title: Alcohol dehydrogenase 3 genotype is not associated with risk of squamous cell carcinoma of the oral cavity and pharynx.
abstract: Alcohol is one of the major risk factors for oral and pharyngeal cancer. The rate-limiting step in alcohol metabolism is the oxidation (activation) of ethanol to acetaldehyde by the alcohol dehydrogenases (ADHs). It has been hypothesized that individuals who are homozygous for the fast allele (ADH(1-1)(3)) are at greater risk for alcohol-related cancers. To test this hypothesis, we investigated the association between the ADH3 genotype and oral and pharyngeal cancer risk in a large racially homogeneous case-control study of 229 patients and 575 matched control subjects with frequency matching on age, sex, and smoking status. Although the smoking status was matched between cases and controls, current and former alcohol use remained a significant risk factor, compared with never use (odds ratio, 2.08; 95% confidence interval, 1.37-3.17; odds ratio, 1.97; 95% confidence interval, 1.25-3.09; and odds ratio, 1.00, respectively). The ADH1(3) allele frequency of controls was 57.4%, consistent with reports of similar racial groups (50-60%). The genotype distribution in controls was also consistent with the Hardy-Weinberg equilibrium (P = 0.51). However, the ADH1(3) allele frequency and ADH(1-1)(3) genotype frequency were not significantly different between cases and controls [55.5% versus 57.4% (P = 0.52), and 30.6% versus 31.3% (P = 0.91), respectively]. There was no association between ADH3 genotypes (ADH(1-1)(3), ADH(1-2)(3), and ADH(2-2)(3)) and risk of oral and pharyngeal cancer (odds ratios, 1.00; 0.96; 95% confidence interval, 0.68-1.37; and odds ratio, 1.23; confidence interval, 0.78-1.93, respectively). Therefore, we found no evidence that supports a main effect of ADH3 genotype or a combined effect of alcohol and ADH3 genotype on risk of cancer of the oral cavity or pharynx.
authors: Department of Head and Neck Surgery, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
authors: E M
authors: EM
authors: Sturgis
authors: K R
authors: KR
authors: Dahlstrom
authors: Y
authors: Y
authors: Guan
authors: S A
authors: SA
authors: Eicher
authors: S S
authors: SS
authors: Strom
authors: M R
authors: MR
authors: Spitz
authors: Q
authors: Q
authors: Wei
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000426:Alcohol Dehydrogenase / Q000032:analysis / Q000235:genetics*; D000437:Alcoholism / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics; D016022:Case-Control Studies; D015331:Cohort Studies; D015897:Comorbidity; D016001:Confidence Intervals; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics; D016017:Odds Ratio; D010610:Pharyngeal Neoplasms / Q000201:enzymology* / Q000453:epidemiology / Q000235:genetics; D012016:Reference Values; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017678:Sex Distribution; D012907:Smoking / Q000453:epidemiology
chemical_list: C420272:ADH1C protein, human; D000426:Alcohol Dehydrogenase