Effects of the NQO1 609C>T Polymorphism on Leukemia Susceptibility: Evidence from a Meta-analysis

A functional polymorphism in the NQO1 gene, featuring a 609C>T substitution,leading to proline to serineamino-acid and enzyme activity changes, has been implicated in cancer risk. However, individually publishedinvestigations showed inconclusive results, especially for leukemia. In this study, we therefore performed a metaanalysisof 21 publications with a total of 3,634 cases and 4,827controls, mainly for leukemia. We summarized thedata on the association between the NQO1 609C>T polymorphism and risk of leukemia and performed subgroupanalyses by ethnicity and leukemia type. We found that the variant TT homozygous genotype o was associatedwith a modestly increased risk of leukemia (TT versus CT/CC: OR = 1.23, 95%CI = 1.00 - 1.51, heterogeneity= 0.76; I2 = 0%). Following further stratified analyses, increased risk was only observed in subgroups ofCaucasians. This meta-analysis suggests that the NQO1 609T allele is a high-penetrance risk factor for leukemiain Caucasians. The effect on leukemia may be modified by ethnicity and leukemia type, and the small samplesizes of the subgroup analyses suggest that further larger studies are needed.