Condition Basics

What is male breast cancer?

Breast cancer is the growth of abnormal cells in one or both breasts. Male breast cancer usually develops in the breast tissue found behind the nipple. Male breast cancer is often a type called invasive ductal carcinoma.

What causes it?

The exact cause of male breast cancer isn't known, but some things increase risk. These include radiation exposure, a family history of breast cancer, and inheriting gene changes such as BRCA. Having Klinefelter syndrome or cirrhosis also increases the risk of male breast cancer. It mostly affects those older than 65.

What are the symptoms?

The most common symptom of male breast cancer is a painless lump or swelling behind the nipple. Other symptoms may include changes in the nipple, a discharge from the nipple, or a lump or thickening in the armpit. Any breast lump in an adult should be checked by a doctor.

How is it diagnosed?

Most male breast cancer is diagnosed with a biopsy. A lump or thick area in the breast or armpit may first be checked with a mammogram or an ultrasound. If either of these tests show signs of cancer, a biopsy will likely be done to see if there is cancer.

Cancer cells from the biopsy are tested to find out more about the cancer. For example, tests can show if the cancer cells have receptors for hormones such as estrogen or progesterone. This helps your doctor know which medicines will work best for you.

How is male breast cancer treated?

Treatment for male breast cancer is based on the stage of the cancer and other things, such as your overall health. The main treatment is:

Surgery.

Usually the doctor removes the breast (mastectomy) and some lymph nodes under the arm. Sometimes the doctor removes just the part of the breast that contains the cancer (breast-conserving surgery).

Other treatment options may include:

Chemotherapy.

These medicines kill fast-growing cells, including cancer cells and some normal cells.

Endocrine therapy.

These medicines block hormones that cause certain cancers to grow. This helps slow or stop cancer growth.

Radiation therapy.

This uses high-dose X-rays to destroy cancer cells and shrink tumors.

Other treatment options may include targeted therapy or immunotherapy. A clinical trial may be a good choice.

Your doctor will talk with you about your options and then make a treatment plan.