A 21-gene test can accurately predict whether women with breast cancer can be treated without chemotherapy, according to a large, long-term study.
The test, called the OncotypeDX, examines the expression of 21 genes in tumor biopsies. Based on the results of the test, researchers were able to correctly predict whether endocrine therapy or endocrine therapy with chemotherapy is best for individual patients.
Researchers said the study, published in the New England Journal of Medicine, is significant because of a lack of good options to help doctors select the safest, most effective course of treatment.
"This should provide a lot of reassurance to women and their physicians," said Dr. Kathy Albain, an oncologist at Loyola University Medical Center, in a press release. "In women whose breast cancer scored low on the multigene test, there was outstanding survival with endocrine therapy alone. The test provides us with greater certainty of who can safely avoid chemotherapy."