Survival outcomes by hormone receptor expression in early-stage HER2-positive breast cancer

e12050 Background: The clinical heterogeneity seen in HER 2 positive breast cancer (BC), mostly related to hormone receptor (HR) expression has been suggested to underlie the variability of response not only to endocrine treatments, but also to anti-HER-2 therapies. Herein, we describe our single institution experience with clinical outcomes by HR expression in early HER 2 positive BC. Methods: An IRB-approved single-institution retrospective analysis was performed for 400 consecutive patients with non-metastatic HER 2 + BC treated at the Ohio State University Comprehensive Cancer Center from 2005-2015. Medical records were reviewed for clinic-pathologic, treatment, and survival information. Disease Free Survival (DFS) was defined as time from diagnosis to first recurrence (loco-regional or distant recurrence) including second primary BC or death. Overall survival (OS) was defined as time from diagnosis to death or last known follow up. OS and DFS estimates were generated using Kaplan Meier methods and compared using Log-rank tests. Cox proportional hazard models were used to calculate univariate and multivariate hazard ratios for OS and DFS. Results: a total of 180/400(45%) patients were diagnosed with HR positive disease. The mean age was 54.1y and patients were predominately white (267, 84%), post-menopausal (190, 60%) and presented with invasive ductal cancer (293, 92%). HR negative disease was significantly associated with high tumor grade (72% vs. 52%, p