Background/Objectives: Male breast cancer (MBC) is a rare malignancy representing less than 1% of all breast cancer cases, with rising incidence worldwide. Current treatment strategies largely rely on extrapolation from female breast cancer, despite clear biological and clinical distinctions. This review aims to summarize current knowledge on non-metastatic MBC, with a particular focus on genetic predisposition, tumor biology, and recent therapeutic advances. Methods: A systematic literature search was conducted using PubMed and PMC databases to identify clinical trials, observational studies and systematic reviews related to MBC published up to 1st June, 2025. Studies were selected for their relevance to genetic and molecular features, as well as treatment outcomes in non-metastatic disease. Results: Fifty-one studies were included in the review. Findings confirm the predominance of hormone receptor–positive tumors in MBC and underscore the central role of BRCA2 mutations. Germline mutations in BRCA2 and BRCA1 were reported in approximately 1 and 2% of male cases, respectively. Additional germline alterations were identified in PALB2, CHEK2, and other DNA repair genes. Comparative analyses of surgical approaches showed no significant difference in survival between breast-conserving surgery and mastectomy. Postmastectomy radiotherapy improved overall survival compared to surgery alone. Adjuvant tamoxifen therapy was independently associated with significant survival benefits, although adherence remains a challenge. Conclusions: MBC is a biologically distinct and molecularly heterogeneous disease. Breast-conserving surgery appears safe and effective in selected patients. Adjuvant radiotherapy and tamoxifen confer clear survival advantages. The lack of male-specific clinical trials remains a major limitation in optimizing evidence-based care for MBC.
Melan et al. (Thu,) studied this question.