Male breast cancer.

Breast cancer in men is a rare condition affecting only 1,000 men each year in the United States. Hormonal, genetic, and perhaps environmental factors appear to be important in development of the disease. Clinically, breast cancer in men resembles that seen in woman. Histologically the diseases are indistinguishable, although lobular cancer is rare in men. Tumors from men are more likely to be estrogen-receptor positive. Treatment strategies draw from experience in women and usually begin with surgical removal of the tumor. Additional modalities often include hormonal, radiation, and cytotoxic therapies. The prognosis corrected for age and stage is similar to that of women. The study of breast cancer in men may provide new insights into epidemiologic and pathogenic factors that affect both sexes.