title: The role of alcohol dehydrogenase genes in head and neck cancers: a systematic review and meta-analysis of ADH1B and ADH1C.
abstract: Alcohol drinking is a major risk factor for head and neck cancer (HNC). This risk may be modified by alcohol dehydrogenase (ADH) genes, particularly ADH1B and ADH1C, that oxidise ethanol to its carcinogenic metabolite, acetaldehyde. A meta-analysis was conducted to assess the association between ADH1B and ADH1C and HNC risk. Twenty-nine studies from 28 articles identified from a literature search were included. Summary odds ratios (meta-ORs) were generated using random effect models. A reduced risk for HNC was associated with carrying the ADH1B*2 and ADH1C*1 alleles that confer faster metabolism of ethanol to acetaldehyde [meta-OR ADH1B, 0.50; 95% confidence interval (CI): 0.37-0.68, 13 studies; meta-OR ADH1C, 0.87; 95% CI: 0.76-0.99, 22 studies]. ADH1B*2 and ADH1C*1 alleles appear to be protective for HNC, possibly due to: (i) decreasing the opportunity for oral microflora to produce acetaldehyde locally from a prolonged systemic circulation of ethanol, (ii) preventing ethanol from acting as a solvent for other carcinogens, and (iii) decreasing the amount of ethanol a person consumes since a consequent peak in systemic acetaldehyde could cause discomfort. These results underscore the importance of ADH1B and ADH1C in the association between alcohol consumption and the risk for HNC.
authors: National Institute of Cancer Research, National Health Research Institutes, Tainan 70456, Taiwan Republic of China. jeffreychang@nhri.org.tw
authors: Jeffrey S
authors: JS
authors: Chang
authors: Kurt
authors: K
authors: Straif
authors: Neela
authors: N
authors: Guha
mesh_terms: D000426:Alcohol Dehydrogenase / Q000235:genetics*; D000431:Ethanol / Q000378:metabolism; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics; D012307:Risk Factors
chemical_list: D007527:Isoenzymes; D000431:Ethanol; C489332:ADH1B protein, human; C420272:ADH1C protein, human; D000426:Alcohol Dehydrogenase