title: Association between -251A>T polymorphism in the interleukin-8 gene and oral cancer risk: a meta-analysis.
abstract: BACKGROUND
  Emerging evidence showed that the most common functional polymorphism (-251A>T, rs4073) in the promoter region of the interleukin-8 (IL-8) gene is involved in the regulation of the activities of interleukin-8, thus increasing an individual's susceptibility to oral cancer; but individually published results are inconclusive. The aim of this meta-analysis was to investigate the associations between IL-8 -251A>T polymorphism and oral cancer risk.
  
  
  METHODS
  The PubMed, Embase, Web of Science and CBM databases were searched for all articles published up to October 1st, 2012 that addressed IL-8 -251A>T polymorphism and oral cancer risk. Statistical analyses were performed using STATA 12.0 software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations.
  
  
  RESULTS
  Six case-control studies were included with a total of 1324 oral cancer cases and 1879 healthy controls. When all available studies were pooled into the meta-analysis, the results showed that the AA and AT genotypes of IL-8 -251A>T polymorphism were associated with increased risk of oral cancer (OR=1.23, 95% CI: 1.03-1.46, P=0.025; OR=1.25, 95% CI: 1.07-1.47, P=0.006; respectively). In the subgroup analysis by ethnicity, significant associations were observed between the AA and AT genotypes of IL-8 -251A>T polymorphism and increased risk of oral cancer among Caucasian populations (OR=1.40, 95% CI: 1.14-1.72, P=0.001; OR=1.29, 95% CI: 1.06-1.57, P=0.011; respectively). However, no statistically significant associations were found between IL-8 -251A>T polymorphism and oral cancer risk among Asian populations.
  
  
  CONCLUSIONS
  Results from the current meta-analysis indicate that the AA and AT genotypes of IL-8 -251A>T polymorphism might increase the risk of oral cancer, especially among Caucasian populations.
authors.affiliation: Department of Stomatology, Shengjing Hospital of China Medical University, Shenyang, PR China. wangzm@sj-hospital.org
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wang
authors.forename: Chuanning
authors.initials: C
authors.lastname: Wang
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhao
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
authors.forename: Xinming
authors.initials: X
authors.lastname: Guan
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Lin
authors.forename: Liping
authors.initials: L
authors.lastname: Zhang
mesh_terms: D044466:Asian People; D016022:Case-Control Studies; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics*; D009062:Mouth Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012306:Risk; D044465:White People
chemical_list: D016209:Interleukin-8