title: GSTM1 polymorphism and oral leukoplakia.
abstract: BACKGROUND
  Molecular epidemiological studies have now provided evidence that an individual susceptibility to cancer is mediated by genetic and environmental factors. Genetic polymorphisms have been described for enzymes involved in the metabolism of tobacco carcinogens and cancer risk is determined by the degree of expression and/or activity of enzymes involved in carcinogen activation or deactivation. The objective of this study was to investigate the GSTM1 null polymorphism and the risk for oral leukoplakia in individuals with tobacco-smoking habit in a Brazilian population.
  
  
  METHODS
  A total of 52 tobacco-smoking patients with oral leukoplakia and 52 tobacco-smoking controls were recruited in a Brazilian population. The GSTM1 genotypes were studied by polymerase chain reaction-based methods.
  
  
  RESULTS
  The frequency of the GSTM1 null genotype in the group with oral leukoplakia (57.7%) was statistically different from the controls (34.6%; OR: 2.57, 95% CI: 1.16-5.69, P < 0.05). The stratification of the samples according to the level of dysplasia showed increased prevalence of GSTM1 null genotype on lesions with moderate/severe histological dysplasia (68.2%) compared with the control group (31.9%). This difference was statistically significant (OR: 4.59, 95% CI: 1.29-16.33, P < 0.05).
  
  
  CONCLUSIONS
  In conclusion, the GSTM1 null genotype may increase the risk for oral leukoplakia development.
authors.affiliation: Department of Oral Pathology and Surgery, School of Dentistry, Universidade Federal de of Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Eliza Carla Barroso
authors.initials: EC
authors.lastname: Duarte
authors.forename: Marina Sena Lopes
authors.initials: MS
authors.lastname: da Silva
authors.forename: Marcus Vinícius
authors.initials: MV
authors.lastname: Gomez
authors.forename: Ricardo Santiago
authors.initials: RS
authors.lastname: Gomez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007972:Leukoplakia, Oral / Q000201:enzymology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012907:Smoking
chemical_list: D005982:Glutathione Transferase