Male Breast Cancer: Epidemiology and Risk Factors.

Male breast cancer is a rare malignancy that accounts for less than 1% of all cancers in men and less than 1% of all breast cancers. But the incidence is rising and in some patient groups reaching 15% over the course of their lives. The major risk factors for the development of male breast cancer include advancing age, hormonal imbalance, radiation exposure, and a family history of breast cancer. Regarding the latter, incidence can be linked to mutations in high- or low-penetrance genes. The most relevant risk factor for the development of male breast cancer is a mutation in the BRCA2 gene. Most cases present late because of a lack of awareness of the existence of such a malignancy in males and ignorance of the related risk factors. Additionally, males with breast cancer are at special risk for developing a second cancer. This in depth review highlights the epidemiology and risk factors for the development of male breast cancer.