Welding and the risk of head and neck cancer: the ICARE study.

OBJECTIVE: To investigate the association between occupational exposure to welding and the risk of head and neck cancer in a large French population-based case-control study, the Investigation of occupational and environmental CAuses of REspiratory cancers study. METHODS: Analyses were restricted to men (2703 controls and 1588 cases of squamous-cell carcinoma of the oral cavity, oropharynx, hypopharynx and larynx). Welding activity and potential confounders were assessed by detailed questionnaires. ORs and CIs (95% CI) were estimated by unconditional logistic regression, adjusted for age, area of residence, tobacco smoking, alcohol consumption and occupational exposure to asbestos. RESULTS: Welding was associated with an increased risk of head and neck cancer overall (OR=1.31, 95% CI 1.03 to 1.67). The association was strongest for laryngeal cancer (OR=1.66, 95% CI 1.15 to 2.38) and the risk increased with the cumulative duration (p-trend <0.01) and the weighted duration (p-trend <0.01) of welding. A cumulative duration and a weighted duration of welding of more than 10 years were also associated with a significantly increased risk of oral cancer (OR=1.82, 95% CI 1.09 to 3.04; OR=2.10, 95% CI 0.99 to 4.45, respectively). A long duration of arc welding was associated with laryngeal cancer, whereas a long duration of spot welding was associated with oral cancer. Welding was not associated with the risk of oropharyngeal and hypopharyngeal cancer. CONCLUSION: Our findings suggest that welding and several welding-related tasks increase the risk of laryngeal cancer and to a lesser extent oral cancer.

Occupational exposure to wood dust and risk of lung cancer: the ICARE study.

OBJECTIVES: In a previous analysis of data from a French population-based case-control study (the Investigation of occupational and environmental CAuses of REspiratory cancers (ICARE) study), 'having ever worked' in wood-related occupations was associated with excess lung cancer risk after adjusting for smoking but not for occupational factors. The present study aimed to investigate the relationship between lung cancer risk and wood dust exposure after adjusting for occupational exposures. METHODS: Data were obtained from 2276 cases and 2780 controls on smoking habits and lifelong occupational history, using a standardised questionnaire with a job-specific questionnaire for wood dust exposure. Logistic regression models were used to calculate ORs and 95% CIs adjusted for age, area of residence, tobacco smoking, the number of job periods and exposure to silica, asbestos and diesel motor exhaust (DME). RESULTS: No significant association was found between lung cancer and wood dust exposure after adjustment for smoking, asbestos, silica and DME exposures. The risk of lung cancer was slightly increased among those who were exposed to wood dust more than 10 years, and had over 40 years since the first exposure. CONCLUSION: Our findings do not provide a strong support to the hypothesis that wood dust exposure is a risk factor for lung cancer. This study showed the importance of taking into account smoking and occupational coexposures in studies on lung cancer and wood dust exposure. Further studies evaluating the level and frequency of exposure during various tasks in woodwork are needed.

Head and neck cancer and occupational exposure to leather dust: results from the ICARE study, a French case-control study.

BACKGROUND: Leather dust is an established carcinogen of the sinonasal cavities; however, evidence is lacking regarding its association with other head and neck cancers (HNC). To date, few studies have been conducted on the association between occupational leather dust exposure and the risk of oral, pharyngeal, and laryngeal cancers. The objective of this study was to investigate the association between the risk of HNC and occupational exposure to leather dust. METHODS: Lifestyle habits and occupational history were collected for 2161 patients with squamous cell carcinoma of oral cavity, pharynx, and larynx, and 3555 controls, using a standardized questionnaire. Occupational exposure to leather dust was assessed using a job-exposure matrix. Odds ratios (OR) and 95% confidence intervals (CI) for HNC globally and by subsite were estimated using multivariate unconditional, and polytomous logistic regressions, respectively. RESULTS: Cumulative lifetime exposure to leather dust < 6 mg/m3-years was associated with an increased risk of laryngeal cancer (OR = 2.26, 95% CI: 1.07-4.76); higher levels were not related to elevated risks of HNC. Some tasks performed and the use of some glues were associated with elevated, although non-significant, risks of HNC. No dose-response relationships were observed. CONCLUSION: Our study did not provide enough evidence for an increased risk of HNC related to occupational exposure to leather dust. Further studies are needed to understand the risks of specific tasks in the leather industry.

Occupational exposure to textile dust and lung cancer risk: Results from the ICARE Study.

BACKGROUND: To investigate the association of lung cancer with occupational exposure to textile dust and specifically to cotton dust in the population-based case-control study ICARE. METHODS: Lifelong occupational history of 2926 cases and 3555 controls was collected using standardized questionnaires, with specific questions for textile dust exposure. Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using unconditional logistic regression models controlling for confounding factors including smoking and asbestos exposure. RESULTS: An inverse association between textile dust exposure and lung cancer was found among workers exposed ≥5% of their work time (OR = 0.80, 95%CI = 0.58-1.09), more pronounced for distant exposures (40+ years; up to a 56% reduced risk, statistically significant). The OR of lung cancer was significantly decreased among workers exposed to cotton fibers (OR = 0.70, 95%CI = 0.48-0.97). CONCLUSIONS: Our results provide some evidence of a decreased risk of lung cancer associated with exposure to textile dust, particularly cotton.

Occupational exposure to endotoxins and lung cancer risk: results of the ICARE Study.

OBJECTIVES: To investigate the role of occupational exposure to endotoxins in lung cancer in a French population-based case-control study (ICARE (Investigation of occupational and environmental causes of respiratory cancers)). METHODS: Detailed information was collected on the occupational history and smoking habits from 2926 patients with histologically confirmed lung cancer and 3555 matched controls. We evaluated each subject's endotoxin exposure after cross referencing International Standard Classification of Occupations (ISCO) codes (for job tasks) and Nomenclature d'Activités Françaises (NAF) codes (for activity sectors). Endotoxin exposure levels were attributed to each work environment based on literature reports. ORs and 95% CIs were estimated using unconditional logistic regression models and controlled for main confounding factors. RESULTS: An inverse association between exposure to endotoxins and lung cancer was found (OR=0.80, 95% CI 0.66 to 0.95). Negative trends were shown with duration and cumulative exposure, and the risk was decreased decades after exposure cessation (all statistically significant). Lung cancer risk was particularly reduced among workers highly exposed (eg, in dairy, cattle, poultry, pig farms), but also in those weakly exposed (eg, in waste treatment). Statistically significant interactions were shown with smoking, and never/light smokers were more sensitive to an endotoxin effect than heavy smokers (eg, OR=0.14, 95% CI 0.06 to 0.32 and OR=0.80, 95% CI 0.45 to 1.40, respectively, for the quartiles with the highest cumulative exposure, compared with those never exposed). Pronounced inverse associations were shown with adenocarcinoma histological subtype (OR=0.37, 95% CI 0.25 to 0.55 in the highly exposed). CONCLUSIONS: Our findings suggest that exposure to endotoxins, even at a low level, reduces the risk of lung cancer.

Multidimensional analysis of the effect of occupational exposure to organic solvents on lung cancer risk: the ICARE study.

BACKGROUND: The association between lung cancer and occupational exposure to organic solvents is discussed. Since different solvents are often used simultaneously, it is difficult to assess the role of individual substances. OBJECTIVES: The present study is focused on an in-depth investigation of the potential association between lung cancer risk and occupational exposure to a large group of organic solvents, taking into account the well-known risk factors for lung cancer, tobacco smoking and occupational exposure to asbestos. METHODS: We analysed data from the Investigation of occupational and environmental causes of respiratory cancers (ICARE) study, a large French population-based case-control study, set up between 2001 and 2007. A total of 2276 male cases and 2780 male controls were interviewed, and long-life occupational history was collected. In order to overcome the analytical difficulties created by multiple correlated exposures, we carried out a novel type of analysis based on Bayesian profile regression. RESULTS: After analysis with conventional logistic regression methods, none of the 11 solvents examined were associated with lung cancer risk. Through a profile regression approach, we did not observe any significant association between solvent exposure and lung cancer. However, we identified clusters at high risk that are related to occupations known to be at risk of developing lung cancer, such as painters. CONCLUSIONS: Organic solvents do not appear to be substantial contributors to the occupational risk of lung cancer for the occupations known to be at risk.

Welding, a risk factor of lung cancer: the ICARE study.

OBJECTIVES: We investigated the relationship between lung cancer and occupational exposure to welding activity in ICARE, a population-based case-control study. METHODS: Analyses were restricted to men (2276 cases, 2780 controls). Welding exposure was assessed through detailed questionnaires, including lifelong occupational history. ORs were computed using unconditional logistic regression, adjusted for lifelong cigarette smoking and occupational exposure to asbestos. RESULTS: Among the regular welders, welding was associated with a risk of lung cancer (OR=1.7, 95% CI 1.1 to 2.5), which increased with the duration (OR=2.0, 95% CI 1.0 to 3.9 when duration >10 years), and was maximum 10-20 years since last welding. The risk was more pronounced in case of gas welding (OR=2.0, 95% CI 1.2 to 3.3), when the workpiece was covered by paint, grease, or other substances (OR=2.0, 95% CI 1.2 to 3.4) and when it was cleaned with chemical substances before welding. No statistically significant increase in lung cancer risk was observed among occasional welders. CONCLUSIONS: Although these results should be confirmed, we showed that type of welding and mode of workpiece preparation are important determinants of the lung cancer risk in regular welders.

Exposure to chlorinated solvents and lung cancer: results of the ICARE study.

OBJECTIVE: To investigate the role of occupational exposure to chlorinated solvents in lung cancer aetiology. METHODS: ICARE (Investigation of occupational and environmental CAuses of REspiratory cancers) is a French, multicentre, population-based, case-control study. Information on the lifelong work history of 2926 cases and 3555 controls was collected using standardised questionnaires. Occupational exposures were assessed using job-exposure matrices for five chlorinated solvents. Solvents were studied separately and in combinations. ORs were computed using unconditional logistic regression models adjusted for classic risk factors, including a history of cigarette smoking and exposure to asbestos. Adjustment for socioeconomic status (SES) was also made. RESULTS: After adjustment for exposure to asbestos, we observed a positive, statistically significant association with lung cancer for men and women exposed to a combination of perchloroethylene (PCE), trichloroethylene and dichloromethane (DCM). Further adjustment for SES slightly decreased this association. In contrast, no statistically significant associations were found for other solvent combinations. CONCLUSIONS: These results suggest that exposure to PCE may constitute a risk factor for lung cancer, especially among women, who seem to have a higher prevalence of exposure than men.

Asbestos-related diseases in automobile mechanics.

PURPOSE: Automobile mechanics have been exposed to asbestos in the past, mainly due to the presence of chrysotile asbestos in brakes and clutches. Despite the large number of automobile mechanics, little is known about the non-malignant respiratory diseases observed in this population. The aim of this retrospective multicenter study was to analyse the frequency of pleural and parenchymal abnormalities on high-resolution computed tomography (HRCT) in a population of automobile mechanics. METHODS: The study population consisted of 103 automobile mechanics with no other source of occupational exposure to asbestos, referred to three occupational health departments in the Paris area for systematic screening of asbestos-related diseases. All subjects were examined by HRCT and all images were reviewed separately by two independent readers; who in the case of disagreement discussed until they reached agreement. Multiple logistic regression models were constructed to investigate factors associated with pleural plaques. RESULTS: Pleural plaques were observed in five cases (4.9%) and interstitial abnormalities consistent with asbestosis were observed in one case. After adjustment for age, smoking status, and a history of non-asbestos-related respiratory diseases, multiple logistic regression models showed a significant association between the duration of exposure to asbestos and pleural plaques. CONCLUSIONS: The asbestos exposure experienced by automobile mechanics may lead to pleural plaques. The low prevalence of non-malignant asbestos-related diseases, using a very sensitive diagnostic tool, is in favor of a low cumulative exposure to asbestos in this population of workers.

Pulmonary carcinoid tumors and asbestos exposure.

OBJECTIVES: The hypothesis that asbestos exposure may have more specific associations with particular histological types of lung cancer remains controversial. The aim of this study was to analyze the relationships between asbestos exposure and pulmonary carcinoid tumors. METHODS: A retrospective case-control study was conducted in 28 cases undergoing surgery for pulmonary carcinoid tumors and aged >40 years and in 56 controls with lung cancer of a different histological type, matched for gender and age, from 1994 to 1999, recruited in two hospitals in the region of Paris. Asbestos exposure was assessed via expertise of a standardized occupational questionnaire and mineralogical analysis of lung tissue, with quantification of asbestos bodies (AB). RESULTS: Definite asbestos exposure was identified in 25% of cases and 14% of controls (ns). Cumulative asbestos exposure was significantly higher in cases than in controls (P < 0.05), and results of the quantification of AB tended to be higher in cases than in controls (24 and 9% had >1000 AB per gram dry lung tissue, respectively, P = 0.09). Mean cumulative smoking was lower in cases than in controls (P < 0.05). CONCLUSIONS: This study argues in favor of a relationship between asbestos exposure and certain pulmonary carcinoid tumors.

Development of a Questionnaire for the Search for Occupational Causes in Patients with Non-Hodgkin Lymphoma: The RHELYPRO Study.

Non-Hodgkin lymphoma (NHL), multiple myeloma and chronic lymphocytic leukemia are possibly related to environmental and/or occupational exposure. The primary objective of this study was to develop a questionnaire for screening patients with these blood disorders who might benefit from a specialized consultation for possible recognition of the disease as an occupational disease. The study included 205 subjects (male gender, 67.3%; mean age, 60 years; NHL, 78.5%). The questionnaire performed very satisfactorily in identifying the exposures most frequently retained by experts for their potential involvement in the occurrence of NHL. Its sensitivity and specificity in relation to the final expertise were 96% and 96% for trichloroethylene, 85% and 82% for benzene, 78% and 87% for solvents other than trichloroethylene and dichloromethane, 87% and 95% for pesticides, respectively. Overall, 15% of the subjects were invited to ask National Social Insurance for compensation as occupational disease. These declarations concerned exposure to pesticides (64%), solvents (trichloroethylene: 29%; benzene: 18%; other than chlorinated solvents: 18%) and sometimes multiple exposures. In conclusion, this questionnaire appears as a useful tool to identify NHL patients for a specialized consultation, in order to ask for compensation for occupational disease.

Shortened telomeres in circulating leukocytes of patients with chronic obstructive pulmonary disease.

RATIONALE: Telomere length is considered a marker for biological aging. Chronic obstructive pulmonary disease (COPD) may be associated with premature aging. OBJECTIVES: To test the hypothesis that patients with COPD experience accelerated telomere shortening and that inflammation is linked to this process. METHODS: We measured telomere length, using a quantitative polymerase chain reaction-based method, and plasma levels of various cytokines in 136 patients with COPD, 113 age- and sex-matched smokers, and 42 nonsmokers with normal lung function. MEASUREMENTS AND MAIN RESULTS: Median (range) telomere length ratio was significantly lower in patients with COPD (0.57 [0.23-1.18]) than in control smokers (0.79 [0.34-1.58]) or nonsmokers (0.85 [0.38-1.55]) (P < 0.001). The difference remained highly significant when using logistic regression analysis adjusted for age, sex, and tobacco exposure. Both females and males with COPD had shorter telomere length than same-sex control subjects. Telomere length was related to age in patients and control subjects but was shorter in patients than in control subjects in all age groups. No relationship was found between telomere length and tobacco exposure in patients or control subjects, with no difference between control smokers and nonsmokers. In patients with COPD, telomere length was related to PaO2 (P < 0.001) and PaCO2 (P < 0.001) but not to lung function parameters or the BODE Index. Patients with COPD also had elevated plasma levels of various cytokines, interleukin-6 correlating negatively with telomere length (P < 0.001). CONCLUSIONS: Given that in vivo telomere length reflects cellular turnover and exposure to oxidative and inflammatory damage, our data support accelerated aging in COPD.

Risk factors for salivary gland cancers in France: Results from a case-control study, the ICARE study.

OBJECTIVES: Epidemiological studies on the risk factors for salivary gland cancers (SGC) are rare, concern a small sample size, and show inconsistent results. The aim of the present work was to analyze several risk factors for SGC, using the data from the ICARE study, a multicenter, population-based case-control study. MATERIALS AND METHODS: Data from 73 SGC cases and 3555 controls were collected using a standardized questionnaire on lifestyle habits, personal and family medical history, and lifetime occupational history. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional logistic regressions. RESULTS: Tobacco use and alcohol consumption were not associated with the risk of SGC. A history of head and neck cancer or that of cervicofacial radiotherapy was associated with a higher risk of SGC (OR = 17.06, 95% CI: 4.34-67.05, and OR = 31.74, 2.48-405.25, respectively). Significantly increased risks were observed for some occupations: waiter (OR = 2.94, 1.11-7.78), charworker (OR = 3.02, 1.38-6.60), electrical and electronic equipment assembler (OR = 7.16, 2.02-25.38), plumber (OR = 3.95, 1.33-11.67), electric arc welder (OR = 6.15, 1.76-21.48), sheet-metal worker (OR = 2.89, 1.01-8.32), building painter (OR = 3.42, 1.01-11.49), and material handling equipment operator (OR = 5.05, 1.71-14.84). Results for industries were consistent with those observed for occupations. CONCLUSION: Our results showed that a history of head and neck cancer, cervicofacial radiotherapy, and several occupations and industries, were associated with an increased risk of SGC. Further studies with larger sample sizes are indicated to confirm our results.

Professional Cleaning Activities and Lung Cancer Risk Among Women: Results From the ICARE Study.

OBJECTIVES: Lung cancer risk associated with occupational cleaning activities has been investigated in the population-based case-control study ICARE. METHODS: Occupational history was collected by standardized interviews. Jobs were first defined according to the International Standard Classification of Occupations (ISCO) codes and then categorized according to activity sectors. Adjusted odds ratios (ORs) were estimated by unconditional logistic regression, separately for women (619 cases and 760 controls) and men (2265 and 2780). RESULTS: Thirty percent of women and 2.3% of men controls ever held a cleaner or care job. Women who worked as housemaids longer than 7 years showed an OR of 1.76 [95% confidence interval (95% CI) 1.09 to 2.87] with respect to controls. Women employed in domestic service sector for a long time had an OR of 2.06 (95% CI 1.15 to 3.66). CONCLUSION: We confirmed and redefined the association of lung cancer with occupational cleaning, which concerns a considerable proportion of women workers.

Hemizygosity of Nf2 is associated with increased susceptibility to asbestos-induced peritoneal tumours.

Biallelic NF2 gene inactivation is frequently found in human malignant mesothelioma. In order to assess whether NF2 hemizygosity may enhance susceptibility to asbestos fibres, we investigated the Nf2 status in mesothelioma developed in mice presenting a heterozygous mutation of the Nf2 gene (Nf2(KO3/+)), after intraperitoneal inoculation of crocidolite fibres. Asbestos-exposed Nf2(KO3/+) mice developed tumoural ascites and mesothelioma at a higher frequency than their wild-type (WT) counterparts (P&<0.05). Six out of seven mesothelioma cell lines established from neoplastic ascitic fluids of Nf2(KO3/+) mice exhibited loss of the WT Nf2 allele and no neurofibromatosis type 2 protein expression was found in these cells. The results show the importance of the NF2 gene in mesothelial oncogenesis, the potential association of asbestos exposure and tumour suppressor gene inactivation, and suggest that NF2 gene mutation may be a susceptibility factor to asbestos.

Occupational Exposure to Diesel Motor Exhaust and Lung Cancer: A Dose-Response Relationship Hidden by Asbestos Exposure Adjustment? The ICARE Study.

Background. In a French large population-based case-control study we investigated the dose-response relationship between lung cancer and occupational exposure to diesel motor exhaust (DME), taking into account asbestos exposure. Methods. Exposure to DME was assessed by questionnaire. Asbestos was taken into account through a global indicator of exposure to occupational carcinogens or by a specific JEM. Results. We found a crude dose response relationship with most of the indicators of DME exposure, including with the cumulative exposure index. All results were affected by adjustment for asbestos exposure. The dose response relationships between DME and lung cancer were observed among subjects never exposed to asbestos. Conclusions. Exposure to DME and to asbestos is frequently found among the same subjects, which may explain why dose-response relationships in previous studies that adjusted for asbestos exposure were inconsistent.

Nosocomial pertussis outbreak among adult patients and healthcare workers.

We describe a pertussis outbreak among adult patients in a French general hospital following transmission from a healthcare worker. This index case transmitted pertussis to other healthcare workers, who, in turn, contaminated other staff and two immunosuppressed patients. This raises questions about infection control.

[News in occupational cancers]. / Actualités sur les cancers professionnels.

Despite the knowledge of the link between many sites of cancer occurence and previous occupational exposure, occupational cancers are generally underestimated. These cancers can be prevented through specific plans. In France, the number of cases requesting and receiving compensation for occupational cancer is increasing. The frequency of occupational exposure to carcinogens was recently evaluated. Legislation was reinforced in order to obtain a better control of exposure to carcinogens in the workplace. Lung cancer is the most frequent of occupational cancers. Epidemiological studies contribute to a better knowledge of etiologies and occupations responsible for the outcome of these cancers and allow quantification of the risk of cancer linked to different situations of exposure. Beside classical epidemiological studies, molecular epidemiology aims at identifying molecular targets of occupational agents. This approach may allow a better knowledge of the part played by occupational agents in these multifactorial diseases.

Risk of lung cancer associated with occupational exposure to mineral wools: updating knowledge from a french population-based case-control study, the ICARE study.

OBJECTIVES: To assess the risk of lung cancer associated with exposure to mineral wools (MWs), while taking into account smoking, asbestos, and crystalline silica exposures. METHODS: The analyses were restricted to men (1350 cases and 1912 controls). Lifelong occupational history was collected. MWs and asbestos exposures were assessed, using task-exposure matrices and silica exposure, a job-exposure matrix. RESULTS: We observed consistent not-significant increased risks of lung cancer of the same order of magnitude among workers exposed to high levels of MWs (odds ratio, 1.4; 95% confidence interval: 0.9 to 2.2; for highest quartile of the Cumulative Exposure Index). CONCLUSIONS: These results do not allow to draw firm conclusion about a carcinogenic effect of MWs on the lung, but they cannot exclude it. Given the high number of potentially exposed workers, it will be necessary to replicate them in a future further removed from the asbestos ban.