The male breast

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.

Learn more about breast anatomy.

Breast cancer in men

In the U.S., less than 1 percent 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 1 in 8 for U.S. women.

Since 1995, the incidence of breast cancer in men in the U.S. has remained stable.

In 2019, it’s estimated that among men in the U.S., there will be:

• 2,670 new cases of invasive breast cancer (includes new cases of primary breast cancer, but not recurrences of original breast cancers)
• 500 breast cancer deaths

Rates of breast cancer incidence (new cases) and mortality (death) are much lower among men than among women.

In 2016 (most recent data available):

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.

Race and ethnicity

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.

For example, in 2016 (most recent data available):

Black men also have higher breast cancer mortality than white and Hispanic men.

For example, in 2016 (most recent data available):

Age at diagnosis

Overall, 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.

The median age of breast cancer diagnosis for men is slightly older than for women (overall, the median age at diagnosis for women is 62).

Race and ethnicity

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 64, compared to 68 for white men.  

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.

If you don’t have a doctor, one of the best ways to find a good one is to get a referral from a trusted family member or friend.

If that’s not an option, call your health department, a clinic or a nearby hospital. If you have insurance, your insurance company may also have a list of doctors in your area. 

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 percent of breast cancers in men begin in the lobules of the breast (invasive lobular carcinoma).

Learn more about the anatomy of the breast.

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).

Learn about treatment for breast cancer in men.

Learn more about the anatomy of the breast.

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.

Learn about benign breast conditions in women.

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 breast cancer risk

Men can inherit a BRCA2 (BReast CAncer 2) mutation from either parent. And, a man who has a BRCA2 mutation can pass the mutation on to both his sons and daughters.

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.

Learn more about BRCA2 mutations and cancer risk in men.

BRCA2 gene mutations and genetic testing

In men, up to 40 percent of breast cancers may be related to BRCA2mutations. In women, 5-10 percent 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. So, 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.)

Cancer screening for men with a BRCA2 or BRCA1mutation

There are special cancer screening recommendations for men with a BRCA2or BRCA1 gene mutation.

Learn about breast cancer screening for men with a BRCA2 or BRCA1mutation.

Other risk factors for breast cancer in men

Although there are some factors that increase the risk of breast cancer in men, most men who are diagnosed have no known risk factors (except for older age).

Age

Older age is the most common risk factor for breast cancer in men (and women). Overall, the median age of breast cancer diagnosis in men in the U.S. is 67.

Family history of breast cancer

Whether or not a man has a BRCA2 mutation, having a family member with breast cancer increases the chances of developing breast cancer.

Learn about breast cancer screening for men with a strong family history of breast cancer.

Gynecomastia

Gynecomastia (enlargement of the breast tissue) is a benign (not cancer) breast condition.

Some studies show gynecomastia may increase the risk of breast cancer in men.

Klinefelter’s syndrome

Klinefelter’s syndrome is a rare condition that occurs when men are born with two X chromosomes instead of one (XXY instead of XY). It’s related to high levels of estrogen in the body.

Men with Klinefelter’s syndrome have a higher risk of breast cancer compared to men without this condition.

Men with Klinefelter’s syndrome may have gynecomastia (enlargement of the breast tissue). Some studies show gynecomastia may also increase the risk of breast cancer in men.

Overweight and obesity

Men who are overweight or obese appear to have an increased risk of breast cancer.

Being overweight can increase estrogen levels in the body and these higher estrogen levels, in turn, may increase breast cancer risk.

Other risk factors

Although data are limited at this time, some factors that can increase estrogen levels in the body are under study for a possible link to breast cancer in men. These include some hormone drugs used to treat prostate cancer.

Other factors under study for breast cancer in men include:

• Diabetes
• Exposure to large amounts of radiation early in life (such as radiation therapy to the chest for the treatment of childhood cancer)
• Lack of exercise
• Some conditions that affect the testicles (such as orchitis (swelling of one or both testicles) or undescended testes)

Learn about risk factors for breast cancer in women.