Breast cancer in men is a rare disease. Less than 1% of all breast cancers occur in men. In 2018, about 2,550 men were expected to be diagnosed with the disease. For men, the lifetime risk of being diagnosed with breast cancer is about 1 in 1,000. Although the disease is rare, it has been on the rise over the past few decades, and early detection is key.

Boys and girls, men and women all have breast tissue. The various hormones in girls and women’s bodies stimulate breast tissue to grow into full breasts. Boys and men’s bodies normally don’t make much of the breast-stimulating hormones. As a result, their breast tissue usually stays flat and small. Still, you may have seen boys and men with medium-sized or big breasts. Usually, these breasts are just mounds of fat. But sometimes men can develop real breast gland tissue because they take certain medicines or have abnormal hormone levels.

A number of factors can increase a man’s risk of getting breast cancer:

  • Growing Older: This is the biggest factor. Just as is the case for women, risk increases as age increases. The average age of men diagnosed with breast cancer is about 68.
  • High Estrogen Levels: Breast cell growth — both normal and abnormal — is stimulated by the presence of estrogen. Men can have high estrogen levels as a result of:
    • Taking hormonal medicines.
    • Being overweight (which increases the production of estrogen).
    • Having been exposed to estrogens in the environment (such as estrogen and other hormones fed to fatten up beef cattle, or the breakdown products of the pesticide DDT, which can mimic the effects of estrogen in the body).
    • Being heavy users of alcohol, which can limit the liver’s ability to regulate blood estrogen levels.
    • Having liver disease, which usually leads to lower levels of androgens (male hormones) and higher levels of estrogen (female hormones). This increases the risk of developing gynecomastia (breast tissue growth that is non-cancerous) as well as breast cancer.
  • Klinefelter Syndrome: Men with Klinefelter syndrome have lower levels of androgens (male hormones) and higher levels of estrogen (female hormones). Therefore, they have a higher risk of developing gynecomastia (breast tissue growth that is non-cancerous) and breast cancer. Klinefelter syndrome is a condition present at birth that affects about 1 in 1,000 men. Normally men have a single X and single Y chromosome. Men with Klinefelter syndrome have more than one X chromosome (sometimes as many as four). Symptoms of Klinefelter syndrome include having longer legs, a higher voice, and a thinner beard than average men; having smaller than normal testicles; and being infertile (unable to produce sperm).
  • A Strong Family History of Breast Cancer or Genetic Mutations: Family history can increase the risk of breast cancer in men — particularly if other men in the family have had breast cancer. The risk is also higher if there is a proven breast cancer gene abnormality in the family. Men who inherit abnormal BRCA1 or BRCA2 have an increased risk of male breast cancer. The lifetime risk of developing breast cancer is approximately 1% with the BRCA1 gene mutation and 6% with the BRCA2 gene mutation. Because of this strong association between male breast cancer and an abnormal BRCA2 gene, first-degree relatives (siblings, parents, and children) of a man diagnosed with breast cancer may want to ask their doctors about genetic testing for abnormal breast cancer genes. Still, the majority of male breast cancers happen in men who have no family history of breast cancer and no inherited gene abnormality.
  • Radiation Exposure: If a man has been treated with radiation to the chest, such as for lymphoma, he has an increased risk of developing breast cancer.

Some signs and symptoms of male breast cancer include:

  • A palpable breast lump
  • Nipple pain
  • A newly inverted nipple
  • Nipple discharge (clear or bloody)
  • Sore on the nipple and areola
  • Enlarged lymph nodes under the arm

Earlier diagnosis could make a life-saving difference. With more research and more public awareness, men will learn that, just as women, they need to go to their doctor right away if they detect any persistent changes to their breasts.

After an abnormality of the breast is found, tests are performed to see if the problem is cancer. One or all of these tests might be done:

  • Mammogram
  • Ultrasound
  • Nipple discharge examination: If you have nipple discharge, some of the fluid may be collected and examined under a microscope to see if any cancer cells are present.
  • Biopsy: A biopsy is necessary to distinguish normal tissue from cancer tissue. If cancer is present, the biopsy also helps your doctors zero in on the size, type, and kind of breast cancer. Biopsies are performed on any kind of abnormality that your doctor can feel or that looks suspicious. Various techniques are used to biopsy tissue, and it’s likely that your surgeon will try to use the least invasive procedure possible while making sure that enough tissue is removed to make a clear diagnosis.

If a cancer diagnosis is made, your doctor might recommend more tests. For example, an MRI can show how much cancer is in the affected breast relative to the normal tissue right under and next to the breast cancer. This information may help the surgeon plan the extent of surgery. Plus, an MRI can help evaluate the other breast. Other tests, such as blood work, chest X-ray, and bone scans, might be done to see if the cancer has spread to other parts of the body.

Most men who have been diagnosed with breast cancer will undergo some form of treatment for the disease. The most favorable course of treatment will depend on a number of factors, including the size and location of the breast tumor, the stage of the cancer, and the results of other laboratory tests. Treatment is similar to female breast cancer and may include a mastectomy (removal of breast tissue), chemotherapy, radiation therapy and/or hormonal therapy.