Chemotherapy is a chemical, or group of chemicals, designed to stop the growth of cancer cells. Chemotherapy drugs may be given intravenously, orally, or as a combination of the two. There are many chemotherapy drugs used to treat breast cancer.
Incidence and Mortality
Estimated new cases and deaths from breast cancer (men only) in the United States in 2013:
New cases: 2,240.
Male breast cancer is rare. Less than 1% of all breast carcinomas occur in men.[3,4] The mean age at diagnosis is between 60 and 70 years, though men of all ages can be affected with the disease.
Predisposing risk factors  appear to include radiation exposure, estrogen administration, and diseases associated with hyperestrogenism,...
If the breast tumor is large, chemotherapy is sometimes given before surgery in order to shrink the tumor so it can be removed more easily, or so that a lumpectomy can be performed instead of a mastectomy.
Chemotherapy may also be given as the main treatment for women whose cancer has spread to other parts of the body outside of the breast and lymph nodes.