BRCA1 and breast cancer: A systematic review found no association between RRSO and the risk of primary breast cancer (RR 0.84; 95% CI 0.59–1.21) or CBC (RR 0.95; 95% CI 0.65–1.39), even when considering combined BRCA1/BRCA2 P/LP or only BRCA1 P/LP variant carriers (RR 0.89; 95% CI 0.68–1.17 and RR 0.85; 95% CI 0.59–1.24, respectively) [141].