Association between NQO1 C609T polymorphism and colorectal cancer risk.

quinone oxidoreductase 1 (NQO1) is a cytosolic enzyme, and the NQO1 C609T polymorphism is associated with the enzymatic activity of NQO1. Many studies were performed to assess the association between NQO1 C609T polymorphism and colorectal cancer risk, but no consensus was available up to now. We conducted a meta-analysis to examine the association between NQO1 C609T polymorphism and colorectal cancer risk, and the pooled odds ratios (OR) with their 95% confidence intervals (95% CI) were used to assess the association. Finally, 12 studies involving 4,026 cases and 4,855 controls were included into the meta-analysis. Overall, there was an obvious association between NQO1 C609T polymorphism and colorectal cancer risk (T versus C: OR = 1.28, 95% CI 1.08-1.51, P = 0.005; TT versus CC: OR = 1.60, 95% CI 1.10-2.33, P = 0.015; TT/CT versus CC: OR = 1.36, 95% CI 1.09-1.69, P = 0.006; TT versus CT/CC: OR = 1.37, 95% CI 1.05-1.80, P = 0.022). Subgroup analysis by ethnicity showed that the association was obvious in both Caucasians and Asians. Therefore, the meta-analysis provides strong evidence for the association between NQO1 C609T polymorphism and colorectal cancer risk, and the T allele of NQO1 C609T polymorphism is an important risk factor of colorectal cancer.