Good news for women with breast cancer: Many don't need chemo

The results of a new study indicate that many women with early-stage breast cancer who would receive chemotherapy under current standards do not need it.

The results of a new study indicate that many women with early-stage breast cancer who would receive chemotherapy under current standards do not need it. The TAILORx study, published online in the <a href="https://www.nejm.org/doi/full/10.1056/NEJMoa1804710?query=main_nav_lg&q…; target="_blank"><i>New England Journal of Medicine</i></a> and presented Sunday at a meeting of the American Society of Clinical Oncology in Chicago, concluded that gene tests on tumor samples were able to identify women who could safely skip chemotherapy and only take a drug that blocks estrogen or stops the body from making it. "We can spare thousands and thousands of women from getting toxic treatment that really wouldn't benefit them," said Ingrid A. Mayer, MD, from Vanderbilt University Medical Center, an author of the study. "This is very powerful. It really changes the standard of care." The research, which began in 2006 and eventually included more than 10,000 women aged 18&#8211;75 years, was backed by the U.S. and Canadian governments, among others. For the study, among the 9,719 women with complete followup information, 70% had scores of 11&#8211;25 on the Oncotype DX Breast Cancer Assay. Previous research has shown that scores of 10 and under on the test do not call for chemo, while scores higher than 25 do. The participants had surgery and radiation and were then randomly assigned to receive either endocrine therapy only or endocrine therapy and chemo, with a median followup time of more than 7 years. After 9 years, 93.9% of the endocrine-only group were still alive, compared with 93.8% of the combined therapy group. In addition, 83.3% of the endocrine group were free of invasive disease, versus 84.3% of those who received both treatments. According to Joseph A. Sparano, MD, of Montefiore Medical Center in New York, the leader of the study, the findings apply to about 60,000 women each year in the United States. However, the authors also noted the data suggested that some women aged 50 years and younger may do well to receive chemotherapy, even if the results of the gene tests indicate otherwise. The reasons for this are not clear; however, they said these women require particularly careful consultation.