Estimates of the current and future burden of cancer attributable to alcohol consumption in Canada

Alcohol consumption is associated with elevated risk of oropharyngeal, laryngeal, esophageal, colon, rectal, breast, liver, pancreatic and stomach cancers. The purpose of this analysis was to provide national and provincial estimates of the number and proportion of cancers attributable to alcohol consumption in Canada and to project the numbers of potentially avoidable cancers using possible intervention scenarios. We estimated the population attributable risk (PAR) for cancers associated with alcohol consumption levels (drinks/day) using: i) relative risks obtained from the World Cancer Research Fund/(WCRF) reports or meta-analyses, ii) alcohol consumption (prevalence) data from the 2003 Canadian Community Health Survey, and iii) cancer incidence data from the 2015 Canadian Cancer Registry. We used potential impact fractions (PIFs) to estimate the future avoidable cancer burden under four counterfactual scenarios: (1) lowering alcohol consumption to meet the WCRF low risk guidelines, (2) meeting the Canada's Low-Risk Drinking Guidelines, (3) reducing daily intake by one drink/day, and (4) decreasing consumption to 50% of the 2003 levels by 2032. We estimated that 3282 incident cancer cases (5.2% of alcohol-associated cancers and 1.8% of all cancers) diagnosed in Canada in 2015 were attributable to alcohol consumption. At the current consumption levels, alcohol-attributable cancers are expected to increase to 10,122 (8.8% of cases among alcohol-associated cancers) by 2042. Under the best case scenario, reducing alcohol consumption to 50% of 2003 levels by 2032, could prevent 70,261 cases by 2042. Strategies that effectively reduce alcohol consumption at a population level can have a meaningful impact on reducing the cancer burden in Canada.