Kras Mutation Status To Predict Response In First-Line Capox And Bevacizumab Therapy For Metastatic Colorectal Cancer.

536Background: Capecitabine and Oxaliplatin (CAPOX) combined with the humanised anti-vascular endothelial growth factor Bevacizumab represents a standard first-line treatment for metastatic colorectal cancer (mCRC). However, the response rate is only approximately 50% and currently there is no biomarker to predict treatment response. This study aims to correlate KRAS status with response to CAPOX and Bevacizumab (CAPOX-Bev). Methods: Forty-five patients with mCRC were retrospectively screened between January 2012 and December 2015 at Broomfield Hospital, UK. DNA was extracted from formalin-fixed paraffin-embedded (FFPE) tissue samples (Qiagen FFPE tissue kit). Twelve types of mutations in Exons 2, 3 and 4 of the KRAS gene were analysed using a real-time quantitative polymerase chain reaction (qPCR) assay (EntroGen). Treatment response was assessed according to RECIST criteria version 1.1 by comparing pre-treatment and post-treatment radiological CT scans. The KRAS status was correlated with CT tumour resp...