Cyclooxygenase-2 polymorphisms and bladder cancer risk: a meta-analysis based on case-control studies.

The current meta-analysis incorporating 15 case-control studies involving 4,138 cases and 4,269 controls was performed on the basis of a systematical search in electronic databases for a more precise estimation on the associations of three common polymorphisms -765 G>C (rs20417), -1195G>A (rs689466) and +8473 C>T (rs5275) in Cyclooxygenase-2 (Cox-2) gene with the susceptibility to bladder cancer. The results showed that there was a significant association between rs5275 polymorphism and bladder cancer risk (C vs. T; OR=0.84; CC vs. TT: OR=0.76), especially among Chinese (CC vs. TC+TT: OR=0.48) and American (C vs. T; OR=0.83; TC vs. TT: OR=0.73; CC+TC vs. TT: OR=0.73). and the rs20417 polymorphism was significantly associated with an increased risk of bladder cancer among Chinese (C vs. G: OR=1.46; GC vs. GG: OR=1.49; CC+GC vs. GG: OR=1.51) and Indian (GC vs. GG: OR=1.63; CC+GC vs. GG: OR=1.46), but a reduced risk among American (C vs. G: OR=0.81; GC vs. GG: OR=0.76; CC+GC vs. GG: OR=0.76). Additionally, we found that the rs689466 polymorphism was associated with a decreased risk of bladder cancer in Indian (GA vs. GG: OR=0.68; AA vs. GG: OR=0.39).The present meta-analysis suggests that Cox-2 rs5275 polymorphism may contribute to the risk of bladder cancer, particularly among Chinese and American. The rs20417 polymorphism may play a protective role in the development of bladder cancer in Indian and Chinese but act as a risk factor among American, while the rs689466 polymorphism was more likely to be associated with a decreased risk of bladder cancer in Indian.