A class of drugs already approved for the treatment of estrogen receptor-positive breast cancer may also have the potential to halt the spread of hard-to-treat, triple-negative breast cancer, a new study finds.

Share on Pinterest Researchers found that CDK 4/6 inhibitors reduced the spread of triple-negative breast cancer in various models.

Published in the journal Nature Communications, the study reveals that drugs that block an enzyme pathway called CDK 4/6 – known as CDK 4/6 inhibitors – prevented the spread of triple-negative breast cancer in a number of models.

After skin cancer, breast cancer is the most common cancer among women in the United States. In 2017, approximately 252,710 new cases of invasive breast cancer will be diagnosed in the U.S., and around 40,610 women will die from the disease.

Estrogen receptor-positive (ER-positive) breast cancer is the most common form of breast cancer, whereby the breast cancer cells contain receptors for the hormone estrogen. When these receptors receive signals from the hormone, this can promote cancer cell growth.

Similarly, in progesterone receptor-positive (PR-positive) breast cancer, cancer cells contain receptors for the hormone progesterone that can promote cancer cell growth, while in HER2-positive breast cancer, the cells possess too many receptors for the HER2 gene, which can exacerbate the disease.

Thankfully, there are a number of hormonal therapies and other medications that can target estrogen, progesterone, and HER2 receptors in order to treat breast cancer, and CDK 4/6 inhibitors fall into this category. This class of drugs has been approved for the treatment of ER- and HER2-positive breast cancers.

Now, study co-author Dr. Matthew Goetz, leader of the Women’s Cancer Program at Mayo Clinic in Rochester, MN, and colleagues suggest that CDK 4/6 inhibitors may also be effective for the treatment of triple-negative breast cancer.