Condition Basics

What is male breast cancer?

Breast cancer is the growth of abnormal cells in one or both breasts. Breast cancer in men develops in the small amount of breast tissue found behind a man's nipple. It is often a type called invasive ductal carcinoma.

What causes it?

The exact cause of breast cancer isn't known. But most experts agree that some men have a greater risk for breast cancer than others. Male breast cancer mostly affects older men.

Things that increase a man's risk of breast cancer include:

• Radiation exposure.
• Family history of breast cancer in his female relatives.
• Inheriting gene mutations, such as BRCA.
• Having a genetic condition called Klinefelter syndrome or a liver disease (cirrhosis).

What are the symptoms?

The most common symptom of male breast cancer is a painless lump or swelling behind the nipple. Other symptoms can include a discharge from the nipple or a lump or thickening in the armpit.

Most men diagnosed with breast cancer are older than 65. But breast cancer can appear in younger men. For this reason, any breast lump in an adult male is thought to be abnormal and should be checked out 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 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 tumours.

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.