The NAD(P)H: Quinine Oxidoreductase 1 (NQO1) Gene 609 C>T Polymorphism is Associated with Gastric Cancer Risk: Evidence from a Case-control Study and a Meta-analysis

The association between the NAD(P)H:quinone oxidoreductase 1 (NQO1) gene C609T polymorphism (rs1800566) and gastric cancer has been widely evaluated, but a definitive answer is so far lacking. We first conducted a case-control study to assess this association in a large Han Chinese population, and then performed a meta-analysis to further address this issue. Although our case-control association study indicated no significant difference in the genotype and allele distributions of C609T polymorphism between gastric cancer patients and controls, in the meta analysis involving 4,000 subjects, comparison of alleles 609T and 609C indicated a significantly increased risk (46%) for gastric cancer (95% confidence interval (95%CI) for odds ratio (OR)=1.20-1.79) in individuals with the T allele. The tendency was similar to the homozygote (OR=1.81, 95%CI: 1.16-2.84), dominant models (OR=1.41, 95%CI: 1.12-1.79), as well as recessive model (OR=1.58, 95%CI: 1.06-2.35). Stratified analysis by study design demonstrated stronger associations in population-based than in hospital-based studies. And ethnicity-based analysis demonstrated a significant association in Asians. We conclude that the NQO1 gene C609T polymorphism increases the risk for gastric cancer, especially in Asian populations.