Though boys and girls begin life with similar breast tissue, over time, men do not 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, but they remain undeveloped, and lobules are most often absent. However, breast problems, including cancer, can occur in men.
Learn more about breast anatomy.
Find statistics on female breast cancer.
Male breast cancer in the United States
Breast cancer in men is rare, but it does happen (about one percent of all breast cancer cases in the U.S.) [40]. In 2013, it is estimated that among U.S. men there will be [35]:
- 2,240 new cases of breast cancer
- 410 breast cancer deaths
Rates of breast cancer incidence (new cases, including new cases of primary breast cancer among survivors, but not recurrence of original breast cancer among survivors) and mortality (death) are much lower among men than among women [36]. For example, in 2009 [36]:
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Men
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Women
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Incidence (new cases)
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1.2 per 100,000
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125.7 per 100,000
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Mortality (deaths)
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0.3 per 100,000
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22.2 per 100,000
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Survival rates for men are about the same as for women with the same stage of cancer at the time of diagnosis [70]. However, men are usually diagnosed at a later stage because they are less likely to report symptoms.
Warning signs of male breast cancer
Any change in the breast or nipple can be a warning sign of male breast cancer including [69-72]:
- Lump, hard knot or thickening in the breast (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
As men tend to have much less breast tissue compared to women, some of these signs can be easier to notice in men than in women. These symptoms may also be signs of a benign (non-cancer) breast condition. If you notice any of these signs or other changes in your breast, chest area or nipple, see your health care provider right away.
Learn about benign breast conditions in women.
Types of male breast cancer
As with female breast cancers, most male breast cancers begin in the milk ducts of the breast (invasive ductal carcinomas). Less often, male breast cancers begin in the lobules of the breast (invasive lobular carcinoma). Learn more about the anatomy of the breast.
In rare cases, men can be diagnosed with inflammatory breast cancer, ductal carcinoma in situ (a non-invasive breast cancer) or Paget disease of the breast (Paget disease of the nipple) [69-71]. Paget disease of the breast is a cancer that begins in the milk ducts of the breast tissue, but spreads to the skin of the nipple. It can cause a scaly rash on the skin of the nipple. Although Paget disease of the breast is rare, it occurs more often in men than in women [71].
Learn about treatment for male breast cancer.
Learn more about the anatomy of the breast.
Benign breast conditions in men
Both men and women may develop benign (not cancer) breast conditions. However, the benign breast conditions most common in women (such as cysts and fibroadenomas) are very rare in men.
Learn about benign breast conditions in women.
Gynecomastia
The most common benign breast condition in men is gynecomastia (GUY-nuh-ko-MASS-tee-uh) (enlargement of the breast tissue). Gynecomastia results from a hormone imbalance in the body. Certain diseases, hormone use, obesity and other hormone changes can cause this imbalance [73]. For example, boys can get a temporary form of gynecomastia during puberty.
Gynecomastia does not need to be treated unless it is desired or it causes pain. In these cases, it can be treated with hormone therapy or surgery [73].
At this time, it is unclear whether gynecomastia is related to male breast cancer. Although some data suggest it may increase the risk of male breast cancer, most studies have found no link between the two [69,74-76].
Risk factors for male breast cancer
Klinefelter's syndrome
The strongest risk factor for male breast cancer is Klinefelter's syndrome, a condition related to high levels of estrogen in the body [69,73-74]. This rare condition occurs when men are born with two X chromosomes instead of one (XXY instead of XY). Men with Klinefelter's syndrome have a 20 to 50 times greater risk of breast cancer compared to men without this condition [69].
Men with Klinefelter's syndrome may have gynecomastia (enlargement of the breast tissue). Although some data suggest gynecomastia may increase the risk of male breast cancer, most studies have found no link between the two [69,74-76].
Age
Getting older increases the risk of male breast cancer. Most breast cancer in men occurs between ages 65 and 67 [69].
BRCA2 gene mutations and family history of breast cancer
Similar to women, men with an inherited mutation in the BRCA2 gene have an increased risk of breast cancer [69,73-74]. Men who carry a BRCA2 mutation have about a seven percent chance of developing breast cancer by age 70 [77]. BRCA2 carriers are also at an increased risk for other types of cancer, such as prostate cancer.
Men can inherit a BRCA2 from either parent. And, a man who is a BRCA2 carrier can pass the mutation on to both his sons and daughters. Learn more about BRCA2 mutations and cancer risk.
Whether or not a man carries a BRCA2 mutation, having a family member with breast cancer increases the chances of developing breast cancer [71-72].
Learn about breast cancer screening for men with BRCA2 mutations or a strong family history of breast cancer.
Gynecomastia
Gynecomastia (enlargement of the breast tissue) is a benign breast condition. At this time, it is unclear whether gynecomastia is related to male breast cancer. Although some data suggest that it may increase the risk of male breast cancer, most studies have found no link between the two [69,74-76].
Other risk factors
Heavy alcohol use, chronic liver disease and obesity may also increase the risk of male breast cancer [69,74,76]. These conditions can increase estrogen levels in the body and these higher estrogen levels, in turn, may increase breast cancer risk. Some hormone drugs used to treat prostate cancer also may increase the risk of male breast cancer [69,71].
Exposure to large amounts of radiation early in life (such as the atomic bomb explosions in Japan and radiation treatment for childhood cancer) may also be linked to an increased risk of male breast cancer [70-72,74].
Learn more about breast cancer.
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For more information on male breast cancer, visit the National Comprehensive Cancer Network (www.nccn.com) or the American Society for Clinical Oncology’s website (www.cancer.net).
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Updated 02/19/13
