Preventing alcohol-related cancer: what if everyone drank within the guidelines?

Objectives: The purpose of this study was to estimate the proportion and number of cancer cases diagnosed in Ontario in 2012 that are attributable to alcohol consumption and to compare the impact of drinking within two sets of guidelines on alcohol-attributable cancer incidence. Methods: We estimated the proportion of cancers in Ontario attributable to alcohol consumption by calculating population-attributable fractions (PAFs) for six cancer types using drinking prevalence from the 2000/2001 Canadian Community Health Survey and relative risks from a meta-analysis. Each PAF was multiplied by the number of incident cancers in 2012, allowing for a 12-year latency period, to calculate the number of alcohol-attributable cases. We also estimated the number of alcohol-attributable cases under two scenarios: (1) assuming consumption had not exceeded the levels recommended by the Low-Risk Alcohol Drinking Guidelines (LRADG) and (2) assuming consumption had not exceeded the recommended levels by the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) guidelines. Results: One thousand two hundred ninety-five (95% confidence interval 1093–1499) new cases of cancer diagnosed in Ontario during 2012 are estimated to be attributed to alcohol consumption, representing approximately 1.7% (1.4–1.9%) of all new cancer cases. If no Ontario adults had exceeded the LRADG, an estimated 321 fewer cancer cases could have been diagnosed in 2012, whereas an estimated 482 fewer cancer cases could have been diagnosed if no Ontario adults had exceeded the stricter WCRF/AICR guidelines. Conclusion: Strategies to limit alcohol consumption to the levels recommended by drinking guidelines could potentially reduce the cancer burden in Ontario.