The cause of breast cancer in men is not clear. But there are risk factors that make breast cancer more likely in men:
- Exposure to radiation
- Higher estrogen levels due to factors such as heavy drinking, cirrhosis, obesity, and some medicines to treat prostate cancer
- Heredity, such as a family history of breast cancer, mutated BRCA1 or BRCA2 gene, and certain genetic disorders, such as Klinefelter syndrome
- Excess breast tissue (gynecomastia)
- Age. Most men are diagnosed with breast cancer between ages 60 to 70.
Breast cancer is cancer that starts in breast tissue. Both males and females have breast tissue. This means that anyone, including men and boys, can develop breast cancer.
Breast cancer in men is rare. Male breast cancer accounts for less than 1% of all breast cancers.
Exams and Tests
You health care provider will take your medical history and family medical history. You will have a physical exam and a breast exam.
Your provider may order other tests, including:
- A mammogram
- Breast ultrasound
- An MRI of the breast
- A blood test to check for signs of cancer
- If any of the tests suggest cancer, your provider will do a biopsy to check for cancer.
If cancer is found, your provider will order other tests to find out:
- How quickly the cancer might grow
- How likely it is to spread
- What treatments might be best
- What are the chances that the cancer might come back
The tests may include:
- Chest x-ray, specifically to see if it has spread to the lungs
- Bone scan
- CT scan
- PET scan
- Sentinel lymph node biopsy to check if the cancer has spread to the lymph nodes
The biopsy and other tests will be used to grade and stage the tumor. The results of those tests will help determine your treatment.
The long-term outlook for men with breast cancer is excellent when the cancer is found and treated early.
- About 91% of men treated before cancer has spread to other areas of the body are cancer-free after 5 years.
- Almost 3 out of 4 men treated for cancer that has spread to lymph nodes but not to other areas of the body are cancer-free at 5 years.
- Men who have cancer that has spread to distant parts of the body have a smaller chance of long-term survival.
Complications include side effects from surgery, radiation, and chemotherapy.
There is no clear way to prevent breast cancer in men. The best way to protect yourself is to:
- Know that men can develop breast cancer
- Know your risk factors and talk with your provider about screening and early detection with tests if needed
- Know the possible signs of breast cancer
- Tell your provider if you notice any changes in your breast
Cancer affects how you feel about yourself and your life. You can ease the stress of illness by joining a cancer support group. Sharing with others who have had the same experiences and problems can help you feel less alone. The group can also point you to helpful resources for managing your condition.
Ask your provider to help you find a support group of men who have been diagnosed with breast cancer.
Symptoms of breast cancer in men include:
- Lump or swelling in the breast tissue. One breast may be larger than the other.
- A small lump beneath the nipple.
- Unusual changes in the nipple or skin around the nipple such as redness, scaling, or puckering.
- Nipple discharge.
Treatment options for breast cancer in men include:
- Surgery to remove the breast, lymph nodes under the arm, the lining over chest muscles, and chest muscles, if needed
- Radiation therapy after surgery to kill any remaining cancer cells and to target specific tumors
- Chemotherapy to kill cancer cells that have spread to other parts of the body
- Hormone therapy to block hormones that may help certain types of breast cancer grow
During and after treatment, your provider may ask you to have more tests. This may include tests you had during diagnosis. The follow-up tests will show how the treatment is working. They will also show if the cancer comes back.
When to Contact a Medical Professional
Contact your provider right away if you notice something unusual about your breast, including any lumps, skin changes, or discharge.
Brinton LA, Cook MB, McCormack V, et al. Anthropometric and hormonal risk factors for male breast cancer: male breast cancer pooling project results. J Natl Cancer Inst. 2014;106(3):djt465. PMID: 24552677
Hunt KK, Mittendorf EA. Diseases of the breast. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 20th ed. Philadelphia, PA: Elsevier; 2017:chap 34.
National Cancer Institute. PDQ: male breast cancer treatment - health professional version. Cancer.gov Web site. Updated February 12, 2016.