BRCA1 and breast cancer: Recent analyses based on population or registry studies involving many patients showed that BCT is associated with even better OS than mastectomy among patients with early-stage breast cancer.6,7,8,9,10,11,12,13,14,15 By contrast, it is still debated whether BCT could be safely used for BRCA1 (OMIM 113705) and BRCA2 (OMIM 600185) variant carriers with breast cancer.