Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure–response relationships

Objectives: The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure-response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints. Methods: Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure-response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. Results: SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates. Conclusion: The established exposure-response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of exposure-response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM

Occupational Benzene Exposure and Lung Cancer Risk: A Pooled Analysis of 14 Case-Control Studies

Rationale: Benzene has been classified as carcinogenic to humans, but there is limited evidence linking benzene exposure to lung cancer. Objectives: We aimed to examine the relationship between occupational benzene exposure and lung cancer. Methods: Subjects from 14 case-control studies across Europe and Canada were pooled. We used a quantitative job-exposure matrix to estimate benzene exposure. Logistic regression models assessed lung cancer risk across different exposure indices. We adjusted for smoking and five main occupational lung carcinogens and stratified analyses by smoking status and lung cancer subtypes. Measurements and Main Results: Analyses included 28,048 subjects (12,329 cases, 15,719 control subjects). Lung cancer odds ratios ranged from 1.12 (95% confidence interval, 1.03-1.22) to 1.32 (95% confidence interval, 1.18-1.48) (Ptrend = 0.002) for groups with the lowest and highest cumulative occupational exposures, respectively, compared with unexposed subjects. We observed an increasing trend of lung cancer with longer duration of exposure (Ptrend < 0.001) and a decreasing trend with longer time since last exposure (Ptrend = 0.02). These effects were seen for all lung cancer subtypes, regardless of smoking status, and were not influenced by specific occupational groups, exposures, or studies. Conclusions: We found consistent and robust associations between different dimensions of occupational benzene exposure and lung cancer after adjusting for smoking and main occupational lung carcinogens. These associations were observed across different subgroups, including nonsmokers. Our findings support the hypothesis that occupational benzene exposure increases the risk of developing lung cancer. Consequently, there is a need to revisit published epidemiological and molecular data on the pulmonary carcinogenicity of benzene

Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure–response relationships

Objectives The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure–response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints. Methods Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure–response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. Results SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates. Conclusion The established exposure–response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of expo-sure–response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM

Occupational Benzene Exposure and Lung Cancer Risk: A Pooled Analysis of 14 Case-Control Studies.

RationaleBenzene has been classified as carcinogenic to humans, but there is limited evidence linking benzene exposure to lung cancer.ObjectivesWe aimed to examine the relationship between occupational benzene exposure and lung cancer.MethodsSubjects from 14 case-control studies across Europe and Canada were pooled. We used a quantitative job-exposure matrix to estimate benzene exposure. Logistic regression models assessed lung cancer risk across different exposure indices. We adjusted for smoking and five main occupational lung carcinogens and stratified analyses by smoking status and lung cancer subtypes.Measurements and main resultsAnalyses included 28048 subjects (12329 cases, 15719 controls). Lung cancer odds ratios ranged from 1.12 (95% CI: 1.03-1.22) to 1.32 (95% CI: 1.18-1.48) (Ptrend=0.002) for groups with the lowest and highest cumulative occupational exposure, respectively, compared to unexposed subjects. We observed an increasing trend of lung cancer with longer duration of exposure (PtrendPtrend=0.02). These effects were seen for all lung cancer subtypes, regardless of smoking status, and were not influenced by specific occupational groups, exposures, or studies.ConclusionWe found consistent and robust associations between different dimensions of occupational benzene exposure and lung cancer after adjusting for smoking and main occupational lung carcinogens. These associations were observed across different subgroups, including non-smokers. Our findings support the hypothesis that occupational benzene exposure increases the risk of developing lung cancer. Consequently, there is a need to revisit published epidemiological and molecular data on the pulmonary carcinogenicity of benzene

Lung Cancer Risks Associated with Occupational Exposure to Pairs of Five Lung Carcinogens: Results from a Pooled Analysis of Case-Control Studies (SYNERGY)

BACKGROUND: While much research has been done to identify individual workplace lung carcinogens, little is known about joint effects on risk when workers are exposed to multiple agents. OBJECTIVES: We investigated the pairwise joint effects of occupational exposures to asbestos, respirable crystalline silica, metals (i.e., nickel, chromium-VI), and polycyclic aromatic hydrocarbons (PAH) on lung cancer risk, overall and by major histologic subtype, while accounting for cigarette smoking.and the general environment. METHODS: In the international 14-center SYNERGY project, occupational exposures were assigned to 16,901 lung cancer cases and 20,965 control subjects using a quantitative job-exposure matrix (SYN-JEM). Odds ratios (ORs) and 95% confidence intervals (CIs) were computed for ever vs. never exposure using logistic regression models stratified by sex and adjusted for study center, age, and smoking habits. Joint effects among pairs of agents were assessed on multiplicative and additive scales, the latter by calculating the relative excess risk due to interaction (RERI). RESULTS: All pairwise joint effects of lung carcinogens in men were associated with an increased risk of lung cancer. However, asbestos/metals and metals/PAH resulted in less than additive effects; while the chromium-VI/silica pair showed marginally synergistic effect in relation to adenocarci-noma (RERI: 0.24; CI: 0.02, 0.46; p = 0.05). In women, several pairwise joint effects were observed for small cell lung cancer including exposure to PAH/silica (OR = 5.12; CI: 1.77, 8.48), and to asbestos/silica (OR = 4.32; CI: 1.35, 7.29), where exposure to PAH/silica resulted in a synergistic effect (RERI: 3.45; CI: 0.10, 6.8). DISCUSSION: Small or no deviation from additive or multiplicative effects was observed, but co-exposure to the selected lung carcinogens resulted generally in higher risk than exposure to individual agents, highlighting the importance to reduce and control exposure to carcinogens in workplaces

Respirable crystalline silica and lung cancer in community-based studies: impact of job-exposure matrix specifications on exposure-response relationships

OBJECTIVES: The quantitative job-exposure matrix SYN-JEM consists of various dimensions: job-specific estimates, region-specific estimates, and prior expert ratings of jobs by the semi-quantitative DOM-JEM. We analyzed the effect of different JEM dimensions on the exposure-response relationships between occupational silica exposure and lung cancer risk to investigate how these variations influence estimates of exposure by a quantitative JEM and associated health endpoints. METHODS: Using SYN-JEM, and alternative SYN-JEM specifications with varying dimensions included, cumulative silica exposure estimates were assigned to 16 901 lung cancer cases and 20 965 controls pooled from 14 international community-based case-control studies. Exposure-response relationships based on SYN-JEM and alternative SYN-JEM specifications were analyzed using regression analyses (by quartiles and log-transformed continuous silica exposure) and generalized additive models (GAM), adjusted for age, sex, study, cigarette pack-years, time since quitting smoking, and ever employment in occupations with established lung cancer risk. RESULTS: SYN-JEM and alternative specifications generated overall elevated and similar lung cancer odds ratios ranging from 1.13 (1st quartile) to 1.50 (4th quartile). In the categorical and log-linear analyses SYN-JEM with all dimensions included yielded the best model fit, and exclusion of job-specific estimates from SYN-JEM yielded the poorest model fit. Additionally, GAM showed the poorest model fit when excluding job-specific estimates. CONCLUSION: The established exposure-response relationship between occupational silica exposure and lung cancer was marginally influenced by varying the dimensions of SYN-JEM. Optimized modelling of exposure-response relationships will be obtained when incorporating all relevant dimensions, namely prior rating, job, time, and region. Quantitative job-specific estimates appeared to be the most prominent dimension for this general population JEM

Occupational Exposure to Solvants and Risk of Head and Neck Cancer

Contexte : Le rôle de l’exposition professionnelle aux solvants dans la survenue de cancers des voies aéro-digestives supérieures (VADS), suggéré dans quelques études, n’a été que peu examiné, malgré leur utilisation très répandue en milieu de travail. Objectif : L’objectif de cette thèse état d’évaluer les associations entre les expositions professionnelles aux solvants et le risque de cancer des VADS. Méthodes : Ce travail est basé sur les données de l’étude Icare, une large étude cas-témoins en population générale conduite en France entre 2001-2007. L’analyse a été restreinte aux hommes et a porté sur 1857 cas de carcinome épidermoïde de la cavité buccale, du pharynx et du larynx, et 2780 témoins. L’histoire professionnelle détaillée ainsi que les consommations de tabac et d’alcool ont été recueillies par questionnaire. Les expositions aux solvants ont été évaluées à l’aide de matrices emplois-expositions et incluaient cinq solvants chlorés (perchloroéthylène, trichloroéthylène, chlorure de méthylène, chloroforme, tétrachlorure de carbone), cinq solvants pétroliers (benzène ; essences carburant ; gazole, fiouls et kérosène ; essences spéciales ; white spirits) et cinq solvants oxygénés (cétones et esters ; alcools ; éther éthylique ; éthylène glycol ; tétrahydrofurane). Les odds-ratios ajustés sur les consommations de tabac et d’alcool et d’autres facteurs de confusion potentiels, et les intervalles de confiances à 95% ont été estimés par régression logistique. Résultats : Aucune association significative n’a été mise en évidence entre exposition professionnelle aux solvants chlorés, pétroliers et oxygénés étudiés et le risque de cancer de l’ensemble des VADS. Dans l’analyse par localisation, le risque de cancer du larynx augmentait significativement avec l’exposition cumulée au perchloroéthylène. Des risques élevés de cancer de l’hypopharynx, bien que non significatifs, étaient observés pour les hommes exposés à des niveaux élevés de chlorure de méthylène, de white spirits et de tétrahydrofurane. Une association entre exposition au tétrahydrofurane et cancer de la cavité buccale était également suggérée. Aucune association claire n’était observée pour les autres solvants, quelle que soit la localisation de cancer. Conclusion : Des associations positives ont été observées avec plusieurs solvants spécifiques. Toutefois, dans l’ensemble, nos résultats ne sont pas en faveur d’un rôle majeur de l’exposition aux solvants dans la survenue de cancer des VADS.Background : The role of occupational exposure to solvents in the risk of head and neck cancer has been suggested in some studies but has been few investigated, despite their widespread use in the workplace. Objective: The objective of this thesis was to examine the associations between occupational exposure to solvents and the risk of head and neck cancer. Methods: This work is based on data from the ICARE study, a large population-based case-control study conducted in France between 2001 and 2007. The analysis was restricted to men and included 1,857 cases of squamous cell carcinoma of the oral cavity, pharynx and larynx and 2,780 controls. Detailed occupational lifetime as well as alcohol and tobacco consumptions were collected by questionnaires. Exposure to solvents was assessed by job exposure matrices and included five chlorinated solvents (perchloroethylene, trichloroethylene, methylene chloride, chloroform, carbon tetrachloride), five petroleum-based solvents (benzene; gasoline; diesel, fuels and kerosene; special petroleum products; white spirits) and five oxygenated solvents (ketones and esters; alcohols; diethyl ether; ethylene glycol; tetrahydrofuran). Odds-ratios adjusted for smoking, alcohol drinking and other potential confounders and 95% confidence intervals were estimated with logistic models. Results: No significant association was found between occupational exposure to chlorinated, petroleum-based and oxygenated solvents and the risk of head and neck cancer overall. In subsite analysis, the risk of laryngeal cancer increased with cumulative exposure to perchloroethylene. Non-significantly elevated risks of hypopharyngeal cancer were found in men exposed to high cumulative levels of methylene chloride, white spirits and tetrahydrofuran. An association between exposure to tetrahydrofuran and oral cavity cancer was also suggested. No other clear association was found for the other solvents under study, for any cancer site. Conclusion: Although positive associations were observed for several solvents, overall the results do not suggest a substantial role of exposure to solvents in head and neck cancer risk

Exposition professionnelle aux solvants et risque de cancer des voies aéro-digestives supérieures

Background : The role of occupational exposure to solvents in the risk of head and neck cancer has been suggested in some studies but has been few investigated, despite their widespread use in the workplace. Objective: The objective of this thesis was to examine the associations between occupational exposure to solvents and the risk of head and neck cancer. Methods: This work is based on data from the ICARE study, a large population-based case-control study conducted in France between 2001 and 2007. The analysis was restricted to men and included 1,857 cases of squamous cell carcinoma of the oral cavity, pharynx and larynx and 2,780 controls. Detailed occupational lifetime as well as alcohol and tobacco consumptions were collected by questionnaires. Exposure to solvents was assessed by job exposure matrices and included five chlorinated solvents (perchloroethylene, trichloroethylene, methylene chloride, chloroform, carbon tetrachloride), five petroleum-based solvents (benzene; gasoline; diesel, fuels and kerosene; special petroleum products; white spirits) and five oxygenated solvents (ketones and esters; alcohols; diethyl ether; ethylene glycol; tetrahydrofuran). Odds-ratios adjusted for smoking, alcohol drinking and other potential confounders and 95% confidence intervals were estimated with logistic models. Results: No significant association was found between occupational exposure to chlorinated, petroleum-based and oxygenated solvents and the risk of head and neck cancer overall. In subsite analysis, the risk of laryngeal cancer increased with cumulative exposure to perchloroethylene. Non-significantly elevated risks of hypopharyngeal cancer were found in men exposed to high cumulative levels of methylene chloride, white spirits and tetrahydrofuran. An association between exposure to tetrahydrofuran and oral cavity cancer was also suggested. No other clear association was found for the other solvents under study, for any cancer site. Conclusion: Although positive associations were observed for several solvents, overall the results do not suggest a substantial role of exposure to solvents in head and neck cancer risk.Contexte : Le rôle de l’exposition professionnelle aux solvants dans la survenue de cancers des voies aéro-digestives supérieures (VADS), suggéré dans quelques études, n’a été que peu examiné, malgré leur utilisation très répandue en milieu de travail. Objectif : L’objectif de cette thèse état d’évaluer les associations entre les expositions professionnelles aux solvants et le risque de cancer des VADS. Méthodes : Ce travail est basé sur les données de l’étude Icare, une large étude cas-témoins en population générale conduite en France entre 2001-2007. L’analyse a été restreinte aux hommes et a porté sur 1857 cas de carcinome épidermoïde de la cavité buccale, du pharynx et du larynx, et 2780 témoins. L’histoire professionnelle détaillée ainsi que les consommations de tabac et d’alcool ont été recueillies par questionnaire. Les expositions aux solvants ont été évaluées à l’aide de matrices emplois-expositions et incluaient cinq solvants chlorés (perchloroéthylène, trichloroéthylène, chlorure de méthylène, chloroforme, tétrachlorure de carbone), cinq solvants pétroliers (benzène ; essences carburant ; gazole, fiouls et kérosène ; essences spéciales ; white spirits) et cinq solvants oxygénés (cétones et esters ; alcools ; éther éthylique ; éthylène glycol ; tétrahydrofurane). Les odds-ratios ajustés sur les consommations de tabac et d’alcool et d’autres facteurs de confusion potentiels, et les intervalles de confiances à 95% ont été estimés par régression logistique. Résultats : Aucune association significative n’a été mise en évidence entre exposition professionnelle aux solvants chlorés, pétroliers et oxygénés étudiés et le risque de cancer de l’ensemble des VADS. Dans l’analyse par localisation, le risque de cancer du larynx augmentait significativement avec l’exposition cumulée au perchloroéthylène. Des risques élevés de cancer de l’hypopharynx, bien que non significatifs, étaient observés pour les hommes exposés à des niveaux élevés de chlorure de méthylène, de white spirits et de tétrahydrofurane. Une association entre exposition au tétrahydrofurane et cancer de la cavité buccale était également suggérée. Aucune association claire n’était observée pour les autres solvants, quelle que soit la localisation de cancer. Conclusion : Des associations positives ont été observées avec plusieurs solvants spécifiques. Toutefois, dans l’ensemble, nos résultats ne sont pas en faveur d’un rôle majeur de l’exposition aux solvants dans la survenue de cancer des VADS

P-87 Are asbestos and strong inorganic acid mists the only occupational exposures that increase laryngeal cancer risk in the construction industry?

International audienc

Night-Shift Work and Risk of Prostate Cancer: Results From a Canadian Case-Control Study, the Prostate Cancer and Environment Study

International audienceNightshift work involving circadian disruption has been associated with breast cancer risk. A role in prostate cancer is also suspected but evidence is limited. We investigated the association between nightshift work and prostate cancer incidence in the Prostate Cancer and Environment Study (PROtEuS), a population-based case-control study conducted in 2005-2012 in Montreal, Canada. Participants were 1,904 prostate cancer cases (432 high-grade cancers) and 1,965 population controls. Detailed work schedules for each job held at least 2 years (n =15,724) were elicited in face-to-face interviews. Nightshift work was defined as having ever worked ≥3 hours between midnight and 5:00 a.m., for ≥1 year, ≥3 nights/month. Unconditional logistic regression estimated odds ratios and 95% confidence intervals for the association between nightshift work and prostate cancer, adjusting for age, ancestry and education. No association was found between overall prostate cancer and nightshift work metrics including ever exposure, duration, intensity, cumulative exposure, rotating and early morning shifts. For none of the exposure indices was there evidence of heterogeneity in ORs between low- and high-grade cancers. Sensitivity analyses restricting exposures to ≥7 nights/month or considering the screening history yielded similar results. Our findings lend no support for a major role of nightshift work in prostate cancer development