Survival outcomes with contralateral profylactic mastectomy in patients with unilateral triple-negative breast cancer

Despite increased utilization of contralateral prophylactic mastectomy (CPM), there is insufficient evidence for a survival advantage with CPM among women with unilateral breast cancer. A retrospective study at Weill Cornell Medicine (New York, NY) and Henri Ford Health System (Detroit, MI) evaluated CPM for women with unilateral triple-negative breast cancer (TNBC). CPM was associated with borderline overall survival benefit (5-year overall survival 95.1% versus 85.0%; p=0.05), which was no longer significant after exclusion of BRCA mutation carriers (94.1% versus 85.2%; p=0,12). Among the BRCA mutation carriers, overall survival was numerically improved with CPM (5-year OS 97.2% versus 84.1%; p=0.35). Among patients not undergoing CPM, the rate of developing a new primary breast cancer was 2.2% with median 3.7 years follow-up. The authors conclude that the study showed no survival advantage with CPM for TNBC in patients without BRCA mutation.