Left Versus Right: Does Location Matter For Refractory Metastatic Colorectal Cancer (Mcrc) Patients In Phase I Clinical Trials?

771Background: Location of the primary tumor is prognostic and predictive of efficacy with VEGF-inhibitors (I) vs EGFR-I given first-line to mCRC patients (pts) (ASCO 2016). However, little is known regarding the effect of location on prognosis and prediction in heavily pretreated mCRC pts. We assessed the efficacy of VEGF-I and EGFR-I in regards to location of the primary tumor in pts with refractory mCRC enrolled in early phase studies. Methods: A historical cohort analysis of mCRC pts enrolled amongst 44 phase I trials at the IDD from 3/2004 - 9/2012. Median Progression free survival (mPFS) and overall survival (mOS) were estimated from Kaplan-Meier curves and groups were statistically compared with the log rank test. The magnitude of association between dichotomous factors and survival was estimated with the hazard ratio (HR). Results: 139 pts, median age 59 (33-81), KRAS mut 20 %, wt 31 %, unknown 49 %. ≥ 3 prior lines therapy 73.9 %; Prior EGFR-I 75.5% (100% of KRAS wt). Location: Right 20.9 %, Left...