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.

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. 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 adenocarcinoma (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 and the general environment. https://doi.org/10.1289/EHP13380.

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.

Genetic Analysis of Lung Cancer and the Germline Impact on Somatic Mutation Burden.

BACKGROUND: Germline genetic variation contributes to lung cancer (LC) susceptibility. Previous genome-wide association studies (GWAS) have implicated susceptibility loci involved in smoking behaviors and DNA repair genes, but further work is required to identify susceptibility variants. METHODS: To identify LC susceptibility loci, a family history-based genome-wide association by proxy (GWAx) of LC (48 843 European proxy LC patients, 195 387 controls) was combined with a previous LC GWAS (29 266 patients, 56 450 controls) by meta-analysis. Colocalization was used to explore candidate genes and overlap with existing traits at discovered susceptibility loci. Polygenic risk scores (PRS) were tested within an independent validation cohort (1 666 LC patients vs 6 664 controls) using variants selected from the LC susceptibility loci and a novel selection approach using published GWAS summary statistics. Finally, the effects of the LC PRS on somatic mutational burden were explored in patients whose tumor resections have been profiled by exome (n = 685) and genome sequencing (n = 61). Statistical tests were 2-sided. RESULTS: The GWAx-GWAS meta-analysis identified 8 novel LC loci. Colocalization implicated DNA repair genes (CHEK1), metabolic genes (CYP1A1), and smoking propensity genes (CHRNA4 and CHRNB2). PRS analysis demonstrated that these variants, as well as subgenome-wide significant variants related to expression quantitative trait loci and/or smoking propensity, assisted in LC genetic risk prediction (odds ratio = 1.37, 95% confidence interval = 1.29 to 1.45; P < .001). Patients with higher genetic PRS loads of smoking-related variants tended to have higher mutation burdens in their lung tumors. CONCLUSIONS: This study has expanded the number of LC susceptibility loci and provided insights into the molecular mechanisms by which these susceptibility variants contribute to LC development.

Oral health, dental care and mouthwash associated with upper aerodigestive tract cancer risk in Europe: the ARCAGE study.

OBJECTIVE: We aimed to assess the association of oral health (OH), dental care (DC) and mouthwash with upper-aerodigestive tract (UADT) cancer risk, and to examine the extent that enzymes involved in the metabolism of alcohol modify the effect of mouthwash. MATERIALS AND METHODS: The study included 1963 patients with incident cancer of the oral cavity, oropharynx, hypopharynx, larynx or esophagus and 1993 controls. Subjects were interviewed about their oral health and dental care behaviors (which were converted to scores of OH and DC respectively), as well as smoking, alcohol drinking, diet, occupations, medical conditions and socio-economic status. Blood samples were taken for genetic analyses. Mouthwash use was analyzed in relation to the presence of polymorphisms of alcohol-metabolizing genes known to be associated with UADT. Adjusted odds ratios (ORs) and 95%-confidence intervals [CI] were estimated with multiple logistic regression models adjusting for multiple confounders. RESULTS: Fully adjusted ORs of low versus high scores of DC and OH were 2.36[CI=1.51-3.67] and 2.22[CI=1.45-3.41], respectively, for all UADT sites combined. The OR for frequent use of mouthwash use (3 or more times/day) was 3.23[CI=1.68-6.19]. The OR for the rare variant ADH7 (coding for fast ethanol metabolism) was lower in mouthwash-users (OR=0.53[CI=0.35-0.81]) as compared to never-users (OR=0.97[CI=0.73-1.29]) indicating effect modification (pheterogeneity=0.065) while no relevant differences were observed between users and non-users for the variant alleles of ADH1B, ADH1C or ALDH2. CONCLUSIONS: Poor OH and DC seem to be independent risk factors for UADT because corresponding risk estimates remain substantially elevated after detailed adjustment for multiple confounders. Whether mouthwash use may entail some risk through the alcohol content in most formulations on the market remains to be fully clarified.

Previous lung diseases and lung cancer risk: a pooled analysis from the International Lung Cancer Consortium.

To clarify the role of previous lung diseases (chronic bronchitis, emphysema, pneumonia, and tuberculosis) in the development of lung cancer, the authors conducted a pooled analysis of studies in the International Lung Cancer Consortium. Seventeen studies including 24,607 cases and 81,829 controls (noncases), mainly conducted in Europe and North America, were included (1984-2011). Using self-reported data on previous diagnoses of lung diseases, the authors derived study-specific effect estimates by means of logistic regression models or Cox proportional hazards models adjusted for age, sex, and cumulative tobacco smoking. Estimates were pooled using random-effects models. Analyses stratified by smoking status and histology were also conducted. A history of emphysema conferred a 2.44-fold increased risk of lung cancer (95% confidence interval (CI): 1.64, 3.62 (16 studies)). A history of chronic bronchitis conferred a relative risk of 1.47 (95% CI: 1.29, 1.68 (13 studies)). Tuberculosis (relative risk = 1.48, 95% CI: 1.17, 1.87 (16 studies)) and pneumonia (relative risk = 1.57, 95% CI: 1.22, 2.01 (12 studies)) were also associated with lung cancer risk. Among never smokers, elevated risks were observed for emphysema, pneumonia, and tuberculosis. These results suggest that previous lung diseases influence lung cancer risk independently of tobacco use and that these diseases are important for assessing individual risk.

Risk of upper aerodigestive tract cancer and type of alcoholic beverage: a European multicenter case-control study.

The general relationship between cancers of the upper aerodigestive tract (UADT) and alcohol drinking is established. Nevertheless, it is uncertain whether different types of alcoholic beverages (wine, beer and liquor) carry different UADT cancer risks. Our study included 2,001 UADT cancer cases and 2,125 controls from 14 centres in 10 European countries. All cases were histologically or cytologically confirmed squamous cell carcinomas. Controls were frequency matched by sex, age and centre. Logistic regression models were used to estimate odds ratios (OR) and 95 % confidence intervals (95 %CI) adjusted for age, sex, centre, education level, vegetable and fruit intake, tobacco smoking and alcohol drinking, where appropriate. Risk of beverage-specific alcohol consumption were calculated among 'pure drinker' who consumed one beverage type exclusively, among 'predominant drinkers' who consumed one beverage type to more than 66 % and among 'mixed drinkers' who consumed more than one beverage type to similar proportions. Compared to never drinkers and adjusted for cumulative alcohol consumption, the OR and 95 %CI for wine, beer and liquor drinking, respectively, were 1.24 (0.86, 1.78), 1.54 (1.05, 2.27) and 0.94 (0.53, 1.64) among 'pure drinkers' (p value for heterogeneity across beverage types = 0.306), 1.05 (0.76,1.47), 1.25 (0.87,1.79) and 1.43 (0.95, 2.16) among 'predominant drinkers' (p value = 0.456), and 1.09 (0.79, 1.50), 1.20 (0.88, 1.63) and 1.12 (0.82, 1.53) among 'mixed drinkers' (p value = 0.889). Risk of UADT cancer increased with increasing consumption of all three alcohol beverage types. Our findings underscore the strong and comparable carcinogenic effect of ethanol in wine, beer and liquor on organs of the UADT.

Occupation and risk of upper aerodigestive tract cancer: the ARCAGE study.

We investigated the association between occupational history and upper aerodigestive tract (UADT) cancer risk in the ARCAGE European case-control study. The study included 1,851 patients with incident cancer of the oral cavity, oropharynx, hypopharynx, larynx or esophagus and 1,949 controls. We estimated odds ratios (OR) and 95% confidence intervals (CI) for ever employment in 283 occupations and 172 industries, adjusting for smoking and alcohol. Men (1,457 cases) and women (394 cases) were analyzed separately and we incorporated a semi-Bayes adjustment approach for multiple comparisons. Among men, we found increased risks for occupational categories previously reported to be associated with at least one type of UADT cancer, including painters (OR = 1.74, 95% CI: 1.01-3.00), bricklayers (1.58, 1.05-2.37), workers employed in the erection of roofs and frames (2.62, 1.08-6.36), reinforced concreters (3.46, 1.11-10.8), dockers (2.91, 1.05-8.05) and workers employed in the construction of roads (3.03, 1.23-7.46), general construction of buildings (1.44, 1.12-1.85) and cargo handling (2.60, 1.17-5.75). With the exception of the first three categories, risks both increased when restricting to long duration of employment and remained elevated after semi-Bayes adjustment. Increased risks were also found for loggers (3.56, 1.20-10.5) and cattle and dairy farming (3.60, 1.15-11.2). Among women, there was no clear evidence of increased risks of UADT cancer in association with occupations or industrial activities. This study provides evidence of an association between some occupational categories and UADT cancer risk among men. The most consistent findings, also supported by previous studies, were obtained for specific workers employed in the construction industry.

Vaccination of patients with diabetes mellitus--a retrospective study.

402 subjects with diabetes mellitus have been vaccinated of the total of 34,000 vaccinees immunized during the study period of 9 and half months. Altogether 229 diabetic patients (56.97%) have been vaccinated'against tick-borne encephalitis (TBE) and 74 (18.4%) against viral hepatitis (41 types A+B, 30 type A, 3 type B). The average age in four most commonly administered vaccines (FSME IMMUN 0.5 ML, Twinrix Adult, Typhim Vi, and Havrix 1440) was 65, 52, 56, and 54 years, respectively. Live attenuated vaccines have been given to 6 patients with diabetes (1.49%)--- 5 travellers to endemic countries received the yellow fever vaccine Stamaril (1 female, 4 male) and one male patient varicella vaccine Varilrix. Among the least common vaccines in diabetic patients were those against invasive pneumococcal and meningococcal infections. Not a single unexpected side effect has been observed following the vaccination procedure in any diabetic patient. Based on the results of this retrospective study we can conclude that vaccination in diabetic patients is free of any ri-k- provided that there are no other contraindications, e.g. allergy to vaccine components or severe acute febrile illness. In the case of unstable glycaemia and significantly impaired immune system due to diabetes mellitus, vaccination with live attenuated vaccines should be carefully considered and measured against the risks of exposure to each and every specific infectious agent. There is no reason to be afraid of vaccination in diabetic patients provided that general contraindications are respected. On the contrary, this risk group can benefit from vaccination more remarkably since it may have some life-saving potential.

Population attributable risk of tobacco and alcohol for upper aerodigestive tract cancer.

Tobacco and alcohol are major risk factors for upper aerodigestive tract (UADT) cancer and significant variation is observed in UADT cancer rates across Europe. We have estimated the proportion of UADT cancer burden explained by tobacco and alcohol and how this varies with the incidence rates across Europe, cancer sub-site, gender and age. This should help estimate the minimum residual burden of other risk factors to UADT cancer, including human papillomavirus. We analysed 1981 UADT cancer cases and 1993 controls from the ARCAGE multicentre study. We estimated the population attributable risk (PAR) of tobacco alone, alcohol alone and their joint effect. Tobacco and alcohol together explained 73% of UADT cancer burden of which nearly 29% was explained by smoking alone, less than 1% due to alcohol on its own and 44% by the joint effect of tobacco and alcohol. Tobacco and alcohol together explained a larger proportion of hypopharyngeal/laryngeal cancer (PAR=85%) than oropharyngeal (PAR=74%), esophageal (PAR=67%) and oral cancer (PAR=61%). Tobacco and alcohol together explain only about half of the total UADT cancer burden among women. Geographically, tobacco and alcohol explained a larger proportion of UADT cancer in central (PAR=84%) than southern (PAR=72%) and western Europe (PAR=67%). While the majority of the UADT cancers in Europe are due to tobacco or the joint effect of tobacco and alcohol, our results support a significant role for other risk factors in particular, for oral and oropharyngeal cancers and also for UADT cancers in southern and western Europe.

Superoxide dismutase and nicotinamide adenine dinucleotide phosphate: quinone oxidoreductase polymorphisms and pancreatic cancer risk.

OBJECTIVES: Pancreatic carcinoma etiology and molecular pathogenesis is weakly understood. According to the assumption that genetic variation in carcinogen metabolism further modifies the risk of exposure-related cancers, an association of functional polymorphisms in oxidative stress-modifying genes superoxide dismutase 2 (SOD2 [Ala16Val, rs4880]), SOD3 (Arg231Gly, rs1799895), nicotinamide adenine dinucleotide phosphate:quinone oxidoreductase (NQO1 [Pro187Ser, rs1800566], and NQO2 (Phe47Leu, rs1143684) with pancreatic cancer risk was studied. METHODS: Polymorphisms were studied by allelic discrimination. RESULTS: In a hospital-based case-control study on 500 individuals (235 cases and 265 controls) of Czech white origin, SOD2, SOD3, NQO1, and NQO2 polymorphisms showed no significant association with pancreatic cancer risk. Major lifestyle factors such as smoking and alcohol, coffee, or tea consumption did not modify the effect of the studied polymorphisms. CONCLUSIONS: The first European study of the SOD2, SOD3, NQO1, and NQO2 roles in pancreatic cancer etiology did not find significant associations. Despite this observation, other populations with different lifestyle(s) may be at risk and should be further studied.

The aetiology of upper aerodigestive tract cancers among young adults in Europe: the ARCAGE study.

BACKGROUND: The incidence of cancers of the upper aerodigestive tract (UADT) is increasing throughout the world. To date the increases have been proportionally greatest among young people. Several reports have suggested that they often do not have a history of tobacco smoking or heavy alcohol consumption. OBJECTIVE: To determine the contribution of lifestyle factors to the etiology of UADT cancers occurring in those aged less than 50 years. METHODS: A case-control study was conducted in 10 European countries. Cases were cancers of the oral cavity and pharynx, larynx and esophagus, and hospital or population controls were age and sex matched. RESULTS: There were 356 cases younger than 50 years and 419 controls. Risk was strongly related to current smoking [odds ratio (OR) 5.5 95%; confidence interval (CI) (3.3, 9.2)], and risk increased with number of pack-years smoked. Risk was also related to alcohol consumption for both current (OR 1.8; 0.97, 3.3) and past (OR 3.4; 1.6, 7.4) drinkers, and risk increased with number of drink-years. Persons frequently consuming fruits and vegetables were at significantly reduced risk. CONCLUSIONS: Risk factors already identified as being important for UADT cancers in adults are also important influences on risk in younger adults. The implication of these results is that the public health message in preventing UADT cancers remains the same to young and old alike.

Diet and upper-aerodigestive tract cancer in Europe: the ARCAGE study.

There is suggestive, but inconclusive, evidence that dietary factors may affect risk of cancers of the upper aerodigestive tract (UADT). In the context of the alcohol-related cancers and genetic susceptibility in Europe study, we have examined the association of dietary factors with UADT cancer risk. We have analyzed data from 2,304 patients with UADT cancer and 2,227 control subjects recruited in 14 centers in 10 European countries. Dietary data were collected through a semi-quantitative food frequency questionnaire that also assessed preferred temperature of hot beverages. Statistical analyses were conducted through multiple logistic regression controlling for potential confounding variables, including alcohol intake and smoking habits. Consumption of red meat (OR per increasing tertile = 1.14, 95% CI: 1.05-1.25), but not poultry, was significantly associated with increased UADT cancer risk and the association was somewhat stronger for esophageal cancer. Consumption of fruits (OR per increasing tertile = 0.68, 95% CI: 0.62-0.75) and vegetables (OR per increasing tertile = 0.73, 95% CI: 0.66-0.81) as well as of olive oil (OR for above versus below median = 0.78, 95% CI 0.67-0.90) and tea (OR for above versus below median = 0.83, 95% CI 0.69-0.98) were significantly associated with reduced risk of UADT cancer. There was no indication that an increase in tea or coffee temperature was associated with increased risk of UADT overall or cancer of the esophagus; in fact, the association was, if anything, inverse. In conclusion, the results of this large multicentric study indicate that diet plays an important role in the etiology of UADT cancer.

Alcohol-related cancers and genetic susceptibility in Europe: the ARCAGE project: study samples and data collection.

Cancers of the upper aerodigestive tract (UADT) include those of the oral cavity, pharynx (other than nasopharynx), larynx, and esophagus. Tobacco smoking and consumption of alcoholic beverages are established causes of UADT cancers, whereas reduced intake of vegetables and fruits are likely causes. The role of genetic predisposition and possible interactions of genetic with exogenous factors, however, have not been adequately studied. Moreover, the role of pattern of smoking and drinking, as well as the exact nature of the implicated dietary variables, has not been clarified. To address these issues, the International Agency for Research on Cancer initiated in 2002 the alcohol-related cancers and genetic susceptibility (ARCAGE) in Europe project, with the participation of 15 centers in 11 European countries. Information and biological data from a total of 2304 cases and 2227 controls have been collected and will be used in a series of analyses. A total of 166 single nucleotide polymorphisms of 76 genes are being studied for genetic associations with UADT cancers. We report here the methodology of the ARCAGE project, main demographic and lifestyle characteristics of the cases and controls, as well as the distribution of cases by histology and subsite. About 80% of cases were males and fewer than 20% of all cases occurred before the age of 50 years. Overall, the most common subsite was larynx, followed by oral cavity, oropharynx, esophagus and hypopharynx. Close to 90% of UADT cancers were squamous cell carcinomas. A clear preponderance of smokers and alcohol drinkers among UADT cases compared with controls was observed.