Long-term outcomes in women with low-risk hormone-sensitive early-stage breast cancer.

e12583Background: Oncotype DX test is useful in the identification of women who have a low risk of recurrence and can safely avoid chemotherapy. However, there are persistent gaps in knowledge on the use of Oncotype testing in treatment decisions to minimize harms and maximize benefits of chemotherapy among women with favorable prognosis breast cancer. We evaluated long-term outcomes in women diagnosed with early-stage, node negative, hormone receptor positive breast cancer with Oncotype scores of 0-10, using an established Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer model. Methods: A Monte Carlo microsimulation was conducted to project long-term (up to 15+ years) outcomes for any first event, recurrence, distant recurrence, and all-cause mortality among women diagnosed with HER2 negative, ER positive, node–negative breast cancer tumors of 1.1-5.0 cm with Oncotype scores of 0-10. The input parameters were derived from the Oxford Overview and published NSABP trial data. We ...