Impact of Reducing Intake of Red and Processed Meat on Colorectal Cancer Incidence in Germany 2020 to 2050-A Simulation Study

BACKGROUND

According to the International Agency for Research on Cancer (IARC), there is sufficient evidence for the carcinogenicity of processed meat consumption in humans, specifically regarding colorectal cancer (CRC) risk. Evidence for the carcinogenicity of red meat consumption is more limited but points in the same direction.

METHODS

A macro-simulation approach was used to calculate age- and sex-specific potential impact fractions in a 30-year period (2020-2050).

AIMS

We estimated numbers and proportions of future CRC cases preventable under different scenarios of reducing the intake of processed and red meat in the German population.

RESULTS

Eliminating processed meat intake could reduce the burden of CRC by approximately 205,000 cases in Germany (9.6%) in 2020-2050, 2/3 among males (145,000) and 1/3 among females (60,000). Without red meat intake, approximately 63,000 CRC cases could be avoided (2.9%), 39,000 among males and 24,000 among females. Reductions in the mean consumption of both processed and red meat by one or two servings (each 11 or 22 g) per day would be expected to reduce CRC case numbers by 68,000 (3.1%) and 140,000 (6.5%), respectively.

CONCLUSION

A reduction in red and processed meat intake might substantially reduce the incidence of CRC in Germany. The means of achieving such a reduction might include price and taxation policies, food labeling, and clearer risk communication aiming to reduce individual intake.

A Bayesian approach for estimating the partial potential impact fraction with exposure measurement error under a main study/internal validation design

The partial potential impact fraction describes the proportion of disease cases that can be prevented if the distribution of modifiable continuous exposures is shifted in a population, while other risk factors are not modified. It is a useful quantity for evaluating the burden of disease in epidemiologic and public health studies. When exposures are measured with error, the partial potential impact fraction estimates may be biased, which necessitates methods to correct for the exposure measurement error. Motivated by the health professionals follow-up study, we develop a Bayesian approach to adjust for exposure measurement error when estimating the partial potential impact fraction under the main study/internal validation study design. We adopt the reclassification approach that leverages the strength of the main study/internal validation study design and clarifies transportability assumptions for valid inference. We assess the finite-sample performance of both the point and credible interval estimators via extensive simulations and apply the proposed approach in the health professionals follow-up study to estimate the partial potential impact fraction for colorectal cancer incidence under interventions exploring shifting the distributions of red meat, alcohol, and/or folate intake.

Impact of reducing alcohol consumption through price-based policies on cancer incidence in Germany 2020-50-a simulation study

BACKGROUND AND AIMS

Alcohol is a major cancer risk factor and contributes considerably to the cancer burden in Germany. We aimed to provide projections of preventable cancer cases under different price-based alcohol policy scenarios.

DESIGN

A macro-simulation approach was used to estimate numbers and proportions of cancer cases prevented under different price-based alcohol policy scenarios.

SETTING AND PARTICIPANTS

Published price elasticities for main alcoholic beverages were applied to the mean daily intake of pure alcohol in the German population calculated from the German Health Interview and Examination Survey for Adults 2008-11 (DEGS1) to obtain hypothetical exposure distributions of alcohol consumption under different scenarios of changing price for alcoholic beverages.

MEASUREMENTS

Age, sex and cancer site-specific potential impact fractions were calculated for different scenarios of changing the price of alcohol (single price increases, repeated price increases, volumetric price increase) for each year of a 30-year study period (2020-50).

FINDINGS

Over a 30-year horizon, an estimated 4.7% (men = 10.1%, women = 1.4%) of alcohol-related cancer cases could be prevented in Germany, if alcohol intake above risk thresholds were reduced to levels below risk thresholds. Accordingly, the burden of new cancers would be reduced by approximately 244 000 cases (men = 200 000, women = 44 000). Of all price-based alcohol policy scenarios, a 100% price increase on alcoholic beverages was estimated to be most effective with approximately 213 000 (4.1%; men = 167 000; women = 47 000) preventable alcohol-related cancer cases, followed by 5-yearly 25% price increases (2.8%; men = 115 000, women = 29 000) and a volumetric price increase according to the beverage-specific alcohol content (1.9%; men = 72 000, women = 24 000).

CONCLUSIONS

Simulations suggest that a substantial number of alcohol-related cancer cases could be avoided in Germany by applying price-based policies to reduce consumption of alcoholic beverages.

The impact of reducing alcohol consumption in Australia: An estimate of the proportion of potentially avoidable cancers 2013-2037

The International Agency for Research on Cancer first concluded that alcohol causes cancer in humans in 1988. The World Cancer Research Fund has declared that alcohol causes cancer of the oral cavity, pharynx, larynx, oesophagus (squamous cell carcinoma), female breast, colon, rectum, stomach and liver. It recommended that alcohol be avoided altogether to prevent cancer. We aimed to quantify the impact of reducing alcohol consumption on future cancer incidence in Australia. We used PREVENT 3.01 simulation modelling software to estimate the proportion of cancers that could potentially be prevented over a 25-year period under two hypothetical intervention scenarios and two latency periods (20 and 30 years). Under a scenario where alcohol consumption abruptly ceases, we estimated up to 4% of alcohol-related cancers could be avoided over a 25-year period (~49,500 cancers, depending on assumed latency). If the maximum consumption of all Australian adults was ≤20 g/day (~two Australian standard drinks), up to 2% of alcohol-related cancers could be avoided (~29,600 cancers). The maximum proportions were higher for men (6% for no alcohol consumption; 5% for ≤20 g/day) than women (3%; 1%). The proportion avoidable was highest for oesophageal squamous cell carcinoma (17% no alcohol consumption; 9% ≤20 g/day), followed by cancers of the oral cavity (12%; 5%) and pharynx (11%; 5%). The cancer sites with the highest numbers of potentially avoidable cases were colon in men (11,500; 9,900) and breast in women (14,400; 4,100). Successful interventions to reduce alcohol intake could lead to significant reductions in cancer incidence.

Estimating the avoidable burden and population attributable fraction of human risk factors of road traffic injuries in iran: application of penalization, bias reduction and sparse data analysis

The aim of this study was to prioritize human risk factors for preventive interventions by estimating the avoidable burden and population attributable fraction (PAF) of each risk factor using penalization and data augmentation method. To avoid the sparse data bias, Bayesian logistic regression via data augmentation methods, were used for multivariable analysis. Informative normal priors adopted from the studies were used for the studied human risk factors. Weakly informative log-f was used for the covariates. The population attributable fraction was calculated based on direct method. The comparative risk assessment methodology of the WHO was used to estimate the potential impact fraction for each risk factor. The most important human factors influencing the traffic-related deaths were overspeeding (OR = 9.6, 95% CI: 2.45-37.7), reckless overtaking (OR = 8.6, 95% CI: 1.82-40.7), and fatigue and drowsiness (OR = 6.7, 95% CI: 1.79-25). The total PAF for the all studied risk factors was about 56% (PAF = 0.567, 95% CI: 0.37-0.7). The greatest avoidable burden was related to fatigue and drowsiness, overspeeding, and not fastening seatbelt. By considering the high contribution of human risk factors in occurrence of fatal traffic injuries appropriate legislation and prevention programs for these risk factors would decrease half of such deaths.

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

INTRODUCTION

The Canadian Population Attributable Risk of Cancer project aims to quantify the number and proportion of cancer cases incident in Canada, now and projected to 2042, that could be prevented through changes in the prevalence of modifiable exposures associated with cancer. The broad risk factor categories of interest include tobacco, diet, energy imbalance, infectious diseases, hormonal therapies and environmental factors such as air pollution and residential radon.

METHODS AND ANALYSIS

Using a national network, we will use population-attributable risks (PAR) and potential impact fractions (PIF) to model both attributable (current) and avoidable (future) cancers. The latency periods and the temporal relationships between exposures and cancer diagnoses will be accounted for in the analyses. For PAR estimates, historical exposure prevalence data and the most recent provincial and national cancer incidence data will be used. For PIF estimates, we will model alternative or 'counterfactual' distributions of cancer risk factor exposures to assess how cancer incidence could be reduced under different scenarios of population exposure, projecting incidence to 2042.

DISSEMINATION

The framework provided can be readily extended and applied to other populations or jurisdictions outside of Canada. An embedded knowledge translation and exchange component of this study with our Canadian Cancer Society partners will ensure that these findings are translated to cancer programmes and policies aimed at population-based cancer risk reduction strategies.

Cancers in Australia in 2010 attributable to insufficient physical activity

Objectives

To estimate the proportion and numbers of cancers occurring in Australia in 2010 attributable to insufficient levels of physical activity.

Methods

We estimated the population attributable fraction (PAF) of cancers causally associated with insufficient physical activity (colon, post-menopausal breast and endometrium) using standard formulae incorporating prevalence of insufficient physical activity (<60 minutes at least 5 days/week), relative risks associated with physical activity and cancer incidence. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that may have occurred assuming that everyone with insufficient activity levels increased their exercise by 30 minutes/week.

Results

An estimated 1,814 cases of colon, post-menopausal breast and endometrial cancer were attributable to insufficient levels of physical activity: 707 (6.5%) colon; 971 (7.8%) post-menopausal breast; and 136 (6.0%) endometrial cancers. If those exercising below the recommended level had increased their activity level by 30 minutes/week, we estimate 314 fewer cancers (17% of those attributable to insufficient physical activity) would have occurred in 2010.

Conclusions

More than 1,500 cancers were attributable to insufficient levels of physical activity in the Australian population.

Implications

Increasing the proportion of Australians who exercise could reduce the incidence of several common cancers.

Cancers in Australia in 2010 attributable to total breastfeeding durations of 12 months or less by parous women

Objectives

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to parous women having breastfed for total durations of ≤12 months.

Methods

We estimated the population attributable fraction (PAF) of breast cancers (the only cancer site with convincing evidence of causal association) associated with women breastfeeding for ≤12 months in total, using standard formulae incorporating breastfeeding prevalence data, relative risks associated with breastfeeding and cancer incidence. We also estimated the proportion change in disease incidence (potential impact fraction [PIF]) that might have occurred under two hypothetical scenarios of women breastfeeding for longer durations.

Results

An estimated 235 (1.7%) breast cancer cases that occurred in Australian in 2010 could be attributed to women breastfeeding for total durations of ≤12 months. Assuming a hypothetical increase in breastfeeding, we estimated that the number of breast cancers prevented would range from 36 to 51 (prevented fraction = 0.3% to 0.4%).

Conclusions

More than 200 breast cancers were attributable to women breastfeeding for total durations of ≤12 months.

Implications

Policies to increase breastfeeding duration may help prevent breast cancers in the future.

Cancers in Australia in 2010 attributable to modifiable factors: introduction and overview

OBJECTIVE

To describe the approach underpinning a national project to estimate the numbers and proportions of cancers occurring in Australia in 2010 that are attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) (or prevented fraction) of cancers associated with exposure to causal (or preventive) factors using standard formulae. Where possible, we also estimated the potential impact on cancer incidence resulting from changes in prevalence of exposure. Analyses were restricted to factors declared causal by international agencies: tobacco smoke; alcohol; solar radiation; infectious agents; obesity; insufficient physical activity; insufficient intakes of fruits, vegetables and fibre; red and processed meat; menopausal hormone therapy (MHT); oral contraceptive pill (OCP); and insufficient breast feeding. Separately, we estimated numbers of cancers prevented by: aspirin; sunscreen; MHT; and OCP use. We discuss assumptions pertaining to latent periods between exposure and cancer onset, choices of prevalence data and risk estimates, and approaches to sensitivity analyses.

RESULTS

Numbers and population attributable fractions of cancer are presented in accompanying papers.

CONCLUSIONS

This is the first systematic assessment of population attributable fractions of cancer in Australia.

Cancers in Australia in 2010 attributable to modifiable factors: summary and conclusions

OBJECTIVE

To estimate the numbers and proportions of cancers occurring in Australia in 2010 attributable to modifiable causal factors.

METHODS

We estimated the population attributable fraction (PAF) of cancers associated with exposure to 13 causal factors using standard formulae incorporating exposure prevalence and relative risk data. We also calculated the potential impact of changing exposure to some factors.

RESULTS

A total of 32% of all cancers diagnosed in Australia in 2010 (excluding keratinocyte cancers) were attributable to the 13 factors assessed (men 33%; women 31%). Leading factors were tobacco smoke (PAF all cancers: 13.4%), solar radiation (6.2%), inadequate diet (6.1%) and overweight/obesity (3.4%). Factors conferring highest PAFs differed by sex: highest PAFs for men were tobacco smoke (15.8%), solar radiation (7.1%) and alcohol (3.0%); while highest PAFs for women were tobacco smoke (10.1%), solar radiation (5.0%) and overweight/obesity (4.5%). Sites with the highest counts of potentially preventable cancers were lung (8,569), colorectal (7,404), melanoma of the skin (7,220) and breast (3,233).

CONCLUSIONS

At least one in three cancers in Australia is attributable to exposure to known modifiable factors.

IMPLICATIONS

Up to 37,000 cancers could be prevented in Australia each year if the population avoided exposure to 13 common factors known or strongly suspected to cause cancer.

Cancers in Australia in 2010 attributable to the consumption of alcohol

OBJECTIVE

To estimate the proportion and numbers of cancers occurring in Australia in 2010 that are attributable to alcohol consumption.

METHODS

We estimated the population attributable fraction (PAF) of cancers causally associated with alcohol consumption using standard formulae incorporating prevalence of alcohol consumption and relative risks associated with consumption and cancer. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that might have occurred under the hypothetical scenario that an intervention reduced alcohol consumption, so that no-one drank >2 drinks/day.

RESULTS

An estimated 3,208 cancers (2.8% of all cancers) occurring in Australian adults in 2010 could be attributed to alcohol consumption. The greatest numbers were for cancers of the colon (868) and female breast cancer (830). The highest PAFs were for squamous cell carcinomas of the oral cavity/pharynx (31%) and oesophagus (25%). The incidence of alcohol-associated cancer types could have been reduced by 1,442 cases (4.3%)--from 33,537 to 32,083--if no Australian adult consumed >2 drinks/day.

CONCLUSIONS

More than 3,000 cancers were attributable to alcohol consumption and thus were potentially preventable.

IMPLICATIONS

Strategies that limit alcohol consumption to guideline levels could prevent a large number of cancers in Australian adults.

Cancers in Australia in 2010 attributable to inadequate consumption of fruit, non-starchy vegetables and dietary fibre

Objectives

To estimate the number and proportion of cancers occurring in Australia in 2010 attributable to consumption deficits in fruit, non-starchy vegetables and dietary fibre.

Methods

We estimated the population attributable fraction (PAF) for cancers causally associated with inadequate intake of fruit and non-starchy vegetables (oral cavity, pharynx, oesophageal squamous cell carcinoma, stomach, larynx); inadequate intake of fruit (lung); and insufficient intake of fibre (colorectum). We used standard formulae incorporating prevalence of exposure (1995 National Nutrition Survey) and relative risks from independent studies.

Results

Overall, 1,555 (1.4% of all) and 311 (0.3% of all) cancers were attributable to inadequate intakes of fruit and non-starchy vegetables, respectively. A further 2,609 colorectal cancers (18% of colorectal) were attributable to insufficient fibre intake. If Australians increased their fibre intake by eating the recommended daily intakes of fruit and vegetables, an estimated 1,293 (8.8%) colorectal cancers could be prevented.

Conclusions

One in six colorectal cancer cases was attributable to inadequate intake of dietary fibre and about 1,800 cancers at other sites were attributable to insufficient fruit and non-starchy vegetable consumption.

Implications

Increasing the proportion of Australians who consume the recommended intake of fruit, vegetables and fibre could prevent up to 4% of all cancers.

Cancers in Australia in 2010 attributable to the consumption of red and processed meat

Objectives

To estimate the proportion and numbers of cancers in Australia in 2010 attributable to consuming red/processed meat.

Methods

We estimated the population attributable fraction (PAF) for cancers causally associated with red/processed meat consumption (colon, rectum) using standard formulae incorporating prevalence of consumption (1995 National Nutrition Survey), relative risks associated with consumption and cancer incidence. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that might have occurred under two hypothetical interventions whereby Australian adults reduced their consumption of red/processed meat from prevailing levels to ≤100 g or ≤65 g per day, respectively.

Results

An estimated 2,614 cases (18%) of colorectal cancer occurring in Australians in 2010 were attributable to red/processed meat consumption (16% of colon cancers; 23% of rectal cancers). We estimated that if all Australian adults had consumed ≤65 g/day or ≤100 g/day of red/processed meat, then the incidence of colorectal cancer would have been 5.4% (798 cancers) or 1.4% (204 cancers) lower, respectively.

Conclusions

About one in six colorectal cancers in Australians in 2010 were attributable to red/processed meat consumption.

Implications

Reducing red/processed meat intake may reduce colorectal cancer incidence, but must be balanced against nutritional benefits of modest lean meat consumption.

Cancers in Australia in 2010 attributable to and prevented by the use of menopausal hormone therapy

OBJECTIVES

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to menopausal hormone therapy (MHT) use.

METHODS

We estimated the population attributable fraction for cancers causally associated with MHT (breast, endometrium, ovary), and the proportion of colorectal cancers prevented by MHT. We used standard formulae incorporating Australian prevalence data, relative risks of cancer associated with MHT and cancer incidence. We also estimated potential change in cancer incidence under two hypothetical scenarios whereby 25% fewer Australian women used MHT, or women exclusively used oestrogen-only MHT.

RESULTS

An estimated 539 cancers in Australia in 2010 were attributable to MHT: 453 breast, 67 endometrial and 19 ovarian cancers equating to 3.4%, 3.1% and 1.6% of each cancer type, respectively. In contrast, MHT may have prevented 52 colorectal cancers. If 25% fewer women used MHT, then 141 cancers may have been avoided. If women exclusively used oestrogen-only MHT then 240 cancers may have been avoided.

CONCLUSIONS

MHT use caused more than 500 cancers in Australian women in 2010 and prevented ∼50 colorectal cancers.

IMPLICATIONS

MHT use continues to cause an excess of cancers. The risks, benefits, regimen and treatment duration should be carefully considered for each woman before MHT is commenced.

Cancers in Australia in 2010 attributable to overweight and obesity

OBJECTIVES

To estimate the proportion and number of cancers occurring in Australia in 2010 attributable to overweight/obesity.

METHODS

We estimated the population attributable fraction (PAF) and number of cancers causally associated with overweight/obesity. We used standard formulae incorporating Australian prevalence data for body mass index (BMI), relative risks associated with BMI and cancer. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that may have occurred assuming that the prevalence of overweight/obesity had remained at 1990 levels.

RESULTS

An estimated 3,917 cancer cases (3.4% of all cancers) diagnosed in 2010 were attributable to overweight/obesity, including 1,101 colon cancers, 971 female post-menopausal breast cancers and 595 endometrial cancers (PAFs of 10%, 8% and 26%, respectively). Highest PAFs were observed for oesophageal adenocarcinoma (31%), endometrial cancer (26%) and kidney cancer (19%). If the prevalence of overweight/obesity in Australia had remained at levels prevailing in 1990, we estimate there would have been 820 fewer cancers diagnosed in 2010 (PIF 2%).

CONCLUSIONS

Overweight/obesity causes a substantial number of cancers in Australia.

IMPLICATIONS

Public health strategies to reduce the prevalence of overweight and obesity will reduce the incidence of cancer, particularly of the colon, breast and endometrium.

Joint effect of modifying selected risk factors on attributable burden of cardiovascular diseases

BACKGROUND

There are few published studies that consider the joint effect of multiple risk factors on avoidable burden of cardiovascular diseases (CVDs). This study aimed to estimate the joint effect of avoidable burden of multiple risk factors to CVDs.

METHODS

Estimates of avoidable burden to CVDs were made using potential impact fraction (PIF). In order to calculate PIF, data on the Prevalence of the risk factors include diabetes, hypertension, central obesity, and hypercholesterolemia were obtained from 3(rd) national Surveillance of Risk Factors of Non-Communicable Diseases-2007 in Iran and data on corresponding measures of effect were derived from a cohort study with multivariate adjusted hazard ratios. Then, joint effect of risk factors was calculated.

RESULTS

About 37% (95% uncertainty interval: 21.7-50.2) of attributable disability adjusted life years (DALYs) to CVDs in adult males and 59.4% (95% uncertainty interval: 30-76) in adult females due to selected risk factors are avoidable in theoretical minimum risk levels. After changing the current prevalence of these risk factors to the plausible minimum risk levels, 17.8% (95% uncertainty interval: 10.1-25.1) of CVDs' attributable DALYs among adult males and 34% (95% uncertainty interval: 20-46.7) in adult females can be avoided.

CONCLUSIONS

To better priority setting as well as reporting the magnitude of avoidable DALYs rather than the percentage of avoidable burden, PIF should be applied to updated and revised burden of CVDs.

Potentially preventable incidence of diabetes due to risk factor modification

BACKGROUND

Increasing diabetes incidence demands investigation of risk factors, prioritization and designing modification interventions. We calculated the potential modifiable incidence of diabetes due to reduction in risk factors.

METHODS

We used counterfactual analysis model to estimate avoidable burden of incident diabetes related to each risk factor. The potential impact fraction (PIF) index calculated utilizing the data of current prevalence, magnitude of impact and counterfactual status of risk factors. We considered the levels of evidence while giving higher priority to domestic data.

RESULTS

The estimated PIF regarding minimum feasible risk for the impaired fasting glucose (IFG), impaired glucose tolerance (IGT), combined IFG/IGT, low HDL, high triglyceride, high total cholesterol, hypertension, general obesity, central obesity and physical inactivity were 0.13, 0.10, 0.18, 0.01, 0.12, 0.03, 0.13, 0.03, 0.02 and 0.10, respectively.

CONCLUSION

While the combined risk factors of IFG and IGT should be noticed as the most important potential factor in prevention of diabetes and reducing its incidence burden, among the other risk factors, modification of hypertension, high triglyceride, and physical inactivity could have more impact.