Is Chemo for Breast Cancer overprescribed?

According to a landmark study, a large percentage of individuals with the most common form of early breast cancer could safely skip chemotherapy. The findings could impact thousands of people each year.

While new therapies such as immunotherapies are becoming increasingly crucial in treating cancer, chemotherapy is still a mainstay. Though chemotherapy is effective, it carries with it a range of significant side effects, such as hair loss, increased risk of bleeding, susceptibility to infection, nausea, vomiting, and anemia. Consequently, chemotherapy is only used when deemed entirely necessary. The challenge lies in determining exactly when it is entirely necessary.

Individuals with breast cancer sometimes have their tumors analyzed using a gene test called the Oncotype DX test. This examines how active 21 specific genes are provides a “recurrence score” of 0-100. When scores are high, chemotherapy will be used following surgery or radiation therapy to lower the risk of the cancer returning. For individuals with low scores, the tumors are considered less dangerous, and chemotherapy is not deemed essential.

This type of testing has proven useful but there is a substantial gray area. As it stands, those who score 1-10 do not receive chemotherapy and those who score above 25 do. The majority of women, however, fall in the intermediate range of 11-25.

To get a better picture of who needs treatment, researchers from Loyola Medicine and Montefiore Medical Center undertook a large-scale investigation. Their findings are now published in the New England Journal of Medicine.

They used data from more than 10,000 women with hormone-receptor-positive, HER-2 negative breast cancer – the most common form of breast cancer, accounting for about half of breast cancer cases in the United States. Of particular interest were the 69% of women who had scored 11-25 on the 21-gene test.