GSTP1 Ile105Val polymorphism is associated with lung cancer risk among Asian population and smokers: an updated meta-analysis.

Many studies have examined the association between the GSTP1 Ile105Val (rs 1695) gene polymorphism and lung cancer risk in various populations, but their results have been inconsistent. To assess this relationship more precisely, a meta-analysis was performed. The PubMed and CNKI database was searched for case-control studies published up to July 2012. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. Ultimately, 42 studies, comprising 12,304 lung cancer cases and 15,729 controls were included. Overall, for G allele carriers (GA + GG) versus homozygote AA, the pooled OR was 1.05 (95% CI 0.99-1.10 P = 0.092 for heterogeneity), for GG versus AA the pooled OR was 1.04 (95% CI 0.96-1.12 P = 0.084 for heterogeneity). In the stratified analysis by ethnicity, gender, histological types of lung cancer and smoking status, a significant association was found in Asians and smokers, not in Caucasian or mixed population, Male, Female population, lung AC, SCC, SCLC or non-smokers. Publication bias was found by using the funnel plot and Egger's test. Overall, there is no evidence showing a significant correlation between GSTP1 Ile105Val gene polymorphism and lung cancer risk in overall population, however stratified analysis by ethnicity, histology, gender and smoking status, it correlate with increased lung cancer susceptibility among Asians and smokers.