Cancer Burden In Canada Research Articles

Abstract PO4-09-03: Environmental Metal Exposures and Breast Cancer Risk: A Prospective Study of Nationally Representative Canadian Data

Abstract Introduction: The impact of metal exposure on breast cancer risk remains unclear. Studies have explored metals independently with limited investigation into chronic exposures and mixture analyses. This project describes exposure to eight heavy and essential metals and evaluates the association between metals and breast cancer risk, independently and in a mixture, among Canadian women. Methods: Demographic information and concentrations of urinary or blood metal biomarkers from 2007-2017 of the Canadian Health Measures Survey (CHMS) were analyzed. Incident breast cancers were ascertained through linkage to the Canadian Cancer Registry. Metal exposure was described using weighted percentiles and categorized by tertiles. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for metal exposure and breast cancer risk. Quantile g-computation was used to estimate the joint association between metal exposure and breast cancer risk. Results: This analysis included 5,100 women (mean age 44.6 years) with an average follow-up of 6.6 years. Higher urinary arsenic (> 13.0 µg/L) and cadmium (> 10.0 µg/L) had a significant increased risk of breast cancer (HR Arsenic T3 vs. T1 = 2.05; 95%CI 1.05-3.94; HR Cadmium T3 vs. T1 = 1.71; 95%CI 1.01 – 5.87). Analyses into the joint association between the metal exposure mixture and breast cancer risk are ongoing, and matrix results will be presented. Conclusion: This represents the first evaluation of metal exposure and breast cancer risk in a nationally representative cohort. Our findings suggest that arsenic and cadmium, even at low levels, may be associated with an increased risk of breast cancer. These findings can inform population-level interventions to reduce the burden of cancer in Canada. Citation Format: Katherine Pullella, Jan Lubinski, Anthony Hanley, Shelley Harris, Steven Narod, Joanne Kotsopoulos. Environmental Metal Exposures and Breast Cancer Risk: A Prospective Study of Nationally Representative Canadian Data [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-03.

Modelling the Potential Impact of Weight Gain During the COVID-19 Pandemic on the Future Burden of Cancer

ObjectivesTo understand potential long-term consequences of the impacts of the COVID-19 pandemic and resulting public health measures on daily life, specifically shifts in health behaviours which contribute to weight gain. MethodsData on unintentional weight gain among adults during the first year of the COVID-19 pandemic was applied to national survey data to simulate pre and post weight gain body mass index (BMI). Population impact measures were estimated using OncoSim, a web-based microsimulation tool, which simulates the trajectory of cancer, calibrated using Canadian cancer incidence and mortality data along with measurable risk for specified cancers from lifestyle risk factors. Projections were estimated until 2042, assuming a 12-year latency period. ResultsFollowing a mean weight gain of 11.4 lbs, the proportion of underweight, overweight, obese and morbidly obese BMI were: 37%, 36%, 18% and 9%, respectively. The projected excess cancer cases would reach 8,651 and 16,915 by 2037 and 2042. The additional cancer burden will disproportionately impact women. The largest projected increases were observed for uterine, kidney and liver cancers among women, with mean potential impact fractions (PIF) of 4.26%, 2.58% and 2.08%, respectively. Among men, the largest mean PIFs were observed for esophageal (3.03%), kidney (2.28%) and liver (1.81%) cancers. The projected excess cancer deaths would reach 6,254 by 2042, with the largest burden projected for colorectal, esophageal and pancreatic cancer (N = 1,087, N = 945, and N = 813). ConclusionsThese projections highlight the possible long-term consequences of changes in health behavior during the COVID-19 pandemic on the burden of cancer in Canada. This underscores the critical need for timely investment into effective cancer prevention strategies, to minimize the likelihood that unhealthy lifestyle changes during the COVID-19 pandemic are sustained. Funding SourcesMichael Smith Foundation for Health Research, the Canadian Partnership Against Cancer, Health Canada.

Projected Impact of Weight Gain During the COVID-19 Pandemic on the Future Burden of Cancer in Canada

The COVID-19 pandemic and resulting public health measures have had significant impacts on daily life, including shifts in health behaviours which contribute to weight gain and may increase subsequent risk of chronic diseases such as cancer. Using OncoSim, a web-based microsimulation tool, we estimated the future burden of cancer in Canada by incorporating data on unintentional weight gain among adults during the first year of the COVID-19 pandemic. Population impact measures were estimated until 2042, assuming a 12-year latency period. We estimated 14,194 excess cancer cases and 5,324 excess cancer deaths by 2042 due to COVID-19 related weight gain. Particularly large impacts were estimated for endometrial and breast cancer among women, with 2,983 and 2,151 excess cases by 2042. For men, 1,700 excess colorectal cases and 1,188 excess kidney cancer cases were projected by 2042. Changes in health behavior during the COVID-19 pandemic are likely to have significant and long-lasting impacts on cancer burden. These projections highlight the immediate need for investment into the development and implementation of effective cancer prevention strategies.

Projected estimates of cancer in Canada in 2022.

Background:Regular cancer surveillance is crucial for understanding where progress is being made and where more must be done. We sought to provide an overview of the expected burden of cancer in Canada in 2022.Methods:We obtained data on new cancer incidence from the National Cancer Incidence Reporting System (1984–1991) and Canadian Cancer Registry (1992–2018). Mortality data (1984–2019) were obtained from the Canadian Vital Statistics — Death Database. We projected cancer incidence and mortality counts and rates to 2022 for 22 cancer types by sex and province or territory. Rates were age standardized to the 2011 Canadian standard population.Results:An estimated 233 900 new cancer cases and 85 100 cancer deaths are expected in Canada in 2022. We expect the most commonly diagnosed cancers to be lung overall (30 000), breast in females (28 600) and prostate in males (24 600). We also expect lung cancer to be the leading cause of cancer death, accounting for 24.3% of all cancer deaths, followed by colorectal (11.0%), pancreatic (6.7%) and breast cancers (6.5%). Incidence and mortality rates are generally expected to be higher in the eastern provinces of Canada than the western provinces.Interpretation:Although overall cancer rates are declining, the number of cases and deaths continues to climb, owing to population growth and the aging population. The projected high burden of lung cancer indicates a need for increased tobacco control and improvements in early detection and treatment. Success in breast and colorectal cancer screening and treatment likely account for the continued decline in their burden. The limited progress in early detection and new treatments for pancreatic cancer explains why it is expected to be the third leading cause of cancer death in Canada.

The Economic Burden of Cancer in Canada from a Societal Perspective.

Cancer patients and their families experience considerable financial hardship; however, the current published literature on the economic burden of cancer at the population level has typically focused on the costs from the health system’s perspective. This study aims to estimate the economic burden of cancer in Canada from a societal perspective. The analysis was conducted using the OncoSim-All Cancers model, a Canadian cancer microsimulation model. OncoSim simulates cancer incidence and deaths using incidence and mortality data from the Canadian Cancer Registry and demography projections from Statistics Canada. Using a phase-based costing framework, we estimated the economic burden of cancer in Canada in 2021 by incorporating published direct health system costs and patients’ and families’ costs (out-of-pocket costs, time costs, indirect costs). From a societal perspective, cancer-related costs were CAD 26.2 billion in Canada in 2021; 30% of costs were borne by patients and their families. The economic burden was the highest in the first year after cancer was diagnosed (i.e., initial care). During this time, patients and families’ costs amounted to almost CAD 4.8 billion in 2021. This study provides a comprehensive estimate of the economic burden of cancer, which could inform cost–benefit analyses of proposed cancer prevention interventions.

Estimating the future cancer management costs attributable to modifiable risk factors in Canada.

An estimated 33-37% of incident cancers in Canada are attributable to modifiable risk factors. Interventions targeting these risk factors would minimize the substantial health and economic burdens Canadians face due to cancer. We estimate the future health and economic burden of cancer in Canada by incorporating data from the Canadian Population Attributable Risk of Cancer (ComPARe) study into OncoSim, a web-based microsimulation tool. Using the integrated OncoSim population attributable risk and population impact measures, we evaluated risk factor-targeted intervention scenarios implemented in 2020, assuming the targeted risk factor prevalence reduction would be achieved by 2032 with a 12-year latency period. We estimate that smoking will be the largest contributor to cancer-related costs, with a cost of CAD $44.4 billion between 2032 and 2044. An estimated CAD $3.3 billion of the cost could be avoided with a 30% reduction in smoking prevalence by 2022. Following smoking, the next highest cancer management costs are associated with inadequate physical activity and excess body weight, accounting for CAD $10.7 billion ($2.7 billion avoidable) and CAD $9.8 billion ($3.2 billion avoidable), respectively. Avoidable costs for other risk factors range from CAD $90 million to CAD $2.5 billion. Interventions targeting modifiable cancer risk factors could prevent a substantial number of incident cancer cases and billions of dollars in cancer management costs. With limited budgets and rising costs in cancer care in Canada, these simulation models and results are valuable for researchers and policymakers to inform decisions and prioritize and evaluate intervention programs.

An assessment of uncertainty using two different modelling techniques to estimate the cost effectiveness of mitigating radon in existing housing in Canada

The burden of lung cancer associated with residential radon in existing housing can be reduced by interventions to screen and mitigate existing housing having radon levels above a mitigation threshold. The objective of this study is to estimate the cost effectiveness of radon interventions for screening and mitigation of existing housing for the 2016 population in Canada and to assess the structural uncertainty associated with the choice of model used in the cost-utility analysis. The incremental cost utility ratios are estimated using both a Markov cohort model and a discrete event simulation model. A societal perspective, a lifetime horizon and a discount rate of 1.5% are adopted. At a radon mitigation threshold of 200 (100) Bq/m3, the discounted ICERs for current rates of screening and mitigation of existing housing are 72,569 (68,758) $/QALY using a Markov cohort model and 84,828 (76,917) $/QALY using discrete event simulation. It appears that minimal structural uncertainty is associated with the choice of model used for this cost-utility analysis, and the cost effectiveness would improve at increased rates of radon testing and mitigation. The mitigation of radon in existing housing is estimated to be a practical policy option for reducing the associated lung cancer burden in Canada.

Projected estimates of cancer in Canada in 2020.

Cancer projections to the current year help in policy development, planning of programs and allocation of resources. We sought to provide an overview of the expected incidence and mortality of cancer in Canada in 2020 in follow-up to the Canadian Cancer Statistics 2019 report. We obtained incidence data from the National Cancer Incidence Reporting System (1984-1991) and Canadian Cancer Registry (1992-2015). Mortality data (1984-2015) were obtained from the Canadian Vital Statistics - Death Database. All databases are maintained by Statistics Canada. Cancer incidence and mortality counts and age-standardized rates were projected to 2020 for 23 cancer types by sex and geographic region (provinces and territories) for all ages combined. An estimated 225 800 new cancer cases and 83 300 cancer deaths are expected in Canada in 2020. The most commonly diagnosed cancers are expected to be lung overall (29 800), breast in females (27 400) and prostate in males (23 300). Lung cancer is also expected to be the leading cause of cancer death, accounting for 25.5% of all cancer deaths, followed by colorectal (11.6%), pancreatic (6.4%) and breast (6.1%) cancers. Incidence and mortality rates will be generally higher in the eastern provinces than in the western provinces. The number of cancer cases and deaths remains high in Canada and, owing to the growing and aging population, is expected to continue to increase. Although progress has been made in reducing deaths for most major cancers (breast, prostate and lung), there has been limited progress for pancreatic cancer, which is expected to be the third leading cause of cancer death in Canada in 2020. Additional efforts to improve uptake of existing programs, as well as to advance research, prevention, screening and treatment, are needed to address the cancer burden in Canada.

The burden of cancer attributable to modifiable risk factors in Canada: Methods overview

Up-to-date estimates of current and projected future cancer burden attributable to various exposures are essential for planning and implementing cancer prevention initiatives. The Canadian Population Attributable Risk of Cancer (ComPARe) study was conducted to: i) estimate the number and proportion of cancers diagnosed among adults in Canada in 2015 that are attributable to modifiable risk factors and ii) project the future avoidable cancers by 2042 under various intervention targets. We estimated the population attributable risk (with 95% confidence intervals) and the potential impact fraction of cancers associated with selected lifestyle, environmental, and infectious factors. Exposure-specific sensitivity analyses were also completed where appropriate. Several exposures of interest included active and passive smoking, obesity and abdominal adiposity, leisure-time physical inactivity, sedentary behaviour, alcohol consumption, insufficient fruit and vegetable intake, red and processed meat consumption, air pollution (PM2.5, NO2), indoor radon gas, ultraviolet radiation (UVR), hepatitis B and C virus, Helicobacter pylori, Epstein-Barr virus, human papillomavirus, human herpesvirus type 8 and human T-cell lymphotropic virus type 1. We used the 2015 cancer incidence data for 35 cancer sites from the Canadian Cancer Registry and projected cancer incidence to 2042 using historical data from 1983 to 2012. Here, we provide an overview of the data sources and methods used in estimating the current and future cancer burden in Canada. Specific methodologic details for each exposure are included in the individual articles included as part of this special issue.

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.

Estimates of the current and future burden of cancer attributable to excess body weight and abdominal adiposity in Canada

The increasing prevalence of obesity among Canadians has important implications for newly diagnosed cases of cancer given that excess body weight and abdominal adiposity are known to increase the risk of several cancers. The purpose of this analysis was to estimate the current attributable and future avoidable burden of cancer related to excess body weight and abdominal adiposity among Canadian adults. We estimated the population attributable risk (PAR) for all cancers associated with excess body weight and abdominal adiposity using contemporary cancer incidence, relative risk and exposure prevalence data for body mass index (BMI), waist circumference and waist-to-hip-ratio. Using the partial impact fraction (PIF), we also estimated the future avoidable burden of cancer from 2015 to 2042 in Canada, and by province, through various hypothetical intervention scenarios. In 2003, approximately half (50.5%) of the Canadian population was estimated to be overweight (BMI 25.0–29.9) or obese (BMI ≥30.0), 56.5% to have excess abdominal adiposity and 56.8% with a high waist-to-hip ratio. In 2015, the estimated PARs of all incident cancers associated with excess body weight, excess abdominal adiposity and high waist-to-hip ratio were 7.2%, 8.9% and 10.0%, respectively. If the population BMI could revert to its 1994 distribution, 72,157 associated cancer cases could be prevented cumulatively by 2042. A reduction in excess body weight and abdominal adiposity has the potential to decrease the future cancer burden in Canada substantially, and hence efforts to reverse increasing trends in obesity should be prioritized.

The future burden of cancer in Canada: Long-term cancer incidence projections 2013–2042

BackgroundCancer is the leading cause of death in Canada and the estimated annual spending associated with cancer is approximately $7.5 billion. Projecting the future burden of cancer in Canada is essential for health planning and evaluation. We aimed to estimate the future incidence of cancer in Canada to 2042. MethodsAge-sex-region-specific cancer incidence data were obtained for the years 1983-2012 and cancer incidence was projected from 2013 to 2042 for the top five cancer sites. The modelling algorithm combined a mixture of cancer projection methods to select the best-fitted model. When the chosen model produced by the modelling algorithm resulted in estimates that were not consistent with expert opinion, an alternate model was selected that took into consideration historical changes in policy, screening and lifestyle behaviours. Incidence projections were made for Canada and its provinces. ResultsLung cancer incidence is estimated to rise to 14,866 cases in men and 19,162 in women in 2042. Colorectal cancer incidence is estimated to rise to 28,146 in men and 21,102 in women. Cases of bladder cancer are projected to rise to 10,708 and 3,364 in men and women, respectively. Breast cancer incidence is predicted to rise to 40,712 and prostate cancer incidence is projected to rise to 92,949. ConclusionThese cancer incidence projections up to 2042 can be used for planning cancer control strategies and prevention programs. Given the ongoing changes in the prevalence of risk factors and in cancer prevention policies, these estimates should be interpreted with caution.

Lessons Learned From Canada in Working Together to Support Indigenous Health and Wellness

Background and context: First Nations, Inuit and Métis bear a disproportionate burden of cancer in Canada. In the spirit of truth and reconciliation, and to have the greatest impact, it is important for nonindigenous and indigenous partners to work together, and reflect on lessons learned in collaborating, to support First Nations, Inuit and Métis health and wellness. Aim: In response to the national Truth and Reconciliation Commission Calls to Action, the Canadian Partnership Against Cancer committed to understanding how collaborative projects funded through the Coalitions Linking Action and Science for Prevention (CLASP) initiative were successful in bringing together diverse groups - both indigenous and nonindigenous - to create and apply culturally-relevant cancer prevention approaches. Strategy/Tactics: Seven projects funded through the CLASP initiative, from 2009 to 2016, brought together over 275 First Nations, Inuit, or Métis communities, schools, and organizations with government, nongovernment, and academic partners in collaborative coalitions. The projects addressed cancer prevention issues prioritized by First Nations, Inuit, and Métis (e.g., unhealthy eating and physical inactivity) through approaches that were holistic and culturally-relevant, such as utilizing intergenerational knowledge sharing, incorporating mental wellness, and supporting existing capacity within communities. Program/Policy process: Over 30 knowledge products developed by the projects were reviewed to identify preliminary lessons learned about partner collaboration. Preliminary lessons learned were verified and expanded upon through nine key informant interviews with CLASP partners. Key informant interviews were informed by four advisors representing indigenous and nonindigenous leaders and partners. The refined set of lessons learned were finalized through qualitative analysis and validated through a conference session and one-day workshop with CLASP partners and First Nations, Inuit, and Métis community leaders. Outcomes: Twenty-seven lessons learned that describe how nonindigenous and First Nations, Inuit and Métis CLASP partners worked together to develop and put into practice culturally-appropriate cancer prevention approaches were identified. The lessons learned were grouped into six themes: 1. respectful relationships; 2. engagement with indigenous communities; 3. addressing accountability requirements, decision-making, and governance; 4. community direction; 5. supports and resources; 6. communication and knowledge exchange. What was learned: The actionable lessons learned are intended to guide future relationship building and engagement between nonindigenous partners and First Nations, Inuit and Métis partners. It is intended that these lessons will be beneficial to collaborative cancer prevention efforts around the world and inform broader system change leading to a reduction in indigenous cancer burden disparities.

Estimating the current and future cancer burden in Canada: methodological framework of the Canadian population attributable risk of cancer (ComPARe) study

IntroductionThe Canadian Population Attributable Risk of Cancer project aims to quantify the number and proportion of cancer cases incident in Canada, now and projected to 2042, that could be prevented...

Cancer incidence in Canada: trends and projections (1983–2032)

Each year, the Canadian Cancer Statistics publication provides an estimate of expected case counts and rates for common cancer sites for the current year in Canada as a whole and in the provinces and territories. This monograph expands on the Canadian Cancer Statistics publication by providing historical and projected cancer incidence frequencies and rates at national and regional levels from 1983 to 2032. The aim is that this monograph will be an important resource for health researchers and planners. Most importantly, it is hoped the monograph will: - provide evidence-based input for the development of public health policy priorities at the regional and national levels; and - guide public health officials in planning strategy including designing and evaluating preventive interventions and planning resources (treatment requirements) and infrastructure for future cancer control and care intended to reduce the burden of cancer in Canada.

The Evaluation of Cancer Control Interventions in Lung Cancer using the Canadian Cancer Risk Management Model

SUMMARY Background: Rising healthcare costs will increasingly require policy-makers to make difficult decisions based on the potential benefits and costs of new healthcare interventions. The Canadian Partnership Against Cancer commissioned the development of the Cancer Risk Management Model as a tool to aid such decisions. This computer microsimulation model projects future population health and economic impacts of cancer control programs in Canada. Lung cancer was the first simulation module to be developed and was selected because of the magnitude of lung cancer burden in Canada and recent screening and treatment interventions that require policy decisions. Methods: The model simulates one individual life at a time, from birth to death, taking account of Canadian demographic and labor force characteristics, risk factor exposures and health histories, and then combines this information from all the simulated lives to produce aggregate measures of health outcomes for the Canadian population as a whole or for particular subpopulations. The direct costs of medical care can be estimated, as well as lost earnings and impacts on tax revenues. Results: The lung module is available through the Canadian Partnership Against Cancer website to registered users where structured scenarios can be explored for their projected impacts. Conclusion: The Cancer Risk Management Model for lung cancer is now available via the internet to assist healthcare policy analysts, researchers and decision-makers in their work.

Cancer in Canada in 2008

In this article, we describe the changing size and nature of the cancer burden in Canada by reviewing the major findings from the 2008 edition of Canadian Cancer Statistics , which has been published annually since 1987. We also examine Canadian cancer statistics in the context of international

Estimating the burden of breast cancer in Canada

Estimating the burden of breast cancer in Canada