Learning About Apocrine Breast Cancer

Apocrine breast cancer (apocrine carcinoma of the breast) is a rare type of breast cancer. It makes up about 1% of all breast cancers. It is most often found in middle-aged and older adults.

It’s called "apocrine" because the cancer cells look similar to normal cells called apocrine cells that are found in certain glands. It’s a form of invasive ductal carcinoma. That means the cancer starts in a milk duct of the breast and then spreads into tissues around the duct.

Apocrine breast cancer may travel to lymph nodes. How recovery looks can depend on the size of the tumor, if the cancer has spread, and how well it responds to treatment. Many people have a good outcome when the cancer is found and treated early.

In the early stages, apocrine breast cancer often does not cause symptoms. In many cases, it is first found during a mammogram.

As the tumor grows, symptoms may include:

• A lump in the breast.
• Mild breast pain or soreness.
• Thickening in part of the breast.
• Changes in the skin or nipple, such as dimpling, redness, or nipple inversion (less common).

Because early breast cancer may not cause symptoms, it’s important to have screening mammograms. These can help detect breast cancer earlier, when treatment works better. Talk with your doctor about when to get screened.

Doctors use several tests to diagnose this type of cancer. They include:

• Mammogram. This is an X-ray of the breast. It can help show abnormal areas that may not be felt during a physical exam.
• Ultrasound. Breast ultrasound uses sound waves to create images of the breast tissue. It can help doctors learn more about an abnormal area seen on a mammogram or felt during an exam.
• Biopsy. A biopsy is needed to confirm a cancer diagnosis. During a biopsy, a small sample of tissue is removed. The tissue is examined under a microscope to see if it has cancer cells.

After diagnosis, tests may be done on the cancer cells. These tests help guide treatment choices. This type of cancer often doesn’t have estrogen or progesterone receptors like some other breast cancers. It often has androgen receptors. The receptors in cancer cells can affect the types of treatment that will work best.

The types of treatment that your doctor advises will be based on these factors:

• The size of the tumor.
• How abnormal the cancer cells look (grade).
• How far they have spread (stage).
• What receptors they have.
• If there are cancer cells in the lymph nodes.
• Your overall health.

The treatment options can include:

• Surgery. This is usually the main treatment for apocrine breast cancer. Surgery options include:
  • Lumpectomy. This is done to remove the tumor and a small amount of surrounding tissue.
  • Mastectomy. This is done to remove all or most of the breast.
• Radiation therapy. This is often used after a lumpectomy to help destroy any remaining cancer cells. It can reduce the risk of the cancer returning.
• Chemotherapy. This is the use of medicines to kill cancer cells throughout the body. It may be used depending on the stage and features of the tumor.
• Targeted therapy. Some apocrine breast cancers may respond to targeted therapies if specific markers are found in the cancer cells. These treatments target certain proteins or pathways involved in cancer growth.

Hormone therapy is not often used. This is because many apocrine breast cancers do not use estrogen or progesterone to grow.

A diagnosis of apocrine breast cancer can feel overwhelming. Support is available for both patients and caregivers.

Some options for getting support include:

• Breast cancer support groups.
• Counseling or therapy.
• Patient advocacy organizations.
• Talking with your care team so that they can connect you to services.