Definition

Breast cancer is a disease in which cancer cells grow in the breast tissue. Although male breasts do not fully develop, they do contain most of the same basic breast structures as women. Male breasts include small glands called lobules, ducts, and the nipple. These structures are also surrounded by fatty tissue. All of these structures are susceptible to developing breast cancer.

Breast cancer in men is rare. This makes awareness of the disease uncommon.

Types of breast cancer found in men are:

• Infiltrating ductal carcinoma—Cancer starts in the ducts of the breast and spreads into surrounding tissues. This is the most common type of breast cancer in men. It is a non-invasive or pre-invasive cancer.
• Ductal carcinoma in situ—Early stage cancer confined to the ducts. This type has the highest cure rate.
• Infiltrating lobular carcinoma—A rare cancer that starts in the lobules of the breast and spreads into surrounding tissues.
• Paget disease —A rare cancer that starts in the ducts and spreads to the nipple and areola.
• Inflammatory —A rare, but aggressive cancer that occurs with visible changes in the skin around the breast and nipple.

Causes

Cancer occurs when cells in the body divide without control or order. Eventually these uncontrolled cells form a growth or tumor. The term cancer refers to malignant growths. These growths can invade nearby tissues including the lymph nodes. Cancer that has invaded the lymph nodes can then spread to other parts of the body. The lymph nodes most commonly associated with breast cancer are in the armpit, above the collarbone, and in the chest.

It is not clear exactly what causes these problems in the cells, but is probably a combination of genetics and environment.

Cancer Cell Growth Copyright © Nucleus Medical Media, Inc.

Risk Factors

Breast cancer is more common in men aged 65 years and older. Other factors that may increase your risk of developing breast cancer include:

• Family history of breast cancer
• Genetic mutations, such as BRCA1, BRCA2, and others
• Exposure to radiation, especially in the chest
• Exposure to increased levels of estrogen, which may occur with:
  • Klinefelter syndrome
  • Liver diseases
  • Alcohol use disorder
  • Testicular disorders, such as an undescended testicle or mumps orchitis
  • Obesity
  • Gynecomastia —breast tissue growth in men unrelated to excess fat in the chest
  • Prostate cancer treatment
  • Certain occupations, such as exposure to high heat or gasoline fumes

Symptoms

When breast cancer first develops, there may be no symptoms at all. As the cancer grows, it can cause the following changes:

• One or more lumps in the breast, which may or may not be painful
• One or more lumps in lymph nodes near the breast, under your arm, or collarbone that which may or may not be painful
• Changes in the skin or nipple, such as dimpling, puckering, or nipple retraction
• Redness, irritation, or ulceration of the skin in the breast area
• Discharge from the nipple, which may be clear or bloody

Diagnosis

You will be asked about your symptoms and medical history. A physical exam will be done. This includes a thorough manual breast exam and blood tests.

Diagnosis is confirmed with a biopsy. A tissue sample will be removed and examined under a microscope for the presence of cancer cells.

Imaging tests can help with diagnosis and determine the extent of cancer. These may include:

• Mammogram
• Ultrasound
• Chest x-ray
• Bone scan
• MRI scan
• PET scan

The physical exam, combined with all of your test results, will help to determine the type and stage of cancer you have. Staging is used to guide your treatment plan. Breast cancer in men is staged from 1-4. Stage 1 is a very localized cancer, while stage 4 indicates a spread to other parts of the body. Cancer cells may also be graded by how fast they might grow and spread.

Treatment

Cancer treatment varies depending on the stage and type of cancer.

A combination of therapies is most effective. For example, radiation may be used before surgery to shrink the tumor, or after to make sure all the cancer has been removed.

Treatment options include:

Prevention

There are no current guidelines to screen for breast cancer in men. Finding breast cancer early and treating it promptly is the best way to prevent death. Since breast cancer does not cause symptoms in the early stages, be aware of any changes in your body and talk to your doctor about them.