Who Needs Chemotherapy for Breast Cancer?
The University of Wisconsin Carbone Cancer Center took part in a large clinical trial to determine the best treatment for women with early stage breast cancer. The findings, announced in early June, showed the majority of women with the most common form of early breast cancer do not need chemotherapy as long as they take medications that block estrogen. A test on tumors removed during surgery can show which women need chemotherapy and which can safely skip it.
Carbone Cancer Center breast cancer oncologist Dr. Kari Wisinski answers some questions on these new findings.
Who needs chemotherapy for breast cancer?
These new results only apply to women with early stage breast cancer, meaning it has not spread to the lymph nodes or elsewhere in the body. The tumor is tested for three receptors: the two hormone receptors (estrogen and progesterone) and the HER2 receptor. These help oncologists divide breast cancer into subtypes. Most patients with triple negative or HER2 positive breast cancer subtypes are still recommended to undergo chemotherapy, sometimes even before surgery. For patients with hormone receptor positive, HER2 negative breast cancers, this test (called Oncotype Dx) of cancer-related genes helps guide the decision on whether chemotherapy is necessary.
What are the side effects of chemotherapy for breast cancer?
There are several different combinations of chemotherapy that are used for the treatment of breast cancer, and side effects depend on the combination. Some common side effects include fatigue, nausea or vomiting, hair loss (which sometimes can be prevented with scalp cooling), numbness or tingling in the hands or feet. Another serious side effect can be reduced white blood cell counts, which are important for fighting infections.
What are the alternatives to chemotherapy for early stage breast cancer?
The same receptors that we discussed above give us targets for other types of medication. For hormone receptor positive breast cancers, anti-estrogen therapies are recommended. These include tamoxifen or the aromatase inhibitors. For HER2 positive breast cancers, antibodies directed against HER2 are often added to chemotherapy. These medications are trastuzumab and, sometimes, pertuzumab. The study found that women with hormone receptor positive, HER2 negative breast cancer with low oncotype scores did just as well taking the anti-estrogens alone as those who also received chemotherapy.
Susan Lampert Smith
Date Published: 06/06/2018