Glutathione S-transferase M1 and T1 null genotypes and bladder cancer risk: A meta-analysis in a single ethnic group

Aim of Study: To further evaluate the influence of glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) null genotypes on bladder cancer risk, we conducted a meta-analysis in the Chinese population. Materials and Methods: PubMed and Chinese databases were electronically searched through April 2016. Results: Nine studies were included for our meta-analysis, involving 1646 bladder cancer cases and 1938 controls. In general, our findings indicated that a significant association existed between GSTM1-null genotype and the risk of bladder cancer in the studied Chinese population (odds ratio = 1.56, 95% confidence interval: 1.36–1.79). However, no significant association between GSTT1 polymorphism and bladder cancer was found. After stratification of the subgroup analyses by source of controls and geographical areas, a substantially elevated risk was revealed between GSTM1-null genotype and bladder cancer in the population-based studies and those conducted in South China and North China. Conclusion: Our meta-analysis suggested that GSTM1-null genotype is associated with an increased bladder cancer risk in the Chinese individuals.