Aim: The genetic polymorphisms of the alcohol metabolizing enzymes alcohol dehydrogenase 1B (ADH1B) rs1229984 may modulate individual differences in alcohol oxidizing capability. A case-control study was conducted to evaluate the genetic effects of these functional single-nucleotide polymorphisms on the development of esophageal cancer.
Methods: Here, a total of 1001 esophageal squamous cell carcinoma (ESCC) cases and 1391 controls were recruited. Genotypes were determined by DNA sequencing. Differences in the distributions of demographic characteristics, selected variables, and genotypes of ADH1B rs1229984 variants between cases and controls were evaluated using the χ(2) test. Associations between ADH1B genotypes and the risk of esophageal cancer were estimated by computing the odds ratios (ORs) and their 95% confidence intervals (CIs) using logistic regression analyses for crude ORs and adjusted ORs when adjusting for age, gender, and tobacco use status.
Results: There were no significant differences between ESCC patients and controls in terms of age and sex distributions, suggesting that the frequency matching was adequate. However, significantly, more smokers were presented among the ESCC cases than among controls (63.1% vs. 49.2%; p=2.14 × 10-11). Smokers had an increased risk for developing ESCC (adjusted OR=2.17, 95% CI=1.78-2.64). This result clearly indicated that smoking is a risk factor for the ESCC in our study population. We found that subjects carrying the rs1229984 GG genotype had significantly increased risk of ESCC (adjusted OR, 2.81; 95% CI, 2.18-3.62; p=1.05 × 10-15) compared with the AA genotype.
Conclusion: The functional polymorphisms ADH1B rs1229984 may contribute to susceptibility to esophageal cancer.