Breast cancer in men: The basics

Although breast cancer is much less common in men than in women, there are still nearly 2,600 men diagnosed with breast cancer in the United States each year.

Breast cancer is mostly found in older men, but it can happen at any age. The average age of diagnosis of male breast cancer is 68 in the United States. Because most men do not expect to have breast cancer, they may not notice symptoms or report them to their doctor. Men are often diagnosed with cancer at a later stage than women, possibly because they aren’t watching for symptoms or getting the screenings women do.

Risk factors for male breast cancer

Researchers don’t know exactly why a small number of men develop breast cancer. They have found some factors that increase a man’s risk of developing breast cancer, including:

• Age. As you get older, your risk increases. Many cases of male breast cancer are found in men between the ages of 68 and 71.
• A family history of breast cancer. Having a close family member diagnosed with breast cancer means a man has a higher chance of developing the disease.
• A rare genetic disorder called Klinefelter syndrome. In this syndrome, the testicles do not develop normally, producing less male hormones and more female hormones. The female hormone estrogen increases breast cancer risk.
• Liver disease. Some liver conditions can increase levels of female hormones in the body, which increases breast cancer risk.
• Obesity. Fat cells can cause higher levels of the female hormone estrogen in the body, which increases breast cancer risk.
• Radiation exposure. Radiation to the chest can increase breast cancer risk later in life.

How breast cancer in men is different than breast cancer in women

While the development and treatment of breast cancer are similar in both men and women, there are some key differences.

• Men tend to develop breast cancer at an older age than women. Men are newly diagnosed with breast cancer approximately five years older than women, on average. This may be partly because men often delay reporting symptoms.
• Men are diagnosed at later stages of disease than women. About half of all affected men are diagnosed with stage II, III or IV breast cancer. This may also be due to delays in reporting symptoms and lack of screening.
• Men have a higher rate of hormone receptor-positive cancer than women. More than 90 percent of all male breast cancers are hormone receptor-positive: either estrogen or progesterone receptor-positive, or both. This compares to about two-thirds of all female breast cancers. The reason for this difference is unclear. Men do generally benefit from this fact because hormone receptor-positive disease responds well to hormonal therapy and some men can avoid other types of treatment.

Note: Both men and women naturally make some amount of estrogen and progesterone in their bodies. The natural amount of estrogen found in a man is not unhealthy or unusual.