Abstract PS6-03: Prognostic value of clinical treatment score post-5 years (CTS5) and late relapse risk in hormone receptor-positive HER2-positive breast cancer in the North Central Cancer Treatment Group (NCCTG) N9831 (Alliance) and NSABP B-31 (NRG) trials

Background: Although risk of late relapse in hormone receptor-positive (HR+) breast cancer is well established, most existing data pertain to the HR+ HER2-negative (HER2-) subgroup. CTS5 is one of the models for predicting risk of late relapse in HR+ HER2- breast cancer. However, the value of this model in HR+ HER2+ disease is less known, particularly in the context of adjuvant trastuzumab. Here, we evaluated CTS5 in patients with early stage...