title: Interactions between cigarette smoking and polymorphisms of xenobiotic-metabolizing genes: the risk of oral leukoplakia.
abstract: BACKGROUND
  This case-control study investigates the role of xenobiotic-metabolizing genes, including glutathione S-transferases (GSTs) and cytochrome P450 1A1 (CYP1A1) and 2E1 (CYP2E1), in the susceptibility to oral potentially malignant disorders (OPMDs).
  
  
  METHODS
  The genotypes of GSTM1, GSTT1, GSTP1, CYP1A1*2C, and CYP2E1 PstI/RsaI polymorphisms were determined for 217 OPMD cases and 492 age- and sex-matched controls from a Taiwanese penitentiary.
  
  
  RESULTS
  Compared to the GSTM1-present genotype, the GSTM1-null genotype was significantly associated with increased risk of leukoplakia (odds ratio [OR]=1.46, 95% confidence interval [CI]=1.01-2.10). Similarly, compared to the CYP1A1*2C A/G+G/G genotype, the CYP1A1*2C A/A genotype was significantly associated with increased risk of leukoplakia (OR=1.64, 95% CI=1.12-2.40), particularly for smokers consuming > 13 pack-years of cigarettes (OR=2.40, 95% CI=1.40-4.11) (Interaction P=0.039). In addition, participants with 4-5 risk genotypes (OR > 1) experienced higher risks for leukoplakia than those with 0-1 risk genotypes (OR=3.19, 95% CI=1.65-6.15) (Trend test P=0.001).
  
  
  CONCLUSIONS
  Our findings suggest that the CYP1A1*2C A/A genotype may increase the risk of leukoplakia, especially for heavy smokers. Xenobiotic-metabolizing genes may simultaneously modulate this disease risk. These observations require further confirmation with larger samples.
authors: Graduate Institute of Biostatistics, College of Public Health, China Medical University, Taichung, Taiwan.
authors: Yu-Fen
authors: YF
authors: Li
authors: Fung-Chang
authors: FC
authors: Sung
authors: Ming-Hsui
authors: MH
authors: Tsai
authors: Chun-Hung
authors: CH
authors: Hua
authors: Chiu-Shong
authors: CS
authors: Liu
authors: Yao-Te
authors: YT
authors: Huang
authors: Chih-Ching
authors: CC
authors: Yeh
mesh_terms: D000328:Adult; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007972:Leukoplakia, Oral / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012907:Smoking; D013624:Taiwan; D014026:Nicotiana; D015262:Xenobiotics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D015262:Xenobiotics