Breast cancer in men is a rare disease. Less than 1% of all breast cancers occur in men. In 2021, about 2,650 men are expected to be diagnosed with the disease, and an estimated 530 men are expected to die from breast cancer. For men, the lifetime risk of being diagnosed with breast cancer is about 1 in 833.
You may be thinking: Men don’t have breasts, so how can they get breast cancer? The truth is that boys and girls, men and women all have breast tissue. The various hormones in girls’ and women’s bodies stimulate the breast tissue to grow into full breasts. Boys’ and men’s bodies normally don’t make much of the breast-stimulating hormones. As a result, their breast tissue usually stays flat and small. Still, you may have seen boys and men with medium-sized or big breasts. Usually these breasts are just mounds of fat. But sometimes men can develop real breast gland tissue because they take certain medicines or have abnormal hormone levels.
Risk Factors for Male Breast Cancer
A number of factors can increase a man’s risk of getting breast cancer:
- Growing older: This is the biggest factor. Just as is the case for women, risk increases as age increases. The average age of men diagnosed with breast cancer is about 68.
- High estrogen levels: Breast cell growth — both normal and abnormal — is stimulated by the presence of estrogen. Men can have high estrogen levels as a result of:
- taking hormonal medicines
- being overweight, which increases the production of estrogen
- having been exposed to estrogens in the environment (such as estrogen and other hormones fed to fatten up beef cattle, or the breakdown products of the pesticide DDT, which can mimic the effects of estrogen in the body)
- being heavy users of alcohol, which can limit the liver’s ability to regulate blood estrogen levels
- having liver disease, which usually leads to lower levels of androgens (male hormones) and higher levels of estrogen (female hormones). This increases the risk of developing gynecomastia (breast tissue growth that is non-cancerous) as well as breast cancer.
- Klinefelter syndrome: Men with Klinefelter syndrome have lower levels of androgens (male hormones) and higher levels of estrogen (female hormones). Therefore, they have a higher risk of developing gynecomastia (breast tissue growth that is non-cancerous) and breast cancer. Klinefelter syndrome is a condition present at birth that affects about 1 in 1,000 men. Normally men have a single X and single Y chromosome. Men with Klinefelter syndrome have more than one X chromosome (sometimes as many as four). Symptoms of Klinefelter syndrome include having longer legs, a higher voice, and a thinner beard than average men; having smaller than normal testicles; and being infertile (unable to produce sperm).
- A strong family history of breast cancer or genetic mutations: Family history can increase the risk of breast cancer in men — particularly if other men in the family have had breast cancer. The risk is also higher if there is a proven breast cancer gene abnormality in the family. Men who inherit abnormal BRCA1 or BRCA2 genes (BR stands for BReast, and CA stands for CAncer) have an increased risk of male breast cancer. The lifetime risk of developing breast cancer is approximately 1% with the BRCA1 gene mutation and 6% with the BRCA2 gene mutation. Because of this strong association between male breast cancer and an abnormal BRCA2 gene, first-degree relatives (siblings, parents, and children) of a man diagnosed with breast cancer may want to ask their doctors about genetic testing for abnormal breast cancer genes. Still, the majority of male breast cancers happen in men who have no family history of breast cancer and no inherited gene abnormality.
- Radiation exposure: If a man has been treated with radiation to the chest, such as for lymphoma, he has an increased risk of developing breast cancer.
Symptoms of Male Breast Cancer:
If you notice any persistent changes to your breasts, you should contact your doctor. Here are some signs to watch for:
- a lump felt in the breast
- nipple pain
- an inverted nipple
- nipple discharge (clear or bloody)
- sores on the nipple and areola (the small ring of color around the center of the nipple)
- enlarged lymph nodes under the arm
It’s important to note that enlargement of both breasts (not just on one side) is usually NOT cancer. The medical term for this is gynecomastia. Sometimes the breasts can become quite large. Non-cancer-related enlargement of the breasts can be caused by medications, heavy alcohol use, weight gain, or marijuana use.
Diagnosis of Male Breast Cancer
After an abnormality of the breast is found, tests are performed to see if the problem is cancer. One or all of these tests might be done:
- Mammogram: A mammogram is an X-ray picture of the breast. Two pictures are taken of the breast after it is compressed between two glass plates. One image is shot from the top and the second picture is taken from the side. A radiologist will look at the pictures and determine if anything looks abnormal. He or she may then decide to get other pictures of a certain area. These are called spot or magnification views.
- Ultrasound: Ultrasound sends high-frequency sound waves through your breast and converts them into images on a viewing screen. Ultrasound complements other tests. If an abnormality is seen on mammography or felt by physical exam, ultrasound is the best way to find out if the abnormality is solid (such as a benign fibroadenoma or a cancer) or fluid-filled (such as a benign cyst). Ultrasound cannot determine whether a solid lump is cancerous.
- Nipple discharge examination: If you have nipple discharge, some of the fluid may be collected and examined under a microscope to see if any cancer cells are present.
- Biopsy: A biopsy is necessary to distinguish normal tissue from cancer tissue. If cancer is present, the biopsy also helps your doctors zero in on the size, type, and kind of breast cancer. Biopsies are performed on any kind of abnormality that your doctor can feel or that looks suspicious. (Because most breast cancers in men are discovered by feeling something abnormal, it’s highly unusual to find an abnormality only by mammography or another imaging modality.) Various techniques are used to biopsy tissue, and it’s likely that your surgeon will try to use the least invasive procedure possible while making sure that enough tissue is removed to make a clear diagnosis.
- Fine needle biopsy of palpable lesions (lesions that can be felt) is least invasive. It can be done in the doctor’s office. Results are often available in 24 hours. A long, thin, hollow needle is placed in the palpable abnormality. If the lesion is only seen by mammography or another test, then your doctor may need the help of this test to guide the needle to the right place. Cells are extracted through the center of the needle. A collapsible hook at the end of the needle keeps the needle in place until the surgery is done. X-rays verify that the abnormal area seen on the original X-rays is the same area into which the surgeon inserts the needle. The tissue is then sent off to pathology for analysis. This biopsy technique has the highest risk of a “false negative” — a biopsy result that says “normal,” even though a cancer is present. The reason for this is probably that the needle doesn’t always pick up the cancer cells.
- Stereotactic needle biopsy (core biopsy) removes multiple pieces of a lesion. If the lesion can’t be felt, the needle is guided to the area of concern with the help of mammography or ultrasound. If a cancer is only found by MRI (magnetic resonance imaging), then stereotatic needle biopsy may be guided by that technique. A small metal clip may be inserted into the breast to mark the site of biopsy in case the biopsy proves cancerous and additional surgery is required. But since most men diagnosed with breast cancer have mastectomy, a clip is usually unnecessary since the whole breast is removed.
- Incisional biopsy is more like regular surgery — it removes a bigger piece of tissue than a fine needle biopsy or a core biopsy. Often, incisional biopsies are done when needle biopsies are inconclusive or if the lump is too extensive or too big to be removed easily. The purpose of this procedure is to make a diagnosis. Because it only takes out part (not all) of the cancer, it is not a treatment. In men, once a breast cancer diagnosis is made, mastectomy is usually done.
- Excisional biopsy is the most involved kind of biopsy. It attempts to remove the entire suspicious lump of tissue from the breast. This is the surest way to establish the diagnosis without missing the cancer tissue (winding up with a false negative). Removing the entire lump may also provide you some peace of mind until the final treatment plan is put in place. Both incisional and excisional biopsies can be done in an outpatient center or hospital, using local anesthesia. The purpose of this procedure is to make a diagnosis. Even if the lumpectomy takes out all of the cancer in the breast with clear margins, if breast cancer is diagnosed, mastectomy is usually done.
If a cancer diagnosis is made, your doctor might recommend more tests. For example, an MRI can show how much cancer is in the affected breast relative to the normal tissue right under and next to the breast cancer. This information may help the surgeon plan the extent of surgery. Plus, an MRI can help evaluate the other breast to see if it’s OK. Other tests, such as blood work, chest X-ray, and bone scan, might be done to see if the cancer has spread to other parts of the body.
Types of Breast Cancer in Males
Most breast cancers in men are ductal carcinomas. Ductal means the cancer started in the milk pipes of the breast, called ducts. These cancers are usually invasive because they start inside the duct and then break through the wall of the duct, growing into the normal surrounding breast tissue. Non-invasive breast cancers, called DCIS (ductal carcinoma in situ), are uncommon in men. These cancers start and stay inside the milk ducts. Men rarely get lobular breast cancer (the kind of cancer that starts in the lobules where milk is made) because lobules are not fully formed in male breast tissue.
Treatment of Male Breast Cancer
Most men who have been diagnosed with breast cancer will undergo some form of treatment for the disease. The most favorable course of treatment will depend on a number of factors, including the size and location of the breast tumor, the stage of the cancer, and results of other laboratory tests. This section provides information about the treatment options for men with breast cancer.
In the following Breastcancer.org pages, you can learn about how the following treatments are performed and what to expect from each:
- Surgery for Male Breast Cancer
- Lymph Node Surgery for Male Breast Cancer
- Radiation Therapy for Male Breast Cancer
- Hormonal Therapy for Male Breast Cancer
- Chemotherapy for Male Breast Cancer
- Targeted Therapy for Male Breast Cancer