Male Breast Cancer

Medical Author: Melissa Conrad Stoppler, MD
Medical Editors: Dennis Lee, MD and William C. Shiel Jr., MD, FACP, FACR

• What is male breast cancer?
• How common is male breast cancer?
• What are causes and risk factors of male breast cancer?
• What are the different types of male breast cancer?
• What are the signs and symptoms of male breast cancer?
• How is male breast cancer diagnosed?
• What is staging of male breast cancer?
• How is male breast cancer treated?
• What is the outcome (prognosis) of male breast cancer?
• Male Breast Cancer At A Glance

What is male breast cancer?

Men possess a small amount of nonfunctioning breast tissue (breast tissue that cannot produce milk) that is concentrated in the area directly behind the nipple on the chest wall. Like breast cancer in women, cancer of the male breast is the uncontrolled growth of the cells of this breast tissue.

Breast tissue in both young boys and girls consists of tubular structures known as ducts. At puberty, a girl's ovaries produce female hormones (estrogen) that cause the ducts to grow and milk glands (lobules) to develop at the ends of the ducts. The amount of fat and connective tissue in the breast also increases as girls reach puberty. On the other hand, male hormones (such as testosterone) secreted by the testes suppress the growth of breast tissue and the development of lobules. The male breast, therefore, is made up of predominantly small, undeveloped ducts and a small amount of fat and connective tissue.

How common is male breast cancer?

Male breast cancer is a rare condition, accounting for only about 1% of all breast cancers. The American Cancer Society estimates that in 2008, about 1,990 new cases of breast cancer in men will be diagnosed, and that breast cancer will cause approximately 480 deaths in men (in comparison, over 40,000 women die of breast cancer each year). Breast cancer is 100 times more common in women than in men. Most cases of male breast cancer are detected in men between the ages of 60 and 70, although the condition can develop in men of any age. A man's lifetime risk of developing breast cancer is about one-tenth of 1%, or one in 1,000.