Significant Association of Glutathione S-Transferase T1 Null Genotype with Prostate Cancer Risk: A Meta-Analysis of 26,393 Subjects

BACKGROUND Recent studies on the association between Glutathione S-transferase T1 (GSTT1) polymorphism and risk of prostate cancer showed inconclusive results. To clarify this possible association, we conducted a meta-analysis of published studies. METHODS DATA WERE COLLECTED FROM THE FOLLOWING ELECTRONIC DATABASES: Pubmed, Embase, and Chinese Biomedical Database (CBM). The odds ratio (OR) and its 95% confidence interval (95%CI) was used to assess the strength of the association. We summarized the data on the association between GSTT1 null genotype and risk of prostate cancer in the overall population, and performed subgroup analyses by ethnicity, adjusted ORs, and types of controls. RESULTS Ultimately, a total of 43 studies with a total of 26,393 subjects (9,934 cases and 16,459 controls) were eligible for meta-analysis. Overall, there was a significant association between GSTT1 null genotype and increased risk of prostate cancer (OR = 1.14, 95%CI 1.01-1.29, P = 0.034). Meta-analysis of adjusted ORs also showed a significant association between GSTT1 null genotype and increased risk of prostate cancer (OR= 1.34, 95%CI 1.09-1.64, P = 0.006). Similar results were found in the subgroup analyses by ethnicity and types of controls. CONCLUSION This meta-analysis demonstrates that GSTT1 null genotype is associated with prostate cancer susceptibility, and GSTT1 null genotype contributes to increased risk of prostate cancer.