title: CYP2A6 gene deletion reduces oral cancer risk in betel quid chewers in Sri Lanka.
abstract: We investigated the relationship between inter-individual difference in CYP2A6 genotype and susceptibility to oral cancer among habitual betel quid chewers in a Sri Lanka population. A total of 286 subjects showing oral malignant or premalignant lesions and 135 control subjects with no lesions were analyzed. The frequency of homozygotes for CYP2A6*4C mutation, a gene deletion type of polymorphism, was significantly lower in the case subjects than the controls. The odds ratio (OR) of the group homozygous for the deletion was significantly lower and calculated to be 0.14 (95% CI; 0.03-0.72). In the allelic base analysis, there was also a significant decrease in the OR of the deletion allele. Our data suggest that deficient CYP2A6 activity due to genetic polymorphism reduces oral cancer risk in betel quid chewers.
authors.affiliation: Laboratory of Drug Metabolism, Graduate School of Pharmaceutical Sciences, Department of Oral Patho-biological Science, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-0812, Japan.
authors.forename: Zeki
authors.initials: Z
authors.lastname: Topcu
authors.forename: Itsuo
authors.initials: I
authors.lastname: Chiba
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujieda
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Shibata
authors.forename: Noritaka
authors.initials: N
authors.lastname: Ariyoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Figen
authors.initials: F
authors.lastname: Sevgican
authors.forename: Malsantha
authors.initials: M
authors.lastname: Muthumala
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kamataki
mesh_terms: D000483:Alleles; D001114:Areca / Q000009:adverse effects*; D001189:Aryl Hydrocarbon Hydroxylases; D065637:Cytochrome P-450 CYP2A6; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D006720:Homozygote; D006801:Humans; D006899:Mixed Function Oxygenases / Q000235:genetics*; D009062:Mouth Neoplasms / Q000235:genetics*; D009154:Mutation; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013188:Sri Lanka
chemical_list: D003577:Cytochrome P-450 Enzyme System; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C585710:CYP2A6 protein, human; D065637:Cytochrome P-450 CYP2A6