Resumen
Male breast cancer (mBC) is a rare disease associated with a high prevalence of pathogenic germline variants (PVs) in the BRCA2 gene. However, data regarding other breast cancer (BC) predisposition genes are limited or conflicting. We investigated the prevalence of PVs in BRCA1/2 and 23 other cancer predisposition genes using an overall study sample of 614 patients with mBC. A high proportion of patients with mBC carried pathogenic germline variants in BRCA2 (23.0%, 142/614) and BRCA1 (4.6%, 28/614). A BRCA1/2 PV prevalence of 11.0% was identified in patients with mBC without a family history of breast and/or ovarian cancer. Patients with BRCA1/2 PVs did not show an earlier disease onset than those without. Case-control analyses revealed significant associations of protein-truncating variants in BRCA1, BRCA2, CHEK2, PALB2, and ATM with mBC. Our findings support the benefit of multi-gene panel testing in patients with mBC.