Polymorphism of IL-8 in 251 Allele and Gastric Cancer Susceptibility: A Meta-Analysis

The relationship of gastric cancer to the presence of interleukin-8 (IL-8) 251 T/A has been reported with conflicting results. To further explore the association of IL-8 251 allele polymorphism with gastric cancer susceptibility. We performed an extensive search of relevant studies and carried out a meta-analysis, including ten studies with 2,195 gastric cancer cases and 3,505 controls, to obtain a more precise estimate. The combined results based on all studies showed that the IL-8 251 allele AA genotype was a risk factor for gastric cancer [AA versus TT: odds ratio (OR) = 1.363, 95% confidence interval (CI): 1.199-1.527]. In subgroup analysis, a clear effect of AA in IL-8 251 allele was shown in Asians (AA versus TT: OR = 1.593, 95% CI: 1.013-2.173) but not in Caucasians or Mexicans. When stratified by Lauren classification, we found that the IL-8 251 allele TA and AA polymorphism was significantly associated with the diffuse type of gastric cancer (TA versus TT: OR = 1.448, 95% CI: 1.177-1.720; AA versus TT: OR = 1.586, 95% CI: 1.128-2.044). The IL-8 251 AA genotype was found to be a risk factor for cardiac gastric cancer (AA versus TT: OR = 1.840, 95% CI: 1.112-2.568) but not for noncardiac gastric cancer. This meta-analysis suggested that IL-8 251 allele A > T polymorphism might be a risk factor for gastric cancer.