reevaluated given the low incidence of breast cancer among these high-risk patients. Confirmation of our findings from larger studies seems to be indicated.