Male breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.

Many men do not realize that have breast tissue and that they can develop breast cancer. Until puberty, young boys and girls have a small amount of breast tissue consisting of a few ducts (tubular passages) located under the nipple and areola (area around the nipple). At puberty, a girl’s ovaries produce female hormones, causing breast ducts to grow, lobules (milk glands) to form at the ends of ducts, and the amount of stroma (fatty and connective tissue surrounding ducts and lobules) to increase. On the other hand, male hormones produced by the testicles prevent further growth of breast tissue.

Like all cells of the body, a man’s breast duct cells can undergo cancerous changes. Because women have many more breast cells than men do and perhaps because their breast cells are constantly exposed to the growth-promoting effects of female hormones, breast cancer is much more common in women. Men at any age may develop breast cancer, but it is usually detected (found) in men between 60 and 70 years of age. Male breast cancer makes up less than 1% of all cases of breast cancer.

Many types of breast disorders can affect both men and women. Most breast disorders are benign (not cancerous). Benign breast tumors do not spread outside of the breast and are not life threatening. Other tumors are malignant (cancerous) and may become life threatening. Benign tumors, such as papillomas and fibroadenomas, are common in women but are extremely rare in men.

General Information about Male Breast Cancer
Male breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
Radiation exposure, high levels of estrogen, and a family history of breast cancer can affect a man’s risk of developing breast cancer.
Male breast cancer is sometimes caused by inherited gene mutations (changes).
Tests that examine the breasts are used to detect (find) and diagnose breast cancer in men.
Survival for men with breast cancer is similar to survival for women with breast cancer.
Certain factors affect prognosis (chance of recovery) and treatment options.