Predictive serum biomarkers in metastatic colorectal cancer (mCRC) patients treated in the BECOX trial with oxaliplatin-capecitabine (CAPOX) plus bevacizumab (BVZ) (GEMCAD 09-01).

e14647 Background: Despite initial responsiveness, acquired resistance to both BVZ and chemotherapy in mCRC is universal. We have recently published that, chronically oxaliplatin resistant LoVo cell line (LoVo-R) up-regulates soluble VEGF receptor 1 (sVEGFR1), down-regulates vascular endothelial growth factor (VEGF) and also promotes c-MET compared with the parental LoVo cell line (Mezquita, Mol Carcinogenesis 2015). We tested whether variation in three serum biomarkers, VEGF, sVEGFR1 and the hepatocyte growth factor (HGF), were associated with efficacy in mCRC patients (pts) treated in the prospective BECOX study. Methods: Serum levels of VEGF, sVEGFR1 and HGF (the c-MET ligand) were assessed by ELISA method assay basally, and every 3 cycles in a pre-planned translational study. Response was evaluated using RECIST 1.1 criteria by Investigators assessment (IA) and by three blinded independent radiologists (IR), and using morphologic criteria (Chun, JAMA 2009) by IR. Ratios variations of sVEGFR1/VEGF and H...