Not All Breast Cancers Need Chemotherapy

Breast cancer is the most common cancer diagnosis among women. Many times when a woman hears the words “breast cancer,” they often think that it will be a long road of surgery, radiation, and chemotherapy. However, with small tumors and no cancer in the lymph nodes, this is not always the case.

Approximately 80% of breast cancers are driven by estrogen (called estrogen receptor positive). This means that individual breast cancer cells receive a signal from estrogen that allows each of those cells to multiply. After surgery and radiation, women who have small estrogen receptor positive breast cancers may be able to skip chemotherapy and only need to take an estrogen-blocking pill. In 2003, a new test was developed, called Oncotype DX, to help determine who will need chemotherapy in addition to the pill and who can skip chemo. The patients who need chemotherapy have a higher risk of cancer coming back somewhere else in the body, and they can reduce that risk with chemotherapy. An update to this test, published in June 2018, identified even more women who can skip chemotherapy and only need to take the anti-estrogen pill. In fact, with the use of this test and other tests like it, such as Mammaprint and Endopredict, women with estrogen receptor-positive breast cancer have the chance for a more personalized approach to treating their cancer without chemotherapy.

When breast cancer is diagnosed, doctors not only test for estrogen. But, they also test for a cancer protein called HER2. If this cancer protein is found, the breast cancer, certain medications are used to target just those cancer cells. Unlike estrogen, these medications are given through an IV and aren’t in pill form. Breast cancer that has this cancer protein is more aggressive and more likely to spread to other parts of the body. Unfortunately, two or three chemotherapies are often recommended in addition to the medications that target the cancer protein. However, new research in breast cancer shows that almost all small HER2 cancers do not come back when only one chemotherapy and one HER2 target medication is used. Currently, there is ongoing breast cancer research to find out if these small tumors can be cured with targeted medications alone.

However, in triple negative breast cancer, it is not driven by estrogen and does not have the HER2 protein. Chemotherapy is the only recommended treatment. This is because the triple negative is the most aggressive type of breast cancer, the most likely to spread to other parts of the body, and there are no targets that can be used to treat cancer.

Whether the breast cancer is small or large, it can be treated by chemotherapy or a pill. Also, breast cancer that is not metastatic remains very curable. As more breast cancer research occurs, there may be treatments that allow all kinds of breast cancer to avoid chemotherapy.

Dr. Melanie Anne Sheen, MD, is a Hematology/Oncology specialist for Crescent City Physicians, Inc. She attended and graduated from Tulane University School Of Medicine in 2010. She has more than 8 years of diverse experience in Hematology and Oncology.