Occupational exposures contribute to educational inequalities in lung cancer incidence among men: Evidence from the EPIC prospective cohort study

Age-period-cohort analysis of lung cancer mortality inequalities in Southern Spain: missed opportunities for implementing equitable tobacco control policies

BACKGROUND

Lung cancer mortality in European countries shows different epidemiological patterns according to sex and socioeconomic variables. Some countries show decreasing rates in both sexes, while others show a delayed profile, with increasing mortality in women, inconsistently influenced by socioeconomic status. Our aim was to evaluate the effect of age, period and birth cohort on lung cancer mortality inequalities in men and women in Andalusia, the southernmost region in Spain.

METHODS

We used the Longitudinal Database of the Andalusian Population, which collects demographic and mortality data from the 2001 census cohort of more than 7.35 million Andalusians, followed up between 2002 and 2016. Mortality rates were calculated for men and women by educational level, and small-area deprivation. Poisson models were used to assess trends in socioeconomic inequalities in men and women. Finally, age-period-cohort (APC) models were used separately for each educational level and gender.

RESULTS

There were 39,408 lung cancer deaths in men and 5,511 in women, yielding crude mortality rates of 78.1 and 11.4 × 105 person-years, respectively. In men higher mortality was found in less educated groups and inequalities increased during the study period: i.e. the rate ratio for primary studies compared to university studies increased from 1.30 (CI95:1.18-1.44) to 1.57 (CI95:1.43-1.73). For women, educational inequalities in favour of the less educated tended to decrease moderately. In APC analysis, a decreasing period effect in men and an increasing one in women were observed. Cohort effect differed significantly by educational level. In men, the lower the educational level, the earlier the peak effect was reached, with a 25-year difference between the least-educated and college-educated. Conversely, college-educated women reached the peak effect with a 12-year earlier cohort than the least-educated women. The decline of mortality followed the same pattern both in men and women, with the best-educated groups experiencing declining rates with earlier birth cohorts.

CONCLUSIONS

Our study reveals that APC analysis by education helps to uncover changes in trends occurring in different socioeconomic and gender groups, which, combined with data on smoking prevalence, provide important clues for action. Despite its limitations, this approach to the study of lung cancer inequalities allows for the assessment of gaps in historical and current tobacco policies and the identification of population groups that need to be prioritised for public health interventions.

Role of Occupation in Shaping Cancer Disparities

Simple Summary

The investigation of cancer disparities is of major importance. In this paper, we address this issue through the occupational point of view, trying to capture how work and its related factors impact on cancer inequalities. The data we provide may increase awareness relevant to cancer control, and stimulate further studies aimed at the identification of the occupational determinants of cancer disparities and the quantification of their role.

Abstract

Cancer occurrence is characterized globally by profound socioeconomic differences. Occupation is a fundamental component of socioeconomic status. In this review, we discuss the role of occupation as a determinant of cancer disparities. First, we address the issue of participation in cancer screening programs based on income, health insurance, occupational status and job title. Second, we review the role of occupation in contributing to disparities by acting as a mediator between cancer and (i) education and (ii) race/ethnicity. Lastly, we analyze data from a multicenter case−control study of lung cancer to calculate the mediating role of occupational exposure to diesel exhaust, silica and welding fumes in the association between education and lung cancer. By addressing the complex paths from occupation to cancer inequalities from multiple points of view, we provide evidence that occupational-related characteristics, such as income, health insurance, unemployment and hazardous exposures impinge on cancer control and outcomes. The increasing awareness of these aspects is fundamental and should lead to public health interventions to avoid inequalities rising from occupational factors.

Education, income and risk of cancer: results from a Norwegian registry-based study

INTRODUCTION

Several studies have shown an association between socioeconomic status and incidence of cancer. In this study, we have examined the association between socioeconomic factors, using income and education as proxies, and cancer incidence in Norway, a country known to be egalitarian, with universal access to health care and scoring high on the human development index.

METHODS

We linked individual data for the total Norwegian population with information on all cancer patients registered in the Cancer Registry of Norway (CRN) with any cancer diagnosed between 2012 and 2016. Data on education, and individual income, were provided from Statistics Norway. We used Poisson regression to obtain incidence rate ratios (IRR) across education and income levels for 23 cancer sites.

RESULTS

A total of 9 cancers among men and 13 cancers among women were observed to have significantly higher incidence rates in cases with the lowest level of education. Melanoma for both sexes, testis and prostate cancer in men, and breast cancer in women were found to have a higher incidence rate among those with the highest level of education. The largest differences in IRR were found for lung cancer, where men and women with college or university education as their highest completed education had a two- to threefold decreased risk, compared to those with primary school (IRR men; 0.40 [0.37-0.43], women 0.34 [0.31-0.37]). The results for income mirrored the results for education among men, while for women we did not observe many differences in cancer risk across income groups.

CONCLUSION

Our findings were consistent with findings from other studies showing that the incidence rate of cancer differs across levels of socioeconomic status. We may need behavioral change campaigns focused on lifestyle changes that lower the risk of cancer and target perhaps to those with lower socioeconomic status.

Association between systemic sclerosis and risk of lung cancer: results from a pool of cohort studies and Mendelian randomization analysis

BACKGROUND

Population-based cohort studies have indicated that systemic sclerosis (SSc) may be associated with an increased risk of lung cancer. However, there are few studies that comprehensively investigate their correlation and the causal effect remains unknown.

METHODS

A systematic search of PubMed, Web of Science, Cochrane Library and Embase from the inception dates to December 1, 2019 was carried out. Meta-analysis was performed to calculate odds ratio (OR) and corresponding 95% confidence interval (CI) using random-effects models. Subgroup analyses were performed regarding gender. Two-sample Mendelian randomization (MR) was carried out with summary data from published genome-wide association studies of SSc (Neale Lab, 3871 individuals; UK Biobank, 463,315 individuals) and lung cancer (International Lung Cancer Consortium, 27,209 individuals; UK Biobank, 508,977 individuals). Study-specific estimates were summarized using inverse variance-weighted, weighted median, and MR-Egger method.

RESULTS

Through meta-analysis of 10 population-based cohort studies involving 12,218 patients, we observed a significantly increased risk of lung cancer among patients with SSc (OR 2.80, 95% CI 1.55-5.03). In accordance with subgroup analysis, male patients (OR 4.11, 95% CI 1.92-8.79) had a 1.5-fold higher lung cancer risk compared with female patients (OR 2.73, 95% CI 1.41-5.27). However, using a score of 11 SSc-related single nucleotide polymorphisms (p < 5*10^-8) as instrumental variables, the MR study did not support a causality between SSc and lung cancer (OR 1.001, 95% CI 0.929-1.100, p = 0.800). Specifically, subgroup MR analyses indicated that SSc was not associated with increased risks of non-small-cell lung cancer (OR 1.000, 95% CI 0.999-1.000, p = 0.974), including lung adenocarcinoma (OR 0.996, 95% CI 0.906-1.094, p = 0.927), squamous cell lung carcinoma (OR 1.034, 95% CI 0.937-1.140, p = 0.507), nor small-cell lung cancer (OR 1.000, 95% CI 0.999-1.000, p = 0.837).

CONCLUSIONS

This study indicated an increased risk of lung cancer among patients with SSc by meta-analysis, whereas the MR study did not support a causality between the two diseases. Further studies are warranted to investigate the factors underlying the attribution of SSc to lung cancer risk.

Socioeconomic inequalities in cancer incidence in Europe: a comprehensive review of population-based epidemiological studies

Background

Since the end of the previous century, there has not been a comprehensive review of European studies on socioeconomic inequality in cancer incidence. In view of recent advances in data source linkage and analytical methods, we aimed to update the knowledge base on associations between location-specific cancer incidence and individual or area-level measures of socio-economic status (SES) among European adults.

Materials and methods

We systematically searched three databases (PubMed, Scopus and Web of Science) for articles on cancer incidence and SES. Qualitative synthesis was performed on the 91 included English language studies, published between 2000 and 2019 in Europe, which focused on adults, relied on cancer registry data and reported on relative risk (RR) estimates.

Results

Adults with low SES have increased risk of head and neck, oesophagogastric, liver and gallbladder, pancreatic, lung, kidney, bladder, penile and cervical cancers (highest RRs for lung, head and neck, stomach and cervix). Conversely, high SES is linked with increased risk of thyroid, breast, prostate and skin cancers. Central nervous system and haematological cancers are not associated with SES. The positive gap in testicular cancer has narrowed, while colorectal cancer shows a varying pattern in different countries. Negative associations are generally stronger for men compared to women.

Conclusions

In Europe, cancers in almost all common locations are associated with SES and the inequalities can be explained to a varying degree by known life-style related factors, most notably smoking. Independent effects of many individual and area SES measures which capture different aspects of SES can also be observed.

Socioeconomic Inequalities in Total and Site-Specific Cancer Incidence in Germany: A Population-Based Registry Study

Most chronic diseases follow a socioeconomic gradient with higher rates in lower socioeconomic groups. A growing body of research, however, reveals cancer to be a disease group with very diverse socioeconomic patterning, even demonstrating reverse socioeconomic gradients for certain cancers. To investigate this matter at the German national level for the first time, this study examined socioeconomic inequalities in cancer incidence in Germany, both for all cancers combined as well as for common site-specific cancers. Population-based data on primary cancers newly diagnosed in 2010-2013 was obtained from the German Centre for Cancer Registry Data. Socioeconomic position was assessed at the district level using the German Index of Socioeconomic Deprivation, which is a composite index of area-based socioeconomic indicators. Absolute and relative socioeconomic inequalities in total and site-specific cancer incidence were analyzed using multilevel Poisson regression models with the logarithm of the number of residents as an offset. Among men, socioeconomic inequalities in cancer incidence with higher rates in more deprived districts were found for all cancers combined and various site-specific cancers, most pronounced for cancers of the lung, oral and upper respiratory tract, stomach, kidney, and bladder. Among women, higher rates in more deprived districts were evident for kidney, bladder, stomach, cervical, and liver cancer as well as for lymphoid/hematopoietic neoplasms, but no inequalities were evident for all cancers combined. Reverse gradients with higher rates in less deprived districts were found for malignant melanoma and thyroid cancer in both sexes, and in women additionally for female breast and ovarian cancer. Whereas in men the vast majority of all incident cancers occurred at cancer sites showing higher incidence rates in more deprived districts and cancers with a reverse socioeconomic gradient were in a clear minority, the situation was more balanced for women. This is the first national study from Germany examining socioeconomic inequalities in total and site-specific cancer incidence. The findings demonstrate that the socioeconomic patterning of cancer is diverse and follows different directions depending on the cancer site. The area-based cancer inequalities found suggest potentials for population-based cancer prevention and can help develop local strategies for cancer prevention and control.

Tobacco-attributable burden of cancer according to socioeconomic position in France

Smoking is a major preventable cause of cancers and is increasingly concentrated among the most deprived individuals leading to increasing socioeconomic inequalities in the incidence of cancers linked to smoking. We aimed to estimate the tobacco-attributable cancer burden according to socioeconomic position in France. The analysis was restricted to cancer sites for which tobacco smoking was recognized as a risk factor. Cancer cases by sex, age group and European Deprivation Index (EDI) among people aged 30-74 between 2006 and 2009 were obtained from cancer registries covering ∼20% of the French population. The tobacco-attributable burden of cancer according to EDI was estimated applying the population attributable fraction (PAF) computed with the Peto-Lopez method. The PAF increased from 56% in the least deprived EDI quintile to 70% in the most deprived EDI quintile among men and from 26% to 38% among women. In total, 28% of the excess cancer cases in the four most deprived EDI quintiles in men and 43% in women could be prevented if smoking in these 4 EDI quintiles was similar to that of the least deprived EDI quintile. A substantial smoking-attributable burden of cancer by socioeconomic position was observed in France. The results highlight the need for policies reducing tobacco consumption. More comprehensive interventions integrating the various dimensions of health determinants and proportionate according to socioeconomic position may essentially contribute to the reduction of socioeconomic inequalities in cancer.

Lung cancer and socioeconomic status in a pooled analysis of case-control studies

BACKGROUND

An association between low socioeconomic status (SES) and lung cancer has been observed in several studies, but often without adequate control for smoking behavior. We studied the association between lung cancer and occupationally derived SES, using data from the international pooled SYNERGY study.

METHODS

Twelve case-control studies from Europe and Canada were included in the analysis. Based on occupational histories of study participants we measured SES using the International Socio-Economic Index of Occupational Status (ISEI) and the European Socio-economic Classification (ESeC). We divided the ISEI range into categories, using various criteria. Stratifying by gender, we calculated odds ratios (OR) and 95% confidence intervals (CI) by unconditional logistic regression, adjusting for age, study, and smoking behavior. We conducted analyses by histological subtypes of lung cancer and subgroup analyses by study region, birth cohort, education and occupational exposure to known lung carcinogens.

RESULTS

The analysis dataset included 17,021 cases and 20,885 controls. There was a strong elevated OR between lung cancer and low SES, which was attenuated substantially after adjustment for smoking, however a social gradient persisted. SES differences in lung cancer risk were higher among men (lowest vs. highest SES category: ISEI OR 1.84 (95% CI 1.61-2.09); ESeC OR 1.53 (95% CI 1.44-1.63)), than among women (lowest vs. highest SES category: ISEI OR 1.54 (95% CI 1.20-1.98); ESeC OR 1.34 (95% CI 1.19-1.52)).

CONCLUSION

SES remained a risk factor for lung cancer after adjustment for smoking behavior.

Occupational prestige trajectory and the risk of lung and head and neck cancer among men and women in France

OBJECTIVES

This study aimed at investigating the associations between occupational prestige trajectories and lung and head and neck (HN) cancer risk and to assess to what extent smoking, alcohol drinking, and occupational exposures contribute to these associations.

METHODS

Using data from the ICARE case-control study (controls (2676 men/715 women), lung cancers (2019 men/558 women), HN cancers (1793 men/305 women), we defined occupational prestige trajectories using group-based modeling of longitudinal data. We conducted logistic regression models.

RESULTS

Among men, a gradient was observed from the downward "low to very low" trajectory to the stable very high trajectory. The associations were reduced when adjusting for tobacco and alcohol consumption and occupational exposures. Among women, when compared to the stable high trajectory, there was an increased cancer risk in all trajectories. The associations remained globally unchanged or even increased after adjustment for tobacco and alcohol consumption and did not change when adjusting for occupational exposures. The ORs were smaller for lung than for HN cancers in men.

CONCLUSIONS

Occupational prestige trajectory is strongly associated with lung and HN cancer risk in men and women.

Socioeconomic position and mortality risk of smoking: evidence from the English Longitudinal Study of Ageing (ELSA)

Background

It is not clear whether the harm associated with smoking differs by socioeconomic status. This study tests the hypothesis that smoking confers a greater mortality risk for individuals in low socioeconomic groups, using a cohort of 18 479 adults drawn from the English Longitudinal Study of Ageing. Methods:- Additive hazards models were used to estimate the absolute smoking-related risk of death due to lung cancer or Chronic Obstructive Pulmonary Disease (COPD). Smoking was measured using a continuous index that incorporated the duration of smoking, intensity of smoking and the time since cessation. Attributable death rates were reported for different levels of education, occupational class, income and wealth.

Results

Smoking was associated with higher absolute mortality risk in lower socioeconomic groups for all four socioeconomic indicators. For example, smoking 20 cigarettes per day for 40 years was associated with 898 (95% CI 738, 1058) deaths due to lung cancer or COPD per 100 000 person-years among participants in the bottom income tertile, compared to 327 (95% CI 209, 445) among participants in the top tertile.

Conclusions

Smoking is associated with greater absolute mortality risk for individuals in lower socioeconomic groups. This suggests greater public health benefits of smoking prevention or cessation in these groups.

Quantifying the mediating effects of smoking and occupational exposures in the relation between education and lung cancer: the ICARE study

Smoking only partly explains the higher lung cancer incidence observed among socially deprived people. Occupational exposures may account for part of these inequalities, but this issue has been little investigated. We investigated the extent to which smoking and occupational exposures to asbestos, silica and diesel motor exhaust mediated the association between education and lung cancer incidence in men. We analyzed data from a large French population-based case-control study (1976 lung cancers, 2648 controls). Detailed information on lifelong tobacco consumption and occupational exposures to various carcinogens was collected. We conducted inverse probability-weighted marginal structural models. A strong association was observed between education and lung cancer. The indirect effect through smoking varied by educational level, with the strongest indirect effect observed for those with the lowest education (OR = 1.34 (1.14-1.57)). The indirect effect through occupational exposures was substantial among men with primary (OR = 1.22 (1.15-1.30) for asbestos and silica) or vocational secondary education (OR = 1.18 (1.12-1.25)). The contribution of smoking to educational differences in lung cancer incidence ranged from 22 % (10-34) for men with primary education to 31 % (-3 to 84) for men with a high school degree. The contribution of occupational exposures to asbestos and silica ranged from 15 % (10-20) for men with a high school degree to 20 % (13-28) for men with vocational secondary education. Our results highlight the urgent need for public health policies that aim at decreasing exposure to carcinogens at work, in addition to tobacco control policies, if we want to reduce socioeconomic inequalities in the cancer field.

Occupational prestige, social mobility and the association with lung cancer in men

BACKGROUND

The nature of the association between occupational social prestige, social mobility, and risk of lung cancer remains uncertain. Using data from the international pooled SYNERGY case-control study, we studied the association between lung cancer and the level of time-weighted average occupational social prestige as well as its lifetime trajectory.

METHODS

We included 11,433 male cases and 14,147 male control subjects. Each job was translated into an occupational social prestige score by applying Treiman's Standard International Occupational Prestige Scale (SIOPS). SIOPS scores were categorized as low, medium, and high prestige (reference). We calculated odds ratios (OR) with 95 % confidence intervals (CI), adjusting for study center, age, smoking, ever employment in a job with known lung carcinogen exposure, and education. Trajectories in SIOPS categories from first to last and first to longest job were defined as consistent, downward, or upward. We conducted several subgroup and sensitivity analyses to assess the robustness of our results.

RESULTS

We observed increased lung cancer risk estimates for men with medium (OR = 1.23; 95 % CI 1.13-1.33) and low occupational prestige (OR = 1.44; 95 % CI 1.32-1.57). Although adjustment for smoking and education reduced the associations between occupational prestige and lung cancer, they did not explain the association entirely. Traditional occupational exposures reduced the associations only slightly. We observed small associations with downward prestige trajectories, with ORs of 1.13, 95 % CI 0.88-1.46 for high to low, and 1.24; 95 % CI 1.08-1.41 for medium to low trajectories.

CONCLUSIONS

Our results indicate that occupational prestige is independently associated with lung cancer among men.

Estimating and explaining the effect of education and income on head and neck cancer risk: INHANCE consortium pooled analysis of 31 case-control studies from 27 countries

Low socioeconomic status has been reported to be associated with head and neck cancer risk. However, previous studies have been too small to examine the associations by cancer subsite, age, sex, global region and calendar time and to explain the association in terms of behavioral risk factors. Individual participant data of 23,964 cases with head and neck cancer and 31,954 controls from 31 studies in 27 countries pooled with random effects models. Overall, low education was associated with an increased risk of head and neck cancer (OR = 2.50; 95% CI = 2.02 - 3.09). Overall one-third of the increased risk was not explained by differences in the distribution of cigarette smoking and alcohol behaviors; and it remained elevated among never users of tobacco and nondrinkers (OR = 1.61; 95% CI = 1.13 - 2.31). More of the estimated education effect was not explained by cigarette smoking and alcohol behaviors: in women than in men, in older than younger groups, in the oropharynx than in other sites, in South/Central America than in Europe/North America and was strongest in countries with greater income inequality. Similar findings were observed for the estimated effect of low versus high household income. The lowest levels of income and educational attainment were associated with more than 2-fold increased risk of head and neck cancer, which is not entirely explained by differences in the distributions of behavioral risk factors for these cancers and which varies across cancer sites, sexes, countries and country income inequality levels.

The environmental roots of non-communicable diseases (NCDs) and the epigenetic impacts of globalization

BACKGROUND

Non-communicable diseases (NCDs) are increasing worldwide. We hypothesize that environmental factors (including social adversity, diet, lack of physical activity and pollution) can become "embedded" in the biology of humans. We also hypothesize that the "embedding" partly occurs because of epigenetic changes, i.e., durable changes in gene expression patterns. Our concern is that once such factors have a foundation in human biology, they can affect human health (including NCDs) over a long period of time and across generations.

OBJECTIVES

To analyze how worldwide changes in movements of goods, persons and lifestyles (globalization) may affect the "epigenetic landscape" of populations and through this have an impact on NCDs. We provide examples of such changes and effects by discussing the potential epigenetic impact of socio-economic status, migration, and diet, as well as the impact of environmental factors influencing trends in age at puberty.

DISCUSSION

The study of durable changes in epigenetic patterns has the potential to influence policy and practice; for example, by enabling stratification of populations into those who could particularly benefit from early interventions to prevent NCDs, or by demonstrating mechanisms through which environmental factors influence disease risk, thus providing compelling evidence for policy makers, companies and the civil society at large. The current debate on the '25 × 25 strategy', a goal of 25% reduction in relative mortality from NCDs by 2025, makes the proposed approach even more timely.

CONCLUSIONS

Epigenetic modifications related to globalization may crucially contribute to explain current and future patterns of NCDs, and thus deserve attention from environmental researchers, public health experts, policy makers, and concerned citizens.

Pollution in the working place and social status: co-factors in lung cancer carcinogenesis

INTRODUCTION

Apart from the association with tobacco consumption, other factors of importance for prevention and early diagnosis of lung cancer have received little attention. We present a case-control study focusing on professional exposure to carcinogens and social status.

METHODS

A written questionnaire was completed by 551 consecutive patients with lung cancer and 494 patients with large bowel cancer. The groups were balanced regarding gender and age distribution. The questionnaire included data on place of birth, education, smoking history, diet and alcohol intake, body weight and height, occupation, housing conditions and family income. According to standard epidemiological criteria, professional exposure to carcinogens was classified as professions with exposure to confirmed lung cancer carcinogens, professions with exposure to suspected lung cancer carcinogens and other professions.

RESULTS

As expected, there were significant differences between the two groups regarding smoking status. While there were no significant differences in educational levels, more immigrants were among patients with lung cancer (17.9% vs 11.6%, p=0.005). On average, lung cancer patients had a lower body mass index (BMI) at 24.77, as compared to 26.14 for large bowel cancer (p=0.000). Lung cancer patients had lower income and poorer housing conditions; the bivariate difference was significant both for income levels (p=0.046) and type of residence (p=0.009). The proportion of patients working in professions with exposures to known carcinogens was 33.5% for lung cancer, and 17.1% for large bowel cancer (p=0.000). In the multivariate analysis, smoking (p=0.000), BMI (p=0.000) and type of occupation (p=0.001) were significant factors.

CONCLUSIONS

While there is no doubt about smoking in lung cancer carcinogenesis, professional exposure to carcinogens and belonging to lower socio-economic strata also play an important role.

Serum concentrations of club cell secretory protein (Clara) and cancer mortality in adults: a population-based, prospective cohort study

BACKGROUND

Club cell secretory protein (Clara) (CC16) is produced mainly by bronchiolar club cells and has been shown to have protective effects against airway inflammation and oxidative stress from cigarette smoking and related carcinogens. The goal of this study was to establish whether serum CC16 concentrations predict all-cause and cancer-specific mortality in adults.

METHODS

We used data from the population-based Tucson Epidemiological Study of Airway Obstructive Diseases (TESAOD), a prospective cohort study of respiratory health initiated in Tucson, AZ, USA, in 1972, that recruited a multistage stratified cluster sample of non-Hispanic white households. We measured serum CC16 concentrations in cryopreserved serum samples and reviewed vital status up to Jan 1, 2011, through contact with next of kin, collection of death certificates, and searches of the National Death Index. Our primary analysis was the relation of baseline serum CC16 to all-cause mortality or cause-specific mortality risk, analysed by adjusted Cox proportional hazards models.

FINDINGS

1086 TESAOD participants aged 21-70 years at enrolment were eligible for inclusion. Of these, 653 (60%) had died by 2011, and cause of death was ascertained for 649 (99%). When adjusted for sex, age, education, body-mass index, smoking and pack-years, and baseline levels of lung function, serum CC16 concentrations at baseline were inversely associated with mortality risk over the study follow-up. Mortality risk increased for each 1-SD decrease in CC16 (adjusted hazard ratio [HR] 1·16 [95% CI 1·06-1·26]; p=0·0007). For cause-specific mortality, each 1-SD decrease in serum CC16 was associated with an increased risk of dying of cancer (adjusted HR 1·41 [1·19-1·67]; p<0·0001). In the subset of smokers, the corresponding adjusted HR for mortality by lung cancer was 1·52 (1·14-2·03; p=0·004).

INTERPRETATION

Serum CC16 concentrations can predict mortality risk in the general adult population. The excess risk associated with lower CC16 concentrations is predominantly driven by cancer, particularly lung cancer.

FUNDING

National Heart, Lung, and Blood Institute.

Work characteristics, socioeconomic position and health: a systematic review of mediation and moderation effects in prospective studies

Social inequalities in health persist in modern societies. The contribution of adverse work and employment conditions towards their explanation is analysed by two approaches, mediation and moderation. Yet the relative significance of each approach remains unclear in respective research. We set out to study this question by conducting a systematic literature review. We included all original papers based on prospective observational studies of employed cohorts that were published between January 1980 and October 2012 meeting our search criteria, by using major databases and by observing established quality criteria. 26 reports were included after quality assessment. 17 studies examined the mediation hypothesis and nine studies tested the moderation hypothesis. Moderate support was found for the mediation hypothesis where OR or HR of health according to socioeconomic position (SEP) were reduced in a majority of analyses after introducing work characteristics in multivariate models. Evidence in favour of the moderation hypothesis was found in some studies, demonstrating stronger effects of adverse work on health among people with low SEP. Despite some support in favour of the two hypotheses future research should aim at reducing the heterogeneity in defining and measuring core variables and at applying advanced statistical analyses. Policy recommendations would benefit from a higher degree of consistency of respective research evidence.

"Normative content" and health inequity enculturation: a logic model of men's health advocacy

Epidemiologic studies and related literature consistently report that males have fewer years of life expectancy than females. Moreover, males experience fewer quality years of life in that they tend to live with greater rates of morbidity such as heart disease, cancer, and diabetes among other conditions. Causal evidence traditionally highlights the role of biology in determining the life course for males. However, emerging literature suggests that social determinants of health play a more central role in male morbidity and mortality, and thus contribute to health inequities between the sexes. The purpose of this article is to explore core concepts of social determinants of health as they pertain to male health inequities and provide a systematic conceptualization of how society has become encultured to view these inequities as "normative." Strategies to improve male health are discussed using a logic model to illustrate male health advocacy in the face of the social climes of encultured health inequities.

Social inequalities and mortality in Europe--results from a large multi-national cohort

BACKGROUND

Socio-economic inequalities in mortality are observed at the country level in both North America and Europe. The purpose of this work is to investigate the contribution of specific risk factors to social inequalities in cause-specific mortality using a large multi-country cohort of Europeans.

METHODS

A total of 3,456,689 person/years follow-up of the European Prospective Investigation into Cancer and Nutrition (EPIC) was analysed. Educational level of subjects coming from 9 European countries was recorded as proxy for socio-economic status (SES). Cox proportional hazard model's with a step-wise inclusion of explanatory variables were used to explore the association between SES and mortality; a Relative Index of Inequality (RII) was calculated as measure of relative inequality.

RESULTS

Total mortality among men with the highest education level is reduced by 43% compared to men with the lowest (HR 0.57, 95% C.I. 0.52-0.61); among women by 29% (HR 0.71, 95% C.I. 0.64-0.78). The risk reduction was attenuated by 7% in men and 3% in women by the introduction of smoking and to a lesser extent (2% in men and 3% in women) by introducing body mass index and additional explanatory variables (alcohol consumption, leisure physical activity, fruit and vegetable intake) (3% in men and 5% in women). Social inequalities were highly statistically significant for all causes of death examined in men. In women, social inequalities were less strong, but statistically significant for all causes of death except for cancer-related mortality and injuries.

DISCUSSION

In this European study, substantial social inequalities in mortality among European men and women which cannot be fully explained away by accounting for known common risk factors for chronic diseases are reported.

Why do males in Scotland die younger than those in England? Evidence from three prospective cohort studies

BACKGROUND

To examine explanations for the higher rates of male mortality in two Scottish cohorts compared with a cohort in south-east England for which similar data were collected.

METHODOLOGY/PRINCIPAL FINDINGS

We compared three cohort studies which recruited participants in the late 1960s and early 1970s. A total of 13,884 men aged 45-64 years at recruitment in the Whitehall occupational cohort (south-east England), 3,956 men in the Collaborative occupational cohort and 6,813 men in the Renfrew & Paisley population-based study (both central Scotland) were included in analyses of all-cause and cause-specific mortality. All-cause mortality was 25% (age-adjusted hazard ratio 1.25, 95% confidence interval (CI)1.21 to 1.30) and 41% (hazard ratio 1.41 (95% CI 1.36 to 1.45) higher in the Collaborative and Renfrew & Paisley cohorts respectively compared to the Whitehall cohort. The higher mortality rates were substantially attenuated by social class (to 8% and 17% higher respectively), and were effectively eliminated upon the further addition of the other baseline risk factors, such as smoking habit, lung function and pre-existing self-reported morbidity. Despite this, coronary heart disease mortality remained 11% and 16% higher, stroke mortality 45% and 37% higher, mortality from accidents and suicide 51% and 70% higher, and alcohol-related mortality 46% and 73% higher in the Collaborative and Renfrew & Paisley cohorts respectively compared with the Whitehall cohort in the fully adjusted model.

CONCLUSIONS/SIGNIFICANCE

The higher all-cause, respiratory, and lung cancer male mortality in the Scottish cohorts was almost entirely explained by social class differences and higher prevalence of known risk factors, but reasons for the excess mortality from stroke, alcohol-related causes, accidents and suicide remained unknown.

The socioeconomic determinants of cancer

This paper provides a synthesis on socioeconomic inequalities in cancer incidence, mortality and survival across countries and within countries, with particular focus on the Italian context; the paper also describes the underlying mechanisms documented for cancer incidence, and reports some remarks on policies to tackle inequalities.From a worldwide perspective, the burden of cancer appears to be particularly increasing in developing countries, where many cancers with a poor prognosis (liver, stomach and oesophagus) are much more common than in richer countries. As in the case of incidence and mortality, also in cancer survival we observe a great variability across countries. Different studies have suggested a possible impact of health care on the social gradients in cancer survival, even in countries with a National Health System providing equitable access to care.In developed countries, there is increasing awareness of social inequalities as an important public health issue; as a consequence, there is a variety of strategies and policies being implemented throughout Europe. However, recent reviews emphasize that present knowledge on effectiveness of policies and interventions on health inequalities is not sufficient to offer a robust and evidence-based guide to the choice and design of interventions, and that more evaluation studies are needed.The large disparities in health that we can measure within and between countries represent a challenge to the world; social health inequalities are avoidable, and their reduction therefore represents an achievable goal and an ethical imperative.