Malone et al. reported 10-year cumulative risks of contralateral breast cancer of 31.6% (BRCA1 PV carriers) and 26.6% (BRCA2 PV carriers) in those diagnosed between 30–34 years, depicting the higher contralateral risks in BRCA1 PV carriers than BRCA2 PV carriers, which is also demonstrated in our study [16]. Here, BRCA1 is linked to breast cancer.