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. © 2013 Elsevier B.V.