title: Positive association between Interleukin-8 -251A > T polymorphism and susceptibility to gastric carcinogenesis: a meta-analysis.
abstract: BACKGROUND
  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.
  1.14 [1.02, 1.26], P = 0.02), especially gastric cancer (A vs.
  1.15 [1.03, 1.29], P = 0.02), but not associated with the risk of precancerous lesion (A vs.
  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.
authors.affiliation: Department of Transfusion, First Hospital of China Medical University, North Nanjing Street, No, 155, Shenyang 110001, Liaoning, PR China. dayecheng_cmu@163.com.
authors.forename: Daye
authors.initials: D
authors.lastname: Cheng
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Hao
authors.forename: Wenling
authors.initials: W
authors.lastname: Zhou
authors.forename: Yiran
authors.initials: Y
authors.lastname: Ma