title: Association of glutathione S-transferase M1 and T1 null polymorphisms with the development of cervical lesions: a meta-analysis.
abstract: OBJECTIVE
  An accumulation of evidence suggests that gene-based self-susceptibility may contribute to the development of cancer. Some studies have found that particular polymorphisms of the glutathione S-transferase M1 and T1 genes are associated with increased risk of cervical lesions, but other studies have had contrary results. The present meta-analysis evaluated the association of glutathione S-transferase M1 and T1 null polymorphisms with the development of cervical lesions. In addition, stratified analyses were performed in an attempt to identify any race-specific effects.
  
  
  METHODS
  Twenty-one related studies were included in the meta-analysis, comprising glutathione S-transferase M1 data from 1423 patients with cervical lesions and 2415 healthy matched controls, and glutathione S-transferase T1 data from 2081 patients with cervical lesions and 2287 healthy matched controls. The fixed-effect model (Mantel-Haenszel method) and the random-effect (DerSimonian and Laird) model were used to examine the difference in frequency of glutathione S-transferase M1 and T1 null polymorphisms between pre- and invasive cervical lesions. Subgroup analyses were also conducted to evaluate any race-specific effect on the frequencies of glutathione S-transferase polymorphisms in cervical lesions. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. Heterogeneity was assessed using the heterogeneity metric (I²) and Chi-squared test.
  
  
  RESULTS
  The glutathione S-transferase M1 null polymorphism was associated with increased risk of low-grade intra-epithelial lesions (OR 1.37, 95% CI 1.05-1.77), but no increased risk of high-grade intra-epithelial lesions (OR 1.29, 95% CI 0.87-1.8) or invasive cervical cancer (OR 1.20, 95% CI 0.99-1.46). The association seemed to be confined to Southeast Asians (OR 1.97, 95% CI 1.44-2.71). No significant associations were found for the glutathione S-transferase T1 null polymorphism for any of the populations.
  
  
  CONCLUSIONS
  The glutathione S-transferase M1 null polymorphism significantly increases susceptibility to early-stage cervical lesions in Southeast Asians. However, the glutathione S-transferase T1 null polymorphism does not appear to be a risk factor for cervical lesions in any population.
authors.affiliation: Key Laboratory of Reproductive Health of Liaoning Province, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sui
authors.forename: Weitian
authors.initials: W
authors.lastname: Han
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yang
authors.forename: Miao
authors.initials: M
authors.lastname: Jiang
authors.forename: Jianxin
authors.initials: J
authors.lastname: Li
mesh_terms: D000328:Adult; D005260:Female; D017353:Gene Deletion; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005982:Glutathione Transferase / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008957:Models, Genetic; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D011110:Polymorphism, Genetic; D002583:Uterine Cervical Neoplasms / Q000201:enzymology / Q000208:ethnology / Q000235:genetics* / Q000473:pathology; D002578:Uterine Cervical Dysplasia / Q000201:enzymology / Q000208:ethnology / Q000235:genetics* / Q000473:pathology
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1