Male Breast Cancer
Updated on March 5, 2026
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, connective 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.
The vast majority of breast cancers in men are:
invasive ductal carcinomas, which begin in the milk ducts
hormone receptor-positive, which means the hormones estrogen and/or progesterone fuel the growth of the cancer
Since breast cancer in men is much less common than in women and people are not as familiar with it, men may face extra barriers to getting diagnosed and treated. For example, men aren't typically screened for breast cancer, and some have had trouble getting insurance to cover diagnostic tests and treatment. It can also be difficult to find doctors who are knowledgeable about male breast cancer.
In the past decade, though, awareness of male breast cancer has grown and access to care is improving.
How common is male breast cancer?
In the United States, fewer than 1% of all breast cancers occur in men. In 2026, about 2,670 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 755 (compared to one in eight for the average woman). But the rate of male breast cancer is increasing around the world.
And statistically, men are more likely than women to be diagnosed with breast cancer at an advanced stage (10% are first diagnosed with metastatic disease, compared to 6% of women). The main reason is men don’t have routine screening mammograms like women do to find breast cancer at an early stage when it is easier to treat. And because men may not know they can get breast cancer, they’re usually not on the lookout for changes in their breast tissue. They may not realize they should talk to their doctor about a lump, pain, swelling, or other symptoms.
Doctors recommend that men become 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.
Research on male breast cancer
Since there are relatively few cases of breast cancer in men compared to women, there is less information and research 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. One of the largest clinical trials on treating breast cancer in men ever is currently underway.
“Soon we’ll have better data on the optimal endocrine therapy for men with early-stage breast cancer, and whether it’s beneficial to add a CDK4/6 inhibitor to their endocrine therapy regimen. It’s not good enough for us to extrapolate from studies on women with breast cancer,” says Elaine Walsh, MD, PhD, a medical oncologist at MedStar Georgetown University Hospital in Washington, D.C.
Risk factors for male breast cancer
Several factors are known to increase the risk that a man will develop breast cancer.
Note that risk factors for trans men are different from those of cisgender men. Generally speaking, transmasculine people taking gender-affirming hormone therapy (testosterone) are at a lower risk of developing breast cancer than cisgender or transgender women but at a higher risk than cisgender men. If you're a trans man concerned about your risk for breast cancer, you may want to seek our an LGBTQ-inclusive healthcare provider so you can get care tailored to your needs.
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 — especially if any male relatives have had the disease.
Genetic mutations
Men who inherit certain genetic mutations from their parents have a higher risk of 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% 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
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 can have high estrogen levels as a result of:
hormone therapy for prostate cancer (androgen suppression therapy)
being overweight or having obesity
heavy drinking
liver disease (like cirrhosis)
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 a rare genetic condition called Klinefelter syndrome have more than one X chromosome. Klinefelter syndrome may cause the testicles to develop abnormally. This can result in lower levels of androgens (sex hormones like testosterone that are higher in males) and higher levels of estrogen. This makes men with Klinefelter syndrome have an increased risk of 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.
Toxic exposures during military service
Research suggests that men who have served in the military have an increased risk of developing breast cancer. This is likely related to exposure to toxins during their military service, such as from open burn pits, contaminated groundwater, or the herbicide agent orange.
Symptoms of male breast cancer
It’s important to see your doctor right away if you notice any changes in the breast, chest, or armpit.
The signs and symptoms of breast cancer in men to watch out for include:
a firm lump felt in the breast, often under the nipple
a lump in the armpit
nipple pain
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
Benign breast conditions in men
Sometimes changes to men’s breasts are caused by conditions that are not cancer.
Gynecomastia
Gynecomastia is an increase in the amount of breast tissue in men and boys. 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), it’s often a sign that he has gynecomastia, not male breast cancer.
Some studies suggest that men who develop gynecomastia are at a slightly higher risk for male breast cancer because of the hormonal imbalance that’s associated with both conditions.
Benign (non-cancerous) breast lumps
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
If you have symptoms of male breast cancer, your doctor may recommend diagnostic tests such as a breast physical exam, mammogram, ultrasound, or biopsy.
If you're diagnosed with breast cancer, your doctor may recommend additional tests, such as breast MRI, chest X-ray, bone scan, CT (CAT) scan, or PET scan.
Getting your pathology report
Each time you have a biopsy or surgery to remove tissue from your breast or lymph nodes, a doctor called a pathologist will do tests on the tissue that was removed. The results of these tests make up your pathology report. The pathology report contains information about characteristics of the cancer, including its type, hormone receptor status, HER2 status, and grade. If lymph nodes were removed during a biopsy or surgery, it will also say whether there are cancer cells in the lymph nodes.
Types of breast cancer in men
Breast cancer diagnosed in men is usually one of the following types:
Invasive ductal carcinoma (IDC): This is the most common type of breast cancer in men and women. It begins inside the milk ducts (the tubes that carry milk to the nipples, which men and women both have) 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.
Metastatic breast cancer: Metastatic breast cancer (also called stage IV) is invasive breast cancer that has spread beyond the breast to other parts of the body.
In very rare cases, a man can develop invasive lobular carcinoma (ILC), inflammatory breast cancer, or Paget disease.
Treatment for male breast cancer
Treatment options for male breast cancer can include surgery, chemotherapy, radiation therapy, hormonal therapy, and targeted therapy. You and your medical team will develop a treatment plan based on the characteristics of the cancer and other factors.
Professional medical societies such as the American Society of Clinical Oncology, the National Comprehensive Cancer Network, and the American College of Radiology have developed guidelines for diagnosing and treating breast cancer in men. It’s a good idea to seek out a treatment team that has experience treating men with breast cancer and is knowledgeable about the treatment guidelines and latest research.
Genetic testing and male breast cancer
Breast cancer in men is sometimes caused by inherited mutations in certain genes. You can inherit gene mutations from your parents and potentially pass them on to your children.
Experts say that 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 consider genetic testing.
Men who have been diagnosed with breast cancer should be offered genetic counseling and genetic testing for mutations linked to a higher risk of breast cancer, according to guidelines from the American Society of Clinical Oncology and the National Comprehensive Cancer Network.
There are several reasons that it’s useful to know if you have a gene mutation linked to a higher risk of breast cancer.
For example, 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.
Also, if you have a gene mutation linked to a higher risk of breast cancer, you may want to tell your children, siblings, and parents so they can look into getting genetic testing too. They may or may not have the mutation. But if testing shows that they do have it, they can take steps to reduce their risk of developing cancer and get 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.
Support is available through nonprofit advocacy organizations like Male Breast Cancer Happens, the Male Breast Cancer Global Alliance, HIS Breast Cancer Awareness, and Man Up to Cancer.
Male Breast Cancer Happens, 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 them for more information.
“I think it’s important for the guys that are living with [male breast cancer] to know they are not alone,” Jake Messier told the Breastcancer.org podcast. After he was diagnosed with breast cancer, he joined the support group Man Up to Cancer. “It’s a place for men to go and release the stress of cancer in a healthy, really beautiful community,” he says.
