Genetic association of NQO1 609C>T polymorphism with risk of gastrointestinal cancer: evidence from case-control studies.

BACKGROUND Numerous studies have evaluated the association between NQO1 609C>T polymorphism and gastrointestinal (GI) cancer. However, the results remain inconclusive. To obtain a more precise estimation of the relation, we conducted an analysis of all available case-control studies. METHODS Eligible studies were identified by searching the databases and finally 19 articles were included in the meta-analysis. Odds ratio (OR) with 95% confidence interval (95% CI) was applied to assess the association between NQO1 609C>T polymorphism and GI cancer risk. Z test was used to evaluate the significance of OR and 95% CI. RESULTS In the overall analysis, there existed a significant association between NQO1 609C>T polymorphism and GI cancer susceptibility (T vs. C: OR = 1.07, 95% CI = 1.01-1.14). The subgroup analysis based on ethnicity showed that NQO1 609C>T polymorphism was associated with susceptibility to GI cancer in mixed population (TT vs. CC: OR = 2.21, 95% CI = 1.44-3.40; TT vs. CT + CC: OR = 2.26, 95% CI = 1.48-3.44; Allele T vs. Allele C: OR = 1.24, 95% CI = 1.05-1.47). For the subgroup analysis according to source of control, a remark relationship of 609C>T with increased risk of GI cancer was observed in HB population (Allele T vs. Allele C: OR = 1.07, 95% CI = 1.01-1.14). CONCLUSION Our results demonstrated that NQO1 609C>T polymorphism might be associated with susceptibility to GI cancer.