Lack of association between −174G>C and −634C>G polymorphisms in interleukin-6 promoter region and lung cancer risk: a meta-analysis

Evidence suggested that the -174GC and -634CG polymorphisms in interleukin-6 (IL6) promoter region may modulate risk of lung cancer; however, the conclusion was still inconclusive. Therefore, we performed this meta-analysis to determine the association between IL6 -174GC and -634CG polymorphisms and lung cancer risk. The association strength was measured by odds ratios (ORs) and 95% confidence intervals (CI). Egger's test and Begg's test were performed to detect potential publication bias. By searching PubMed, EMBASE and China National Knowledge Infrastructure, we included 16 eligible studies in this meta-analysis, involving 6,202 lung cancer cases and 7,067 controls. Five studies about -174GC polymorphism and 11 studies about -634CG polymorphism were analyzed. By pooling eligible studies, we found no significant association of -174GC with lung cancer risk (C vs. G: OR = 1.029; 95% CI, 0.957-1.106; heterogeneity, P = 0.478) and no statistic association of -634CG with lung cancer susceptibility (G vs. C: OR = 1.050; 95% CI, 0.893-1.235; Heterogeneity, P0.001). No significant publication bias was observed. In conclusion, we found that -634CG and -174GC polymorphisms in IL6 promoter region were not associated with lung cancer risk.