Gene polymorphisms in the ornithine decarboxylase–polyamine pathway modify gastric cancer risk by interaction with isoflavone concentrations

Background The study aimed to examine the association between genes encoding molecules in the ornithine decarboxylase (ODC)–polyamine pathway ( ODC1 , AMD1 , NQO1 , NOS2A , and OAZ2 ) and gastric cancer risk and whether the gene–phytoestrogen interaction modifies gastric cancer risk. Methods Among 76 gastric cancer cases and their 1:4 matched controls within the Korean Multi-center Cancer Cohort, a total of 30 SNPs in five genes involved in the ODC pathway were primarily analyzed. The second-stage genotyping in 388 matched case–control sets was conducted to reevaluate the significant SNPs interacting with phytoestrogens during the primary analysis. The summary odds ratios (ORs) [95 % confidence intervals (CIs)] for gastric cancer were estimated. Interaction effects between the SNPs and plasma concentrations of phytoestrogens (genistein, daidzein, equol, and enterolactone) were evaluated. Results In the pooled analysis, NQO1 rs1800566 showed significant genetic effects on gastric cancer without heterogeneity [OR 0.83 (95 % CI 0.70–0.995)] and a greater decreased risk at high genistein/daidzein levels [OR 0.36 (95 % CI 0.15–0.90) and OR 0.26 (95 % CI 0.10–0.64), respectively; p interaction