Population Attributable and Preventable Fractions: Cancer Risk Factor Surveillance, and Cancer Policy Projection

Projected Time for the Elimination of Cervical Cancer Under Various Intervention Scenarios: Age-Period-Cohort Macrosimulation Study

BACKGROUND

The World Health Organization aims for the global elimination of cervical cancer, necessitating modeling studies to forecast long-term outcomes.

OBJECTIVE

This paper introduces a macrosimulation framework using age-period-cohort modeling and population attributable fractions to predict the timeline for eliminating cervical cancer in Taiwan.

METHODS

Data for cervical cancer cases from 1997 to 2016 were obtained from the Taiwan Cancer Registry. Future incidence rates under the current approach and various intervention strategies, such as scaled-up screening (cytology based or human papillomavirus [HPV] based) and HPV vaccination, were projected.

RESULTS

Our projections indicate that Taiwan could eliminate cervical cancer by 2050 with either 70% compliance in cytology-based or HPV-based screening or 90% HPV vaccination coverage. The years projected for elimination are 2047 and 2035 for cytology-based and HPV-based screening, respectively; 2050 for vaccination alone; and 2038 and 2033 for combined screening and vaccination approaches.

CONCLUSIONS

The age-period-cohort macrosimulation framework offers a valuable policy analysis tool for cervical cancer control. Our findings can inform strategies in other high-incidence countries, serving as a benchmark for global efforts to eliminate the disease.

Association of long-term exposure to various ambient air pollutants, lifestyle, and genetic predisposition with incident cognitive impairment and dementia

BACKGROUND

Long-term exposure to air pollution has been found to contribute to the development of cognitive decline. Our study aimed to assess the association between various air pollutants and cognitive impairment and dementia. Additionally, explore the modification effects of lifestyle and genetic predisposition.

METHODS

The exposure levels to various air pollutants, including particulate matter (PM) with diameters ≤ 2.5 (PM2.5), ≤ 10 (PM10), and between 2.5 and 10 μm (PM2.5-10) and nitrogen oxides (NO and NO2) were identified. An air pollution score (APS) was calculated to evaluate the combined exposure to these five air pollutants. A genetic risk estimate and healthy lifestyle score (HLS) were also generated. The Cox regression model adjusted by potential confounders was adopted to access the association between pollution exposure and cognitive decline, and several sensitivity analyses were additionally conducted to test the robustness.

RESULTS

The combined exposure to air pollutants was associated with an increased risk of incident cognitive decline. Compared with the low exposure group, the hazard ratio (HR) and 95% confidence interval (CI) for all-cause dementia, Alzheimer's dementia, vascular dementia, and mild cognitive impairment (MCI) in those exposed to the highest levels of air pollutants were respectively 1.07 (95% CI: 1.04 to 1.09), 1.08 (95% CI: 1.04 to 1.12), 1.07 (95% CI: 1.02 to 1.13), and 1.19 (95% CI: 1.12 to 1.27). However, the modification effects from genetic predisposition were not widely observed, while on the contrary for the healthy lifestyle. Our findings were proven to be reliable and robust based on the results of sensitivity analyses.

CONCLUSIONS

Exposure to air pollution was found to be a significant contributing factor to cognitive impairment and dementia, and this association was not easily modified by an individual's genetic predisposition. However, adopting a healthy lifestyle may help to manage the risk of cognitive decline related to air pollution.

Dose-response relationship between device-measured physical activity and incident type 2 diabetes: findings from the UK Biobank prospective cohort study

BACKGROUND

Most studies investigating the association between physical activity (PA) and the risk of type 2 diabetes are derived from self-reported questionnaires, with limited evidence using device-based measurements. Therefore, this study aimed to investigate the dose-response relationship between device-measured PA and incident type 2 diabetes.

METHODS

This prospective cohort study included 40,431 participants of the UK Biobank. Wrist-worn accelerometers were used to estimate total, light, moderate, vigorous and moderate-to-vigorous PA. The associations between PA and incident type 2 diabetes were analysed using Cox-proportional hazard models. The mediating role of body mass index (BMI) was tested under a causal counterfactual framework.

RESULTS

The median follow-up period was 6.3 years (IQR: 5.7-6.8), with 591 participants developing type 2 diabetes. Compared to those achieving < 150 min/week of moderate PA, people achieving 150-300, 300-600 and > 600 min/week were at 49% (95% CI 62-32%), 62% (95% CI 71-50%) and 71% (95% CI 80-59%) lower risk of type 2 diabetes, respectively. For vigorous PA, compared to those achieving < 25 min/week, individuals achieving 25-50, 50-75 and > 75 min/week were at 38% (95% CI 48-33%), 48% (95% CI 64-23%) and 64% (95% CI 78-42%) lower type 2 diabetes risk, respectively. Twelve per cent and 20% of the associations between vigorous and moderate PA and type 2 diabetes were mediated by lower BMI, respectively.

CONCLUSIONS

PA has clear dose-response relationship with a lower risk of type 2 diabetes. Our findings support the current aerobic PA recommendations but suggest that additional PA beyond the recommendations is associated with even greater risk reduction.

TRIAL REGISTRATION

The UK Biobank study was approved by the North West Multi-Centre Research Ethics Committee (Ref 11/NW/0382 on June 17, 2011).

Proportion and number of cancer cases and deaths attributable to behavioral risk factors in Vietnam

Identifying modifiable risk factors that contribute to cancer is essential in setting up preventive strategies. Therefore, this study aimed to estimate the number and proportion of cancer cases and deaths attributable to five behavior-related risk factors-tobacco smoking, second-hand smoking, alcohol consumption, high body mass index and insufficient physical activity in Vietnam in 2020. Population attributable fractions were calculated for relationships of risk factors and cancer types based on sufficient evidence according to IARC or strong evidence according to WCRF/AICR. Relative risks were retrieved from meta-analyses where possible. Prevalence of risk factors was obtained from the most current available nationally representative population surveys in Vietnam. Cancer cases and deaths were obtained from GLOBOCAN 2020. An estimated 40.5% of all cancer cases in men (39 924 cases) and 7.8% in women (6542 cases) were attributable to these risk factors. The proportions of cancer deaths attributable to these risk factors were 44.0% in men (32 807 cases) and 8.9% in women (4235 cases). Tobacco smoking was the leading cause of cancer cases and deaths in men, followed by alcohol consumption and high BMI. In women, high BMI accounted for the highest proportion of cancer cases and second-hand smoking accounted for the highest proportion of cancer deaths. Lung and upper aerodigestive tract cancer cases and deaths could have been reduced at least by half if these risk factors had been eliminated. To reduce cancer incidence and mortality, preventive actions focusing on tobacco control are likely to have the most significant impact, especially in men.

Impact of mental disorders on clinical outcomes of physical diseases: an umbrella review assessing population attributable fraction and generalized impact fraction

Empirical evidence indicates a significant bidirectional association between mental disorders and physical diseases, but the prospective impact of men-tal disorders on clinical outcomes of physical diseases has not been comprehensively outlined. In this PRISMA- and COSMOS-E-compliant umbrella review, we searched PubMed, PsycINFO, Embase, and Joanna Briggs Institute Database of Systematic Reviews and Implementation Reports, up to March 15, 2022, to identify systematic reviews with meta-analysis that examined the prospective association between any mental disorder and clinical outcomes of physical diseases. Primary outcomes were disease-specific mortality and all-cause mortality. Secondary outcomes were disease-specific incidence, functioning and/or disability, symptom severity, quality of life, recurrence or progression, major cardiac events, and treatment-related outcomes. Additional inclusion criteria were further applied to primary studies. Random effect models were employed, along with I2 statistic, 95% prediction intervals, small-study effects test, excess significance bias test, and risk of bias (ROBIS) assessment. Associations were classified into five credibility classes of evidence (I to IV and non-significant) according to established criteria, complemented by sensitivity and subgroup analyses to examine the robustness of the main analysis. Statistical analysis was performed using a new package for conducting umbrella reviews (https://metaumbrella.org). Population attributable fraction (PAF) and generalized impact fraction (GIF) were then calculated for class I-III associations. Forty-seven systematic reviews with meta-analysis, encompassing 251 non-overlapping primary studies and reporting 74 associations, were included (68% were at low risk of bias at the ROBIS assessment). Altogether, 43 primary outcomes (disease-specific mortality: n=17; all-cause mortality: n=26) and 31 secondary outcomes were investigated. Although 72% of associations were statistically significant (p<0.05), only two showed convincing (class I) evidence: that between depressive disorders and all-cause mortality in patients with heart failure (hazard ratio, HR=1.44, 95% CI: 1.26-1.65), and that between schizophrenia and cardiovascular mortality in patients with cardiovascular diseases (risk ratio, RR=1.54, 95% CI: 1.36-1.75). Six associations showed highly suggestive (class II) evidence: those between depressive disorders and all-cause mortality in patients with diabetes mellitus (HR=2.84, 95% CI: 2.00-4.03) and with kidney failure (HR=1.41, 95% CI: 1.31-1.51); that between depressive disorders and major cardiac events in patients with myocardial infarction (odds ratio, OR=1.52, 95% CI: 1.36-1.70); that between depressive disorders and dementia in patients with diabetes mellitus (HR=2.11, 95% CI: 1.77-2.52); that between alcohol use disorder and decompensated liver cirrhosis in patients with hepatitis C (RR=3.15, 95% CI: 2.87-3.46); and that between schizophrenia and cancer mortality in patients with cancer (standardized mean ratio, SMR=1.74, 95% CI: 1.41-2.15). Sensitivity/subgroup analyses confirmed these results. The largest PAFs were 30.56% (95% CI: 27.67-33.49) for alcohol use disorder and decompensated liver cirrhosis in patients with hepatitis C, 26.81% (95% CI: 16.61-37.67) for depressive disorders and all-cause mortality in patients with diabetes mellitus, 13.68% (95% CI: 9.87-17.58) for depressive disorders and major cardiac events in patients with myocardial infarction, 11.99% (95% CI: 8.29-15.84) for schizophrenia and cardiovascular mortality in patients with cardiovascular diseases, and 11.59% (95% CI: 9.09-14.14) for depressive disorders and all-cause mortality in patients with kidney failure. The GIFs confirmed the preventive capacity of these associations. This umbrella review demonstrates that mental disorders increase the risk of a poor clinical outcome in several physical diseases. Prevention targeting mental disorders - particularly alcohol use disorders, depressive disorders, and schizophrenia - can reduce the incidence of adverse clinical outcomes in people with physical diseases. These findings can inform clinical practice and trans-speciality preventive approaches cutting across psychiatric and somatic medicine.

Estimated number of cancers attributable to occupational exposures in France in 2017: an update using a new method for improved estimates

BACKGROUND

Over the last 50 years, occupational exposure to carcinogenic agents has been widely regulated in France.

OBJECTIVE

Report population-attributable fraction (PAF) and number of attributable cancer cases linked to occupational exposure in France based on an updated method to estimate lifetime occupational exposure prevalence.

METHODS

Population-level prevalence of lifetime exposure to ten carcinogenic agents (asbestos, benzene, chromium VI, diesel engine exhaust, formaldehyde, nickel compounds, polycyclic aromatic hydrocarbons, silica dust, trichloroethylene, wood dust) and two occupational circumstances (painters and rubber industry workers) were estimated using the French Census linked with MATGÉNÉ job-exposure matrices and French occupational surveys. PAF and number of attributable cancer cases were calculated using the estimated prevalence, relative risks from systematic review and national estimates of cancer incidence in 2017.

RESULTS

The lifetime occupational exposure prevalences were much higher in men than in women ranging from 0.2% (workers in the rubber industry) to 10.2% in men (silica), and from 0.10% (benzene, PAH and workers in the rubber industry) to 5.7% in women (formaldehyde). In total, 4,818 cancer cases (men: 4,223; women: 595) were attributable to the ten studied carcinogens and two occupational circumstances, representing 5.2% of cases among the studied cancer sites (M: 7.0%; W: 1.9%). In both sexes, mesothelioma (M: 689 cases; W: 160) and lung cancer (M: 3,032; W: 308) were the largest cancer sites impacted by the studied occupational agents and circumstances.

SIGNIFICANCE

A moderate proportion of the cancer cases in France is linked to carcinogens in occupational settings. Our method provides more precise estimates of attributable cancer taking into account evolution of exposure to occupational agents by sex, age and time. This methodology can be easily replicated using cross-sectional occupational data to aid priority making and implementation of prevention strategies in the workplace.

High sugar intake from sugar-sweetened beverages is associated with prevalence of untreated decay in US adults: NHANES 2013-2016

OBJECTIVES

To assess the association between sugar from sugar-sweetened beverages (SSBs) and untreated decay in permanent teeth and calculate the cost burden of sugar from SSBs on untreated decay in US adults.

METHODS

Cross-sectional data from the 2013-2014 and 2015-2016 cycles of the National Health and Nutrition Examination Survey (NHANES) were analysed in 2020 (n = 9001 adults aged ≥20). Multivariable analyses assessed sugar intake from SSB consumption with the presence of untreated decay in permanent teeth and number of untreated decayed teeth. Population attributable risk was used to estimate the cost burden arising from SSBs on untreated decay in US adults.

RESULTS

One fourth (25.1%) of US adults had untreated dental decay, and higher prevalence was observed among those with low income, low education and race/ethnicity of non-Hispanic Black. Overall, 53% of adults reported no intake of SSBs. For the remaining 47%, the median 24-h intake was 46.8 g of sugar from SSBs. The adjusted prevalence ratio (PR) for untreated decay was 1.3 (95% confidence interval [CI] 1.1-1.5) for consumption of 46.8 g or more of sugar from SSBs compared to those reporting no sugar from SSBs. Number of untreated decayed teeth increased with sugar intake from SSBs from lowest to highest tertile: 0.1, (p = .35); 0.4, (p = .006); and 0.6, (p < .001). The cost burden of untreated decay attributable to SSBs in US adults is estimated conservatively at $1.6 billion USD.

CONCLUSIONS

Community level interventions directed at sugar from SSBs are justified to address disparities in the burden of untreated dental decay.

Association Between Device-Measured Physical Activity and Incident Heart Failure: A Prospective Cohort Study of 94 739 UK Biobank Participants

BACKGROUND

Studies of objectively measured physical activity (PA) have investigated acute cardiovascular outcomes but not heart failure (HF), an emerging chronic condition. This study aimed to investigate the dose-response relationship between device-measured PA and HF by intensity of PA.

METHODS

This was a prospective cohort study of 94 739 UK Biobank participants who had device-measured PA in 2013 to 2015 and were free from myocardial infarction and HF. PA was measured with a wrist-worn accelerometer, and time spent on light-, moderate-, and vigorous-intensity PA was extracted. Incident HF was ascertained from linked hospital and death records. Cox proportional hazard models with cubic penalized splines were used to study the associations, which were adjusted for sociodemographic and lifestyle factors. Competing risk was handled with cause-specific hazard ratios.

RESULTS

The overall incidence of HF was 98.5 per 10 000 person-years over a median 6.1 years of follow-up. Compared with participants who undertook no moderate- to vigorous-intensity PA, those who performed 150 to 300 min/wk of moderate-intensity PA (hazard ratio, 0.37 [95% CI, 0.34-0.41]) and 75 to 150 min/wk of vigorous-intensity PA (hazard ratio, 0.34 [95% CI, 0.25-0.46]) were at lower HF risk. The association between vigorous-intensity PA and HF was reverse-J shaped with a potentially lower risk reduction above 150 min/wk.

CONCLUSIONS

Device-measured PA, especially moderate-intensity PA, was associated with a lower risk of HF. Current vigorous-intensity PA recommendations should be encouraged but not increased. In contrast, increasing moderate-intensity PA may be beneficial even among those meeting current recommendations.

Device-measured physical activity and incident affective disorders

BACKGROUND

Studies on physical activity (PA) and mental health are largely limited to self-reported PA. This study aims to use prospective cohort data to investigate the association between device-measured PA and affective disorders.

METHODS

A total of 37,327 participants from UK Biobank who had not had any prior affective disorder diagnoses were included in this prospective cohort study. Wrist-worn accelerometers were used to measure total, light (LPA), moderate (MPA), and vigorous (VPA) PA. Associations between PA domains and affective disorders were analysed using penalised splines in Cox proportional hazard models. Analyses were adjusted for other intensity-specific PA and sociodemographic and lifestyle factors. Sensitivity analyses were conducted adjusting for body mass index and longstanding illnesses as well as excluding events in the first 2 years of follow-up. Preventable fractions for the population were estimated for MPA and VPA.

RESULTS

Over a median follow-up of 6.8 years, 1262 (3.4%) individuals were diagnosed with affective disorders. Replacing 30 min of sedentary behaviour in a week with MPA (HR 0.95, 95% CI 0.94-0.97) or VPA (HR 0.91, 95% CI 0.85-0.98) was associated with lower risk of affective behaviours, up to 500 and 120 min of MPA and VPA. Assuming causality, 5.14% and 18.88% of affective disorders could have been prevented if MPA ≥150 min/week and VPA ≥75 min/week were achieved, respectively, across the study population.

CONCLUSIONS

Device-measured MPA and VPA were associated with lower risk of affective disorders. The potential mental health benefits of MPA continue to accrue above the current World Health Organization recommendation.

Global population attributable fraction of potentially modifiable risk factors for mental disorders: a meta-umbrella systematic review

Numerous risk factors for mental disorders have been identified. However, we do not know how many disorders we could prevent and to what extent by modifying these risk factors. This study quantifies the Population Attributable Fraction (PAF) of potentially modifiable risk factors for mental disorders. We conducted a PRISMA 2020-compliant (Protocol: https://osf.io/hk2ag ) meta-umbrella systematic review (Web of Science/PubMed/Cochrane Central Register of Reviews/Ovid/PsycINFO, until 05/12/2021) of umbrella reviews reporting associations between potentially modifiable risk factors and ICD/DSM mental disorders, restricted to highly convincing (class I) and convincing (class II) evidence from prospective cohorts. The primary outcome was the global meta-analytical PAF, complemented by sensitivity analyses across different settings, the meta-analytical Generalised Impact Fraction (GIF), and study quality assessment (AMSTAR). Seven umbrella reviews (including 295 meta-analyses and 547 associations) identified 28 class I-II risk associations (23 risk factors; AMSTAR: 45.0% high-, 35.0% medium-, 20.0% low quality). The largest global PAFs not confounded by indication were 37.84% (95% CI = 26.77-48.40%) for childhood adversities and schizophrenia spectrum disorders, 24.76% (95% CI = 13.98-36.49%) for tobacco smoking and opioid use disorders, 17.88% (95% CI = not available) for job strain and depression, 14.60% (95% CI = 9.46-20.52%) for insufficient physical activity and Alzheimer's disease, 13.40% (95% CI = 7.75-20.15%) for childhood sexual abuse and depressive disorders, 12.37% (95% CI = 5.37-25.34%) for clinical high-risk state for psychosis and any non-organic psychotic disorders, 10.00% (95% CI = 5.62-15.95%) for three metabolic factors and depression, 9.73% (95% CI = 4.50-17.30%) for cannabis use and schizophrenia spectrum disorders, and 9.30% (95% CI = 7.36-11.38%) for maternal pre-pregnancy obesity and ADHD. The GIFs confirmed the preventive capacity for these factors. Addressing several potentially modifiable risk factors, particularly childhood adversities, can reduce the global population-level incidence of mental disorders.

Attribution of Cancer Origins to Endogenous, Exogenous, and Preventable Mutational Processes

Mutational processes in tumors create distinctive patterns of mutations, composed of neutral "passenger" mutations and oncogenic drivers that have quantifiable effects on the proliferation and survival of cancer cell lineages. Increases in proliferation and survival are mediated by natural selection, which can be quantified by comparing the frequency at which we detect substitutions to the frequency at which we expect to detect substitutions assuming neutrality. Most of the variants detectable with whole-exome sequencing in tumors are neutral or nearly neutral in effect, and thus the processes generating the majority of mutations may not be the primary sources of the tumorigenic mutations. Across 24 cancer types, we identify the contributions of mutational processes to each oncogenic variant and quantify the degree to which each process contributes to tumorigenesis. We demonstrate that the origination of variants driving melanomas and lung cancers is predominantly attributable to the preventable, exogenous mutational processes associated with ultraviolet light and tobacco exposure, respectively, whereas the origination of selected variants in gliomas and prostate adenocarcinomas is largely attributable to endogenous processes associated with aging. Preventable mutations associated with pathogen exposure and apolipoprotein B mRNA-editing enzyme activity account for a large proportion of the cancer effect within head-and-neck, bladder, cervical, and breast cancers. These attributions complement epidemiological approaches-revealing the burden of cancer driven by single-nucleotide variants caused by either endogenous or exogenous, nonpreventable, or preventable processes, and crucially inform public health strategies.

A systematic review on estimating population attributable fraction for risk factors for small-for-gestational-age births in 81 low- and middle-income countries

Background

Small for gestational age (SGA) is a public health concern since it is associated with mortality in neonatal and post-neonatal period. Despite the large magnitude of the problem, little is known about the population-attributable risk (PAR) of various risk factors for SGA. This study estimated the relative contribution of risk factors for SGA, as a basis for identifying priority areas for developing and/or implementing interventions to reduce the incidence of SGA births and related mortality and morbidity.

Methods

We conducted a literature review on 63 potential risk factors for SGA to quantify the risk relationship and estimate the prevalence of risk factors (RFs). We calculated the population-attributable fraction for each of the identified RF for 81 Countdown countries and calculated regional estimates. Twenty-five RFs were included in the final model while extended model included all the 25 RFs from the final model and two additional RFs.

Results

In the final and extended models, the RFs included in each model have a total PAF equal to 63.97% and 69.66%, respectively of SGA across the 81 LMICs. In the extended model, maternal nutritional status has the greatest PAF (28.15%), followed by environmental and other exposures during pregnancy (15.82%), pregnancy history (11.01%), and general health issues or morbidity (10.34%). The RFs included in the final and extended model for Sub-Saharan African (SSA) region have a total PAF of 63.28% and 65.72% of SGA, respectively. In SSA, the top three RF categories in the extended model are nutrition (25.05%), environment and other exposure (13.01%), and general health issues or morbidity (10.72%), while in South-Asia's it was nutrition (30.56%), environment and other exposure (15.27%) and pregnancy history (11.68%).

Conclusions

The various types of RFs that play a role in SGA births highlight the importance of a multifaceted approach to tackle SGA. Depending on the types of RFs, intervention should be strategically targeted at either individual or household and/or community or policy level. There is also a need to research the mechanisms by which some of the RFs might hinder fetal growth.

Population attributable fractions for risk factors for spontaneous preterm births in 81 low- and middle-income countries: A systematic analysis

Background

Complications associated with preterm birth (PTB) are the largest contributor to under-five mortality globally. Success in reaching the Sustainable Development Goal target requires identifying potentially modifiable risk factors for PTB, estimating the relative importance of these risk factors, and identifying/implementing effective prevention strategies to address them.

Methods

We conducted a literature review to define risk relationships and estimate prevalence for established risk factors for spontaneous PTB (sPTB). We then estimated population attributable fractions (PAF) for the sPTB risk factors identified in the review as statistically significant for the 81 low- and middle-income (LMIC) countries included in the Countdown 2030 initiative. We summed country-level findings to produce PAFs for each risk factor and regional estimates for sub-Saharan Africa and South Asia.

Results

Forty-four potential sPTB risk factors were identified. and the final analysis included twenty-four risk factors with evidence of significant associations with sPTB. A second model with three additional risk factors with borderline insignificant associations was also run. Taken together, the twenty-four risk factors had a total PAF of 73% for all 81 countries and 77% and 72% of sPTB in sub-Saharan Africa and South Asia, respectively. For all countries, maternal undernutrition had the highest PAF (17.5%), followed by maternal infections (16.6%), environmental exposures (16%) and pregnancy history (8.7%).

Conclusions

While multiple risk factors contribute to sPTB, no single risk factor addresses a predominant fraction, and 27% of spontaneous preterm births are not associated with risk factors that we identified. Despite the significant role of preterm birth in child survival, there are major data gaps in LMIC settings. Furthermore, there is a paucity of evidence for effective interventions to prevent preterm birth. Preventing sPTB requires understanding underlying mechanisms leading to sPTB in different populations, and the identification/implementation of effective interventions.

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.

Cost-Effectiveness of Posthospital Management of Acute Coronary Syndrome: A Real-World Investigation From Italy

OBJECTIVES

This study aimed to assess the cost-effectiveness profile of adherence to recommendations for the community management of patients discharged with a diagnosis of acute coronary syndrome (ACS).

METHODS

The cohort of 50 282 residents in the Lombardy Region (Italy) who were discharged with a diagnosis of ACS during 2011 to 2015 was followed up until 2018. Adherence to selected recommendations including drug therapies (DTs), outpatient controls, and rehabilitation, experienced during the first year after index discharge, was considered. Adherent and nonadherent cohort members were matched on high-dimensional propensity scores. Composite clinical outcomes (cardiovascular hospital admissions and all-cause mortality) and healthcare costs were assessed for a time horizon of 5 years. Cost-effectiveness profile of adherence to recommendations was measured through the incremental cost-effectiveness ratio, that is, the incremental cost for 1 day free from the composite clinical outcome.

RESULTS

Adherence to DTs, outpatient controls, and rehabilitation, respectively, regarded 39%, 81%, and 3% of cohort members. Compared with nonadherent patients, those adherent to DTs, outpatient controls, and rehabilitation had (1) a delay in the occurrence of the composite clinical outcome of 50, 43, and 73 days, respectively, and (2) lower (on average, €199 per year for DTs) and higher costs (€292 and €1024 for outpatient controls and rehabilitation). Cost-effectiveness profiles were better for patients with myocardial infarction than those with angina and for patients with more severe clinical complexity than those with milder conditions.

CONCLUSIONS

Health-related and economic benefits are expected from improving adherence to international guidelines recommendations concerning outpatient treatments and monitoring of patients with ACS.

Population-Based Impact of Smoking, Drinking, and Genetic Factors on HDL-Cholesterol Levels in J-MICC Study Participants

BACKGROUND

Environmental and genetic factors are suggested to exhibit factor-based association with HDL-cholesterol (HDL-C) levels. However, the population-based effects of environmental and genetic factors have not been compared clearly. We conducted a cross-sectional study using data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study to evaluate the population-based impact of smoking, drinking, and genetic factors on low HDL-C.

METHODS

Data from 11,498 men and women aged 35-69 years were collected for a genome-wide association study (GWAS). Sixty-five HDL-C-related SNPs with genome-wide significance (P < 5 × 10^-8) were selected from the GWAS catalog, and seven representative SNPs were defined, and the population-based impact was estimated using population attributable fraction (PAF).

RESULTS

We found that smoking, drinking, daily activity, habitual exercise, egg intake, BMI, age, sex and the SNPs CETP rs3764261, APOA5 rs662799, LIPC rs1800588, LPL rs328, ABCA1 rs2575876, LIPG rs3786247, and APOE rs429358 were associated with HDL-C levels. The gene-environmental interactions on smoking and drinking were not statistically significant. The PAF for low HDL-C was the highest in men (63.2%) and in rs3764261 (31.5%) of the genetic factors, and the PAFs of smoking and drinking were 23.1% and 41.8%, respectively.

CONCLUSIONS

The present study showed that the population-based impact of genomic factor CETP rs3764261 for low HDL-C was higher than that of smoking and lower than that of drinking.

Cardiorespiratory Fitness and Atherosclerotic Cardiovascular Outcomes by Levels of Baseline-Predicted Cardiovascular Risk: The Look AHEAD Study

BACKGROUND

We evaluated the associations of cardiorespiratory fitness with atherosclerotic cardiovascular disease (ASCVD) by levels of baseline-predicted ASCVD risk among adults with type 2 diabetes.

METHODS

We analyzed data from 4203 adults with type 2 diabetes in the Look AHEAD (Action for Health in Diabetes) study. Cardiorespiratory fitness was assessed using maximal exercise testing and categorized into low, moderate, and high; baseline-predicted. ASCVD risk was calculated using the American College of Cardiology/American Heart Association Pooled Cohort Equation. We used Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for ASCVD events (fatal and nonfatal myocardial infarction and stroke).

RESULTS

Over a median of 9.6 years, there were 295 ASCVD events. The effect of fitness on outcomes was different across levels of 10-year predicted ASCVD risk (P for interaction < .001). Among participants with a baseline-predicted risk of 7.5% to 20%, the HR of low (vs high) fitness group was 1.94 (95% CI, 1.12-3.35) for ASCVD events. Fitness was not significantly associated with ASCVD events in the groups with baseline-predicted risk <7.5% (HR 1.53; 95% CI, 0.49-4.76) or ≥20% (HR 1.40; 95% CI, 0.88-2.24). A similar pattern was observed for myocardial infarction and stroke separately.

CONCLUSIONS

In a large sample of type 2 diabetes individuals, the association of low fitness with incident ASCVD was modified by the baseline-predicted 10-year ASCVD risk. Our findings suggest the utility of assessing fitness in ASCVD risk stratification in type 2 diabetes, especially among those with intermediate predicted 10-year risk of ASCVD.

Burden of cancers attributable to modifiable risk factors in Malaysia

Background

This is a systematic assessment of the burden of cancers in Malaysia in 2018 using epidemiologic approach. The purpose of this study was to identify the proportion of cancers in Malaysia that were attributable to the modifiable risk factors of excess weight, alcohol intake, physical inactivity, tobacco smoking and to estimate the number of cancer cases that could be prevented if the exposure to the modifiable risk factor was reduced.

Methods

We estimated the Population Attributable Fraction (PAF) of the modifiable risk factors to cancers incidences in Malaysia. The two parameters used for the estimation were exposure prevalence from national representative surveys and the relative risk of getting the cancers from worldwide literature review.

Results

Among 38,426 cancer incidences in 2018 from Globocan data, we estimated that 22.2% (95% confidence interval (CI):14.9 to 29.6%) of the cancer incidences included in this study were attributable to the investigated modifiable risk factors. 39.1% (95% CI:27.2 to 49.7%) and 10.5% (95% CI:5.8 to 15.7%) of cancers in male and female respectively, were attributable to the studied modifiable risk factors. The top main cancers attributed by the risk factors were lung cancer (65.1%; 95% CI:56.4 to 72.9%), laryngeal cancer (63.6%; 95% CI:39.9 to 80.5%), and oesophageal cancer (51.5%; 95% CI:39.9 to 62.0%). For each risk factor studied across genders, tobacco smoking contributed the most (14.3%; 95% CI:9.9 to 17.3%), followed by excess weight (7.0%; 95% CI:4.1 to 10.2%), physical inactivity (1.0%; 95% CI:0.4 to 1.7%) and alcohol intake (0.6%; 95% CI:0.2 to 1.0%).

Conclusion

Findings from this study suggests that tobacco smoking and excess weight are the two predominant factors out of the four studied risk factors for cancer cases in Malaysia. Nationwide public health prevention campaigns tailored to these risk factors are recommended. However, the other risk factors such as physical inactivity and alcohol intake shall not be neglected. PAFs are estimated based on the best available data that we have currently. Regular collection of other risk factor exposure prevalence data is vital for future analyses.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10412-9.

Alcohol consumption. A leading risk factor for cancer

In 2016, alcohol consumption was one of the leading risk factors for cancer development and cancer death globally, causing an estimated 376 200 cancer deaths, representing 4.2% of all cancer deaths, and 10.3 million cancer disability-adjusted life years lost, representing 4.2% of all cancer disability-adjusted life years lost. The impact of alcohol consumption on cancer in 2016 varied by age group; the proportion of cancer deaths attributable to alcohol consumption ranged from 13.9% of cancer deaths among people aged 30-34 years to 2.7% of cancer deaths among people aged 80-84 years. The burden of cancers caused by alcohol consumption might be decreased through (i) individual-level and societal-level interventions that reduce alcohol consumption, and (ii) measures that target those risk factors that interact with alcohol consumption to increase the risk of cancer or that directly affect the risk of alcohol-related cancers.

Regional differences in tobacco smoking and lung cancer in Portugal in 2018: a population-based analysis using nationwide incidence and mortality data

OBJECTIVES

This study aims to estimate the proportion of lung cancer cases and deaths attributable to tobacco smoking in Portugal in 2018, complemented by trends in incidence and mortality, by sex and region.

DESIGN

Cancer cases for 1998-2011 and cancer deaths for 1991-2018 were obtained from population-based registries and Statistics Portugal, respectively. We projected cases for 2018 and used reported deaths for the same year to estimate, using Peto's method, the number and proportion of lung cancer cases and deaths caused by tobacco smoking in 2018. We calculated the age-adjusted incidence and mortality rates in each year of diagnosis and death. We fitted a joinpoint regression to the observed data to estimate the annual percentage change (APC) in the rates.

SETTING

Portugal.

RESULTS

In 2018, an estimated 3859 cases and 3192 deaths from lung cancer were attributable to tobacco smoking in Portugal, with men presenting a population attributable fraction (PAF) of 82.6% (n=3064) for incidence and 84.1% (n=2749) for mortality, while in women those values were 51.0% (n=795) and 42.7% (n=443), respectively. In both sexes and metrics, the Azores were the region with the highest PAF and the Centre with the lowest. During 1998-2011, the APC for incidence ranged from 0.6% to 3.0% in men and 3.6% to 7.9% in women, depending on region, with mortality presenting a similar pattern between sexes.

CONCLUSION

Exposure to tobacco smoking has accounted for most of the lung cancer cases and deaths estimated in Portugal in 2018. Differential patterns of tobacco consumption across the country, varying implementation of primary prevention programmes and differences in personal cancer awareness may have contributed to the disparities observed. Primary prevention of lung cancer remains a public health priority, particularly among women.

Special Report: The Biology of Inequalities in Health: The Lifepath Consortium

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the efficacy of selected policies, and the general implications of our findings for theories and policies. The project adopted a life-course and comparative approach, considering lifetime effects from childhood and adulthood, and pooled data on up to 1.7 million participants of longitudinal cohort studies from Europe, USA, and Australia. These data showed that socioeconomic circumstances predicted mortality and functional decline as strongly as established risk factors currently targeted by global prevention programmes. Analyses also looked at socioeconomically patterned biological markers, allostatic load, and DNA methylation using richly phenotyped cohorts, unraveling their association with aging processes across the life-course. Lifepath studies suggest that socioeconomic circumstances are embedded in our biology from the outset-i.e., disadvantage influences biological systems from molecules to organs. Our findings have important implications for policy, suggesting that (a) intervening on unfavorable socioeconomic conditions is complementary and as important as targeting well-known risk factors, such as tobacco and alcohol consumption, low fruit and vegetable intake, obesity and a sedentary lifestyle, and that (b) effects of preventive interventions in early life integrate interventions in adulthood. The report has an executive summary that refers to the different sections of the main paper.

Kampani D, Al Hasham N, M. Assker M, Shawa N, Saleh D, Alfarouk KO. Assessing the Knowledge of Environmental Risk Factors for Cancer among the UAE Population: A Pilot Study

The incidence of cancer is increasing worldwide as well as in the United Arab Emirates (UAE). Currently, researchers are advocating not only for prevention programs but also for early detection. In this study, we aimed to assess the general awareness of cancer among the UAE population, with a focus on environmental risk factors. A descriptive cross-sectional design was employed, and a structured questionnaire was used to collect data from 385 participants. A total of 91.2% of the study population identified cancer as the leading cause of death, while 64.6% of the subjects were able to identify the key causes of cancer. A total of 87.3% and 70.5% of the participants were able to define tobacco and alcohol, respectively, as cancer-causing agents. Most of the study population failed to identify cancer-related infectious agents and incense smoke as carcinogens. Respondents in the medical professions had the highest knowledge score when compared with respondents with a non-medical profession and unemployed participants (p < 0.0005). To fill the gaps in cancer-related knowledge, participants were asked about their preferred method for cancer education, and 83.9% of the participants favored the media as a source of information. Conclusively, our findings indicated a gap in cancer knowledge among UAE residents, which highlights the importance of educational campaigns by health authorities; a follow-up study evaluating the success of educational campaigns is also warranted.

Cancer in Africa 2018: The role of infections

We estimate the fractions of cancer attributed to infections in Africa in 2018. The number of new cancer cases occurring was taken from Globocan2018 with some additional estimations based on data from African population-based registries. Population attributable fractions were calculated using prevalence of infection and relative risk in exposed vs. nonexposed. The greatest share of infection-associated cancers is due to the human papillomaviruses (12.1% of all cancers in Africa and 15.4% in sub-Saharan Africa [SSA]); of these, cervical cancer is by far the most common. Kaposi sarcoma-associated herpesvirus is responsible for 3.1% of all cancers in Africa, the hepatitis viruses (B and C) for 2.9% and Helicobacter pylori for 2.7% (non-Cardia Gastric cancer and primary gastric lymphomas). Two percent of cancers are attributable to the Epstein-Barr virus, Schistosoma haematobium increases the risk of bladder cancer resulting in 1.0% of all cancers. HIV-related NHL and squamous cell carcinoma of the conjunctiva account for 0.6% of cancers. Altogether 24.5% of cancers in Africa and 28.7% in SSA are due to infectious agents. Infections are by far the most common cancer risk factor for cancer in Africa-the traditional risk factors (smoking, alcohol and unhealthy diet) probably cause only one in eight cancers in Africa. Prevention should focus on those infectious diseases preventable through vaccination (HPV and hepatitis B) which could reduce two-thirds of the burden. Helicobacter pylori and schistosomiasis are treatable with antibiotics and praziquantel, with a potential reduction of one in eight infection-associated cancers.

Preventability of Colorectal Cancer in Saudi Arabia: Fraction of Cases Attributable to Modifiable Risk Factors in 2015-2040

A rise in colorectal cancer (CRC) burden is expected around the globe. This study aimed to determine the population attributable fractions (PAFs) of CRC cases contributed by modifiable risk factors in Saudi Arabia. The PAF was calculated for modifiable risk factors with strong evidences of a causal association with CRC. CRC incidence was obtained from the National Cancer Registry, relative risks were retrieved from recent meta-analysis studies, and the prevalence of exposure to risk factors was obtained from national surveys. Conventional statistical formulas were used to calculate PAFs from registered CRC cases, stratified by sex. Three scenarios were proposed to make projections and present the expected effects of prevention interventions on the number of CRC cases in Saudi Arabia for 2025–2040. The results showed the largest fraction of attributable CRC cases among men and women was contributed by physical inactivity (16.13% and 16.45%), followed by excess weight (obesity: 9.71% and 6.93%; overweight: 6.05% and 1.9%); and tobacco smoking (current smoker: 3.04% and 0.18%; former smoker: 3.29% and 0.12%). We estimated that the number of projected cases attributable to physical inactivity, smoking, and excess weight in men and women would increase from 807 and 315 in 2025 to 1360 and 556 in 2040, respectively. In conclusion, physical inactivity, being overweight or obese, and tobacco smoking are major lifestyle factors affecting the incidence of CRC in Saudi Arabia. Prevention interventions and public health programs to reduce their prevalence are warranted.

Special Report: The Biology of Inequalities in Health: The Lifepath Consortium

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the efficacy of selected policies, and the general implications of our findings for theories and policies. The project adopted a life-course and comparative approach, considering lifetime effects from childhood and adulthood, and pooled data on up to 1.7 million participants of longitudinal cohort studies from Europe, USA, and Australia. These data showed that socioeconomic circumstances predicted mortality and functional decline as strongly as established risk factors currently targeted by global prevention programmes. Analyses also looked at socioeconomically patterned biological markers, allostatic load, and DNA methylation using richly phenotyped cohorts, unraveling their association with aging processes across the life-course. Lifepath studies suggest that socioeconomic circumstances are embedded in our biology from the outset-i.e., disadvantage influences biological systems from molecules to organs. Our findings have important implications for policy, suggesting that (a) intervening on unfavorable socioeconomic conditions is complementary and as important as targeting well-known risk factors, such as tobacco and alcohol consumption, low fruit and vegetable intake, obesity and a sedentary lifestyle, and that (b) effects of preventive interventions in early life integrate interventions in adulthood. The report has an executive summary that refers to the different sections of the main paper.

Alcohol consumption's attributable disease burden and cost-effectiveness of targeted public health interventions: a systematic review of mathematical models

Background

Around 6% of total deaths are related to alcohol consumption worldwide. Mathematical models are important tools to estimate disease burden and to assess the cost-effectiveness of interventions to address this burden.

Methods

We carried out a systematic review on models, searching main health literature databases up to July 2017. Pairs of reviewers independently selected, extracted data and assessed the quality of the included studies. Discrepancies were resolved by consensus. We selected those models exploring: a) disease burden (main metrics being attributable deaths, disability-adjusted life years, quality-adjusted life years) or b) economic evaluations of health interventions or policies, based on models including the aforementioned outcomes. We grouped models into broad families according to their common central methodological approach.

Results

Out of 4295 reports identified, 63 met our inclusion criteria and were categorized in three main model families that were described in detail: 1) State transition -i.e Markov- models, 2) Life Table-based models and 3) Attributable fraction-based models. Most studies pertained to the latter one (n = 29, 48.3%). A few miscellaneous models could not be framed into these families.

Conclusions

Our findings can be useful for future researchers and decision makers planning to undertake alcohol-related disease burden or cost-effectiveness studies. We found several different families of models. Countries interested in adopting relevant public health measures may choose or adapt the one deemed most convenient, based on the availability of existing data at the local level, burden of work, and public health and economic outcomes of interest.

Effectiveness of adherence to recommended clinical examinations of diabetic patients in preventing diabetes-related hospitalizations

Objective

To validate a set of indicators for quality of diabetes care through their relationship with measurable clinical outcomes.

Design

A retrospective cohort study was carried out from 2010 to 2015.

Setting

Population-based study. Data were retrieved from healthcare utilization databases of three Italian regions (Lombardy, Emilia Romagna and Lazio) on the whole covering 20 million citizens.

Participants

The 77 285 individuals who were newly taken in care for diabetes during 2010 entered into the cohort.

Interventions

Exposure to selected clinical recommendations (i.e. periodic controls for glycated hemoglobin, lipid profile, urine albumin excretion, serum creatinine and dilated eye exams) was recorded.

Main outcomes measures

A composite outcome was employed taking into account hospitalizations for brief-term diabetes complications, uncontrolled diabetes, long-term vascular outcomes and no traumatic lower limb amputation. A multivariable proportional hazards model was fitted to estimate hazard ratio, and 95% confidence intervals (CI), for the exposure-outcome association.

Results

Among the newly taken in care patients with diabetes, those who adhered to almost none (0 or 1), just some (2 or 3) or almost all (4 or 5) recommendations during the first year after diagnosis were 44%, 36% and 20%, respectively. Compared patients who adhered to almost none recommendation, significant risk reductions of 16% (95% CI, 6–24%) and 20% (7–28%) were observed for those who adhered to just some and almost all recommendations, respectively.

Conclusions

Tight control of patients with diabetes through regular clinical examinations must to be considered the cornerstone of national guidance, national audits and quality improvement incentives schemes.

The risk of cancer attributable to diagnostic medical radiation: Estimation for France in 2015

Although medical ionizing radiation (IR) has clear clinical benefits, it is an established carcinogen. Our study estimates the number of new cancer cases in France in 2015 attributable to IR exposure from medical procedures. Exposures from external (X-rays, CT scans, interventional radiology) and internal (nuclear medicine) sources were considered. We used 2007 national frequencies of diagnostic examinations by sex and age to estimate the lifetime organ dose exposure adjusted for changes in the use of such procedures over time. The Biological Effects of Ionizing Radiation VII risk models were used to estimate the corresponding excess cancer risk, assuming an average latency period of 10 years. Additionally, we used cancer incidence data from the French Cancer Registries Network. Of the 346,000 estimated new cancer cases in adults in France in 2015, 2300 cases (940 among men and 1360 among women) were attributable to diagnostic IR, representing 0.7% of all new cancer cases (0.5% for men and 0.9% for women). The leading cancers attributable to medical IR were female breast (n = 560 cases), lung (n = 500 cases) and colon (n = 290 cases) cancers. Compared to other risk factors, the contribution of medical IR to the cancer burden is small, and the benefits largely outweigh its harms. However, some of these IR-associated cancer cases may be preventable through dose optimization of and enhanced justification for diagnostic examinations.

Proportion of cancers attributable to major lifestyle and environmental risk factors in the Eastern Mediterranean region

Cancer is a major contributing cause of morbidity and mortality in the Eastern Mediterranean region. The aim of the current study was to estimate the cancer burden attributable to major lifestyle and environmental risk factors. We used age-, sex- and site-specific incidence estimates for 2012 from IARC's GLOBOCAN, and assessed the following risk factors: smoking, alcohol, high body mass index, insufficient physical activity, diet, suboptimal breastfeeding, infections and air pollution. The prevalence of exposure to these risk factors came from different sources including peer-reviewed international literature, the World Health Organization, noncommunicable disease Risk Factor Collaboration, and the Food and Agriculture Organization. Sex-specific population-attributable fraction was estimated in the 22 countries of the Eastern Mediterranean region based on the prevalence of the selected risk factors and the relative risks obtained from meta-analyses. We estimated that approximately 33% (or 165,000 cases) of all new cancer cases in adults aged 30 years and older in 2012 were attributable to all selected risk factors combined. Infections and smoking accounted for more than half of the total attributable cases among men, while insufficient physical activity and exposure to infections accounted for more than two-thirds of the total attributable cases among women. A reduction in exposure to major lifestyle and environmental risk factors could prevent a substantial number of cancer cases in the Eastern Mediterranean. Population-based programs preventing infections and smoking (particularly among men) and promoting physical activity (particularly among women) in the population are needed to effectively decrease the regional cancer burden.

Population attributable risk of factors associated with the repetition of self-harm behaviour in young people presenting to clinical services: a systematic review and meta-analysis

The repetition of hospital-treated self-harm by young people is common. However, little work has summarised the modifiable factors associated with this. A thorough understanding of those factors most strongly associated with repetition could guide the development of relevant clinical interventions. We systematically reviewed four databases (EMBASE, Medline, PubMed and PsycINFO) until 15 April 2016 to identify all observational studies of factors for the repetition of self-harm or suicide reattempts (together referred to as 'self-harm behaviour') in young people. We quantified the magnitude of association with odds ratios (OR) and 95% confidence intervals (CIs) and calculated the population attributable risk (PAR) and population preventable fraction (PPF) for modifiable factors to provide an indication of the potential impact in reducing subsequent self-harm behaviour in this population. Seventeen studies were included comprising 10,726 participants. Borderline personality disorder (OR 3.47, 95% CI 1.84-6.53; PAR 42.4%), any personality disorder (OR 2.54, 95% CI 1.71-3.78; PAR 16.3%), and any mood disorder (OR 2.16, 95% CI 1.09-4.29; PAR 42.2%) are important modifiable risk factors. Severity of hopelessness (OR 2.95, 95% CI 1.74-5.01), suicidal ideation (OR 2.01, 95% CI 1.43-2.81), and previous sexual abuse (OR 1.52, 95% CI 1.02-2.28; PAR 12.8%) are also associated with repetition of self-harm. We recommend that clinical services should focus on identifying key modifiable risk factors at the individual patient level, whilst the reduction of exposure to child and adolescent sexual abuse would also be a useful goal for public health interventions.

Cancers in France in 2015 attributable to occupational exposures

BACKGROUND

Recent and comprehensive estimates for the number of new cancer cases in France attributable to occupational exposures are lacking.

OBJECTIVES

To estimate the number of new cancer cases attributable to occupational exposures, using a newly developed methodology and the most recent data, for a comprehensive set of occupational carcinogens in France in 2015.

METHODS

Surveys among employees, the national labor force data, a cohort of agricultural workers, national monitoring of workers exposed to ionizing radiation and job-exposure matrix in France were used. The number and proportion of new cancer cases attributable to established occupational carcinogens (Group 1) was estimated using estimation of lifetime exposure and risk estimates from cohort studies. Cancer data were obtained from the French Cancer Registries Network.

RESULTS

In France in 2015, an estimated 7905 new cancer cases, 7336 among men and 569 among women, were attributable to occupational exposures, representing 2.3% of all new cancer cases (3.9% and 0.4% among men and women respectively). Among men and women, lung cancer was impacted the most, followed by mesothelioma and bladder cancer in men, and by mesothelioma and ovary in women. These cancers contributed to 89% of the total cancers attributable to occupational carcinogens in men, and to 80% in women. The main contributing occupational agent was asbestos among men (45%) and women (60%).

CONCLUSIONS

Currently, occupational exposures contribute to a substantial burden of cancer in France. Enhanced monitoring and implementation of protective labor policies could potentially prevent a large proportion of these cancers.

Obesity Among High School Students in the United States: Risk Factors and Their Population Attributable Fraction

Introduction

The prevalence of obesity among children and adolescents in the United States is high. The aim of this study was to assess the association between modifiable risk factors and obesity and to estimate the population attributable fractions (PAFs) of modifiable risk factors among high school students in the United States.

Methods

For this retrospective study, we used a nationally representative sample of 15,624 students who participated in the 2015 Youth Risk Behavior Survey (YRBS). Obesity was defined as body mass index at or above the 95th percentile, based on sex- and age-specific data from the Centers for Disease Control and Prevention. We examined unhealthy dietary behaviors, physical inactivity, and other modifiable risk factors (tobacco use, alcohol consumption, and sleep). We used multivariable logistic regression, accounting for the complex survey design of YRBS, to assess the association between risk factors and obesity and to calculate PAFs. Confidence intervals of PAFs were estimated by using the jackknife repeated replication method.

Results

Among all students included in the study, 13.9% were classified as obese. Not being on a sports team (odds ratio [OR], 1.61; 95% confidence interval [CI], 1.31–1.98), current tobacco use (OR, 1.42; 95% CI, 1.14–1.77), and watching television for 3 hours or more per day (OR, 1.38; 95% CI, 1.09–1.76) were significantly correlated with obesity. The combined PAF for all modifiable risk factors was 34.80% (95% CI, 32.09%–37.51%). The single modifiable risk factor with the largest PAF was not participating on a sports team (PAF, 16.57%; 95% CI, 15.30%–17.84%).

Conclusion

Findings about PAFs help demonstrate the importance of promoting physical activity, healthy diet, and other healthy lifestyles in reducing obesity among high school students in the United States.

A blueprint for the primary prevention of cancer: Targeting established, modifiable risk factors

In the United States, it is estimated that more than 1.7 million people will be diagnosed with cancer, and more than 600,000 will die of the disease in 2018. The financial costs associated with cancer risk factors and cancer care are enormous. To substantially reduce both the number of individuals diagnosed with and dying from cancer and the costs associated with cancer each year in the United States, government and industry and the public health, medical, and scientific communities must work together to develop, invest in, and implement comprehensive cancer control goals and strategies at the national level and expand ongoing initiatives at the state and local levels. This report is the second in a series of articles in this journal that, together, describe trends in cancer rates and the scientific evidence on cancer prevention, early detection, treatment, and survivorship to inform the identification of priorities for a comprehensive cancer control plan. Herein, we focus on existing evidence about established, modifiable risk factors for cancer, including prevalence estimates and the cancer burden due to each risk factor in the United States, and established primary prevention recommendations and interventions to reduce exposure to each risk factor.

New cancer cases attributable to diet among adults aged 30-84 years in France in 2015

This study aimed to estimate the number of new cancer cases attributable to diet among adults aged 30-84 years in France in 2015, where convincing or probable evidence of a causal association exists, and, in a secondary analysis, where at least limited but suggestive evidence of a causal association exists. Cancer cases attributable to diet were estimated assuming a 10-year latency period. Dietary intake data were obtained from the 2006 French National Nutrition and Health Survey. Counterfactual scenarios of dietary intake were based on dietary guidelines. Corresponding risk relation estimates were obtained from meta-analyses, cohort studies and one case-control study. Cancer incidence data were obtained from the French Network of Cancer Registries. Nationally, unfavourable dietary habits led to 16 930 new cancer cases, representing 5·4 % of all new cancer cases. Low intake of fruit and dietary fibre was the largest contributor to this burden, being responsible for 4787 and 4389 new cancer cases, respectively. If this is expanded to dietary component and cancer pairs with at least limited but suggestive evidence of a causal association, 36 049 new cancer cases, representing 11·6 % of all new cancer cases, were estimated to be attributable to diet. These findings suggest that unfavourable dietary habits lead to a substantial number of new cancer cases in France; however, there is a large degree of uncertainty as to the number of cancers attributable to diet, including through indirect mechanisms such as obesity, and therefore additional research is needed to determine how diet affects cancer risk.

Occupational exposures and cancer: a review of agents and relative risk estimates

OBJECTIVES

The contribution of occupational exposures to the cancer burden can be estimated using population-attributable fractions, which is of great importance for policy making. This paper reviews occupational carcinogens, and presents the most relevant risk relations to cancer in high-income countries using France as an example, to provide a framework for national estimation of cancer burden attributable to occupational exposure.

METHODS

Occupational exposures that should be included in cancer burden studies were evaluated using multiple criteria: classified as carcinogenic or probably carcinogenic by the International Agency for Research on Cancer (IARC) Monographs volumes 1-114, being a primary occupational exposure, historical and current presence of the exposure in France and the availability of exposure and risk relation data. Relative risk estimates were obtained from published systematic reviews and from the IARC Monographs.

RESULTS

Of the 118 group 1 and 75 group 2A carcinogens, 37 exposures and 73 exposure-cancer site pairs were relevant. Lung cancer was associated with the most occupational carcinogenic exposures (namely, 18), followed by bladder cancer and non-Hodgkin's lymphoma. Ionising radiation was associated with the highest number of cancer sites (namely, 20), followed by asbestos and working in the rubber manufacturing industry. Asbestos, bis(chloromethyl)ether, nickel and wood dust had the strongest effect on cancer, with relative risks above 5.

CONCLUSIONS

A large number of occupational exposures continues to impact the burden of cancer in high-income countries such as France. Information on types of exposures, affected jobs, industries and cancer sites affected is key for prioritising policy and prevention initiatives.

New cancer cases in France in 2015 attributable to different levels of alcohol consumption

BACKGROUND AND AIMS

Alcohol consumption increases the risk of cancer. Thus, to inform policy decisions, this study estimated the number of new cancer cases in France in 2015 attributable to alcohol consumption generally and to light (< 20 g per day (g/day) among women; < 40 g/day among men), moderate (20 to < 40 g/day among women; 40 to < 60 g/day among men) and heavy drinking (≥ 40 g/day among women; ≥ 60 g/day among men), and the number of cancer cases that would have been prevented assuming a previous 10% decrease in alcohol consumption.

DESIGN

New cancer cases attributable to alcohol were estimated using a population-attributable fraction methodology, assuming a 10-year latency period between exposure and diagnosis.

SETTING AND PARTICIPANTS

Population of France, 2015.

MEASUREMENTS

Alcohol consumption was estimated by coordinating data from the Baromètre santé 2005, a national representative survey (n = 30 455), with data from the Global Information System on Alcohol and Health. Relative risks were obtained from meta-analyses. Cancer data were estimated based on data from the French Cancer Registries Network. Uncertainty intervals (UI) were estimated using a Monte Carlo procedure.

FINDINGS

In France in 2015, an estimated 27 894 (95% UI = 24 287-30 996) or 7.9% of all new cancer cases were attributable to alcohol. The number of alcohol-attributable new cancer cases was similar for both men and women, with oesophageal squamous cell carcinomas having the largest attributable fraction (57.7%). Light, moderate, heavy and former alcohol drinking were responsible for 1.5, 1.3, 4.4 and 0.6% of all new cancer cases, respectively. Lastly, if there had been a previous 10% reduction in alcohol consumption, 2178 (95% UI = 1687-2601) new cancer cases would have been prevented.

CONCLUSIONS

Alcohol consumption in France appears to cause almost 8% of new cancer cases, with light and moderate drinking contributing appreciably to this burden. A 10% drop in drinking in France would have prevented more than 2000 (estimated) new cancer cases in 2015.

How do general practitioners put preventive care recommendations into practice? A cross-sectional study in Switzerland and France

OBJECTIVES

We previously identified that general practitioners (GPs) in French-speaking regions of Europe had a variable uptake of common preventive recommendations. In this study, we describe GPs' reports of how they put different preventive recommendations into practice.

DESIGN, SETTING AND PARTICIPANTS

Cross-sectional study conducted in 2015 in Switzerland and France. 3400 randomly selected GPs were asked to complete a postal (n=1100) or online (n=2300) questionnaire. GPs who exclusively practiced complementary and alternative medicine were not eligible for the study. 764 GPs (response rate: postal 47%, online 11%) returned the questionnaire (428 in Switzerland and 336 in France).

MAIN OUTCOME MEASURES

We investigated how the GPs performed five preventive practices (screening for dyslipidaemia, colorectal and prostate cancer, identification of hazardous alcohol consumption and brief intervention), examining which age group they selected, the screening frequency, the test they used, whether they favoured shared decision for prostate cancer screening and their definition of hazardous alcohol use.

RESULTS

A large variability was observed in the way in which GPs provide these practices. 41% reported screening yearly for cholesterol, starting and stopping at variable ages. 82% did not use any test to identify hazardous drinking. The most common responses for defining hazardous drinking were, for men, ≥21 drinks/week (24%) and ≥4 drinks/occasion for binge drinking (20%), and for women, ≥14 drinks/week (28%) and ≥3 drinks/occasion (21%). Screening for colorectal cancer, mainly with colonoscopy in Switzerland (86%) and stool-based tests in France (93%), was provided every 10 years in Switzerland (65%) and 2 years in France (91%) to patients between 50 years (87%) and 75 years (67%). Prostate cancer screening, usually with shared decision (82%), was provided yearly (62%) to patients between 50 years (74%) and 75-80 years (32%-34%).

CONCLUSIONS

The large diversity in the way these practices are provided needs to be addressed, as it could be related to some misunderstandingof the current guidelines, to barriers for guideline uptake or, more likely, to the absence of agreement between the various recommendations.

General practitioners' views and preferences about quality improvement feedback in preventive care: a cross-sectional study in Switzerland and France

Background

Feedback is widely used as a strategy to improve the quality of care in primary care settings. As part of a study conducted to explore the quality of preventive care, we investigated general practitioners’ (GPs) views on the usefulness of feedback and their preferences regarding how feedback is provided.

Methods

This cross-sectional study was conducted in 2015 among randomly selected community-based GPs in two regions of Switzerland and France. GPs were asked to complete an anonymous questionnaire about how often they provided 12 measures of preventive care: blood pressure, weight and height measurements, screening for dyslipidemia, at-risk drinking (and advice to reduce for at-risk drinkers), smoking (and advice to stop for smokers), colon and prostate cancer, and influenza immunization for patients >65 years and at-risk patients. They were also asked to estimate the usefulness of a feedback regarding their preventive care practice, reason(s) for which a feedback could be useful, and finally, to state which type of feedback they would like to receive. Chi-square tests were used to compare frequencies. Multivariate logistic regression was used to identify factors associated with GPs considering feedback as useful.

Results

Five hundred eighteen of 1100 GPs (47.1%) returned the questionnaire. They were predominantly men (62.5%) and most (40.1%) were aged between 55 and 64 years old. Overall, 44.3% stated that a feedback would be useful. Younger GPs and those carrying out more measures of preventive care were more likely to consider feedback useful. The two main reasons for being interested in feedback were to receive knowledge about the study results and to modify or improve practice. The two preferred feedback interventions were a brief report and a report with specific information regarding prevention best practice, whereas less than 1% would like to discuss the results face-to-face with the study investigators.

Conclusions

These findings suggest that GPs have preferences regarding the types of feedback they would like to receive. Because the implementation of guidelines is highly related to the acceptance of feedback, we strongly encourage decision makers to take GPs’ preferences into account when developing strategies to implement guidelines, in order to improve the quality of primary care.

Causality in cancer research: a journey through models in molecular epidemiology and their philosophical interpretation

In the last decades, Systems Biology (including cancer research) has been driven by technology, statistical modelling and bioinformatics. In this paper we try to bring biological and philosophical thinking back. We thus aim at making different traditions of thought compatible: (a) causality in epidemiology and in philosophical theorizing-notably, the "sufficient-component-cause framework" and the "mark transmission" approach; (b) new acquisitions about disease pathogenesis, e.g. the "branched model" in cancer, and the role of biomarkers in this process; (c) the burgeoning of omics research, with a large number of "signals" and of associations that need to be interpreted. In the paper we summarize first the current views on carcinogenesis, and then explore the relevance of current philosophical interpretations of "cancer causes". We try to offer a unifying framework to incorporate biomarkers and omic data into causal models, referring to a position called "evidential pluralism". According to this view, causal reasoning is based on both "evidence of difference-making" (e.g. associations) and on "evidence of underlying biological mechanisms". We conceptualize the way scientists detect and trace signals in terms of information transmission, which is a generalization of the mark transmission theory developed by philosopher Wesley Salmon. Our approach is capable of helping us conceptualize how heterogeneous factors such as micro and macro-biological and psycho-social-are causally linked. This is important not only to understand cancer etiology, but also to design public health policies that target the right causal factors at the macro-level.