According to a large, long-term study recently published in the New England Journal of Medicine, a test called the OncotypeDX can accurately predict whether a breast cancer patient should receive chemotherapy as part of her treatment.
The OncotypeDX text examines 21 genes in tumor biopsies and assigns a score of 0 to 100 based on the chances for cancer to spread or recur. In this study, 15.9 percent of the 10,253 women participants had a score between 1 and 10. They were prescribed endocrine therapy (such as the drug tamoxifen) and no chemotherapy. Five years after treatment, the study found a 98 percent survival rate among these women and less than 2 percent chance that the cancer had spread. Researchers are also continuing to study an additional 68 percent of the women who had a score between 11 and 25. They were randomly assigned either endocrine therapy alone or endocrine therapy plus chemotherapy.
“This should provide a lot of reassurance to women and their physicians,” says Dr. Kathy Albain, an oncologist at Loyola University Medical Center. “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.”
The OncotypeDX test costs approximately $4000 and is covered by Medicare and other insurers, and most importantly, it is one more step toward precision treatment.