Male 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:
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.
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.
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.
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
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.
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.
Symptoms of male breast cancer
The first sign of male breast cancer is usually a lump in the breast that feels like a hard knot or pebble. Since most men aren’t regularly checking their breasts and aren’t aware of the early warning signs of male breast cancer, it may take some time for them to notice a lump or other breast change and bring it to the attention of their doctor. While the majority of lumps are not breast cancer, it’s important to have any unusual changes to your breast, chest, or armpit checked by a doctor as soon as you can. When breast cancer is found early, it’s usually easier to treat successfully.
The signs and symptoms of breast cancer in men to watch out for include:
a firm lump felt in the breast, often right under the nipple
a lump in the armpit
nipple turning inward
nipple discharge (clear or bloody)
sores or a rash on the nipple and areola (the dark area around the nipple)
changes to the breast skin, such as irritation, redness, dimpling, or puckering
change in the size or shape of the breast
These changes can also can be signs of less serious conditions that are not cancer. Some benign (non-cancerous) breast conditions in men are:
Gynecomastia is an increase in the amount of breast tissue in males. It can involve swelling or overall enlargement of one or both breasts. Often, the first symptom is a lump of fatty tissue under the nipple that may be tender or sore.
Gynecomastia can occur in male babies, boys going through puberty, or adult men. It is typically caused by an imbalance of the hormones estrogen and testosterone. This imbalance can be due to normal changes in hormone levels or to other factors such as taking certain medicines, heavy alcohol use, marijuana use, weight gain, liver disease, or kidney disease. Gynecomastia is the most common non-cancerous breast condition in males. If a man has enlargement of both breasts (not just on one side) that is often a sign that he doesn’t have male breast cancer and is more likely to have gynecomastia.
Men can develop other types of abnormal lumps or masses of tissue in the breast that are not cancer and do not spread outside the breast. Some examples are lipomas (lumps of fatty tissue), cysts (fluid-filled sacs), hematomas (accumulations of blood), and fat necrosis (firm scar tissue).
Again, be sure to see your doctor right away if you notice any abnormal change in the breast, chest, or armpit.
Diagnosis of male breast cancer
Doctors use a number of different diagnostic tests to find out whether or not breast cancer is present and, if so, whether it has spread outside the breast. Diagnostic tests are also used to gather more information about the cancer to guide decisions about treatment.
If you have possible symptoms of male breast cancer, your doctor may recommend some combination of the following diagnostic tests:
If you are diagnosed with breast cancer, your doctor may recommend additional tests, including:
blood marker tests
Each time your doctors remove tissue from your breast or lymph nodes — whether as part of the initial biopsy or during surgery for breast cancer — they will send it to a lab for testing. The tests will tell whether or not cancer is present and, if so, will provide information about the characteristics of the cancer. All of the test results together make up your pathology report. Your doctors will discuss the results in your pathology report with you. The information in the report will help you and your doctors decide which treatments are best for you.
In most cases, you can expect the pathology report to classify the breast cancer as one of the following:
Invasive ductal carcinoma (IDC): This is the most common type of breast cancer in men and in women. It begins inside the milk ducts (the tubes that carry milk to the nipples) and grows into and through the surrounding tissue inside the breast. It may or may not spread to the lymph nodes or other parts of the body.
Ductal carcinoma in situ (DCIS): This type of breast cancer starts and stays inside the lining of the milk ducts. It is not considered life threatening, but if left untreated it can turn into invasive cancer.
Invasive lobular carcinoma (ILC): This type of breast cancer begins inside the milk-making glands (called lobules) and grows into the surrounding tissue inside the breast. It may or may not spread to the lymph nodes or other parts of the body. It’s very rare in men.
Inflammatory breast cancer: This is a fast-growing form of breast cancer. The first symptoms are usually reddening and swelling of the breast instead of a distinct lump. Symptoms can worsen within days or even hours and prompt treatment is important. It’s very rare in men.
Paget disease: This cancer develops in the nipple and areola. The nipple and areola often become scaly, red, itchy, and irritated. It's very rare in men.
Metastatic breast cancer: Metastatic breast cancer (also called stage IV) is breast cancer that has spread beyond the breast to other parts of the body.
Learn more about the information that may be in your pathology report.
Treatment of male breast cancer
Depending on the details of your diagnosis, treatment options for male breast cancer can include:
If you are a man who has been diagnosed with breast cancer, you and your medical team will develop a treatment plan based on the characteristics of the cancer and other factors.
Learn more about the Treatment of Male Breast Cancer.
Genetic testing in men with or at risk for breast cancer
Breast cancer in men is sometimes caused by inherited mutations in certain genes. You can inherit gene mutations from your mother or your father and can potentially pass them on to your sons and daughters.
The lifetime risk of developing breast cancer is approximately 1% for men who have a BRCA1 gene mutation and 7-8% for men who have a BRCA2 gene mutation, compared to a risk of 0.1% for men in the general population. Mutations in the ATM, CHEK2, PALB2, and other genes are also associated with breast cancer in men, but more research is needed to understand the specific risks from those genes.
According to guidelines from the American Society of Clinical Oncology and the National Comprehensive Cancer Network, all men who have been diagnosed with breast cancer should be offered genetic counseling and genetic testing for genetic mutations linked to a higher risk of breast cancer.
Men who haven’t been diagnosed with breast cancer but who have a family history of breast, ovarian, pancreatic, or prostate cancer, or who have a family member who was found to have an inherited gene mutation that increases the risk of cancer, should also consider getting genetic testing.
Here are some of the reasons it’s useful for you and your medical team to know if you have a gene mutation linked to a higher risk of breast cancer:
If you have been diagnosed with male breast cancer and you have a BRCA1 or BRCA2 mutation, you might benefit from certain treatments, such as PARP inhibitors.
If you haven’t been diagnosed with male breast cancer and you have a BRCA1 or BRCA2 mutation, your doctors may recommend that you receive periodic screenings for breast cancer and other cancers. Men with BRCA1 and BRCA2 mutations also have an increased risk of prostate cancer and pancreatic cancer.
You may want to tell your first-degree relatives (such as your children, siblings, and parents) that you have a genetic mutation linked to a higher risk of breast cancer, so they can look into getting genetic testing, too. If they find out that they do have the mutation, they can take steps to reduce their risk of developing cancer and to start getting cancer screenings more frequently or at an earlier age than they otherwise would.
Finding support as a man with breast cancer
Men may feel particularly isolated after a breast cancer diagnosis because they don’t know any other men who’ve had the disease and most of the resources for breast cancer information and support are tailored to women.
The Male Breast Cancer Coalition, a nonprofit patient advocacy organization, can connect you with other men who’ve been diagnosed with breast cancer for one-to-one peer support. The organization also has conferences, an email list, online message boards, and monthly virtual support group meetings. Contact the coalition for more information.
— Last updated on April 4, 2022, 7:50 PM