Genetic variants of TCF7L2 and AXIN2 predict gender and tumor location-dependent clinical outcome in FIRE-3 trial: A validation study.

3602 Background: Wnt signaling pathway genes TCF7L2 and AXIN2 complex control the proliferation and differentiation of intestinal epithelial cells. Our previous study showed that TCF7L2 and AXIN2 polymorphisms(SNPs) were associated with clinical outcome of mCRC patients(pts) treated with first line FOLFIRI/BEV from TRIBE (arm A) and PROVETTA trials (n=455) (ASCO 2013#3566). Our data demonstrated that the association of TCF7L2rs7903146 and AXIN2 rs2240308 snps with PFS and OS is depended on gender and location. The goal of the current study was to prospectively validate our previous findings in mCRC pts enrolled in FIRE-3 clinical trial, which treated with either first line FOLFIRI/BEV or FOLFIRI/cetuximab. Methods: Genomic DNA was isolated from tissue samples of 592 pts (patient characteristics gender, median age median follow up) treated with first-line FOLFIRI/ bevacizumab (n=295) or FOLFIRI cetuximab (n=297) from the FIRE-3 trial (NCT00433927). All pts were KRAS exon 2 wild-type. The bevacizumab arm se...