The association between each genetic variant and the disease risk was estimated by the odds ratio (OR) per allele and ninety-five percent confidence intervals (CI) using multivariate unconditional logistic regression assuming a log-additive genetic model with sex and country of recruitment included in the regression model as covariates. Results that obtained a level of significance of a two sided p<5×10−7 were considered significant at a genome wide level [39]. All analyses were conducted using PLINK [43]. We also conducted analyses restricting to UADT cancer subtypes (oral/pharyngeal cancer, laryngeal cancer, esophageal cancer) and restricting to heavy (>median) drinkers and heavy (>median) smokers.
