title: Genetic association of NQO1 609C>T polymorphism with risk of gastrointestinal cancer: evidence from case-control studies.
abstract: 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).
  
  
  CONCLUSIONS
  Our results demonstrated that NQO1 609C>T polymorphism might be associated with susceptibility to GI cancer.
authors.affiliation: Department of Radiation Oncology, Chinese PLA General Hospital Beijing, China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of General Surgery, Chinese PLA General Hospital Beijing, China.
authors.forename: Sixin
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Department of Radiation Oncology, Chinese PLA General Hospital Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Radiation Oncology, First Affiliated Hospital of Xinxiang Medical University Xinxiang, Henan, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Radiation Oncology, Inner Mongolia Cancer Hospital Hohhot, Inner Mongolia, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Yang
keywords: NQO1; gastrointestinal cancer; polymorphism