The current and future burden of cancer attributable to modifiable risk factors in Canada: Summary of results

The fraction of cancer attributable to modifiable risk factors in Turkey in 2018

Cancer is the second leading cause of death in Turkey, with nearly one in six deaths attributed to the disease. In 2018, Turkey recorded 211,273 new cancer cases. Many cancers are linked to modifiable lifestyle risk factors, such as tobacco use, alcohol consumption, obesity, and inadequate diet and physical activity. Modifying these risk factors could potentially prevent 30%-50% of cancer cases and deaths. This study aims to estimate the population attributable fraction (PAF) of cancer cases and deaths due to various modifiable risk factors in Turkey. Modifiable cancer risk factors were identified as smoking, infections, obesity, physical inactivity, alcohol consumption, inadequate intake of fruits, vegetables, fiber, and calcium. Data on exposure prevalence and cancer incidence were sourced from national surveys and reports. Relative risks (RRs) were obtained from global studies. PAFs were calculated using Levin's equation, accounting for overlaps between risk factors. In 2018, 32% of the cancer cases were attributable to lifestyle risk factors. Smoking was the most significant factor, accounting for 28.4% of cases in men, while high BMI was the leading factor in women, contributing to 11.5% of cases. Lifestyle risk factors were responsible for 41.6% of cancer deaths, with smoking being the leading cause. Lifestyle risk factors contribute significantly to cancer incidence and mortality in Turkey. Prioritizing interventions to reduce tobacco use and obesity could substantially lower the cancer burden. These results are crucial for developing effective cancer prevention strategies and informing public health policies.

Living with and beyond cancer: What older adults tell us about healthy aging

INTRODUCTION

Healthy aging is a process that allows for optimal functional ability and wellbeing, but little is known about older adults' experiences living with and beyond cancer (also called survivorship). The purpose of this study was to explore the experiences and perceptions of healthy aging among older adults living with and beyond cancer.

MATERIALS AND METHODS

Community-dwelling older adults diagnosed with cancer at age ≥ 65 were recruited to participate in a series of in-depth semi-structured interviews. We used interpretive description and patient-oriented research methods. Data were thematically analyzed.

RESULTS

A total of 20 older adults living with and beyond cancer (mean age 74) in British Columbia, Canada, participated. Coping with cancer and age-related changes in older age was important for healthy aging and quality of life. Older adults coped by adapting to maintain their health and function, accepting and rejecting barriers, and defying ageist norms about cancer in older age. Participants reported discrepancies between their own priorities for healthy aging and their perceptions of healthcare providers' priorities for them. For example, older adults identified a lack of attention to quality of life and minimal integration of psychosocial supports in cancer treatment and survivorship care. Our findings also address the nuances of how cancer influences health behaviours in the context of pursuing healthy aging.

DISCUSSION

Understanding the experiences and perceptions of healthy aging among older adults living with and beyond cancer is critical to promoting health for this growing population. Our findings highlight the need for individualized care and the importance of quality of life for older adults living with and beyond cancer. This work can inform interventions to support healthy aging.

Gardening initiatives as an approach to cancer prevention for children and youth

OBJECTIVES

Gardening initiatives may be used to address modifiable risk factors for cancer from an early age. This review synthesizes evidence on the effects of gardening initiatives on modifiable cancer risk factors among school-aged children and youth.

STUDY DESIGN

Rapid review.

METHODS

A rapid review was conducted in March 2024 using databases (e.g., MEDLINE, PubMed), registers (e.g., ClinicalTrials.gov), and other sources (e.g., Healthevidence.org, Google Scholar). Two reviewers independently screened and selected articles for inclusion, and one completed quality appraisal. Peer-reviewed studies from the past ten years on gardening initiatives in schools, daycares, or community settings in high-income countries were included. Studies had to report health outcomes for children and youth (aged 0-18 years) related to modifiable cancer risk factors including: nutrition behaviors, body weight, physical activity (PA), sedentary behavior, psychosocial factors, and ultraviolet ray (UVR) behaviors.

RESULTS

This resulted in forty-eight included studies. Most measured outcomes related to nutrition behaviors, psychosocial factors, body weight, and PA. Fewer studies measured sedentary behavior, and none included UVR behaviors. Gardening initiatives generally led to positive nutrition behaviors (e.g., improved knowledge, dietary diversity), increased PA, decreased sedentary behavior, and improved psychosocial factors (e.g., depression, social cohesion). Effects on body weight and abdominal adiposity were inconclusive.

CONCLUSIONS

Gardening initiatives in educational and community settings could help prevent cancer by improving diet, PA, and psychosocial health in children and youth. However, more rigorous, longitudinal studies are needed to better understand their effectiveness, mechanisms, and long-term impact on cancer prevention into adulthood.

Burden and Trends of Diet-Related Colorectal Cancer in OECD Countries: Systematic Analysis Based on Global Burden of Disease Study 1990-2021 with Projections to 2050

Background: An unhealthy diet is a major risk factor for colorectal cancer (CRC). This study assessed the diet-related CRC burden from 1990 to 2021 in Organisation for Economic Co-operation and Development (OECD) nations and estimated the burden until 2050. Methods: Data for OECD countries on diet-related CRC disability-adjusted life years (DALYs) and deaths were obtained from the Global Burden of Disease 2021 study. The estimated annual percent change (EAPC) was calculated to analyse the CRC burden attributable to dietary factors. A generalised additive model with a negative binomial distribution was used to predict the future burden of CRC attributable to dietary factors from 2021 to 2050. Results: In 2021, the age-standardised percentages of diet-related CRC DALYs and deaths were 39.1% (95% uncertainty interval (UI): 9.3, 61.3) and 39.0% (95% UI: 9.7, 60.9), respectively, in the OECD countries. Between 1990 and 2021, the age-standardised DALYs decreased from 185 to 129 per 100,000, and deaths decreased from 8 to 6 per 100,000 population for OECD countries. Similarly, the EAPC in the rates showed a downward trend (EAPCdeaths = -1.26 and EAPCDALYs = -1.20). The estimated diet-related CRC DALYs and deaths are projected to increase to 4.1 million DALYs and 0.2 million deaths by 2050. There is a downward trend in CRC deaths (EAPC = 1.33 for both sexes) and in DALYs (-0.90 for males and -1.0 for females) from 1990 to 2050. Conclusions: The diet-related CRC burden remains significant. Implementing nutrition intervention programmes is necessary to promote access to affordable and nutritious foods and raise awareness about the importance of a healthy diet in reducing CRC risk.

Global, regional, and national burden of liver cancer in adolescents and young adults from 1990 to 2021: an analysis of the global burden of disease study 2021 and forecast to 2040

Background

The global burden of liver cancer among adolescents and young adults (AYAs) has often been underestimated, despite significant shifts in its etiology. This study analyzes the disease burden of liver cancer in AYAs from 1990 to 2021 and forecasts trends up to 2040 using data from the Global Burden of Disease Study 2021. Our goal is to provide insights that can inform resource allocation and policy planning.

Methods

Incidence, mortality, and disability-adjusted life years (DALYs) data were extracted and estimated annual percentage changes calculated to assess trends. Correlation between age-standardized rates and sociodemographic index (SDI) was analyzed using Spearman correlation, and future trends were predicted using the Bayesian age-period-cohort model.

Findings

Globally, there were 24,348 new liver cancer cases and 19,270 deaths among AYAs in 2021, with decreases in age-standardized rates for incidence, mortality, and DALYs from 1990 to 2021. East Asia bears the highest burden, with males experiencing significantly higher rates than females. The burden increases with age, peaking at 35-39 years. Higher SDI is associated with lower incidence, mortality, and DALYs. While HBV remains the leading cause, NASH is the fastest-growing contributor to liver cancer incidence and mortality. Projections indicate a continued decline in liver cancer burden among AYAs, though female cases are expected to rise.

Interpretation

Despite a gradual decline in liver cancer burden among AYAs, NASH is emerging as a significant and rising cause of incidence and mortality. Regional and gender disparities persist, highlighting the need for tailored prevention and healthcare strategies to alleviate the liver cancer AYA's burden globally.

Cancers attributed to modifiable factors in Norway 2016-2020

BACKGROUND

Targeting modifiable factors offers significant potential for primary cancer prevention. For public health strategies, it is essential to quantify the contribution from each factor on a national level. We estimated the contribution of 12 modifiable factors on cancer incidence in the Norwegian population.

METHODS

Nationally representative data (1990-2015) on the prevalence of tobacco smoking, over-exposure to ultraviolet radiation (UVR), alcohol consumption, physical inactivity, overweight and obesity, intake of processed and red meat, fibre and calcium, menopausal hormone therapy (MHT), human papilloma virus (HPV) infection and insufficient breastfeeding were collected from health surveys. Using these prevalences, cancer risk estimates for for the exposures, and average annual cancer incidence rates for 2016-2020, we estimated annual population-attributable fractions (PAFs) and numbers of preventable cases.

RESULTS

Of the average 24,608 annual cases of cancers related to our included modifiable factors, 12,250 (6240 in women and 6009 in men) (41 %) were attributed to these factors. Tobacco smoking caused the highest proportion of cancers cases, 20 % in men and 13 % in women. Sunburn and indoor tanning caused 13 % and 10 % of cancers in men and women, respectively, and overweight and obesity caused 4.5 % of the cases. Cancers of skin, lung, colon and female breast had the highest number of preventable cases.

CONCLUSION

Over a third of the annual cancer cases in Norway were attributed to 12 modifiable factors. Based on this study, efforts to reduce tobacco smoking, UVR over-exposure, and overweight and obesity could be the most effective in primary prevention of cancer.

Shooting for the Moon: Can We Cut Cancer Mortality in Canada By 50% By 2050?

INTRODUCTION

The United States of America reignited their Cancer Moonshot Initiative in 2022 with an ambitious goal to reduce cancer mortality by 50% over the next 25 years. In this study, we estimated how and whether a similar cancer control initiative could be achieved in Canada.

METHODS

We used the OncoSim microsimulation suite to address three questions: (1) what is the expected mortality from cancer in Canada by 2050 given the current trends?; (2) what would be the maximal impact on reducing cancer mortality with prevention and increased screening activities? and, (3) if a 50% reduction in projected cancer mortality could not be achieved through the primary and secondary intervention efforts, what additional advancements and discoveries would be needed to fill the "lunar gap"? We modeled the joint impact of risk-factor reduction and screening, as well as the independent effects of prevention and screening alone, on projected cancer mortality.

RESULTS

Our models suggest that there will be an expected 133,395 cancer deaths in 2050 in Canada. Approximately 33% of these cancer deaths could be prevented by risk-factor reduction and increased screening programs by the year 2050. This would leave a "lunar gap" of about 16%-17% that would need to be bridged with novel discoveries in cancer risk prevention, early detection, and treatment.

CONCLUSION

While current knowledge and implementation of prevention and screening would have a considerable impact on a Canadian cancer moonshot, additional efforts are needed to implement cancer control initiatives and fuel additional discoveries to fill the gap.

Comparison of Population Attributable Fractions of Cancer Incidence and Mortality Linked to Excess Body Weight in Korea from 2015 to 2030

BACKGRUOUND

The increasing rate of excess body weight (EBW) in the global population has led to growing health concerns, including cancer-related EBW. We aimed to estimate the population attributable fraction (PAF) of cancer incidence and deaths linked to EBW in Korean individuals from 2015 to 2030 and to compare its value with various body mass index cutoffs.

METHODS

Levin's formula was used to calculate the PAF; the prevalence rates were computed using the Korean National Health and Nutrition Examination Survey data, while the relative risks of specific cancers related to EBW were estimated based on the results of Korean cohort studies. To account for the 15-year latency period when estimating the PAF in 2020, the prevalence rates from 2015 and attributable cases or deaths from 2020 were used.

RESULTS

The PAF attributed to EBW was similar for both cancer incidence and deaths using either the World Health Organization (WHO) Asian-Pacific region standard or a modified Asian standard, with the WHO standard yielding the lowest values. In the Korean population, the PAFs of EBW for cancer incidence were 2.96% in men and 3.61% in women, while those for cancer deaths were 0.67% in men and 3.06% in women in 2020. Additionally, PAFs showed a gradual increase in both sexes until 2030.

CONCLUSION

The EBW continues to have a significant impact on cancer incidence and deaths in Korea. Effective prevention strategies targeting the reduction of this modifiable risk factor can substantially decrease the cancer burden.

Social, Behavioral, and Clinical Risk Factors Are Associated with Clonal Hematopoiesis

BACKGROUND

Risk factors including smoking, alcohol intake, physical activity (PA), and sleep patterns have been associated with cancer risk. Clonal hematopoiesis (CH), including mosaic chromosomal alterations and clonal hematopoiesis of indeterminate potential, is linked to increased hematopoietic cancer risk and could be used as common preclinical intermediates for the better understanding of associations of risk factors with rare hematologic malignancies.

METHODS

We analyzed cross-sectional data from 478,513 UK Biobank participants without hematologic malignancies using multivariable-adjusted analyses to assess the associations between lifestyle factors and CH types.

RESULTS

Smoking was reinforced as a potent modifiable risk factor for multiple CH types, with dose-dependent relationships persisting after cessation. Males in socially deprived areas of England had a lower risk of mosaic loss of chromosome Y (mLOY), females with moderate/high alcohol consumption (2-3 drinks/day) had increased mosaic loss of the X chromosome risk [OR = 1.17; 95% confidence interval (CI), 1.09-1.25; P = 8.31 × 10-6] compared with light drinkers, active males (moderate-high PA) had elevated risks of mLOY (PA category 3: OR = 1.06; 95% CI, 1.03-1.08; P = 7.57 × 10-6), and men with high body mass index (≥40) had reduced risk of mLOY (OR = 0.57; 95% CI, 0.51-0.65; P = 3.30 × 10-20). Sensitivity analyses with body mass index adjustment attenuated the effect in the mLOY-PA associations (IPAQ2: OR = 1.03; 95% CI, 1.00-1.06; P = 2.13 × 10-2 and IPAQ3: OR = 1.03; 95% CI, 1.01-1.06; P = 7.77 × 10-3).

CONCLUSIONS

Our study reveals associations between social deprivation, smoking, and alcohol consumption and CH risk, suggesting that these exposures could contribute to common types of CH and potentially rare hematologic cancers.

IMPACT

This study underscores the impact of lifestyle factors on CH frequency, emphasizing social, behavioral, and clinical influences and the importance of sociobehavioral contexts when investigating CH risk factors.

Geographical Disparities in Colorectal Cancer in Canada: A Review

PURPOSE OF REVIEW

Colorectal cancer (CRC) is a prominent contributor to cancer-related mortality in Canada. This review paper sheds light on the research conducted in Canada to scrutinize the influence of economicfactors. The review seeks to uncover notable disparities in Colorectal cancer incidence and mortality rate across diverse Canadian populations, including Indigenous communities, rural dwellers, and individuals with lower socioeconomic status (SES).

RECENT FINDINGS

Recent investigations reveal significant disparities in CRC incidence, mortality, and treatment outcomes among various demographic groups in Canada. Indigenous peoples, rural populations, and those with lower SES are particularly vulnerable to these disparities. Access to screening and specialized cancer care is notably limited for these marginalized populations, exacerbating existing health inequities. Furthermore, emerging evidence underscores the potential influence of dietary factors on CRC risk, highlighting the importance of tailored prevention and treatment strategies. The findings underscore the urgent need for targeted interventions aimed at enhancing access to CRC screening and specialized cancer care for disadvantaged populations in Canada. By addressing these disparities, more individuals can undergo timely screening and receive early-stage diagnoses, thereby improving prognosis and ultimately saving lives. However, to effectively bridge these gaps, further research is imperative to elucidate the underlying mechanisms driving these disparities and to identify and implement effective interventions.

Assessing the effectiveness of "BETTER Women", a community-based, primary care-linked peer health coaching programme for chronic disease prevention: protocol for a pragmatic, wait-list controlled, type 1 hybrid effectiveness-implementation trial

INTRODUCTION

The Building on Existing Tools to Improve Cancer and Chronic Disease Prevention and Screening in Primary Care (BETTER) programme trains allied health professionals working in primary care settings to develop personalised chronic disease 'prevention prescriptions' with patients. However, maintenance of health behaviour changes is difficult without ongoing support. Sustainable options to enhance the BETTER programme and ensure accessibility to underserved populations are needed. We designed the BETTER Women programme, which uses a digital app to match patients with a trained peer health coach (PHC) who provides ongoing support for health behaviour change after receipt of a BETTER prevention prescription in primary care.

METHODS AND ANALYSIS

We will conduct a type 1 hybrid implementation-effectiveness patient-randomised trial. Interested women aged 40-68 years will be recruited from three large, sociodemographically distinct primary care clinics (urban, suburban and rural). Patients will be randomised 1:1 to intervention or wait-list control after receipt of their BETTER prevention prescription. We will aim to recruit 204 patients per group (408 total). Effectiveness will be assessed by the primary outcome of targeted behaviours achieved for each participant at 6 months, consisting of three cancer screening tests (cervical, breast and colorectal) and four behavioural determinants of cancer and chronic disease (diet, smoking, alcohol use and physical activity). Data will be collected through patient survey and clinical chart review, measured at 3, 6 and 12 months. Implementation outcomes will be assessed through patient surveys and interviews with patients, peer health coaches and healthcare providers. An embedded economic evaluation will examine cost per quality-adjusted life-year and per additional health behavioural targets achieved.

ETHICS AND DISSEMINATION

This study has been approved by Women's College Hospital Research Ethics Board (REB), the Royal Victoria Regional Health Centre REB and the University of Toronto REB. All participants will provide informed consent prior to enrolment. Participation is voluntary and withdrawal will have no impact on the usual care received from their primary care provider. The results of this trial will be published in peer-reviewed journals and shared via conference presentations. Deidentified datasets will be shared on request, after publication of results.

TRIAL REGISTRATION NUMBER

NCT04746859.

Chasing cancer: does the social-to-medical spending ratio relate to cancer incidence and mortality in Canadian provinces? A retrospective cohort study

Introduction

Cancer is the leading cause of death in Canada, and cases are expected to rise by 83% between 2012 and 2042. Jurisdictions with higher ratios of social-to-medical spending exhibit better population health outcomes; however, the connection between the ratio and both cancer incidence and mortality is not well established. We aim to determine the association between the ratio and both age-standardised cancer incidence and mortality.

Methods

Using linear regressions with provincial and yearly fixed effects, we measured associations between the ratio and incidence of the four most common cancers in Canada (ie, lung and bronchus, colorectal, breast and prostate cancer), and mortality from any cancer, from 1992 to 2017 (incidence) and 2000 to 2019 (mortality).

Results

A one-cent increase in social spending for each dollar spent on medical services was significantly associated with a decrease in colorectal (-0.2%), breast (-0.1%), and prostate cancer (-0.6%). The relationship is statistically insignificant and negligible for lung cancer incidence and cancer mortality.

Conclusion

The ratio was significantly associated with a decrease in three out of four cancer incidence categories, but not mortality. This implies that, consistent with the social determinants of health, preventing cancer incidence might be a function of social spending, whereas medical spending is more relevant for individuals already diagnosed with cancer. This analysis points to the importance of a health-in-all-policies perspective, as social spending might be more important for population health than spending on the medical care system. We provide evidence that morbidity measures are responsive to the ratio, building on a literature focused on mortality.

Proportion of cancer cases and deaths attributable to potentially modifiable risk factors in Peru

BACKGROUND

Limited evidence exists on the population attributable fraction (PAF) of cancer cases and deaths in Latin America. In Peru several studies have been published regarding the PAF of various risk factors and their associated diseases. The objective of this study was to estimate the fraction of cancer cases and deaths attributable to potentially modifiable risk factors in Peru in 2018, before the COVID-19 pandemic in the population of 15 years old and older.

METHODS

An ecological study was conducted using the prevalence of exposure of the Peruvian population to modifiable risk factors for cancer, the relative risk associated with each factor, and the number of cancer cases and deaths in 2018 as inputs. We used the Parkin formula with a Montecarlo statistical simulation model to calculate the PAF and confidence intervals. The number of new cancer cases and deaths attributed to each risk factor was determined by multiplying the number of cases and deaths in each gender by the PAF of each risk factor.

FINDINGS

In Peru, 38.5% of new cases (34.5% in men and 42% in women) and 43.4% of cancer-related deaths (43.4% in men and 43.4% in women) were attributable to modifiable risk factors. The number of cancers attributable was 25,308 (10,439 in men and 14,869 in women) and the number of deaths attributable to cancer was 14,839 (6,953 in men and 7,886 in women). The predominant modifiable risk factors contributing to the highest number of cases and deaths were HPV infection (4,563 cases, 2,409 deaths), current tobacco use (3,348 cases, 2,180 deaths), and helicobacter pylori infection (2,677 cases, 1,873 deaths). Among the risk factors, oncogenic infections constituted the group with the highest PAF (16.6% for cases, 19.2% for deaths) followed by other unhealthy lifestyle factors (14.2% for cases, 16.7% for deaths), tobacco (7.2% for cases, 7.2% for deaths) and ultraviolet radiation (0.5% for cases, 0.3% for deaths).

CONCLUSIONS

Prior to the COVID-19 pandemic, 38.5% of cancer cases and 43.4% of cancer-related deaths in Peru were linked to modifiable risk factors in the population of 15 years old and older. Most preventable cancer cases and deaths were related to oncogenic infections, primarily caused by HPV and helicobacter pylori, followed by tobacco and obesity.

Cancer cases attributable to modifiable lifestyle risk factors in Switzerland between 2015 and 2019

Several modifiable lifestyle risk factors have been linked to higher cancer risk in the literature. Determining the proportion and number of cancer cases attributable to these risk factors is pivotal in informing effective cancer prevention and control plans that have the greatest effect on reducing cancer incidence. We aimed to estimate the proportion and number of incident cancer cases that were attributable to modifiable lifestyle risk factors (ie, tobacco smoking, high alcohol consumption, excess body weight, physical inactivity and unhealthy diet) in Switzerland between 2015 and 2019. The exposure prevalence of selected risk factors was estimated based on the representative national nutrition survey menuCH, the associated relative risks were obtained from systematic literature reviews and the numbers of incident cancer cases were provided by the National Institute for Cancer Epidemiology and Registration. The fractions and numbers of attributable cases were calculated overall, by sex and by the three major language regions of Switzerland. The investigated modifiable risk factors combined were linked to 25.2% of potentially preventable incident cancer cases in Switzerland between 2015 and 2019. The proportion and numbers were slightly larger in males (28.4%, 6945 cases per year) than in females (21.9%, 4493 cases per year), and variations were observed between language regions. Tobacco smoking, excess body weight and high alcohol consumption were the leading contributors to lifestyle-attributable cancer cases. The observed differences in the leading risk factors both within Switzerland and compared to other countries underline the need for regionally and nationally tailored cancer prevention and education strategies.

Screening for lung cancer with computed tomography: protocol for systematic reviews for the Canadian Task Force on Preventive Health Care

PURPOSE

Lung cancer is the leading cause of cancer deaths in Canada, and because early cancers are often asymptomatic screening aims to prevent mortality by detecting cancer earlier when treatment is more likely to be curative. These reviews will inform updated recommendations by the Canadian Task Force on Preventive Health Care on screening for lung cancer.

METHODS

We will update the review on the benefits and harms of screening with CT conducted for the task force in 2015 and perform de novo reviews on the comparative effects between (i) trial-based selection criteria and use of risk prediction models and (ii) trial-based nodule classification and different nodule classification systems and on patients' values and preferences. We will search Medline, Embase, and Cochrane Central (for questions on benefits and harms from 2015; comparative effects from 2012) and Medline, Scopus, and EconLit (for values and preferences from 2012) via peer-reviewed search strategies, clinical trial registries, and the reference lists of included studies and reviews. Two reviewers will screen all citations (including those in the previous review) and base inclusion decisions on consensus or arbitration by another reviewer. For benefits (i.e., all-cause and cancer-specific mortality and health-related quality of life) and harms (i.e., overdiagnosis, false positives, incidental findings, psychosocial harms from screening, and major complications and mortality from invasive procedures as a result of screening), we will include studies of adults in whom lung cancer is not suspected. We will include randomized controlled trials comparing CT screening with no screening or alternative screening modalities (e.g., chest radiography) or strategies (e.g., CT using different screening intervals, classification systems, and/or patient selection via risk models or biomarkers); non-randomized studies, including modeling studies, will be included for the comparative effects between trial-based and other selection criteria or nodule classification methods. For harms (except overdiagnosis) we will also include non-randomized and uncontrolled studies. For values and preferences, the study design may be any quantitative design that either directly or indirectly measures outcome preferences on outcomes pertaining to lung cancer screening. We will only include studies conducted in Very High Human Development Countries and having full texts in English or French. Data will be extracted by one reviewer with verification by another, with the exception of result data on mortality and cancer incidence (for calculating overdiagnosis) where duplicate extraction will occur. If two or more studies report on the same comparison and it is deemed suitable, we will pool continuous data using a mean difference or standardized mean difference, as applicable, and binary data using relative risks and a DerSimonian and Laird model unless events are rare (< 1%) where we will pool odds ratios using Peto's method or (if zero events) the reciprocal of the opposite treatment arm size correction. For pooling proportions, we will apply suitable transformation (logit or arcsine) depending on the proportions of events. If meta-analysis is not undertaken we will synthesize the data descriptively, considering clinical and methodological differences. For each outcome, two reviewers will independently assess within- and across-study risk of bias and rate the certainty of the evidence using GRADE (Grading of Recommendations Assessment, Development, and Evaluation), and reach consensus.

DISCUSSION

Since 2015, additional trials and longer follow-ups or additional data (e.g., harms, specific patient populations) from previously published trials have been published that will improve our understanding of the benefits and harms of screening. The systematic review of values and preferences will allow fulsome insights that will inform the balance of benefits and harms.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022378858.

Facilitators and barriers for implementing screening brief intervention and referral for health promotion in a rural hospital in Alberta: using consolidated framework for implementation research

BACKGROUND

Screening, brief intervention, and referral (SBIR) is an evidence-based, comprehensive health promotion approach commonly implemented to reduce alcohol and substance use. Implementation research on SBIR demonstrate that patients find it acceptable, reduces hospital costs, and it is effective. However, SBIR implementation in hospital settings for multiple risk factors (fruit and vegetable consumption, physical activity, alcohol and tobacco use) is still emergent. More evidence is needed to guide SBIR implementation for multiple risk factors in hospital settings.

OBJECTIVE

To explore the facilitators and barriers of SBIR implementation in a rural hospital using the Consolidated Framework for Implementation Research (CFIR).

METHODS

We conducted a descriptive qualitative investigation consisting of both inductive and deductive analyses. We conducted virtual, semi-structured interviews, guided by the CFIR framework. All interviews were audio-recorded, and transcribed verbatim. NVivo 12 Pro was used to organize and code the raw data.

RESULTS

A total of six key informant semi-structured interviews, ranging from 45 to 60 min, were carried out with members of the implementation support team and clinical implementers. Implementation support members reported that collaborating with health departments facilitated SBIR implementation by helping (a) align health promotion risk factors with existing guidelines; (b) develop training and educational resources for clinicians and patients; and (c) foster leadership buy-in. Conversely, clinical implementers reported several barriers to SBIR implementation including, increased and disrupted workflow due to SBIR-related documentation, a lack of knowledge on patients' readiness and motivation to change, as well as perceived patient stigma in relation to SBIR risk factors.

CONCLUSION

The CFIR provided a comprehensive framework to gauge facilitators and barriers relating to SBIR implementation. Our pilot investigation revealed that future SBIR implementation must address organizational, clinical implementer, and patient readiness to implement SBIR at all phases of the implementation process in a hospital.

Pairwise association of key lifestyle factors and risk of solid cancers - A prospective pooled multi-cohort register study

Smoking, alcohol consumption, obesity, and physical inactivity are key lifestyle risk factors for cancer. Previously these have been mostly examined singly or combined as an index, assuming independent and equivalent effects to cancer risk. The aim of our study was to systematically examine the joint pairwise and interactive effects of these lifestyle factors on the risk of a first solid primary cancer in a multi-cohort prospective setting. We used pooled data from seven Finnish health survey studies during 1972-2015, with 197,551 participants diagnosed with 16,373 solid malignant primary tumors during follow-up. Incidence of any cancer was analyzed separately without and with lung cancers using Poisson regression with main and interaction effects of key lifestyle factors. When excluding lung cancer, the highest risk of any cancer in men was observed for smokers with a BMI of ≥25 kg/m2 (HR 1.36, 95 % CI 1.25-1.48) and in women for smokers consuming alcohol (HR 1.22, 1.14-1.30). No statistically significant interactions between any studied risk factor pairs were observed. When including lung cancer, the highest HRs among men were observed for smokers who consume alcohol (HR 1.72, 1.57-1.89) and among women for smokers who were physically inactive (HR 1.38, 1.27-1.49). Smoking combined with other lifestyle factors at any exposure level resulted in highest pairwise risks, both in men and women. These results highlight the importance of smoking prevention, but also the importance of preventing obesity and reducing alcohol consumption.

Every tenth malignant solid tumor attributed to overweight and alcohol consumption: A population-based cohort study

BACKGROUND

Recent studies have shown that some four in ten cancers are attributable to a few key risk factors. The aim of this study was to estimate cohort-based population attributable fractions (PAFs) in Finland for potentially modifiable cancer risk factors.

METHODS

Data from eight health studies including 253,953 subjects with 29,802 incident malignant solid tumors were analysed using Bayesian multivariate regression model with multiplicative risk factor effects. We estimated the effects of smoking, excess body weight, alcohol consumption, physical activity, parity and education on cancer incidence and related PAFs by cancer site, accounting for competing mortality.

RESULTS

PAF for all cancer sites and exposures combined was 34% (95% credible interval 29%-39%) in men and 24% (19%-28%) in women. In men, 23% (21%-27%) and in women 8% (6%-9%) of all cancers were attributed to smoking. PAF related to excess body weight was 4% (2%-6%) in men and 5% (2%-7%) in women, to alcohol 7% (3%-10%) in men and 4% (0%-7%) in women, and to excess body weight and alcohol combined 10% (6%-15%) in men and 9% (4%-13%) in women.

CONCLUSION

Smoking was the most important factor contributing to cancer burden in Finnish men and women over the last 40 years. The contribution of excess body weight and alcohol consumption together outweighed the role of smoking in women. As the prevalence of overweight is expected to increase, more efficient public health measures supporting adherence to healthy weight are essential to reduce cancer burden.

Health, Wellness, and the Effect of Comorbidities on the Multiple Sclerosis Disease Course: Tackling the Modifiable

Multiple sclerosis (MS) is a disease of the central nervous system characterized by inflammatory demyelination and neurodegeneration. Numerous disease-modifying therapies for MS exist but are only partially effective, making it essential to optimize all factors that may influence the course of the disease. This includes conscientious management of both mental and physical comorbidities, as well as a comprehensive strategy for promoting wellness in patients with MS. Thoughtful engagement of those living with MS through shared decision making and involvement of a multidisciplinary team that includes primary care, relevant specialists, psychology, and rehabilitation is likely to lead to better outcomes.

Seven-plus hours of daily sedentary time and the subsequent risk of breast cancer: Japan Multi-Institutional Collaborative Cohort Study

This study aimed to investigate the association between daily sedentary time and the risk of breast cancer (BC) in a large Japanese population. The participants were 36,023 women aged 35-69 years from the Japan Multi-Institutional Collaborative Cohort Study. Cox proportional hazards analysis was used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for BC incidence in relation to time spent sedentarily (categorical variables: <7 and ≥7 hours/day [h/d]). Additionally, the associations of BC incidence to the joint effect of sedentary time with each component of physical activity, such as leisure-time metabolic equivalents (METs), frequency of leisure-time physical activity, and daily walking time, were examined. During 315,189 person-years of follow-up, 554 incident cases of BC were identified. When compared to participants who spent <7 h/d sedentary, those who spent ≥7 h/d sedentary have a significantly higher risk of BC (HR, 1.36; 95% CI, 1.07-1.71). The corresponding HRs among participants who spent ≥7 h/d sedentary with more physical activity, such as ≥1 h/d for leisure-time METs, ≥3 days/week of leisure-time physical activity, and ≥1 h/d of daily walking were 1.58 (95% CI, 1.11-2.25), 1.77 (95% CI, 1.20-2.61), and 1.42 (95% CI, 1.10-1.83), respectively, compared with those who spent <7 h/d sedentary. This study found that spending ≥7 h/d of sedentary time is associated with the risk of BC. Neither leisure-time physical activity nor walking had a BC-preventive effect in those with ≥7 h/d of sedentary time.

Canadians' knowledge of cancer risk factors and belief in cancer myths

BACKGROUND

Many untrue statements about cancer prevention and risks are circulating. The objective of this study was to assess Canadians' awareness of known cancer risk factors and cancer myths (untruths or statements that are not completely true), and to explore how awareness may vary by sociodemographic and cognitive factors.

METHODS

Cancer myths were identified by conducting scans of published, grey literature, and social media. Intuitive-analytic thinking disposition scores included were actively open- and close-minded thinking, as well as preference for intuitive and effortful thinking. A survey was administered online to participants aged 18 years and older through Prolific. Results were summarized descriptively and analyzed using chi-square tests, as well as Spearman rank and Pearson correlations.

RESULTS

Responses from 734 Canadians were received. Participants were better at identifying known cancer risk factors (70% of known risks) compared to cancer myths (49%). Bivariate analyses showed differential awareness of known cancer risk factors (p < 0.05) by population density and income, cancer myths by province, and for both by ethnicity, age, and all thinking disposition scores. Active open-minded thinking and preference for effortful thinking were associated with greater discernment. Tobacco-related risk factors were well-identified (> 90% correctly identified), but recognition of other known risk factors was poor (as low as 23% for low vegetable and fruit intake). Mythical cancer risk factors with high support were consuming additives (61%), feeling stressed (52%), and consuming artificial sweeteners (49%). High uncertainty of causation was observed for glyphosate (66% neither agreed or disagreed). For factors that reduce cancer risk, reasonable awareness was observed for HPV vaccination (60%), but there was a high prevalence in cancer myths, particularly that consuming antioxidants (65%) and organic foods (45%) are protective, and some uncertainty whether drinking red wine (41%), consuming vitamins (32%), and smoking cannabis (30%) reduces cancer risk.

CONCLUSIONS

While Canadians were able to identify tobacco-related cancer risk factors, many myths were believed and numerous risk factors were not recognized. Cancer myths can be harmful in themselves and can detract the public's attention from and action on established risk factors.

Screening, brief intervention, and referral to treatment for tobacco consumption, alcohol misuse, and physical inactivity: an equity-informed rapid review

OBJECTIVE

This rapid review systematically synthesizes evidence of the effectiveness of the Screening, Brief Intervention, and Referral (SBIR/T) approach for tobacco use, alcohol misuse, and physical inactivity.

STUDY DESIGN

This was a rapid review.

METHODS

We searched primary studies between 2012 and 2022 in seven electronic databases. The search strategy used concepts related to alcohol-related disorders, intoxication, cigarette, nicotine, physical activity, exercise, sedentary, screening, therapy, and referral. We reviewed both title/abstract and full-text using a priori set inclusion and exclusion criteria to identify the eligible studies. We appraised study quality, extracted data, and summarized the characteristics of the included studies. We applied health equity lenses in the synthesis.

RESULTS

Of the 44 included studies, most focused on alcohol misuse. SBIR/T improved patients' attitudes toward alcohol behavior change, improved readiness and referral initiation for change, and effectively reduced alcohol consumption. Few studies pertained to smoking and physical inactivity. Most studies on smoking demonstrated effectiveness pertaining to patients' acceptance of referral recommendations, improved readiness and attempts to quitting smoking, and reduced or cessation of smoking. Findings were mixed about the effectiveness of SBIR/T in improving physical activity. Minimal studies exist on the impacts of SBIR/T for these three risk factors on healthcare resource use or costs. Studies considering diverse population characteristics in the design and effectiveness assessment of the SBIR/T intervention are lacking.

CONCLUSIONS

More research on the impacts of SBIR/T on tobacco use, alcohol misuse, and physical inactivity is required to inform the planning and delivery of SBIR/T for general and disadvantaged populations.

Differences in site-specific cancer incidence by individual- and area-level income in Canada from 2006 to 2015

Income, a component of socioeconomic status, influences cancer risk as a social determinant of health. We evaluated the independent associations between individual- and area-level income and site-specific cancer incidence in Canada. We used data from the 2006 and 2011 Canadian Census Health and Environment Cohorts, which are probabilistically linked datasets constituted by 5.9 million and 6.5 million respondents of the 2006 Canadian long-form census and 2011 National Household Survey, respectively. Individuals were linked to the Canadian Cancer Registry through 2015. Individual-level income was derived using after-tax household income adjusted for household size. Annual tax return postal codes were used to assign area-level income quintiles to individuals for each year of follow-up. We calculated age-standardized incidence rates (ASIR) and rate ratios for cancers overall and by site. We conducted multivariable negative binomial regression to adjust these rates for other demographic and socioeconomic variables. Individuals of lower individual- and area-level income had higher ASIRs compared to those in the wealthiest income quintile for head and neck, oropharyngeal, esophageal, stomach, colorectal, anal, liver, pancreas, lung, cervical and kidney and renal pelvis cancers. Conversely, individuals of wealthier individual- and area-level income had higher ASIRs for melanoma, leukemia, Hodgkin's lymphoma, non-Hodgkin's lymphoma, breast, uterine, prostate and testicular cancers. Most differences in site-specific incidence by income quintile remained after adjustment. Although Canada's publicly funded healthcare system provides universal coverage, inequalities in cancer incidence persist across individual- and area-level income gradients. Our estimates suggest that individual- and area-level income affect cancer incidence through independent mechanisms.

What is the optimal type and dose of physical activity for colorectal cancer prevention?

Epidemiological evidence shows that higher levels of physical activity reduce the relative risk of colon cancer by up to 20%. To design optimal physical activity interventions for primary prevention, it is important to understand how the specific characteristics of physical activity (type, intensity, overall volume) influence the magnitude of colon cancer risk reduction. Improving our understanding of the underlying biological mechanisms will also help to manipulate physical activity characteristics to precisely target mechanisms of action and identify populations most likely to benefit. This review synthesizes the best available evidence to explore how the type and dose of physical activity moderate the protective effect of physical activity on colon cancer.

The future burden of oesophageal and stomach cancers attributable to modifiable behaviours in Australia: a pooled cohort study

BACKGROUND

We quantified the individual and joint contribution of contemporaneous causal behavioural exposures on the future burden of oesophageal and stomach cancers and their subtypes and assessed whether these burdens differ between population groups in Australia, as such estimates are currently lacking.

METHODS

We combined hazard ratios from seven pooled Australian cohorts (N = 367,058) linked to national cancer and death registries with exposure prevalence from the 2017-2018 National Health Survey to estimate Population Attributable Fractions (PAFs) with 95% confidence intervals (CIs), accounting for competing risk of death.

RESULTS

Current and past smoking explain 35.2% (95% CI = 11.7-52.4%), current alcohol consumption exceeding three drinks/day 15.7% (95% CI = 0.9-28.4%), and these exposures jointly 41.4% (95% CI = 19.8-57.3%) of oesophageal squamous cell carcinomas in Australia. Current and past smoking contribute 38.2% (95% CI = 9.4-57.9%), obesity 27.0% (95% CI = 0.6-46.4%), and these exposures jointly 54.4% (95% CI = 25.3-72.1%) of oesophageal adenocarcinomas. Overweight and obesity explain 36.1% (95% CI = 9.1-55.1%), current and past smoking 24.2% (95% CI = 4.2-40.0%), and these exposures jointly 51.2% (95% CI = 26.3-67.8%) of stomach cardia cancers. Several population groups had a significantly higher smoking-attributable oesophageal cancer burden, including men and those consuming excessive alcohol.

CONCLUSIONS

Smoking is the leading preventable behavioural cause of oesophageal cancers and overweight/obesity of stomach cancers.

Mental health, cancer risk, and the mediating role of lifestyle factors in the CARTaGENE cohort study

BACKGROUND

Evidence on the association between mental health disorders and cancer risk is inconclusive, despite well-established associations between mental health disorders and lifestyle factors such as smoking. This study examines the relationships between depression, anxiety and cancer risk, and the potential mediating effects of lifestyle factors.

METHODS

A study of 34,571 participants aged 40-69 years in the CARTaGENE cohort was conducted. Depression was defined by questionnaire (PHQ-9), antidepressant use, and a composite of questionnaire, antidepressant use, or lifetime self-reported physician diagnosis. Anxiety was defined by questionnaire (GAD-7). Co-morbid depression and anxiety was also assessed. Cox regression models were used to investigate associations between mental health and risk of prostate, lung, and all cancers combined. Mediating effects of lifestyle factors were assessed using Baron and Kenny mediation criteria.

RESULTS

There were positive associations between mental health disorders, all cancers and lung cancer risk, however with the exception of anxiety and lung cancer in women (Hazard Ratio [HR] = 1.67, 95% CI: 1.01-2.76), associations were attenuated with adjustment for sociodemographics, health status and lifestyle factors. In the mediation analysis, smoking accounted for 27%, 18%, and 26%, of the total effect between depression (PHQ-9), anxiety, and co-morbidity and lung cancer, respectively in women. In men, smoking accounted for 17% of the total effect between depression (PHQ-9, antidepressant, or lifetime self-report of physician diagnosis) and all cancers.

CONCLUSIONS

Positive associations were observed between mental health disorders, all cancer and lung cancer risk, however most relationships were attenuated with adjustment for lifestyle factors. Smoking status mediated a significant proportion of the relationships between mental health disorders and cancer risk.

Implementing Screening, Brief Intervention and Referral Intervention for Health Promotion and Disease Prevention in Hospital Settings in Alberta: A Pilot Study

Objective: This study assessed the feasibility of implementing screening, brief intervention and referral (SBIR) intervention in hospital settings. Methods: This cross-sectional study evaluated the implementation of the SBIR intervention in a hospital in Alberta for tobacco use, alcohol intake, physical inactivity, and insufficient vegetable and fruit consumption. Patients were interviewed approximately 4-month later to collect data on the acceptability and effectiveness of the intervention received (n = 108). The data were primarily analyzed using descriptive statistics. Results: Of 108 patients, >80% agreed that "they were ok with being screened" for the risk factors during their hospital visit. Up to 68% of patients recalled the provider's brief education. At the follow-up, 20% of patients quit tobacco, 50% reduced alcohol use, 30% increased physical activity, and 25% increased vegetable and fruit intake. Conclusion: Risk factor screening was acceptable for patients. Patients recalled the brief education they received from healthcare providers. Patients reported risk-reducing changes in their risk factors. Our future work will integrate the SBIR approach within the Electronic Clinical Information System and use robust research methods to investigate the impact of SBIR on patients' behavior change.

Metabolic Health, Mitochondrial Fitness, Physical Activity, and Cancer

Cancer continues to be a significant global health issue. Traditional genetic-based approaches to understanding and treating cancer have had limited success. Researchers are increasingly exploring the impact of the environment, specifically inflammation and metabolism, on cancer development. Examining the role of mitochondria in this context is crucial for understanding the connections between metabolic health, physical activity, and cancer. This study aimed to review the literature on this topic through a comprehensive narrative review of various databases including MedLine (PubMed), Cochrane (Wiley), Embase, PsychINFO, and CinAhl. The review highlighted the importance of mitochondrial function in overall health and in regulating key events in cancer development, such as apoptosis. The concept of "mitochondrial fitness" emphasizes the crucial role of mitochondria in cell metabolism, particularly their oxidative functions, and how proper function can prevent replication errors and regulate apoptosis. Engaging in high-energy-demanding movement, such as exercise, is a powerful intervention for improving mitochondrial function and increasing resistance to environmental stressors. These findings support the significance of considering the role of the environment, specifically inflammation and metabolism, in cancer development and treatment. Further research is required to fully understand the mechanisms by which physical activity improves mitochondrial function and potentially reduces the risk of cancer.

Characterizing occupational radon exposure greater than 100 Bq/m3 in a highly exposed country

Radon is an established lung carcinogen concentrating in indoor environments with importance for many workers worldwide. However, a systematic assessment of radon levels faced by all workers, not just those with direct uranium or radon exposure, has not previously been completed. The objective of this study was to estimate the prevalence of workers exposed to radon, and the level of exposure (> 100-200 Bq/m3, 200-400 Bq/m3, 400-800 Bq/m3, and > 800 Bq/m3) in a highly exposed country (Canada). Exposures among underground workers were assessed using the CAREX Canada approach. Radon concentrations in indoor workplaces, obtained from two Canadian surveys, were modelled using lognormal distributions. Distributions were then applied to the susceptible indoor worker population to yield the number of exposed workers, by occupation, industry, province, and sex. In total, an estimated 603,000 out of Canada's 18,268,120 workers are exposed to radon in Canada. An estimated52% of exposed workers are women, even though they comprise only 48% of the labour force. The majority (68%) are exposed at a level of > 100-200 Bq/m3. Workers are primarily exposed in educational services, professional, scientific and technical services, and health care and social assistance, but workers in mining, quarrying, and oil and gas extraction have the largest number of exposed workers at high levels (> 800 Bq/m3). Overall, a significant number of workers are exposed to radon, many of whom are not adequately protected by existing guidelines. Radon surveys across multiple industries and occupations are needed to better characterize occupational exposure. These results can be used to identify exposed workers, and to support lung cancer prevention programs within these groups.

Investigating the early impacts of the COVID-19 pandemic on modifiable risk factors for cancer and chronic disease: a repeated cross-sectional study in Alberta, Canada

OBJECTIVES

This study contributes to empirical evidence by examining the impact of the first and second waves of the COVID-19 pandemic on modifiable risk factors (MRF) and whether these patterns differ according to level of material deprivation among people living in Alberta.

METHODS

Using data from a repeated cross-sectional provincial health survey (Alberta Community Health Survey (ACHS): 2018-2021), we conducted logistic regression analyses examining the impacts of the COVID-19 pandemic on meeting national guidelines on four MRFs (tobacco use, physical activity, fruit and vegetable consumption, alcohol use) (n=11,249). We compared population-level changes in MRFs from one year before the COVID-19 pandemic (March 2019-February 2020) to one year during the pandemic (March 2020-February 2021) in Alberta. We also assessed whether these trends differed by a measure of material deprivation.

RESULTS

Compared to the pre-COVID-19 period, the fully adjusted odds of meeting recommended guidelines for fruit and vegetable consumption (OR=0.42) decreased during the pandemic. Individuals experiencing high material deprivation had lower odds of meeting recommended guidelines for physical activity (OR=0.65) and higher odds of not being current tobacco users (OR=1.36) during the pandemic versus during the pre-pandemic period.

CONCLUSION

At a population level, analyses from the ACHS showed minimal impacts of the first year of the COVID-19 pandemic on MRFs, besides fruit and vegetable consumption. Yet, stratifying results showed statistically significant differences in pandemic impacts on MRFs by level of material deprivation. Therefore, understanding the influence of material deprivation on MRFs during the pandemic is key to tailoring future public health interventions promoting health and preventing cancer and chronic disease.

Inflammation: the incubator of the tumor microenvironment

An inflammatory microenvironment, either conferred by an underlying chronic overt or smoldering inflammatory condition constitutes a prerequisite and fuel to essentially all cancers. The complex reciprocal interplay of different cell types in the tumor microenvironment (TME) determines patient outcome. Apart from the actual tumor cells, local and recruited nonmalignant cells as well as the intestinal microbiome actively shape polarization and plasticity of cells in the TME, thereby augmenting protumorigenic and prometastatic inflammatory processes. Here, we address the universality of inflammation in carcinogenesis, review distinct forms of tumor related inflammation and highlight critical processes in the TME actively sustaining a nurturing incubator for cancer progression and therapy resistance.

The global burden of cancer attributable to risk factors, 2010-19: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally.

METHODS

The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented.

FINDINGS

Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01-4·94) deaths and 105 million (95·0-116) DALYs for both sexes combined, representing 44·4% (41·3-48·4) of all cancer deaths and 42·0% (39·1-45·6) of all DALYs. There were 2·88 million (2·60-3·18) risk-attributable cancer deaths in males (50·6% [47·8-54·1] of all male cancer deaths) and 1·58 million (1·36-1·84) risk-attributable cancer deaths in females (36·3% [32·5-41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6-28·4) and DALYs by 16·8% (8·8-25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9-42·8] and 33·3% [25·8-42·0]).

INTERPRETATION

The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden.

FUNDING

Bill & Melinda Gates Foundation.

Interaction of leisure-time physical activity with body mass index on the risk of obesity-related cancers: a pooled study

Physical activity (PA) has been associated with a lower risk of some obesity-related cancers, but the combined association and interaction of PA and body weight on obesity-related cancer risk is less clear. We examined the association of leisure-time PA (high/low) and its combination with body mass index (BMI, <25 [low]/≥25 [high] kg/m² ) on obesity-related cancer risk in 570 021 individuals, aged 43 years on average at baseline, in five Scandinavian cohorts. We used Cox regression to calculate hazard ratios of obesity-related cancers (n = 19 074) and assessed multiplicative and additive interactions between PA and BMI on risk. High leisure-time PA, recorded in 19% of the individuals, was associated with a 7% (95% confidence interval [CI] 4-10%) lower risk of any obesity-related cancer compared to low PA, with similar associations amongst individuals with a low and a high BMI (6% [1-11%] and 7% [2-11%]). High PA was also associated with decreased risks of renal cell (11% [9-31%]) and colon cancer (9% [2-16%]). When high PA and low BMI were combined, the relative risk reduction for all obesity-related cancers was 24% (95% CI 20-28%); endometrial cancer, 47% (35-57%); renal cell cancer, 39% (27-51%); colon cancer, 27% (19-35%); multiple myeloma, 23% (2-40%); and pancreatic cancer, 21% (4-35%), compared to low PA-high BMI. There were no additive or multiplicative interactions between PA and BMI on risk. The result of this study suggests a reduced risk of obesity-related cancer by leisure-time PA in both normal weight and overweight individuals, which further decreased for PA and normal weight combined.

Identifying Novel Causes of Cancers to Enhance Cancer Prevention: New Strategies Are Needed

The burden of cancer from a clinical, societal, and economic viewpoint continues to increase in all parts of the world, along with much debate regarding how to confront this. Projected increases in cancer indicate a 50% increase in the number of cases over the next 2 decades, with the greatest proportional increase in low- and medium-income settings. In contrast to the historic high cancer burden due to viral and bacterial infections in these regions, future increases are expected to be due to cancers linked to westernization including breast, colorectum, lung, and prostate cancer. Identifying the reasons underlying these increases will be paramount to informing prevention efforts. Evidence from epidemiological and laboratory studies conducted in high-income countries over the last 70 years has led to the conclusion that approximately 40% of the cancer burden is explained by known risk factors-the 2 most important being tobacco and obesity in that order-raising the question of what is driving the rest of the cancer burden. International cancer statistics continue to show that approximately 80% of the cancer burden in high-income countries could be preventable in principle, implying that there are important environmental or lifestyle risk factors for cancer that have not yet been discovered. Emerging genomic evidence from population and experimental studies points to an important role for nonmutagenic promoters in driving cancer incidence rates. New research strategies and infrastructures that combine population-based and laboratory research at a global level are required to break this deadlock.

Burden of cancer attributable to modifiable factors in Japan in 2015

The This study estimated the cancer burden attributable to modifiable factors in Japan in 2015 using the best available epidemiological evidence and a standard methodology. We selected the following factors for inclusion in the estimates, namely tobacco smoking (active smoking and secondhand smoking), alcohol drinking, excess bodyweight, physical inactivity, infectious agents (Helicobacter pylori, hepatitis C virus, hepatitis B virus, human papilloma virus, Epstein-Barr virus, and human T-cell leukemia virus type 1), dietary intake (highly salted food, fruit, vegetables, dietary fiber, red meat, processed meat), exogenous hormone use, never breastfeeding and air pollution, given that these were considered modifiable, in theory at least. We first estimated the population attributable fraction (PAF) of each cancer attributable to these factors using representative relative risks of Japanese and the prevalence of exposures in Japanese around 2005, in consideration of the 10-year interval between exposure and cancer outcomes. Using nationwide cancer incidence and mortality statistics, we then estimated the attributable cancer incidence and mortality in 2015. We finally obtained the PAF for site-specific and total cancers attributable to all modifiable risk factors using this formula, with statistical consideration of the effect of overlap between risk factors. The results showed that 35.9% of all cancer incidence (43.4% in men and 25.3% in women) and 41.0% of all cancer mortality (49.7% in men and 26.8% in women) would be considered preventable by avoidance of these exposures. Infections and active smoking followed by alcohol drinking were the greatest contributing factors to cancer in Japan in 2015.

An Integrated Fluorescent Probe for Ratiometric Detection of Glutathione in the Golgi Apparatus and Activated Organelle-Targeted Therapy

Cancer is a serious threat to human health, and there is an urgent need to develop new treatment methods to overcome it. Organelle targeting therapy, as a highly effective and less toxic side effect treatment strategy, has great research significance and development prospects. Being an essential organelle, the Golgi apparatus plays a particularly major role in the growth of cancer cells. Acting as an indispensable and highly expressed antioxidant in cancer cells, glutathione (GSH) also contributes greatly during the Golgi oxidative stress. Therefore, it counts for much to track the changes of GSH concentration in Golgi for monitoring the occurrence and development of tumor cells, and exploring Golgi-targeted therapy is also extremely important for effective treatment of cancer. In this work, we designed and synthesized a simple Golgi-targeting fluorescent probe GT-GSH for accurately detecting GSH. The probe GT-GSH reacting with GSH decomposes toxic substances to Golgi, thereby killing cancer cells. At the same time, the ratiometric fluorescent probe can detect the concentration changes of GSH in Golgi stress with high sensitivity and selectivity in living cells. Therefore, such a GSH-responsive fluorescent probe with a Golgi-targeted therapy effect gives a new method for accurate treatment of cancer.

The future excess fraction of cancer due to lifestyle factors in Australia

BACKGROUND

Many cancers are caused by exposure to lifestyle, environmental, and occupational factors. Earlier studies have estimated the number of cancers occurring in a single year which are attributable to past exposures to these factors. However, there is now increasing appreciation that estimates of the future burden of cancer may be more useful for policy and prevention. We aimed to calculate the future number of cancers expected to arise as a result of exposure to 23 modifiable risk factors.

METHODS

We used the future excess fraction (FEF) method to estimate the lifetime burden of cancer (2016-2098) among Australian adults who were exposed to modifiable lifestyle, environmental, and occupational risk factors in 2016. Calculations were conducted for 26 cancer sites and 78 cancer-risk factor pairings.

RESULTS

The cohort of 18.8 million adult Australians in 2016 will develop an estimated 7.6 million cancers during their lifetime, of which 1.8 million (24%) will be attributable to exposure to modifiable risk factors. Cancer sites with the highest number of future attributable cancers were colon and rectum (n = 717,700), lung (n = 380,400), and liver (n = 103,200). The highest number of future cancers will be attributable to exposure to tobacco smoke (n = 583,500), followed by overweight/obesity (n = 333,100) and alcohol consumption (n = 249,700).

CONCLUSION

A significant proportion of future cancers will result from recent levels of exposure to modifiable risk factors. Our results provide direct, pertinent information to help determine where preventive measures could best be targeted.

Spatiotemporal variability of exposure to secondhand smoke in Iran during 2009-2020: a systematic review

The present study aimed to provide a systematic review of studies on the prevalence of secondhand smoke (SHS) exposure in the Iran population as a serious indoor health hazard. A literature review of studies that considered SHS exposure, available in multiple electronic databases including Web of Science, PubMed, and Scopus published 2009-2020 in English and two Persian databases (SID and Magiran), was carried out following the PRISMA recommendations. A total of 55 studies were included based on the inclusion and exclusion criteria and the quality assessment. The results showed no specific decrease in the prevalence of exposure to secondhand smoke in Iran; however, it appeared that the exposure has been increasing. Distribution of studies in terms of age group revealed that most studies (38%) investigated adults (more than 18 years old), while 34% of the studies considered less than 18 years of age group and a single article considered infants (6-24 months). Based on the present study results, a large population of Iran was exposed to SHS. Moreover, based on Iran's STEPs 2016 (Stepwise Non-communicable Diseases Risk Factors Survey in Iran) study, the overall prevalence of SHS exposure at home (57.5%) was higher than in workplaces (49.2%). The results of the present study recommended that protection measures should be comprehensive in terms of exposure places, and since the exposure prevalence in some provinces was higher than the others, it is especially important to consider the local measures and cultural aspects in SHS control programs.

International strategy in cancer epidemiology: Japan's involvement in global projects and future role

In recent years, collaboration among researchers in the field of cancer epidemiology has been accelerating in various forms. Here, we review recent trends in international collaborative research activities in the cancer epidemiology field in Japan. These include not only support for other countries with less developed cancer statistics infrastructures, but also large-scale compilations and international comparisons through collaborative studies, as well as integration with analytical epidemiology and clinical research. Formation of international cohort consortia and estimates of cancer and risk factors in each country have contributed to raising the skill levels of cancer epidemiologists as well as to expanding research networks and activities among cancer epidemiologists. Molecular and genome epidemiological studies on cancer have progressed over decades and these continue to increase in size and dimension. Application of evidence from this area in prevention is still underway and needs further effort. Japanese epidemiologists have great potential to assume international leadership roles by taking advantage of the uniqueness, originality and characteristics of Japanese cohorts.

Simulation study on the validity of the average risk approach in estimating population attributable fractions for continuous exposures

BACKGROUND

The population attributable fraction (PAF) is an important metric for estimating disease burden associated with causal risk factors. In an International Agency for Research on Cancer working group report, an approach was introduced to estimate the PAF using the average of a continuous exposure and the incremental relative risk (RR) per unit. This 'average risk' approach has been subsequently applied in several studies conducted worldwide. However, no investigation of the validity of this method has been done.

OBJECTIVE

To examine the validity and the potential magnitude of bias of the average risk approach.

METHODS

We established analytically that the direction of the bias is determined by the shape of the RR function. We then used simulation models based on a variety of risk exposure distributions and a range of RR per unit. We estimated the unbiased PAF from integrating the exposure distribution and RR, and the PAF using the average risk approach. We examined the absolute and relative bias as the direct and relative difference in PAF estimated from the two approaches. We also examined the bias of the average risk approach using real-world data from the Canadian Population Attributable Risk of Cancer study.

RESULTS

The average risk approach involves bias, which is underestimation or overestimation with a convex or concave RR function (a risk profile that increases more/less rapidly at higher levels of exposure). The magnitude of the bias is affected by the exposure distribution as well as the value of RR. This approach is approximately valid when the RR per unit is small or the RR function is approximately linear. The absolute and relative bias can both be large when RR is not small and the exposure distribution is skewed.

CONCLUSIONS

We recommend that caution be taken when using the average risk approach to estimate PAF.

Dietary patterns with combined and site-specific cancer incidence in Alberta's Tomorrow Project cohort

BACKGROUND/OBJECTIVES

Poor diet quality has been associated with an increased risk of cancer. Here, we examine the association between dietary patterns derived with two methods, and combined and site-specific cancer incidence in Canada.

SUBJECTS/METHODS

Dietary data were obtained from participants enrolled in Alberta's Tomorrow Project, a prospective cohort study, between 2000 and 2008. Principle component analysis (PCA) and reduced rank regression (RRR) were used to derive dietary patterns, and data linkage with the Alberta Cancer Registry was used for incident cancer cases. Cox proportional hazard regressions were used to estimate multivariable-adjusted models for the association between each dietary pattern score with combined and site-specific cancer incidence.

RESULTS

PCA revealed three dietary patterns ("western", "prudent", and "sugar, fruits, and dairy") and RRR resulted in four patterns ("dietary fiber", "vitamin D", "fructose", and "discretionary fat"). Five cancer sites were included in our site-specific analysis: lung, colon, breast, prostate, and endometrial cancers. The most protective dietary patterns for combined cancer sites were the "Prudent" pattern (HR = 0.82, CI = 0.73-0.92) and the "Dietary fiber" pattern (HR = 0.82, CI = 0.69-0.97). The "Fructose" pattern was associated with increased risk of combined cancers (HR = 1.14, CI = 1.02-1.27). Three dietary patterns were protective against colon cancer ("Prudent", "Dietary fiber", and "Discretionary fats"), and other risk reductions were seen for the "sugar, fruit, and dairy" pattern (lung cancer), and the "Dietary fiber" pattern (prostate cancer).

CONCLUSIONS

These results support cancer prevention strategies for a diet high in vegetables, fruits, fish, and whole grains. Further studies should explore the possible association between discretionary fats and colon cancer.

Metabolomics and cancer preventive behaviors in the BC Generations Project

Metabolomics can detect metabolic shifts resulting from lifestyle behaviors and may provide insight on the relevance of changes to carcinogenesis. We used non-targeted nuclear magnetic resonance to examine associations between metabolic measures and cancer preventive behaviors in 1319 participants (50% male, mean age 54 years) from the BC Generations Project. Behaviors were dichotomized: BMI < 25 kg/m², ≥ 5 servings of fruits or vegetables/day, ≤ 2 alcoholic drinks/day for men or 1 drink/day for women and ≥ 30 min of moderate or vigorous physical activity/day. Linear regression was used to estimate coefficients and 95% confidence intervals with a false discovery rate (FDR) of 0.10. Of the 218 metabolic measures, 173, 103, 71 and 6 were associated with BMI, fruits and vegetables, alcohol consumption and physical activity. Notable findings included negative associations between glycoprotein acetyls, an inflammation-related metabolite with lower BMI and greater fruit and vegetable consumption, a positive association between polyunsaturated fatty acids and fruit and vegetable consumption and positive associations between high-density lipoprotein subclasses with lower BMI. These findings provide insight into metabolic alterations in the context of cancer prevention and the diverse biological pathways they are involved in. In particular, behaviors related to BMI, fruit and vegetable and alcohol consumption had a large metabolic impact.

Risk of gastric cancer in the environs of industrial facilities in the MCC-Spain study

BACKGROUND

Gastric cancer is the fifth most frequent tumor worldwide. In Spain, it presents a large geographic variability in incidence, suggesting a possible role of environmental factors in its etiology. Therefore, epidemiologic research focused on environmental exposures is necessary.

OBJECTIVES

To assess the association between risk of gastric cancer (by histological type and tumor site) and residential proximity to industrial installations, according to categories of industrial groups and specific pollutants released, in the context of a population-based multicase-control study of incident cancer conducted in Spain (MCC-Spain).

METHODS

In this study, 2664 controls and 137 gastric cancer cases from 9 provinces, frequency matched by province of residence, age, and sex were included. Distances from the individuals' residences to the 106 industries located in the study areas were computed. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (95%CIs) for categories of distance (from 1 km to 3 km) to industries, adjusting for matching variables and potential confounders.

RESULTS

Overall, no excess risk of gastric cancer was observed in people living close to the industrial installations, with ORs ranging from 0.73 (at ≤2.5 km) to 0.93 (at ≤1.5 km). However, by industrial sector, excess risks (OR; 95%CI) were found near organic chemical industry (3.51; 1.42-8.69 at ≤2 km), inorganic chemical industry (3.33; 1.12-9.85 at ≤2 km), food/beverage sector (2.48; 1.12-5.50 at ≤2 km), and surface treatment using organic solvents (3.59; 1.40-9.22 at ≤3 km). By specific pollutant, a statistically significant excess risk (OR; 95%CI) was found near (≤3 km) industries releasing nonylphenol (6.43; 2.30-17.97) and antimony (4.82; 1.94-12.01).

CONCLUSIONS

The results suggest no association between risk of gastric cancer and living in the proximity to the industrial facilities as a whole. However, a few associations were detected near some industrial sectors and installations releasing specific pollutants.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Estimates of future cancer mortality attributable to modifiable risk factors in Canada

OBJECTIVES

Modifiable lifestyle, environmental, and infectious risk factors associated with cancer impact both cancer incidence and mortality at the population level. Most studies estimating this burden focus on cancer incidence. However, because these risk factors are associated with cancers of disparate mortality rates, the burden associated with cancer incidence could differ from cancer mortality. Therefore, estimating the cancer mortality attributable to these risk factors provides additional insight into cancer prevention. Here, we estimated future cancer deaths and the number of avoidable deaths in Canada due to modifiable risk factors.

METHODS

The projected cancer mortality data came from OncoSim, a web-based microsimulation tool. These data were applied to the methodological framework that we previously used to estimate the population attributable risks and the potential impact fractions of modifiable risk factors on Canadian cancer incidence.

RESULTS

We estimated that most cancer deaths will be attributed to tobacco smoking with an average of 27,900 deaths annually from 2024 to 2047. If Canada's current trends in excess body weight continue, cancer deaths attributable to excess body weight would double from 2786 deaths in 2024 to 5604 deaths in 2047, becoming the second leading modifiable cause of cancer death. Applying targets to reduce these risk factors, up to 34,600 cancer deaths could be prevented from 2024 to 2047.

CONCLUSION

Our simulated results complement our previous findings on the cancer incidence burden since decreasing the overall burden of cancer will be accelerated through a combination of decreasing cancer incidence and improving survival outcomes through improved treatments.

The Future Burden of Head and Neck Cancers Attributable to Modifiable Behaviors in Australia: A Pooled Cohort Study

BACKGROUND

Estimates of future burden of cancer attributable to current modifiable causal exposures can guide cancer prevention. We quantified future head and neck cancer burden in Australia attributable to individual and joint causal exposures, and assessed whether these burdens differ between population subgroups.

METHODS

We estimated the strength of the associations between exposures and head and neck cancer using adjusted proportional hazards models from pooled data from seven Australian cohorts (N = 367,058) linked to national cancer and death registries and estimated exposure prevalence from the 2017 to 2018 Australian National Health Survey. We calculated population attributable fractions (PAF) with 95% confidence intervals (CI), accounting for competing risk of death, and compared PAFs for population subgroups.

RESULTS

Contemporary levels of current and former smoking contribute 30.6% (95% CI, 22.7%-37.8%), alcohol consumption exceeding two standard drinks per day 12.9% (95% CI, 7.6%-17.9%), and these exposures jointly 38.5% (95% CI, 31.1%-45.0%) to the future head and neck cancer burden. Alcohol-attributable burden is triple and smoking-attributable burden is double for men compared with women. Smoking-attributable burden is also at least double for those consuming more than two alcoholic drinks daily or doing less than 150 minutes of moderate or 75 minutes of vigorous activity weekly, and for those aged under 65 years, unmarried, with low or intermediate educational attainment or lower socioeconomic status, compared with their counterparts.

CONCLUSIONS

Two-fifths of head and neck cancers in Australia are preventable by investment in tobacco and alcohol control.

IMPACT

Targeting men and other identified high-burden subgroups can help to reduce head and neck cancer burden disparities.

Co-designing Behavior Change Resources With Treatment-Seeking Smokers: Engagement Events' Findings

Background: Primary care organizations are well-suited to help patients change their unhealthy behaviors. Evidence shows that risk communication and self-monitoring of behavior are is an effective strategy practitioners can use to promote health behavior change with their patients. In order for this evidence to be actionable, it is important to understand how patients would like this information to be communicated and to operationalize the self-monitoring resources. The objective of this study was to co-create resources that encourage behavior change based on the scientific evidence and from patients with lived experiences.

Materials and Methods: Twenty-seven individuals who participated in a smoking cessation program and engaged in at least one other unhealthy behavior joined one of two engagement events. Each event was 3 h in duration and consisted of two exercises that provided support to participants in reaching a consensus about the types of messages they would like to receive from their practitioner as well as self-monitoring resources they would prefer to use. The first exercise followed an adapted version of the Consensus Methodology developed by the Institute of Cultural Affairs Canada, while the second exercise was in accordance to the Nominal Group Technique.

Results: Participants' preference was to have practitioners convey messages to promote health behavior change that include positive affirmation and to monitor all their health behaviors using a single self-reported tracking sheet.

Conclusions: This paper features the use of engagement events to reflect upon and identify potential resources that treatment seeking smokers prefer to receive while attempting to modify unhealthy behaviors. These resources can be used by health care providers in primary care settings to support health promotion interventions and assist their patients to increase their likelihood of adopting positive changes to risk behaviors.

Cancer prevention through weight control-where are we in 2020?

Growing data from epidemiological studies highlight the association between excess body fat and cancer incidence, but good indicative evidence demonstrates that intentional weight loss, as well as increasing physical activity, offers much promise as a cost-effective approach for reducing the cancer burden. However, clear gaps remain in our understanding of how changes in body fat or levels of physical activity are mechanistically linked to cancer, and the magnitude of their impact on cancer risk. It is important to investigate the causal link between programmes that successfully achieve short-term modest weight loss followed by weight-loss maintenance and cancer incidence. The longer-term impact of weight loss and duration of overweight and obesity on risk reduction also need to be fully considered in trial design. These gaps in knowledge need to be urgently addressed to expedite the development and implementation of future cancer-control strategies. Comprehensive approaches to trial design, Mendelian randomisation studies and data-linkage opportunities offer real possibilities to tackle current research gaps. In this paper, we set out the case for why non-pharmacological weight-management trials are urgently needed to support cancer-risk reduction and help control the growing global burden of cancer.

A prospective study of the associations among fine particulate matter, genetic variants, and the risk of colorectal cancer

BACKGROUND

Fine particulate matter (PM_2.5) is suspected to increase the risk of colorectal cancer, but the mechanism remains unknown. We aimed to investigate the association between PM_2.5 exposure, genetic variants and colorectal cancer risk in the Prostate, Lung, Colon and Ovarian (PLCO) Cancer Screening trial.

METHODS

We included a prospective cohort of 139,534 cancer-free individuals from 10 United States research centers with over ten years of follow-up. We used a Cox regression model to assess the association between PM_2.5 exposure and colorectal cancer incidence by calculating the hazard ratio (HR) and 95% confidence interval (CI) with adjustment for potential confounders. The polygenic risk score (PRS) and genome-wide interaction analysis (GWIA) were used to evaluate the multiplicative interaction between PM_2.5 exposure and genetic variants in regard to colorectal cancer risk.

RESULTS

After a median of 10.43 years of follow-up, 1,666 participants had been diagnosed with colorectal cancer. PM_2.5 exposure was significantly associated with an increased risk of colorectal cancer (HR = 1.27; 95% CI = 1.17-1.37 per 5 μg/m³ increase). Five independent susceptibility loci reached statistical significance at P < 1.22 × 10^-8 in the interaction analysis. Furthermore, a joint interaction was observed between PM_2.5 exposure and the PRS based on these five loci with colorectal cancer risk (P = 3.11 × 10^-29). The Gene Ontology analysis showed that the vascular endothelial growth factor (VEGF) receptor signaling pathway was involved in the biological process of colorectal cancer.

CONCLUSIONS

Our large-scale analysis has shown for the first time that long-term PM_2.5 exposure potential increases colorectal cancer risk, which might be modified by genetic variants.

Pan-cancer analysis demonstrates that integrating polygenic risk scores with modifiable risk factors improves risk prediction

Cancer risk is determined by a complex interplay of environmental and heritable factors. Polygenic risk scores (PRS) provide a personalized genetic susceptibility profile that may be leveraged for disease prediction. Using data from the UK Biobank (413,753 individuals; 22,755 incident cancer cases), we quantify the added predictive value of integrating cancer-specific PRS with family history and modifiable risk factors for 16 cancers. We show that incorporating PRS measurably improves prediction accuracy for most cancers, but the magnitude of this improvement varies substantially. We also demonstrate that stratifying on levels of PRS identifies significantly divergent 5-year risk trajectories after accounting for family history and modifiable risk factors. At the population level, the top 20% of the PRS distribution accounts for 4.0% to 30.3% of incident cancer cases, exceeding the impact of many lifestyle-related factors. In summary, this study illustrates the potential for improving cancer risk assessment by integrating genetic risk scores.