Male Breast Cancer.

Breast cancer is a rare disease in men representing nearly 1% of the total breast cancer cases worldwide. Due to the low incidence, there are no randomized clinical studies giving information on the optimal diagnostics and therapy for male breast cancer patients. Therefore, treatment recommendations are derived from established guidelines for breast cancer in women. However, the lack of awareness of this disease leads to its detection at a later stage in men associated with a worse prognostic outcome. The gender-specific differences in breast cancer are among others related to the differing genetic and hormonal environment and the anatomic constitution in men. For example, males have a much higher percentage of hormone receptor-positive tumors but a significantly lower fraction of carcinomas overexpressing HER2. This review focuses on epidemiology, pathogenesis, and clinical findings of male breast cancer, and discusses current findings available to treat this disease. To optimize disease outcome and tolerability of treatment, these data should be considered to improve the therapeutic index of male breast cancer patients.