Though boys and girls begin life with similar breast tissue, over time, men don’t have the same complex breast growth and development as women. At puberty, high testosterone and low estrogen levels stop breast development in males. Some milk ducts exist in men, but they remain undeveloped. Lobules are most often absent. However, breast problems, including breast cancer, can occur in men.
Breast cancer in men is rare, but it does happen. In the U.S., less than 1% of all breast cancer cases occur in men. Breast cancer risk is much lower in men than in women. The lifetime risk of getting breast cancer is about 1 in 833 in U.S. men compared to one in eight for U.S. women.
Rates of breast cancer incidence and mortality are much lower among men than among women. Survival rates for men are about the same as for women with the same stage of breast cancer at the time of diagnosis. However, men are often diagnosed at a later stage of breast cancer. Men may be less likely than women to report signs and symptoms, which may lead to delays in diagnosis.
Breast cancer incidence in U.S. men varies by race and ethnicity. Black men have the highest breast cancer incidence overall. Asian/Pacific Islander men have the lowest. Black men also have higher breast cancer mortality than white and Hispanic men. The median age of breast cancer diagnosis for men varies by race and ethnicity. For example, black men tend to be diagnosed at a younger age than white men. The median age at diagnosis for black men is 63, compared to 68 for white men.
The median age of breast cancer diagnosis for men in the U.S. is 67. The median is the middle value of a group of numbers, so about half of men are diagnosed before age 67 and about half are diagnosed after age 67.
Warning signs of breast cancer in men
The most common sign of breast cancer in men is a painless lump or thickening in the breast or chest area. However, any change in the breast or nipple can be a warning sign of breast cancer in men including:
• Lump, hard knot or thickening in the breast, chest or underarm area (usually painless, but may be tender)
• Change in the size or shape of the breast
• Dimpling, puckering or redness of the skin of the breast
• Itchy, scaly sore or rash on the nipple
• Pulling in of the nipple (inverted nipple) or other parts of the breast
• Nipple discharge (rare)
These may also be signs of a benign breast condition.Some of these signs can be easier to notice in men than in women since men tend to have much less breast tissue than women.
Don’t delay seeing a doctor
Some men may be embarrassed about a change in their breast or chest area and put off seeing a doctor. This may result in a delay in diagnosis. Survival is highest when breast cancer is found early and treated. If you notice any of the signs above or other changes in your breast, chest area or nipple, see a doctor right away.
Types of breast cancer in men
Most breast cancers in men begin in the milk ducts of the breast (invasive ductal carcinomas). Fewer than 2% of breast cancers in men begin in the lobules of the breast (invasive lobular carcinoma).
Rare breast cancers in men
In rare cases, men can be diagnosed with ductal carcinoma in situ (a non-invasive breast cancer), inflammatory breast cancer or Paget disease of the breast (Paget disease of the nipple).
Benign breast conditions in men
Benign breast conditions (also known as benign breast diseases) are noncancerous disorders of the breast. The most common benign breast condition in men is gynecomastia. Gynecomastia is an enlargement of the breast. It is the most common benign breast condition in men. Gynecomastia results from a hormone imbalance in the body. Certain diseases, hormone use, obesity and other hormone changes can cause this imbalance. For example, boys can get a temporary form of gynecomastia during puberty. Gynecomastia doesn’t need to be treated unless it causes pain or you want to have the enlarged tissue reduced. In these cases, it can be treated with hormone therapy or surgery. Some studies show gynecomastia may increase the risk of breast cancer in men.
BRCA2 gene mutations and cancer risk
Men (and women) with an inherited BRCA2 gene mutation have an increased risk of breast cancer. For example, the lifetime risk of breast cancer (up to age 80) is:
• About 50-80 in 1,000 men with a BRCA2 mutation
• Less than 1 in 1,000 men without a BRCA2 mutation
Men who have a BRCA2 mutation are also at an increased risk for prostate cancer and pancreatic cancer. Men who have a BRCA1 mutation may also have an increased risk of breast cancer, but this link is less clear. Other gene mutations are under study for a possible link to breast cancer in men.
In men, up to 40% of breast cancers may be related to BRCA2 mutations. In women, 5% to 10% of breast cancers in women are thought to be due to BRCA1, BRCA2 and other inherited gene mutations. This means men who get breast cancer are more likely to have an inherited gene mutation than women who get breast cancer. It’s recommended men diagnosed with breast cancer have genetic testing. (You may want to meet with a genetic counselor to learn more about genetic testing.)