The estimated risk for contralateral breast cancer is 83% (95% CI, 69%-94%) for BRCA1 carrier and 62% (95% CI, 44%-79.5%) for BRCA2. A meta-analysis of ten eligible studies that looked at the penetrance rates of BRCA1 and BRCA2 reached similar conclusions (20). Here, BRCA1 is linked to breast carcinoma.