Abstract P6-10-25: Characterization of the tumor immune microenvironment (TME) in early stage HR-positive HER2-positive breast cancer

Background: In patients (pts) with early stage HER2-positive breast cancer (BC) who are treated with combination neoadjuvant chemotherapy (NAC) and HER2-targeted therapy, recent studies report that increased tumor infiltrating lymphocyte (TIL) density is associated with higher rates of pathologic complete response (pCR) and improved overall survival. However, in the subset of HER2-positive pts who are hormone receptor (HR)-positive, less is known about the relationship between the composition of the tumor immune infiltrate and clinical outcomes. In this study, we sought to characterize the TME of pts with early stage HR+ HER2+ BC using HE 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-10-25.