Association of IL-17 polymorphisms with gastric cancer risk in Asian populations

AIM: To investigate associations between the IL-17 rs2275913 G> A and rs763780 T> C polymorphisms and susceptibility to gastric cancer in Asian populations. METHODS: We reviewed studies published up to 2014 on IL-17 polymorphisms with gastric cancer susceptibility systematically. Relevant articles were identified in the MEDLINE, Science Citation Index, Cochrane Library, PubMed, EMBASE, CINAHL and Current Contents Index databases. We used version 12.0 STATA statistical software to evaluate the statistical data. Two reviewers abstracted the data independently. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. RESULTS: Seven independent, case-control studies were chosen for the meta-analysis, which included 3210 gastric cancer patients and 3889 healthy controls. The overall estimation showed a positive association between the IL-17 rs2275913 G> A polymorphism and the occurrence of gastric cancer for five genetic models (all P < 0.05) and similar results were observed for the IL-17 rs763780 T> C variation with four genetic models (all P < 0.05), but not for the dominant model (P > 0.05). Subgroup analysis by country revealed that the rs2275913 G> A and rs763780 T> C polymorphisms may be the main risk factor for gastric cancer in Chinese and Japanese populations. CONCLUSION: The IL-17 gene may be significantly correlated with gastric cancer risk in Asian populations, especially those carrying the rs2275913 G> A and rs763780 T> C polymorphisms.