Association of il-8-251t>a (Rs4073) polymorphism with susceptibility to gastric cancer: A systematic review and meta-analysis based on 33 case-control studies

Abstract

Background – The role of-251A>T polymorphism in the anti-inflammatory cytokine interleukin-8 (IL-8) gene in gastric cancer was intensively evaluated, but the results of these studies were inconsistent. Objective – Therefore, we performed a meta-analysis to provide a comprehensive data on the association of IL-8-251T>A polymorphism with gastric cancer. Methods – All eligible studies were identified in PubMed, Web of Science, EMBASE, Wanfang and CNKI databases before September 01, 2019. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were derived from a fixed effect or random effect model. Results – A total of 33 case-control studies with 6,192 cases and 9,567 controls were selected. Overall, pooled data showed that IL-8-251T>A polymorphism was significantly associated with an increased risk of gastric cancer under all five genetic models, i.e., allele (A vs T: OR=1.189, 95% CI 1.027–1.378, P=0.021), homozygote (AA vs TT: OR=1.307, 95% CI 1.111–1.536, P=0.001), heterozygote (AT vs TT: OR=1.188, 95% CI 1.061–1.330, P=0.003), dominant (AA+AT vs TT: OR=1.337, 95% CI 1.115–1.602, P=0.002) and recessive (AA vs AT+TT: OR=1.241, 95% CI 1.045–1.474, P=0.014). The stratified analysis by ethnicity revealed an increased risk of gastric cancer in Asians and mixed populations, but not in Caucasians. Moreover, stratified by country found a significant association in Chinese, Korean and Brazilian, but not among Japanese. Conclusion – This meta-analysis suggests that the IL-8-251T>A polymorphism is associated with an increased risk of gastric cancer, especially by ethnicity (Asian and mixed populations) and country (Chinese, Korean and Brazilian).