Association of interleukin-17 gene polymorphisms and Helicobacter pylori infection with gastric cancer susceptibility: a cumulative and comprehensive meta-analysis.

BACKGROUND

The association between Interleukin-17(IL-17) gene polymorphisms and Helicobacter pylori (H. pylori) infection and gastric cancer susceptibility were inconsistent. We therefore performed a comprehensive meta-analysis about all three genetic polymorphisms of IL-17 to derive a more precise estimation.

METHODS

PubMed, Embase, CNKI and Wanfang databases were researched on the associations between IL-17A rs2275913G>A, rs3748067C>T and IL-17F rs763780 T>C and gastric cancer risk. Odds ratio (OR) with a 95% confidence interval (CI) was applied to assess the relationships. Publication bias, sensitivity and cumulative analysis was conducted to guarantee the strength of meta-analysis.

RESULTS

Overall, eleven related studies involving 4,478 cases and 5,612 controls were collected. Significantly increased risk between IL-17A rs2275913G>A polymorphism and gastric cancer were observed (A vs. G: OR = 1.22, 95% CI = 1.08-1.37, P<0.01, I(2) = 72.3%; AA vs. GG: OR = 1.55, 95% CI = 1.21-1.99, P<0.01, I(2) = 74.3%; GA + AA vs. GG: OR = 1.19, 95% CI = 1.05-1.39, P<0.01, I(2) = 48.2%; AA vs. GG + GA: OR = 1.50, 95% CI = 1.16-1.95, P<0.01, I(2) = 81.2%). For IL-17F rs3748067C>T and rs763780 T>C polymorphisms, only few significantly increased risk could be found in genetic models. Moreover, H. pylori infection also be proved to increase the risk of gastric cancer combined with rs3748067C>T mutation.

CONCLUSIONS

Our meta-analysis suggests that the three IL-17 polymorphisms were associated with a significantly increased risk of gastric cancer, especially in Chinese.