A methodologic framework to evaluate the number of cancers attributable to lifestyle and environment in Alberta.

BACKGROUND Previous research to estimate population attributable risks for cancer in Alberta has been limited. Attributable burden estimates are important for planning and implementing population-based cancer prevention strategies. This article describes a methodologic framework to estimate the number of incident cancers attributable to modifiable lifestyle and environmental risk factors in Alberta. METHODS We estimated population attributable risks for cancer for exposures to 24 established cancer risk factors including tobacco consumption and environmental tobacco exposure, environmental factors, infectious agents, hormone therapies, dietary intake, obesity and physical inactivity. We used risk estimates to quantify the association between individual exposures and cancer sites as well as prevalence estimates for individual exposures in Alberta to estimate the proportion of cancer in Alberta that could be attributed to each exposure. These estimations were conducted in the context of a theoretical minimum risk principle, whereby exposures corresponding to the lowest levels of population risk were used as the comparisons for alternative exposure levels. INTE RPRETATION We outline the main methodologic principles for the protocol used in evaluating population attributable risks for modifiable lifestyle and environmental risk factors for cancer in Alberta. The data produced by this project will provide important information concerning which known cancer risk factors are responsible for the largest proportions of cancer in Alberta and could inform future cancer prevention strategies.