Objective: To assess the association between tumor necrosis factor-alpha (TNF-alpha) gene promoter region -308 gene polymorphisms and gastric cancer (GC) susceptibility.
Methods: Published work about TNF-alpha-308 and GC from PubMed, EMBASE, Cochrane library in English and from Wanfang, CBM in Chinese were searched for relevant articles published by the end of July, 2009. Thirty-nine relevant articles were selected and 26 of them met the criteria. The correlated index was extracted for aggregate analysis in RevMan 4.2.
Results: There were 5225 GC patients and 8473 controls for TNF-alpha-308 in 26 papers. Overall, allele contrast (G:A and AA:GG) genotype of TNF-alpha-308 polymorphisms produced significant results in worldwide populations, the OR values were 0.85 (95%CI: 0.76 - 0.96, P = 0.01) and 1.19 (95%CI: 1.01 - 1.39, P = 0.03). Subgroup analysis showed that OR values of G:A and AA:GG in west population were 0.79 (95%CI: 0.70 - 0.89, P < 0.01) and 1.26 (95%CI: 1.04 - 1.52, P = 0.02), while in east populations subgroup analysis, the OR was 0.97 (95%CI: 0.75 - 1.26, P = 0.84). No significant association was observed in non-cardia GC and Helicobacter pylori positive GC, the OR values were 0.90 (95%CI: 0.79 - 1.02, P = 0.10) and 1.08 (95%CI: 0.62 - 1.88, P = 0.79).
Conclusion: TNF-alpha-308 A allele and AA genotype were associated with a statistically significant increased risk of gastric cancer in western people.