Apiramy Jeyapalan, MPH
Project Coordinator, Knowledge Translation, ComPARe Study
Canadian Cancer Society
The current and future preventable burden of cancer in Canada: The Canadian Population Attributable Risk of Cancer (ComPARe) study
Study rationale:
Several studies have quantified the burden of cancer attributable to modifiable risk factors using the statistical measure called population attributable risk (PAR). However, in Canada, there are limited PAR estimates. Although some Canadian provincial estimates exist, they are often for a limited number of risk factors and/or cancer types, and don’t reflect the unique age, sex and regional distribution of risk factor prevalence across Canada. The Canadian Population Attributable Risk of Cancer (ComPARe) study addresses these gaps by providing the most comprehensive, up-to-date estimates of the preventable burden of cancer in Canada.
Overview of ComPARe:
The ComPARe study provides estimates of the number and percentage of new cases for more than 30 cancer types due to more than 20 modifiable lifestyle, environmental and infectious agent risk factors in Canada in 2015. In addition, the study projects how modifying the prevalence of these risk factors could change cancer incidence in the future (by 2042). The study used a combination of data from the published literature, population health surveys and the Canadian Cancer Registry. The ComPARe study, both funded by and carried out in partnership with the Canadian Cancer Society (CCS), brought together a pan-Canadian team of experts in cancer epidemiology, biostatistics, chronic disease prevention and knowledge translation. Prior to the ComPARe study, the Occupational Burden of Cancer study led by Dr. Paul Demers, estimated the number of cancer cases due to occupational exposures in Canada. Given the role workplace exposures plays in the overall burden of cancer in Canada, these results were incorporated into many of the knowledge products developed for the ComPARe study to provide a more comprehensive picture of the preventable burden of cancer in Canada.
What we learned:
The study was recently published in a special issue of the journal Preventive Medicine. Other knowledge products aimed at policy makers, healthcare providers, researchers and the general public are available on the ComPARe study website, which is available in English (prevent.cancer.ca) and French (prevenir.cancer.ca).
A few key findings include:
- About 4 in 10 cancer cases can be prevented through healthy living and policies that protect the health of Canadians.
- This translates to roughly 70,200 cancer cases (out of 187,070) which could have been prevented in 2015 by reducing the risk associated with factors related to lifestyle, the environment, occupational, and infectious agents.
- Smoking tobacco was the leading preventable cause of cancer, followed by physical inactivity, excess body weight, low fruit intake and exposure to the sun.
- The most preventable cancers were cancers of the cervix (100%), lung (86%) and head and neck (75%).
- If current risk factor prevalence trends continue, the number of preventable cancer cases could rise to 111,700 in 2042.
- By 2042, excess body weight is projected to be the second leading preventable cause of cancer, after smoking.
- Over 11,000 tobacco-related cancer cases and 6,000 cancer cases related to excess weight could be prevented every year with a substantial reduction in these two risk factors.
Implications of these findings:
The results from the ComPARe study are directly relevant for guiding prevention research, informing program development, influencing behaviour change and supporting new policies and interventions aimed at decreasing the burden of cancer in Canada. Results will also inform national and provincial policymakers about the risk factors and cancer sites most amenable to intervention(s) and help identify which cancer prevention policies could have the greatest impact.
The ComPARe study was done in partnership with the Canadian Cancer Society using an integrated knowledge translation (iKT) approach. In ComPARe’s iKT approach, members of CCS were integrated into the study team and other knowledge users were engaged in an advisory capacity. This approach capitalized on both researchers’ and knowledge users’ expertise leading to findings that are contextually relevant; maximizing their potential impact on cancer prevention planning and decision-making in Canada. The ComPARe study’s iKT approach contributes to iKT science research and could be used as a model by others interested in collaborative research.
This research is funded by the Canadian Cancer Society (grant #703106).
Full Articles, HERE