Metastatic Breast Cancer

Definition

Metastatic breast cancer is the most advanced stage of breast cancer. Breast cancer develops when abnormal cells in the breast start to divide uncontrollably. A tumor is a mass or collection of these abnormal cells.

Metastasis refers to cancer cells that have spread to a new area of the body. In metastatic breast cancer, cells may spread to the:

Bones
Brain
Liver
Lungs

Healthcare providers name cancer based on its primary origin. That means breast cancer that spreads to other body parts is still considered breast cancer. The cancer cells are still breast cancer cells. Your care team will use breast cancer therapies, even if the cancer cells are in other areas.

De novo metastatic breast cancer means that at the time of initial diagnosis, the breast cancer has already spread to other parts of the body. In the absence of treatment, the cancer spreads.

There is nothing you can do to keep breast cancer from metastasizing. And metastatic breast cancer doesn’t happen because of something you did.

Around 170,000 people in the United States are living with metastatic breast cancer, according to the Cleveland Clinic. Fewer than 1 in 3 women who are diagnosed with early-stage breast cancer later develop metastatic breast cancer.

Although breast cancer is more common in white women, Black women are more likely to develop advanced-stage disease, according to a study published in September 2018 by the journal Cancer.

Black women are also more likely than white women to be diagnosed at a younger age, and have more aggressive forms of breast cancer — including metastatic cancer, according to the Centers for Disease Control and Prevention (CDC).

As a result, Black women are also up to 40 percent more likely to die from the disease than women from other racial and ethnic backgrounds and to develop breast cancer before turning 50, the CDC says.

The cause for this is likely due to Black women being twice as likely as white women to develop triple-negative breast cancer, the National Institutes of Health (NIH) reports.