It’s rare, but men can and do get breast cancer. Men’s breasts don’t fully develop like women’s do, but all men have breast tissue.

Male breast cancer is most likely to develop in the milk ducts. This is called ductal carcinoma. For a small number of men, it starts in milk-producing glands. This is called lobular carcinoma.

Only about 1 percent of all cases of breast cancer are in men. In 2015, there were about 2,350 new cases of male breast cancer. About 440 men lost their lives to the disease.

Because it’s uncommon, men may be more inclined to ignore warning signs and delay seeing a doctor. Awareness that men can and do develop breast cancer is essential to early diagnosis and treatment.

Early diagnosis and treatment generally lead to a more positive outcome. Read on to learn more about risk factors and symptoms of breast cancer in men, and what you should do about it.

The exact cause of male breast cancer isn’t known. Risk factors for breast cancer in men include the following:

  • Young men can get breast cancer, but the risk increases as you age. The mean age for men at diagnosis is between 60 and 70 years.
  • An inflammation of the testicles, which is called orchitis, increases your risk.
  • You’re at greater risk for breast cancer if close relatives have had breast cancer. Also, some inherited mutated genes, like BRCA2, can increase your risk of breast and prostate cancers.
  • Surgical removal of a testicle, which is called an orchiectomy, increases your risk.
  • Exposure to estrogen, a female hormone, can also raise your risk. Men who have a genetic condition called Klinefelter’s syndrome often produce higher levels of estrogen. Other things that can increase estrogen levels include hormone therapy, cirrhosis of the liver, and obesity.
  • Previous radiation treatment to the chest increases your risk.

The symptoms of breast cancer in men are similar to those in women. These include:

  • a breast lump that you can see or feel
  • an enlargement of one breast
  • nipple pain
  • discharge from the nipple
  • sores on the nipple or areola
  • an inverted nipple
  • enlarged underarm lymph nodes

You should contact your doctor right away if you have any of these symptoms.

When both breasts grow larger in a man, it’s called gynecomastia. This condition is unlikely to be cancerous, and it may be caused by:

  • weight gain
  • certain medications
  • marijuana use
  • excessive alcohol use

When in doubt, it’s best to ask your doctor, especially if you have known risk factors.

Your doctor will ask you about your medical history and conduct a physical examination.

An ultrasound and an MRI are two noninvasive tests that may be used to get detailed pictures. Blood work can help check for signs of disease.

You may need a biopsy if cancer can’t be ruled out. Using a needle, your doctor will remove a sample of the suspicious tissue. In some cases, the entire lump may have to be removed. The tissue will be sent to a pathologist who will examine it under a microscope to determine if it’s cancerous.

Pathology tests can help identify the type of cancer you have and how quickly it can be expected to grow. This will help your doctor recommend the best treatment plan for you.

There are a few surgical options:

  • In a lumpectomy, the tumor, plus some healthy tissue around it, is removed. If the tumor is larger or you have more than one tumor, it may be better to remove the entire breast. This is called a mastectomy. This sometimes involves removal of chest wall muscles and nearby lymph nodes.
  • Radiation therapy is used to kill cancer cells that may have been missed by surgery.
  • Chemotherapy is a systemic treatment. It’s used to kill cancer cells throughout your body.

Targeted therapy focuses on specific substances that are helping your cancer grow. If your lab tests showed particular hormone receptors in the cancer cells, hormone therapy may be prescribed. These medications can block the production of certain hormones. Monoclonal antibody therapy also targets specific substances that are helping your cancer grow.

A combination of treatments is usually necessary.

Men survive breast cancer at about the same rate as women who are diagnosed at the same stage.

The five-year relative survival rate for male breast cancer is 84 percent. The 10-year relative survival rate is 72 percent. These are only averages, though. Breast cancer also tends to be diagnosed later in men than in women.

Besides the type of breast cancer you have and the stage at diagnosis, your individual outlook depends on a lot of unique factors, including:

  • your age
  • your general health
  • the treatment you choose
  • how well you respond to that treatment

Your doctor is the best source of information regarding your outlook.