Overview

Male breast cancer is a rare cancer that begins as a growth of cells in the breast tissue of men.

Breast cancer is typically thought of as a condition that happens in women. But everyone is born with some breast tissue. So anyone can get breast cancer.

Male breast cancer is rare. It happens most often in older men, though it can occur at any age.

Treatment for male breast cancer typically involves surgery to remove the breast tissue. Other treatments, such as chemotherapy and radiation therapy, may be recommended as well.

Symptoms

Signs and symptoms of male breast cancer can include:

  • A painless lump or thickening of the skin on the chest.
  • Changes to the skin covering the chest, such as dimpling, puckering, scaling or changes in the color of the skin.
  • Changes to the nipple, such as changes in the skin color or scaling, or a nipple that begins to turn inward.
  • Discharge or bleeding from the nipple.

When to see a doctor

Make an appointment with a doctor or other health care professional if you have symptoms that worry you.

Causes

It's not clear what causes male breast cancer.

Male breast cancer starts when cells in the breast tissue develop changes in their DNA. A cell's DNA holds the instructions that tell the cell what to do. In healthy cells, the DNA gives instructions to grow and multiply at a set rate. The instructions tell the cells to die at a set time.

In cancer cells, the DNA changes give different instructions. The changes tell the cancer cells to make many more cells quickly. Cancer cells can keep living when healthy cells would die. This causes too many cells.

The cancer cells might form a mass called a tumor. The tumor can grow to invade and destroy healthy body tissue. In time, cancer cells can break away and spread to other parts of the body. When cancer spreads, it's called metastatic cancer.

Where breast cancer begins in men

Everyone is born with a small amount of breast tissue. Breast tissue consists of milk-producing glands, ducts that carry milk to the nipples and fat.

During puberty, people assigned female at birth typically begin growing more breast tissue. People assigned male at birth generally do not grow more breast tissue. But because everyone is born with a small amount of breast tissue, breast cancer can develop in anyone.

Types of male breast cancer include:

  • Cancer that begins in the milk ducts, called ductal carcinoma. This type of breast cancer starts in the tubes that connect to the nipple. These tubes are called ducts. Ductal carcinoma is the most common type of male breast cancer.
  • Cancer that begins in the milk-producing glands, called lobular carcinoma. This type of cancer begins in the glands that have the potential to make breast milk. These glands are called lobules. Lobular carcinoma is less common in people assigned male at birth because they usually have fewer lobular cells.
  • Other types of cancer. Other, rarer types of male breast cancer include Paget's disease of the nipple and inflammatory breast cancer.

Risk factors

Factors that increase the risk of male breast cancer include:

  • Older age. The risk of breast cancer increases with age. Male breast cancer is most often diagnosed in men in their 60s.
  • Hormone therapy for prostate cancer or medicines containing estrogen. If you take estrogen-related medicines, such as those used for hormone therapy for prostate cancer, your risk of breast cancer rises.
  • Family history of breast cancer. If you have a blood relative with breast cancer, you have a greater chance of getting the disease.
  • Inherited DNA changes that increase breast cancer risk. Some of the DNA changes that can lead to breast cancer are passed down from parents to children. People born with these DNA changes have a greater risk of breast cancer. For example, the DNA changes BRCA1 and BRCA2 increase the risk of male breast cancer.
  • Klinefelter syndrome. This genetic syndrome occurs when males are born with more than one copy of the X chromosome. Klinefelter syndrome affects the development of the testicles. It causes changes in the balance of hormones in the body, which can increase the risk of male breast cancer.
  • Liver disease. Certain conditions, such as cirrhosis of the liver, can change the balance of hormones in the body. This raises the risk of male breast cancer.
  • Obesity. Obesity is linked with higher levels of estrogen in the body. This increases the risk of male breast cancer.
  • Testicle disease or surgery. Having inflamed testicles, called orchitis, or surgery to remove a testicle, called orchiectomy, can increase the risk of male breast cancer.

Prevention

For most men, there's no way to prevent male breast cancer. For those that have an increased risk of cancer, there may be ways to lower the risk.

  • If breast cancer runs in your family. Certain DNA changes are linked to breast cancer. If these DNA changes run in your family, you might have an increased risk of breast cancer. DNA changes that increase the risk of male breast cancer include BRCA1 and BRCA2.

    If you know that a blood relative carries DNA changes linked to breast cancer, tell your doctor or other health care professional. Together you can decide whether you should have genetic testing to see if you also carry the DNA changes.

    If you carry a DNA change that increases your risk, you might need breast cancer screening. Usually this involves becoming familiar with the skin and tissue on your chest. Tell your health professional if you notice any changes. You also might have an annual exam of your chest.

  • If you're a transgender man. If you haven't had gender-affirming surgery on your chest, talk with your doctor or other health care professional about breast cancer screening. In general, follow the screening guidelines for people assigned female at birth.

    If you've had gender-affirming surgery to your chest, breast cancer is still possible, though it's rare. Often a small amount of breast tissue remains after surgery. Get to know the look and feel of the skin on your chest. Report any changes to your health care team right away.

Sept. 08, 2023

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