Objectives: We investigated the effects of alcohol consumption on the risk of cancers of the upper aerodigestive tract (UADT) in a hospital-based case-control study in Brazil.
Methods: A total of 784 cases of cancers of the mouth, pharynx, and larynx and 1578 non-cancer controls matched on age, gender, hospital area, and admission period provided information on alcohol drinking, smoking, and other characteristics via interview. Using logistic regression, we evaluated the relative risks (RR) of UADT cancer for different beverage types based on cumulative ethanol content exposure and frequency of consumption.
Results: Relative to nondrinkers of any alcohol, risks of UADT cancers varied across sites both with increased exposure to ethanol and by alcohol type. RRs at equivalent levels of ethanol consumption were highest for cancers of the mouth for hard liquor (6.9 for > 100 kg lifetime consumption, 95% confidence interval (CI) = 2.8-17.1) and cachaça (4.5 for 101-500 kg, 95% CI = 2.2-9.0). Although RRs increased with frequency of drinks per week, when evaluated against higher proportional alcohol intake, reductions in risk were observed for beer and wine.
Conclusion: Although methods of measurement can influence the interpretation of the carcinogenic nature of alcohols, increased RRs persisted with continued exposure for all types.