Association of GSTT1 gene polymorphisms with the risk of prostate cancer: an updating meta-analysis.

It has been demonstrated that the glutathione S-transferase (GST) superfamily helps remove carcinogens from the body and thus might be associated with prostate cancer risk. In recent years, GSTT1 polymorphism has been extensively studied as a potential prostate cancer risk factor; however, the results are inconsistent. To investigate the association between GSTT1 and prostate cancer, we conducted a meta-analysis of 33 studies with 6,697 prostate patients and 7,643 controls. For GSTM1 null versus present genotype, the random effects odds ratio was 0.98 (95 % confidence interval (CI) 0.83-1.16) based on a wide population. Subgroup analyses in the different ethnic groups and different controls were performed. The OR was 1.01 (95 % CI 0.86-1.19) in Caucasians, 1.01 (95 % CI 0.70-1.47) in Asians, and 0.77 (95 % CI 0.42-1.42) in Africans. The OR was 0.98 (95 % CI 0.82-1.16) in non-benign prostate hyperplasia (BPH) controls and 1.09 (95 % CI 0.66-1.79) in BPH controls. In conclusion, our present meta-analysis demonstrates that there is no association between GSTT1 polymorphism and prostate cancer, even in the sub-analysis concerning different races and control sources. The direction of further research should focus not only on the simple relationship of GSTT1 and prostate cancer but also on gene-environment interaction and distinctions of different GSTs.