Association between NQO1 Pro187Ser polymorphism and esophageal cancer: a meta-analysis

quinone oxidoreductase 1 (NQO1) is an important enzyme which can catalyze the two-electron reduction of quinoid compounds into hydroquinones. NQO1 Pro187Ser polymorphism can change the enzymatic activity of NQO1, and it has been proposed to be associated with risk of esophageal cancer. We performed a meta-analysis to examine the association between NQO1 Pro187Ser polymorphism and esophageal cancer. Odds ratio (OR) with a 95% confidence interval (95% CI) was used to assess the association. Twelve case-control studies with 1,725 cases with esophageal cancer and 2,341 controls were finally included in the meta-analysis. Overall, there was an obvious association between NQO1 Pro187Ser polymorphism and esophageal cancer (allele model: OR = 1.24, 95% CI 1.06-1.46, P OR = 0.009; homozygote model: OR = 1.59, 1195% CI 1.10-2.30, P OR = 0.013; dominant model: OR = 1.31, 95% CI 1.05-1.64, P OR = 0.018). In the subgroup analysis by ethnicity, there was an obvious association between NQO1 Pro187Ser polymorphism and esophageal cancer in Asians but not in Caucasians. Therefore, the meta-analysis suggests that NQO1 Pro187Ser polymorphism is associated with esophageal cancer risk.