Improved Overall Survival after Contralateral Risk-Reducing Mastectomy in Brca1/2 Mutation Carriers with a History of Unilateral Breast Cancer: A Prospective Analysis

Data on survival of BRCA1/2-associated primary breast cancer (PBC) patients who opt for subsequent contralateral risk-reducing mastectomy (CRRM) are scarce and inconsistent. We examined the efficacy of CRRM on overall survival in mutation carriers with a history of PBC. From a Dutch multicentre cohort, we selected 583 BRCA-associated PBC patients, being diagnosed between 1980 and 2011. Over time, 242 patients (42%) underwent CRRM and 341 patients (58%) remained under surveillance. Survival analyses were performed using Cox models, with CRRM as a time-dependent covariate. The median follow-up after PBC diagnosis was 11.4 years. In the CRRM group, four patients developed contralateral breast cancer (2%), against 64 patients (19%) in the surveillance group (p