No associations of Toll-like receptor 2 (TLR2)-196 to-174del polymorphism with the risk of Helicobacter pylori seropositivity, gastric atrophy, and gastric cancer in Japanese

Recently, the association between gastric cancer risk and a functional polymorphism of Toll-like receptor 2 (TLR2), -196 to -174del, was reported for a Japanese population. This study aimed to confirm the associations of the polymorphism with the risk of gastric cancer, as well as Helicobacter pylori seropositivity and the risk of gastric atrophy in Japanese. The study subjects were 583 histologically diagnosed gastric cancer patients and 1636 age- and sex-frequencymatched control outpatients who visited Aichi Cancer Center Hospital from the years 2001 to 2005. Serum anti-H. pylori IgG antibody and pepsinogens were measured to evaluate H. pylori infection and gastric atrophy, respectively. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by a logistic model. The age- and sex-adjusted ORs of gastric cancer were 1.13 (95% CI: 0.88-1.46) for ins/del, 1.17 (95% CI: 0.79-1.73) for del/del, and 1.14 (95% CI: 0.89-1.45) for ins/del + del/del, relative to the ins/ins genotype compared with gastric atrophy controls; none of these findings were statistically significant. The TLR2 -196 to 174del polymorphism was not significantly associated with either H. pylori seropositivity or gastric atrophy. Our study did not reproduce the association between gastric cancer risk and the TLR2 -196 to -174del polymorphism in Japanese. Further examinations with sufficient numbers of study subjects are required to verify our findings.