Novel biomarkers of habitual alcohol intake and associations with risk of pancreatic and liver cancers and liver disease mortality

Abstract

Background: Alcohol is an established risk factor for several cancers, but modest alcohol-cancer associations may be missed due to measurement error in self-reported assessments. The identification of biomarkers of habitual alcohol intake may enhance evidence on the role of alcohol in cancer onset. Methods: Untargeted metabolomics was used to identify metabolites correlated with habitual alcohol intake in a discovery dataset from the European Prospective Investigation into Cancer and Nutrition (EPIC; n=454). Significant correlations were replicated in independent datasets of controls from casecontrol studies nested within EPIC (n=281) and the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC; n=438) study. Conditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals for associations of alcohol-associated metabolites and selfreported alcohol intake with risk of pancreatic cancer, hepatocellular carcinoma (HCC), liver cancer, and liver disease mortality in the contributing studies. Results: Two metabolites displayed a dose-response association with alcohol intake: 2-hydroxy-3- methylbutyric acid and an unidentified compound (m/z(+):231.0839). A 1-SD increase in log2- transformed levels of 2-hydroxy-3-methylbutyric acid was associated with risk of HCC (OR=2.14; 1.39-3.31) and pancreatic cancer (OR=1.65; 1.17-2.32) in EPIC and liver cancer (OR=2.00; 1.44-2.77) and liver disease mortality (OR=2.16; 1.63-2.86) in ATBC. Conversely, a 1-SD increase in log2- transformed questionnaire-derived alcohol intake was not associated with HCC or pancreatic cancer in EPIC or liver cancer in ATBC but was associated with liver disease mortality (OR=2.19; 1.60-2.98) in ATBC. Conclusions: 2-Hydroxy-3-methylbutyric acid is a candidate biomarker of habitual alcohol intake that may advance the study of alcohol and cancer risk in population-based studies.