Association between endothelial nitric oxide synthase 894G>T polymorphism and prostate cancer risk: a meta-analysis of literature studies

To date, several studies have been conducted to assess the association between endothelial nitric oxide synthase (eNOS) gene 894G>T polymorphismand prostate cancer (PCa) risk, but the results are conflicting. To derive a more precise estimation of the relationship between 894G>T polymorphism and PCa risk, the present meta-analysis was performed. A total of eight case-control studies were included in this meta-analysis. The pooled odds ratio (OR) with 95% confidence interval (CI) was calculated to evaluate the associations. Our results suggested that 894G>T polymorphism is associated with PCa risk under codominant (GT vs. GG) (OR=1.11, 95 % CI=1.01-1.22, P=0.04) and overdominant (GT vs. GG+ TT) (OR=1.12, 95 % CI=1.02-1.23, P=0.02) models in the overall population, while there are no associations observed under dominant (GT+TT vs. GG), recessive (TT vs. GG+ GT), and allelic (T vs. G) models. Moreover, when the eligible studies were stratified according to sources of control, significant association between 894G>T polymorphism and susceptibility of PCa was also identified under codominant (OR=1.12, 95 % CI=1.01-1.24, P=0.03) and overdominant (OR=1.13, 95 % CI=1.02-1.25, P=0.02) models when using healthy individuals as control. However, there are no significant associations found under any genetic models when using BPH patients as control group. In conclusion, the present meta-analysis suggested that the eNOS gene 894G>T polymorphism might be a risk factor in the onset of PCa.