Pharmacogenetic profiling for oxaliplatin-based adjuvant chemotherapy (CT) benefit in stage II-III colon cancer (CC) patients: A GEMCAD study.

3618 Background: Identifying molecular biomarkers for tumour recurrence is critical in successfully selecting early-stage CC patients who are more likely to benefit from adjuvant CT. We tested whether single nucleotide polymorphisms (SNP) within genes involved in biological pathways of interest for CC progression and treatment resistance would predict the risk of recurrence in stage II-III CC patients treated with oxaliplatin and fluoropyrimidines-based adjuvant CT. Methods: Genomic DNA was extracted from formalin-fixed paraffin-embedded samples from 202 surgically treated high-risk stage II (29.7%) and stage III (70.29%) CC patients receiving adjuvant CT (25.24% FOLFOX, 74.75% XELOX) from January 2004 to December 2008. Minimum follow-up was 36 months. Genotyping was performed for 62 SNPs in 31 genes using the MassARRAY (SEQUENOM) technology. Our results were validated in an independent cohort of 177 stage II-III CC. Results: After a median follow-up of 51.4 months (7-96), 63 patients (31.18%) had experie...