title: Association between aldehyde dehydrogenase gene polymorphisms and the phenomenon of field cancerization in patients with head and neck cancer.
abstract: Patients with squamous-cell carcinoma in the head and neck (HNSCC) often develop second primary esophageal squamous-cell carcinomas (ESCC). In addition, widespread epithelial oncogenic alterations are also frequently observed in the esophagus and can be made visible as multiple Lugol-voiding lesions (multiple LVL) by Lugol chromoendoscopy. Multiple occurrences of neoplastic change in the upper aerodigestive tract have been explained by the concept of 'field cancerization', usually associated with repeated exposure to carcinogens such as alcohol and cigarette smoke. However, the etiology of second ESCC in HNSCC patients remains unclear and acetaldehyde, the first metabolite of ethanol, has been implicated as the ultimate carcinogen in alcohol-related carcinogenesis. We first investigated the relation between second ESCC and multiple LVL in 78 HNSCC patients. Multiple LVL and second ESCC were observed in 29 (37%) and 21 (27%) patients, respectively. All of the second ESCC were accompanied by multiple LVL. This may indicate that episodes of multiple LVL are precursors for second ESCC. We then examined the association of multiple LVL with the patients' characteristics, including genetic polymorphisms of the alcohol metabolizing enzymes, alcohol dehydrogenase type 3 (ADH3) and aldehyde dehydrogenase type 2 (ALDH2). We also investigated acetaldehyde concentrations in the breath of 52 of the 78 patients. All the patients with multiple LVL were both drinkers and smokers. Multivariable logistic analysis showed that the inactive ALDH2 allele (ALDH2-2) was the strongest contributing factor for the development of multiple LVL (odds ratio 17.6; 95% confidence intervals 4.7-65.3). After alcohol ingestion, acetaldehyde in the breath was elevated to a significantly higher level in all patients with the ALDH2-2 allele than in those without it. The high levels of breath acetaldehyde were significantly modified by the slow-metabolizing ADH3-2 allele. These results reveal strong evidence for a gene-environmental interaction between the ALDH2-2 allele and alcohol consumption, for the risk of developing multiple LVL, resulting in the development of second ESCC in patients with HNSCC. Ultimately, increased local acetaldehyde exposure thus appears to be a critical determinant of the phenomenon of 'field cancerization'.
authors.affiliation: Division of Digestive Endoscopy and Gastrointestinal Oncology, National Cancer Center Hospital East, Kashiwanoha 6-5-1, Kashiwa 277-8577, Japan. mmuto@east.ncc.go.jp
authors.forename: Manabu
authors.initials: M
authors.lastname: Muto
authors.forename: Mari
authors.initials: M
authors.lastname: Nakane
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hitomi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Yoshida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ohtsu
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Yoshida
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ebihara
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Esumi
mesh_terms: D000428:Alcohol Drinking; D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D000483:Alleles; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D005260:Female; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012907:Smoking; D013997:Time Factors
chemical_list: D000444:Aldehyde Dehydrogenase