Purpose: Several studies have evaluated the efficacy of neoadjuvant treatment using oxaliplatin and fluoropyrimidines in advanced gastric cancer(GC).However,preoperative biomarkers for clinical outcomes are lacking.We studied polymorphisms in the MTHFR,DPYD,UMPS,ABCB1,ABCC2,GSTP1,ERCC1,and XRCC1 genes to evaluate their usefulness as pharmacogenetic markers in a cohort of 103 patients with GC treated with preoperative chemotherapy.