Positive association between Interleukin-8-251A > T polymorphism and susceptibility to gastric carcinogenesis: a meta-analysis

Backgrounds: The associations between the polymorphisms of interleukin-8 (IL-8) gene and gastric carcinogenesis have been extensively investigated in recent years. However, the results remain conflicting rather than conclusive. Methods: A meta-analysis of 18 eligible studies was performed to evaluate the association of IL-8 -251A>T polymorphism with risk of gastric carcinogenesis. A systematic literature search of MEDLINE, Embase, and Web of Science, CNKI databases was conducted. Statistical analysis was performed by using the Revman 5.1 software and the Stata 12.0 software. Results: Of the 293 unique studies identified using our search criteria, 18 studies fulfilled our inclusion criteria and were included in the meta-analysis. These studies cumulatively reported 5,321 cases and 6,465 controls. The combined results based on all studies showed that the IL-8 -251A>T polymorphism was associated with the risk of gastric carciongenesis (A vs. T: OR: 1.14 [1.02, 1.26], P = 0.02), especially gastric cancer (A vs. T: OR: 1.15 [1.03, 1.29], P = 0.02), but not associated with the risk of precancerous lesion (A vs. T: OR: 1.09 [0.99, 1.20], P = 0.08). Analysis stratified by ethnicity may seem that IL-8 -251A> T polymorphism was susceptible to gastric cancer in Asian population, but not in Caucasian population. Conclusions: Our meta-analysis results provide evidence that IL-8 -251A> T polymorphism is significantly associated with increased risk of gastric carcinogenesis in Asian population, particularly in gastric cancer. Further large and well-designed studies are required to confirm this conclusion.