Community clinical practice patterns and mortality in patients with intermediate oncotype DX recurrence scores: Who benefits from chemotherapy?

Abstract

Background: The Oncotype DX recurrence score (RS) is used as a tool for making decisions about chemotherapy for patients who have hormone receptor (estrogen receptor or progesterone receptor)-positive, HER2-negative breast cancer. There is no benefit from chemotherapy among patients aged ≥50 years who have lymph node-negative disease and an RS from 11 to 25, but the benefit of chemotherapy in the lymph node-positive group remains unknown. Methods: On the basis of data from the National Cancer Data Base between 2010 and 2014, a nationwide, retrospective cohort study included 73,185 women who had stage I through IIIA breast cancer and an RS between 11 and 30. Results: Receipt of chemotherapy was associated with a reduced risk of death among patients who had lymph node-positive breast cancer (hazard ratio [HR] 0.58; 95% confidence interval [CI], 0.45-0.74; P