How common is breast cancer among men?

Very rare.: Less than 1% of all cases of breast cancer diagnosed in the US annually are in men. The lifetime risk of a man developing breast cancer is about 1:1000.

Not that common: Although it is rare, breast cancer can occur in men as well. Men possess a small amount of nonfunctioning breast tissue that is concentrated in the area directly behind the nipple on the chest wall. In a recent large international population-based study, men represented 0.6% of all breast cancer patients. http://womenshealthbeverlyhills.com/womens-health-blog/male-breast-cancer-rox-center/.