BRCA1 and breast cancer: Among the studies included in this meta-analysis, the individual analyses reported hazard ratios showing that BCSM is reduced in BC-affected BRCA1 carriers (HR 0.27, 95%CI 0.12–0.58 [58]; HR 0.38, 95%CI 0.19–0.77 [59]; HR 0.30 95%CI 0.12–0.75 [89]) but not in BC-affected BRCA2 carriers (HR 0.87, 95%CI 0.32–2.2.37 [58]; HR 0.57 95%CI 0.23–1.43 [59]).