Quantitative assessment of the association between glutathione S-transferase P1 Ile105Val polymorphism and bladder cancer risk

Previous studies investigating the association between glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism and bladder cancer risk reported controversial results. This study aimed to quantify the strength of the association between GSTP1 Ile105Val polymorphism and bladder cancer risk by performing a meta-analysis. We searched the PubMed, Embase, and Wanfang databases for publications on the association between GSTP1 Ile105Val polymorphism and bladder cancer risk. We estimated the pooled odds ratios (ORs) with their confidence intervals (95 %CIs) to assess the association. Twenty-five individual studies with a total of 12,360 subjects were finally included. Meta-analysis of all 25 studies showed that GSTP1 Ile105Val polymorphism was associated with increased risk of bladder cancer risk under four genetic comparison models (for G versus A, random-effect OR = 1.19, 95 %CI 1.05–1.35; for GG versus AA, random-effect OR = 1.49, 95 %CI 1.12–1.97; for GG/GA versus AA, random-effect OR = 1.20, 95 %CI 1.03–1.39; for GG versus GA/AA, random-effect OR = 1.41, 95 %CI 1.10–1.80). Sensitivity analysis showed that GSTP1 Ile105Val polymorphism was still associated with bladder cancer risk under three genetic comparison models (for G versus A, random-effects OR = 1.13, 95 %CI 1.01–1.26; for GG versus AA, random-effects OR = 1.29, 95 %CI 1.01–1.65; for GG versus GA/AA, random-effects OR = 1.19, 95 %CI 1.04–1.35). No evidence of publication bias was observed. This meta-analysis shows that there is an obvious association between GSTP1 Ile105ValIle105Val polymorphism and bladder cancer risk, and GSTP1 ILE105VAL polymorphism contributes to bladder cancer risk.