Scenarios of future lung cancer incidence by educational level: Modelling study in Denmark

Planning for tomorrow: global cancer incidence and the role of prevention 2020-2070

Cancer is currently the first or second most common contributor to premature mortality in most countries of the world. The global number of patients with cancer is expected to rise over the next 50 years owing to the strong influence of demographic changes, such as population ageing and growth, on the diverging trends in cancer incidence in different regions. Assuming that the latest incidence trends continue for the major cancer types, we predict a doubling of the incidence of all cancers combined by 2070 relative to 2020. The greatest increases are predicted in lower-resource settings, in countries currently assigned a low Human Development Index (HDI), whereas the predicted increases in national burden diminish with increasing levels of national HDI. Herein, we assess studies modelling the future burden of cancer that underscore how comprehensive cancer prevention strategies can markedly reduce the prevalence of major risk factors and, in so doing, the number of future cancer cases. Focusing on an in-depth assessment of prevention strategies that target tobacco smoking, overweight and obesity, and human papillomavirus infection, we discuss how stepwise, population-level approaches with amenable goals can avert millions of future cancer diagnoses worldwide. In the absence of a step-change in cancer prevention delivery, tobacco smoking will remain the leading preventable cause of cancer, and overweight and obesity might well present a comparable opportunity for prevention, given its increasing prevalence globally in the past few decades. Countries must therefore instigate national cancer control programmes aimed at preventing cancer, and with some urgency, if such programmes are to yield the desired public health and economic benefits in this century.

Obesity as an Avoidable Cause of Cancer (Attributable Risks)

Excess body weight, commonly categorised as overweight (body mass index, BMI 25.0-29.9 kg/m2) and obesity (BMI ≥30 kg/m2) is an established risk factor for increased incidence of several adult cancers. As body weight is modifiable, there is a potential for cancer prevention. Calculation of attributable risk (here expressed at population attributable fraction, PAF) offers an estimate of the burden of excess cancers attributable to elevated BMI in populations, and thus an approximation of avoidable cases and the opportunity for prevention. Using counterfactual methods, the estimated PAF worldwide attributed to elevated BMI is 3.6 % or nearly half a million new cancer cases in adults (aged 30 years and older after a 10-year lag period). PAFs are higher in women compared with men (5.4 % vs. 1.9 %). Endometrial, post-menopausal breast, and colon cancers account for nearly two-thirds of cancers attributable to elevated BMI. Globally, excess body weight is the third commonest attributable risk factor for cancer (after smoking and infection); in western populations such as the UK, excess weight ranks as second commonest risk factor.

Avoidable cancer cases in the Nordic countries - The impact of overweight and obesity

BACKGROUND

Several types of cancers are causally linked to overweight and obesity, which are increasing in the Nordic countries. The aim of this study was to quantify the proportion of the cancer burden linked to overweight and obesity in the Nordic countries and estimate the potential for cancer prevention.

METHODS

Under different prevalence scenarios of overweight and obesity, the number of cancer cases in the Nordic countries in the next 30 years (i.e. 2016-2045) was estimated for 13 cancer sites and compared to the projected number of cancer cases if the prevalence stayed constant. The Prevent macro-simulation model was used.

RESULTS

Over the period 2016-2045, 205,000 cancer cases out of the 2.1 million expected for the 13 cancer sites (9.5%) that have been studied, could be avoided in the Nordic countries by totally eliminating overweight and obesity in the target population. The largest proportional impact was found for oesophageal adenocarcinoma (24%), and the highest absolute impact was observed for colon (44638) and postmenopausal breast cancer (41135).

CONCLUSION

Decreased prevalence of overweight and obesity would reduce the cancer burden in the Nordic countries. The results from this study form an important step to increase awareness and priorities in cancer control by controlling overweight and obesity in the population.

The incidence and mortality of lung cancer and their relationship to development in Asia

BACKGROUND

Lung cancer is the deadliest cancer worldwide and the most common cancer in Asia. It is necessary to get information on epidemiology and inequalities related to incidence and mortality of the cancer to use for planning and further research. This study aimed to investigate epidemiology and inequality of incidence and mortality from lung cancer in Asia.

METHODS

The study was conducted based on data from the world data of cancer and the World Bank [including the Human Development Index (HDI) and its components]. The incidence and mortality rates, and cancer distribution maps were drawn for Asian countries. To analyze data, correlation test between incidence and death rates, and HDI and its components at significant was used in the significant level of 0.05 using SPSS software.

RESULTS

A total of 1,033,881 incidence (71.13% were males and 28.87% were females. Sex ratio was 2.46) and 936,051 death (71.45% in men and 28.55% in women. The sex ratio was 2.50) recorded in Asian countries in 2012. Five countries with the highest standardized incidence and mortality rates of lung cancer were Democratic Republic of Korea, China, Armenia, Turkey, and Timor-Leste, respectively. Correlation between HDI and standardized incidence rate was 0.345 (P=0.019), in men 0.301 (P=0.042) and in women 0.3 (P=0.043); also between HDI and standardized mortality rate 0.289 (P=0.052), in men 0.265 (P=0.075) and in women 0.200 (P=0.182).

CONCLUSIONS

The incidence of lung cancer has been increasing in Asia. It is high in men. Along with development, the incidence and mortality from lung cancer increases. It seems necessary to study reasons and factors of increasing the incidence and mortality of lung cancer in Asian countries.

Mathematical Modeling in Tobacco Control Research: Initial Results From a Systematic Review

OBJECTIVES

The US Food and Drug Administration has expressed interest in using mathematical models to evaluate potential tobacco policies. The goal of this systematic review was to synthesize data from tobacco control studies that employ mathematical models.

METHODS

We searched five electronic databases on July 1, 2013 to identify published studies that used a mathematical model to project a tobacco-related outcome and developed a data extraction form based on the ISPOR-SMDM Modeling Good Research Practices. We developed an organizational framework to categorize these studies and identify models employed across multiple papers. We synthesized results qualitatively, providing a descriptive synthesis of included studies.

RESULTS

The 263 studies in this review were heterogeneous with regard to their methodologies and aims. We used the organizational framework to categorize each study according to its objective and map the objective to a model outcome. We identified two types of study objectives (trend and policy/intervention) and three types of model outcomes (change in tobacco use behavior, change in tobacco-related morbidity or mortality, and economic impact). Eighteen models were used across 118 studies.

CONCLUSIONS

This paper extends conventional systematic review methods to characterize a body of literature on mathematical modeling in tobacco control. The findings of this synthesis can inform the development of new models and the improvement of existing models, strengthening the ability of researchers to accurately project future tobacco-related trends and evaluate potential tobacco control policies and interventions. These findings can also help decision-makers to identify and become oriented with models relevant to their work.

Educational inequalities in three smoking-related causes of death in 18 European populations

INTRODUCTION

Smoking is an important determinant of socioeconomic inequalities in mortality in many countries. As the smoking epidemic progresses, updates on the development of mortality inequalities attributable to smoking are needed. We provide estimates of relative and absolute educational inequalities in mortality from lung cancer, aerodigestive cancers, and chronic obstructive pulmonary disease (COPD)/asthma in Europe and assess the contribution of these smoking-related diseases to inequalities in all-cause mortality.

METHODS

We use data from 18 European populations covering the time period 1998-2007. We present age-adjusted mortality rates, relative indices of inequality, and slope indices of inequality. We also calculate the contribution of inequalities in smoking-related mortality to inequalities in overall mortality.

RESULTS

Among men, relative inequalities in mortality from the 3 smoking-related causes of death combined are largest in the Czech Republic and Hungary and smallest in Spain, Sweden, and Denmark. Among women, these inequalities are largest in Scotland and Norway and smallest in Italy and Spain. They are often larger among men and tend to be larger for COPD/asthma than for lung and aerodigestive cancers. Relative inequalities in mortality from these conditions are often larger in younger age groups, particularly among women, suggesting a possible further widening of inequalities in mortality in the coming decades. The combined contribution of these diseases to inequality in all-cause mortality varies between 13% and 32% among men and between -5% and 30% among women.

CONCLUSION

Our results underline the continuing need for tobacco control policies, which take into account socioeconomic position.

Simulation models for socioeconomic inequalities in health: a systematic review

Background: The emergence and evolution of socioeconomic inequalities in health involves multiple factors interacting with each other at different levels. Simulation models are suitable for studying such complex and dynamic systems and have the ability to test the impact of policy interventions in silico. Objective: To explore how simulation models were used in the field of socioeconomic inequalities in health. Methods: An electronic search of studies assessing socioeconomic inequalities in health using a simulation model was conducted. Characteristics of the simulation models were extracted and distinct simulation approaches were identified. As an illustration, a simple agent-based model of the emergence of socioeconomic differences in alcohol abuse was developed. Results: We found 61 studies published between 1989 and 2013. Ten different simulation approaches were identified. The agent-based model illustration showed that multilevel, reciprocal and indirect effects of social determinants on health can be modeled flexibly. Discussion and Conclusions: Based on the review, we discuss the utility of using simulation models for studying health inequalities, and refer to good modeling practices for developing such models. The review and the simulation model example suggest that the use of simulation models may enhance the understanding and debate about existing and new socioeconomic inequalities of health frameworks.

Diverging trends in educational inequalities in cancer mortality between men and women in the 2000s in France

BACKGROUND

Socioeconomic inequalities in cancer mortality have been observed in different European countries and the US until the end of the 1990s, with changes over time in the magnitude of these inequalities and contrasted situations between countries. The aim of this study is to estimate relative and absolute educational differences in cancer mortality in France between 1999 and 2007, and to compare these inequalities with those reported during the 1990s.

METHODS

Data from a representative sample including 1% of the French population were analysed. Educational differences among people aged 30-74 were quantified with hazard ratios and relative indices of inequality (RII) computed using Cox regression models as well as mortality rate difference and population attributable fraction.

RESULTS

In the period 1999-2007, large relative inequalities were found among men for total cancer and smoking and/or alcohol related cancers mortality (lung, head and neck, oesophagus). Among women, educational differences were reported for total cancer, head and neck and uterus cancer mortality. No association was found between education and breast cancer mortality. Slight educational differences in colorectal cancer mortality were observed in men and women. For most frequent cancers, no change was observed in the magnitude of relative inequalities in mortality between the 1990s and the 2000s, although the RII for lung cancer increased both in men and women. Among women, a large increase in absolute inequalities in mortality was observed for all cancers combined, lung, head and neck and colorectal cancer. In contrast, among men, absolute inequalities in mortality decreased for all smoking and/or alcohol related cancers.

CONCLUSION

Although social inequalities in cancer mortality are still high among men, an encouraging trend is observed. Among women though, the situation regarding social inequalities is less favourable, mainly due to a health improvement limited to higher educated women. These inequalities may be expected to further increase in future years.

Cancer in relation to socioeconomic status: stage at diagnosis in Texas, 2004-2008

OBJECTIVES

To determine whether stage of cancer diagnosis was associated with the socioeconomic status (SES) of the census tract where the patient resides, and to assess whether this is modified by race, ethnicity, or urban/rural residence, other factors known to affect cancer diagnosis stage.

METHODS

Using 2004-2008 data from the Texas Cancer Registry, we examined the distribution of stage at diagnosis in Texas residents for 15 cancer sites by the SES of the census tract of residence. Stage at diagnosis was categorized into the summary stage categories of early (in situ [preinvasive disease] and localized) and late stage (regional and distant spread). Age-adjusted odds ratios for late-stage versus early-stage cancer diagnosis in low versus high SES census tracts were evaluated by cancer site, race, ethnicity, and urban versus rural residence.

RESULTS

For most cancer sites, late-stage cancer diagnosis increased with decreasing SES. These findings were consistent by cancer site, race, ethnicity, and in urban and rural areas of the state.

CONCLUSIONS

For most cancer sites, particularly those likely to have patients diagnosed early by screening, late-stage cancer diagnosis is increased in Texas populations residing in lower SES census tracts compared with higher SES census tracts.

Potential impact of interventions resulting in reduced exposure to ultraviolet (UV) radiation (UVA and UVB) on skin cancer incidence in four European countries, 2010-2050

BACKGROUND

Behavioural interventions to reduce exposure to ultraviolet radiation (UVR) can reduce risk of skin cancer.

OBJECTIVES

To integrate the data and to evaluate the impact of interventions to limit exposure to UVR on skin cancer incidence in four selected countries.

METHODS

Using PREVENT, a dynamic simulation model, we modelled the potential for skin cancer prevention in four European countries under various scenarios to avoid damage by UVR.

RESULTS

In general, the most effective interventions were those aimed at protecting people during outdoor work and outdoor hobbies against the harmful effects of UVR, and combinations of several interventions. These could in theory lead to reductions of up to 45% in skin cancer cases projected for the year 2050.

CONCLUSIONS

The scope for prevention depends on the prevalence of the risk factors in the different countries, as well as the associated risk factors and time lags modelled.

Foreword: Implementing cancer prevention in Europe

The understanding of risk factors underpinning the aetiology of many common cancers is well established, yet the conversion of this knowledge into prevention lags considerably behind. The title of this Special Issue - Implementing cancer prevention in Europe - captures the central theme within; namely, the translation of cancer epidemiology into public health policy. The Special Issue is supported by focused evidence-based case studies of how these processes might be best taken forward.