How is breast cancer diagnosed and treated in men?

The same techniques -- physical exams, mammograms, and biopsies (examining small samples of the tissue under a microscope) -- that are used to diagnose breast cancer in women are also used in men.
The same four treatments that are used in treating breast cancer in women -- surgery, radiation, chemotherapy, and hormones -- are also used to treat the disease in men. The one major difference is that men with breast cancer respond much better to hormone treatments than women do. As discussed in the section on breast cancer in women, many breast cancers have hormone receptors, that is, they have specific sites on the cancer cells where specific hormones like estrogen can act.
Men are much more likely to have these receptors than women, making hormonal treatment more likely to be effective.