Breast Cancer in Men: Risk Factors and Prevention

Approved by the Cancer.Net Editorial Board, 11/2015

ON THIS PAGE: You will find out more about the factors that increase the chance of developing this type of cancer. To see other pages, use the menu on the side of your screen.

A risk factor is anything that increases a person’s chance of developing cancer. Although risk factors often influence the risk of developing of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and talking about them with your doctor may help you make more informed lifestyle and health care choices.

A man’s average risk for breast cancer is very low – 1 out of every 1,000 men with an average risk of the disease will develop breast cancer. Generally, most breast cancers are sporadic, meaning they develop from damage to a person’s genes that occurs by chance after they are born. There is no risk of passing this gene on to a person's children. Inherited breast cancers are less common, making up 5% to 10% of all breast cancers, and occur when gene changes called mutations are passed down within a family from one generation to the next (see below). The following factors can raise a man’s risk of breast cancer:

  • Family history of breast disease or presence of a genetic mutation. About 1 out of 5 men who develop breast cancer has a family history of the disease. Men with breast cancer gene (BRCA1 or BRCA2) gene mutations may be at increased risk for breast cancer and prostate cancer. Men with BRCA2 gene mutations have a 6 in 100 chance of developing breast cancer, whereas men with BRCA1 gene mutations have a 1 in 100 chance of developing breast cancer. Men with breast cancer are often referred to a genetic counselor to discuss genetic testing for BRCA1 and BRCA2 and other inherited cancer risk genes. Learn more about BRCA gene mutations and hereditary breast cancer risk in a separate article on this website.

  • Age. The average age for men to be diagnosed with breast cancer is 65.

  • Elevated estrogen levels. Certain diseases, conditions, or treatments can increase the levels of female hormones such as estrogen, which contributes to the development of breast cancer.

    • Klinefelter’s syndrome is a rare genetic condition in which men are born with an extra X chromosome. Men with this syndrome may have an increased risk of breast cancer because they have higher levels of estrogen and lower levels of male hormones called androgens.

    • Liver disease, such as cirrhosis, can change hormone levels and cause low levels of androgens and higher levels of estrogens.

    • Low doses of estrogen-related drugs that are given for the treatment of prostate cancer may slightly increase the risk of breast cancer.

  • Lifestyle factors. As with other types of cancer, studies continue to show that various lifestyle factors may contribute to the development of breast cancer.

    • Being obese or even overweight increases the risk of breast cancer.

    • Lack of exercise may increase the risk of breast cancer because exercise lowers hormone levels, alters metabolism, and boosts the immune system. Increased physical activity is associated with a decreased risk of developing breast cancer.

    • Drinking 2 or more alcoholic drinks per day may raise the risk of breast cancer. However, this risk factor has not been studied in men.

The next section in this guide is Screening and it explains how tests may find cancer before signs or symptoms appear. Or, use the menu on the side of your screen to choose another section to continue reading this guide.