Controversies in clinicopathological characteristics and treatment strategies of male breast cancer: A review of the literature.

Male breast cancer (MaBC) is a rare disease, accounting for less than 1% of malignancies in men. For this reason, literature data on its clinicopathological characteristics are very heterogeneous and treatment strategies have mostly been extrapolated from the female counterpart. However, immunohistochemical peculiarities of MaBC have recently emerged, defining it as a distinct entity from female breast cancer (FBC), thus requiring a tailored clinical approach. MaBC appears to be more often hormone receptor positive than FBC, while data on HER2 status still remain inconclusive, indicating a possible higher incidence of HER2 alterations. Treatment strategies for MaBC have evolved and less invasive local treatments such as lumpectomy and sentinel lymph node biopsy have become part of everyday clinical practice, while there are still controversies on the indication of radiotherapy, especially after mastectomy. Similarly, differences between male and female hormonal status have raised some concerns in the use of aromatase inhibitors in male patients and the choice of best endocrine therapy is still controversial.