Association between the GSTP1 Ile105Val polymorphism and prostate cancer risk: a systematic review and meta-analysis.

Many studies have reported the role of glutathione S-transferase P1 (GSTP1) Ile105Val polymorphism with prostate cancer (PCa) risk. However, these studies have yielded conflicting results. Hence, we performed this meta-analysis to investigate the association between GSTP1 Ile105Val polymorphism and PCa in different inheritance models. A total of 13 eligible studies were pooled into this meta-analysis. There was significant association between the GSTP1 Ile158Val variant genotypes and PCa for Ile/Ile vs Val/Val comparison [odds ratio (OR) =0.705; I (2) =63.7 %; 95 % confidence interval (95 % CI) = 0.508-0.977], Ile/Val vs Val/Val comparison (OR=0.736; I (2) =8.0 %; 95 % CI=0.613-0.883), and dominant model (OR=0.712; I (2) =45.5 %; 95 % CI=0.555-0.913). However, no associations were detected for other genetic models. In the stratified analysis by ethnicity, significant associations between GSTP1 Ile105Val polymorphism and PCa risk were also found among Caucasians (Ile/Ile vs Val/Val comparison OR=0.818, I (2) =0.0 %, 95 % CI=0.681-0.982; Ile/Val vs Val/Val comparison OR=0.779, I (2) =0.0 %, 95 % CI=0.651-0.933; and dominant model OR=0.794, I (2) =0.0 %, 95 % CI=0.670-0.941), while there were no associations found for other genetic models. However, no associations were found in Asians and African-Americans for all genetic models when stratified by ethnicity. In conclusion, our meta-analysis indicates that GSTP1 Ile105Val polymorphisms contributed to the PCa susceptibility. However, a study with the larger sample size is needed to further evaluate gene-environment interaction on GSTP1 Ile105Val polymorphisms and PCa risk.