This information is provided by Breastcancer.org.
Although breast cancer is much more common in women, men can develop breast cancer.
People often assume that men don’t get breast cancer. Although breast cancer is much more common in women, men do have a small amount of breast tissue and can develop breast cancer. Men and women both have breasts that are made up of fatty tissue, fibrous tissue called stroma, nipples, ducts (tubes that carry milk to the nipples), and lobules (milk-producing glands). During puberty, the hormones in girls’ bodies cause their breast tissue to grow. The hormones in boys’ bodies restrict the growth of their breasts, so their breast tissue stays smaller. Most breast cancers in men are ductal carcinomas, which begin in the milk ducts. Male breast cancer is a rare disease. In the United States, fewer than 1% of all breast cancers occur in men. In 2022, about 2,710 American men are expected to be diagnosed with breast cancer, and about 530 are expected to die from the disease. An average man’s risk of being diagnosed with breast cancer in his lifetime is about one in 1,000 (compared to one in eight for the average woman). Unfortunately, men are often diagnosed with breast cancer at a more advanced stage. The main reason is they don’t have routine screening mammograms like women do to find breast cancer at an early stage when it is easier to treat. And since men may not know they can get breast
cancer, they’re usually not on the lookout for changes in their breast tissue, and may not realize they should talk to their doctor about a lump, pain, swelling, or other symptoms. Doctors say that men should be familiar with how their breast tissue normally looks and feels so they can be aware of any changes. The earlier breast cancer is detected, the better the chances it can be successfully treated. The outcomes of men with breast cancer are about the same as those of women diagnosed at the same age and stage. Since there are relatively few cases of breast cancer in men compared to women, there is less information and research focused specifically on male breast cancer. As a result, treatment decisions for male breast cancer are often based on studies of breast cancer in women. Fortunately, more clinical trials of breast cancer treatments are now including men. If you’re a man who has been diagnosed with breast cancer, it’s worth finding out if you can enroll in a clinical trial of a treatment that might be beneficial for you.
Some men who’ve had breast cancer say they felt especially shocked and isolated by their diagnosis because everyone views breast cancer as a women’s disease. Many say they had never met other men who had breast cancer. It’s important to know that support is available through groups like the Male Breast Cancer Coalition.
Risk factors for male breast cancer Several factors are known to increase the risk that a man will develop breast cancer. But it’s important to know that many men who develop breast cancer do not have any of these risk factors. Factors that can increase a man’s breast cancer risk include: Growing older The risk of male breast cancer increases as you age. The average age of men diagnosed with breast cancer in the United States is about 67. But breast cancer can occur in young men, too. Family history of breast cancer A man’s risk for breast cancer is higher if any of his close relatives have had breast cancer, and especially if any male relatives have had the disease. Genetic mutations Men who inherit certain genetic mutations from their mothers or fathers have a higher risk of developing breast cancer. A man who inherits a BRCA1 mutation has about a 1% risk of developing breast cancer in his lifetime, compared to a risk of 0.1% (about one in 1,000) for the average man. A man who inherits a BRCA2 mutation has a 7% to 8% risk.
Mutations in the ATM, CHEK2, PALB2, and other genes are also linked to breast cancer in men, but more research is needed to understand those risks. High estrogen levels You may think of testosterone as a male hormone and estrogen as a female hormone. The truth is, both men and women have different levels of testosterone and estrogen in their bodies. Men have less estrogen than women, but all men have some estrogen in their bodies. Higher levels of estrogen can increase the risk of male breast cancer. Men (and people assigned male at birth) can have high estrogen levels as a result of: hormone therapy for prostate cancer (androgen suppression therapy) hormone therapy taken by transgender women (as part of male-to-female transition; also called feminizing hormone therapy or gender affirming hormone replacement therapy) being overweight or obese being a heavy drinker or having liver disease (like cirrhosis), both of which can limit the liver’s ability to balance hormone levels in the blood having an undescended testicle surgery to remove one or both testicles (orchiectomy) swelling or injury of the testicles Klinefelter syndrome Men usually have one X and one Y chromosome in their cells. But men born with Klinefelter syndrome — a rare genetic condition that happens when a male is born with more than one X chromosome in their cells — may increase their risk of breast cancer. Kinefelter syndrome may cause the testicles to develop abnormally. This can result in lower levels of androgens (usually higher in males) and higher levels of estrogen. Men with Klinefelter’s syndrome may have an increased risk of developing gynecomastia (breast tissue growth that is not cancer) and male breast cancer. Radiation exposure If a man has received radiation therapy to the chest, such as for the treatment of Hodgkin lymphoma, he has an increased risk of developing breast cancer.
