Contralateral breast cancer occurred in 4.5% of patients with BRCA1/2 PV/LPV who did not undergo contralateral RRNSM, whereas no cases of contralateral breast cancer were reported among patients who underwent RRNSM regardless of BRCA1/2 status.<h4>Conclusions</h4>This study highlights NSM as a safe and effective surgical option for BRCA1/2 PV/LPV carriers with breast cancer, as well as a risk-reducing strategy. Here, BRCA1 is linked to breast cancer.