Risk of lung cancer and occupational history: results of a French population-based case-control study, the ICARE study

Lung cancer risk associated with occupations in women: a pooling study

BACKGROUND

Occupation is an important risk factor for lung cancer. This knowledge is mainly based on studies conducted on men, with the results being generalized to women.

AIMS

We aimed to identify the relationship between different occupations and lung cancer in women.

METHODS

Pooling study in which data were pooled from six case-control studies conducted at 13 Spanish hospitals and 1 hospital in Portugal. Each woman's longest held job was coded as per the ISCO-08. Results were adjusted for age, smoking, and exposure to residential radon.

RESULTS

The study population comprised 1262 women: 618 cases and 644 controls. The reference group were white-collar workers. The adjusted multivariate analysis showed a higher risk of developing lung cancer among teaching professionals (odds ratio [OR]: 4.36; 95% confidence interval [CI] 1.73-11.02), cooks (OR: 3.59; 95% CI 1.52-8.48), domestic cleaners and helpers (OR: 2.98; 95% CI 1.54-5.78), homemakers (OR: 2.30; 95% CI 1.26-4.21) and crop farmers, livestock farmers and gardeners (OR: 2.06, 95% CI: 1.11-3.81). For adenocarcinoma, the highest risk was observed in teaching professionals, and for small-cell carcinoma, the highest risk was observed in cooks. Higher risks were observed for small-cell carcinoma compared to other histological types.

CONCLUSIONS

Some occupations may be associated with an increased risk of lung cancer in women and this risk could vary by histologic subtype; however, further research is needed to confirm these associations. In any case, protection measures must be implemented in the workplace aimed at reducing the risk of lung cancer among women workers, and more studies exclusively focused on women are warranted.

Prevalent occupational exposures and risk of lung cancer among women: Results from the application of the Canadian Job-Exposure Matrix (CANJEM) to a combined set of ten case-control studies

BACKGROUND

Worldwide, lung cancer is the second leading cause of cancer death in women. The present study explored associations between occupational exposures that are prevalent among women, and lung cancer.

METHODS

Data from 10 case-control studies of lung cancer from Europe, Canada, and New Zealand conducted between 1988 and 2008 were combined. Lifetime occupational history and information on nonoccupational factors including smoking were available for 3040 incident lung cancer cases and 4187 controls. We linked each reported job to the Canadian Job-Exposure Matrix (CANJEM), which provided estimates of probability, intensity, and frequency of exposure to each selected agent in each job. For this analysis, we selected 15 agents (cleaning agents, biocides, cotton dust, synthetic fibers, formaldehyde, cooking fumes, organic solvents, cellulose, polycyclic aromatic hydrocarbons from petroleum, ammonia, metallic dust, alkanes C18+, iron compounds, isopropanol, and calcium carbonate) that had lifetime exposure prevalence of at least 5% in the combined study population. For each agent, we estimated lung cancer risk in each study center for ever-exposure, by duration of exposure, and by cumulative exposure, using separate logistic regression models adjusted for smoking and other covariates. We then estimated the meta-odds ratios using random-effects meta-analysis.

RESULTS AND CONCLUSIONS

None of the agents assessed showed consistent and compelling associations with lung cancer among women. The following agents showed elevated odds ratio in some analyses: metallic dust, iron compounds, isopropanol, and organic solvents. Future research into occupational lung cancer risk factors among women should prioritize these agents.

Occupation as a risk factor of small cell lung cancer

Small cell lung cancer (SCLC) comprises approximately 10% of all lung cancer cases. Tobacco is its main risk factor; however, occupation might play a role in this specific lung cancer subtype. The effect of occupation on SCLC risk has been hardly studied and therefore we aim to assess the role of occupation on the risk of SCLC. To do this, we designed a multicentric, hospital-based, case-control study. Cases consisted exclusively in SCLC patients and controls were recruited from patients having minor surgery at the participating hospitals. Face to face interviews emphasizing occupation and tobacco consumption were held and residential radon was also measured. Logistic regression models were adjusted with odds ratios with 95%CI as estimations of the effect. 423 cases and 905 controls were included. Smoking prevalence was higher in cases compared to controls. Those who worked in known-risk occupations for lung cancer showed an OR of 2.17 (95%CI 1.33; 3.52), with a similar risk when men were analysed separately. The results were adjusted by age, sex, smoking and indoor radon exposure. Those who worked in known-risk occupations and were moderate or heavy smokers had a SCLC risk of 12.19 (95%CI 5.68-26.38) compared with never or moderate smokers who had not worked in such occupations. Occupation is a relevant risk factor of SCLC, and it seems that its effect is boosted when tobacco smoking is present.

Sleep Traits, Night Shift Work and Lung Cancer Risk among Women: Results from a Population-Based Case-Control Study in France (The WELCA Study)

Circadian rhythm disruption due to night shift work and/or sleep disorders is associated with negative health outcomes including cancer. There is only scant evidence of an association with lung cancer, unlike breast and prostate cancer. We explore the role of sleep disorders and night shift work in lung cancer risk among women in a population-based case-control study, including 716 lung cancer cases and 758 controls. Multivariable logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) associated with sleep duration per day (<7 h, 7−7.9 h, ≥8 h), a summary index of sleep disorders, chronotype, and night shift work exposure metrics. When compared to women with an average sleep duration of 7−7.9 h per day, the OR was 1.39 (95% CI 1.04−1.86) in long sleepers (≥8 h) and 1.16 (95% CI 0.86−1.56) in short sleepers (<7 h). Overall, lung cancer was not associated with the sleep disorder index, nor with night shift work, regardless of the duration of night work or the frequency of night shifts. However, elevated OR associated with the sleep disorder index were found in the subgroup of current smokers. The U-shaped association of lung cancer with sleep duration was more particularly pronounced among women who worked at night ≥5 years. Our findings suggested that sleep patterns are associated with lung cancer risk in women with a potential modifying effect by night shift work duration or tobacco smoking.

Lung cancer risk in relation to jobs held in a nationwide case-control study in Iran

BACKGROUND

Globally, lung cancer is the most frequent occupational cancer, but the risk associated with the occupations or occupational environment in Iran is not clear. We aimed to assess occupations with the risk of lung cancer.

METHODS

We used the IROPICAN nationwide case-control study data including 658 incident lung cancer cases and 3477 controls. We assessed the risk of lung cancer in relation to ever working in major groups of International Standard Classification of Occupations, high-risk occupations for lung cancer and duration of employment and lung cancer subtype among construction workers and farmers while controlling for cigarette smoking and opium consumption. We used unconditional regression logistic models to estimate ORs for the association between increased lung cancer risk and occupations.

RESULTS

We observed elevated ORs for lung cancer in male construction workers (OR=1.4; 95% CI: 1.0 to 1.8), petroleum industry workers (OR=3.2; 95% CI: 1.1 to 9.8), female farmers (OR=2.6; 95% CI: 1.3 to 5.3) and female bakers (OR=5.5; 95% CI: 1.0 to 29.8). A positive trend by the duration of employment was observed for male construction workers (p< 0.001). Increased risk of squamous cell carcinoma was observed in male construction workers (OR=1.9; 95% CI: 1.2 to 3.0) and female farmers (OR=4.3; 95% CI: 1.1 to 17.2), who also experienced an increased risk of adenocarcinoma (OR=3.8; 95% CI: 1.4 to 9.9).

DISCUSSION

Although we observed associations between some occupations and lung cancer consistent with the literature, further studies with larger samples focusing on exposures are needed to better understand the occupational lung cancer burden in Iran.

The effect of occupational exposure to welding fumes on trachea, bronchus and lung cancer: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are the producers of the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury (WHO/ILO Joint Estimates). Welding fumes have been classified as carcinogenic to humans (Group 1) by the WHO International Agency for Research on Cancer (IARC) in IARC Monograph 118; this assessment found sufficient evidence from studies in humans that welding fumes are a cause of lung cancer. In this article, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from trachea, bronchus, and lung cancer attributable to occupational exposure to welding fumes, to inform the development of WHO/ILO Joint Estimates on this burden of disease (if considered feasible).

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of any (or high) occupational exposure to welding fumes, compared with no (or low) occupational exposure to welding fumes, on trachea, bronchus, and lung cancer (three outcomes: prevalence, incidence, and mortality).

DATA SOURCES

We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic databases for potentially relevant records from published and unpublished studies, including Medline, EMBASE, Web of Science, CENTRAL and CISDOC. We also searched grey literature databases, Internet search engines, and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any Member State of WHO and/or ILO but excluded children (<15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies, and other non-randomized intervention studies with an estimate of the effect of any (or high) occupational exposure to welding fumes, compared with occupational exposure to no (or low) welding fumes, on trachea, bronchus, and lung cancer (prevalence, incidence, and mortality).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first review stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. If studies reported odds ratios, these were converted to risk ratios (RRs). We combined all RRs using random-effects meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence, and strength of evidence, using the Navigation Guide tools and approaches adapted to this project. Subgroup (e.g., by WHO region and sex) and sensitivity analyses (e.g., studies judged to be of "high"/"probably high" risk of bias compared with "low"/"probably low" risk of bias) were conducted.

RESULTS

Forty-one records from 40 studies (29 case control studies and 11 cohort studies) met the inclusion criteria, comprising over 1,265,512 participants (≥22,761 females) in 21 countries in three WHO regions (Region of the Americas, European Region, and Western Pacific Region). The exposure and outcome were generally assessed by job title or self-report, and medical or administrative records, respectively. Across included studies, risk of bias was overall generally probably low/low, with risk judged high or probably high for several studies in the domains for misclassification bias and confounding. Our search identified no evidence on the outcome of having trachea, bronchus, and lung cancer (prevalence). Compared with no (or low) occupational exposure to welding fumes, any (or high) occupational exposure to welding fumes increased the risk of acquiring trachea, bronchus, and lung cancer (incidence) by an estimated 48 % (RR 1.48, 95 % confidence interval [CI] 1.29-1.70, 23 studies, 57,931 participants, I² 24 %; moderate quality of evidence). Compared with no (or low) occupational exposure to welding fumes, any (or high) occupational exposure to welding fumes increased the risk dying from trachea, bronchus, and lung cancer (mortality) by an estimated 27 % (RR 1.27, 95 % CI 1.04-1.56, 3 studies, 8,686 participants, I² 0 %; low quality of evidence). Our subgroup analyses found no evidence for difference by WHO region and sex. Sensitivity analyses supported the main analyses.

CONCLUSIONS

Overall, for incidence and mortality of trachea, bronchus, and lung cancer, we judged the existing body of evidence for human data as "sufficient evidence of harmfulness" and "limited evidence of harmfulness", respectively. Occupational exposure to welding fumes increased the risk of acquiring and dying from trachea, bronchus, and lung cancer. Producing estimates for the burden of trachea, bronchus, and lung cancer attributable to any (or high) occupational exposure to welding fumes appears evidence-based, and the pooled effect estimates presented in this systematic review could be used as input data for the WHO/ILO Joint Estimates. PROTOCOL IDENTIFIER: https://doi.org/10.1016/j.envint.2020.106089.

Occupational Exposure to Polycyclic Aromatic Hydrocarbons and Lung Cancer Risk: Results from a Pooled Analysis of Case-Control Studies (SYNERGY)

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAH) occurs widely in occupational settings. We investigated the association between occupational exposure to PAH and lung cancer risk and joint effects with smoking within the SYNERGY project.

METHODS

We pooled 14 case-control studies with information on lifetime occupational and smoking histories conducted between 1985 and 2010 in Europe and Canada. Exposure to benzo[a]pyrene (BaP) was used as a proxy of PAH and estimated from a quantitative general population job-exposure matrix. Multivariable unconditional logistic regression models, adjusted for smoking and exposure to other occupational lung carcinogens, estimated ORs, and 95% confidence intervals (CI).

RESULTS

We included 16,901 lung cancer cases and 20,965 frequency-matched controls. Adjusted OR for PAH exposure (ever) was 1.08 (CI, 1.02-1.15) in men and 1.20 (CI, 1.04-1.38) in women. When stratified by smoking status and histologic subtype, the OR for cumulative exposure ≥0.24 BaP μg/m3-years in men was higher in never smokers overall [1.31 (CI, 0.98-1.75)], for small cell [2.53 (CI, 1.28-4.99)] and squamous cell cancers [1.33 (CI, 0.80-2.21)]. Joint effects between PAH and smoking were observed. Restricting analysis to the most recent studies showed no increased risk.

CONCLUSIONS

Elevated lung cancer risk associated with PAH exposure was observed in both sexes, particularly for small cell and squamous cell cancers, after accounting for cigarette smoking and exposure to other occupational lung carcinogens.

IMPACT

The lack of association between PAH and lung cancer in more recent studies merits further research under today's exposure conditions and worker protection measures.

Occupational Exposures and Lung Cancer Risk-An Analysis of the CARTaGENE Study

OBJECTIVE

To determine the associations between prevalent occupational agents and lung cancer risk.

METHODS

A case-cohort design (ncases= 147; nsub-cohort= 1,032) was nested within the CARTaGENE prospective cohort study. The Canadian Job Exposure Matrix was used to determine the probability of exposure to 27 agents in participants' longest-held jobs. Multivariable logistic regression with robust variance estimators was used to determine the associations between each agent and lung cancer risk while adjusting for established lung cancer risk factors.

RESULTS

Increased lung cancer risk was observed among those exposed to ashes, calcium sulfate, formaldehyde, cooking fumes, alkanes, aliphatic aldehydes, and cleaning agents. Lower lung cancer risk was found among participants exposed to carbon monoxide and polycyclic aromatic hydrocarbons from petroleum.

CONCLUSION

Our findings support the role of several occupational agents, for which we have limited knowledge, in contributing to lung cancer risk.

Association of hairdressing with cancer and reproductive diseases: A systematic review

OBJECTIVES

To review recent epidemiological studies investigating carcinogenic or reprotoxic effects among hairdressers who seem to be at greater risk for systemic adverse effects of chemicals released from hair care products than consumers.

METHODS

A systematic review according to the PRISMA-P guidelines was performed and included studies published from 2000 to August 2021, in which cancer or adverse reproductive effects were diagnosed in 1995 and onward. Data were synthetized qualitatively due to the small number of studies, heterogeneity of study designs, outcomes, and methods.

RESULTS

Four studies investigating cancer frequencies and six studies investigating effects on reproduction among hairdressers were identified. All were of good quality and with low risk of bias. Only one of the four studies found an increased risk of cancer reporting nine times higher odds for bladder cancer in hairdressers than the population-based controls. Three other studies investigating bladder and lung cancer, and non-Hodgins lymphoma did not find an increased risk in hairdressers. Regarding reprotoxic effects, numerous outcomes were investigated including menstrual disorders, congenital malformations, fetal loss, small-for-gestational age newborns, preterm delivery, and infertility. Increased risk was found for ventricular septal defect in newborns of fathers working as hairdressers. Furthermore, several indices of poor neonatal or maternal health were significantly associated with mothers working as hairdresser.

CONCLUSIONS

Despite the scarce evidence that hairdressers are at increased risk of carcinogenic or reprotoxic effects related to their trade, such health risks cannot be ruled out. Therefore, preventive efforts to diminish occupational exposures to hairdressing chemicals should be targeted.

A critical review of the 2020 EPA risk assessment for chrysotile and its many shortcomings

From 2018 to 2020, the United States Environmental Protection Agency (EPA) performed a risk evaluation of chrysotile asbestos to evaluate the hazards of asbestos-containing products (e.g. encapsulated products), including brakes and gaskets, allegedly currently sold in the United States. During the public review period, the EPA received more than 100 letters commenting on the proposed risk evaluation. The Science Advisory Committee on Chemicals (SACC), which peer reviewed the document, asked approximately 100 questions of the EPA that they expected to be addressed prior to publication of the final version of the risk assessment on 30 December 2020. After careful analysis, the authors of this manuscript found many significant scientific shortcomings in both the EPA's draft and final versions of the chrysotile risk evaluation. First, the EPA provided insufficient evidence regarding the current number of chrysotile-containing brakes and gaskets being sold in the United States, which influences the need for regulatory oversight. Second, the Agency did not give adequate consideration to the more than 200 air samples detailed in the published literature of auto mechanics who changed brakes in the 1970-1989 era. Third, the Agency did not consider more than 15 epidemiology studies indicating that exposures to encapsulated chrysotile asbestos in brakes and gaskets, which were generally in commerce from approximately 1950-1985, did not increase the incidence of any asbestos-related disease. Fourth, the concern about chrysotile asbestos being a mesothelioma hazard was based on populations in two facilities where mixed exposure to chrysotile and commercial amphibole asbestos (amosite and crocidolite) occurred. All 8 cases of pleural cancer and mesothelioma in the examined populations arose in facilities where amphiboles were present. It was therefore inappropriate to rely on these cohorts to predict the health risks of exposure to short fiber chrysotile, especially of those fibers filled with phenolic resins. Fifth, the suggested inhalation unit risk (IUR) for chrysotile asbestos was far too high since it was not markedly different than for amosite, despite the fact that the amphiboles are a far more potent carcinogen. Sixth, the approach to low dose modeling was not the most appropriate one in several respects, but, without question, it should have accounted for the background rate of mesothelioma in the general population. Just one month after this assessment was published, the National Academies of Science notified the EPA that the Agency's systematic review process was flawed. The result of the EPA's chrysotile asbestos risk evaluation is that society can expect dozens of years of scientifically unwarranted litigation. Due to an aging population and because some fraction of the population is naturally predisposed to mesothelioma given the presence of various genetic mutations in DNA repair mechanisms (e.g. BAP1 and others), the vast majority of mesotheliomas in the post-2035 era are expected to be spontaneous and unrelated in any way to exposure to asbestos. Due to the EPA's analysis, it is our belief that those who handled brakes and gaskets in the post-1985 era may now believe that those exposures were the cause of their mesothelioma, when a risk assessment based on the scientific weight of evidence would indicate otherwise.

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.

Phthalates Exposure and Occupational Symptoms among Slovakian Hairdressing Apprentices

The objectives of the study were to examine occupational exposure to phthalates of hairdressing apprentices from Slovakia (n = 74, 89.2% females; 10.8% males), outcomes related to body composition and pulmonary functions. We used high-performance liquid chromatography and tandem mass spectrometry to the quantified urinary concentration of phthalates. Pulmonary function test (PFT), anthropometric measurements, and questionnaire were also conducted. We observed a decrease of % of predicted values of forced vital capacity (FVC% of PV) related exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP; p = 0.054) and sum of bis(2-ethylhexyl) phthalate metabolites (∑DEHP; p = 0.037), and a decrease of % of predicted values of vital capacity (VC% of PV) related to exposure to MEOHP, ∑DEHP (p = 0.008), and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP; p = 0.014) in females. We detected associations between forced vital capacity (FVC) with weight (p = 0.002) and fat-free mass index (FFMI, p = 0.010). Vital capacity (VC) and VC% of PV increased with weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR), the waist-height ratio (WHtR), fat mass index (FMI) and FFMI in females (p ≤ 0.014). Results of multivariate regression between PFT and anthropometric parameters adjusted to phthalates indicated exposure to MnBP and MEHP, changing body structure (BMI and FMI), subsequently affecting values of FEV1/FVC.

Circular RNA hsa_circ_0007059 restrains proliferation and epithelial-mesenchymal transition in lung cancer cells via inhibiting microRNA-378

As newly discovered non-coding RNA (ncRNA), circular RNA (circRNA) has become a research hotspot in manifold cancers. But, the influences of hsa_circ_0007059 in lung cancer remain obscure. Expression of hsa_circ_0007059 in lung cancer tissues was firstly determined through RT-qPCR. After overexpressing hsa_circ_0007059, cell viability, apoptosis, p53/CyclinD1, Bax and Pro/Cleaved-Caspase-3 and EMT-correlative factors (E-cadherin, Vimetin, Twist1 and Zeb1) were tested in A549 and H1975 cells. MiR-378 expression in lung cancer tissues and cells was evaluated after miR-378 mimic transfection. Wnt/β-catenin and ERK1/2 pathways were finally evaluated in A549 and H1975 cells. Inhibition of hsa_circ_0007059 was discovered in lung cancer tissues. Overexpressed hsa_circ_0007059 evidently restrained cell proliferation, elevated p53 and repressed CyclinD1 expression, meanwhile triggered apoptosis and enhanced Bax and Cleaved-Caspase-3 expression. Increased hsa_circ_0007059 abated EMT via enhancement of E-cadherin and inhibition of Vimentin, Twist and Zeb1 in A549 and H1975 cells. MiR-378 was up-regulated in lung cancer tissues, declined by hsa_circ_0007059 overexpression in A549 and H1975 cells. Overexpressed hsa_circ_0007059 hindered Wnt/β-catenin and ERK1/2 pathways via suppressing miR-378 in A549 and H1975 cells. The investigations manifested that hsa_circ_0007059 abated cell proliferation and EMT process in lung cancer cells via inactivation of Wnt/β-catenin and ERK1/2 pathways via suppressing miR-378.

LUCSO-1-French pilot study of LUng Cancer Screening with low-dose computed tomography in a smokers population exposed to Occupational lung carcinogens: study protocol

INTRODUCTION

Guidelines concerning the follow-up of subjects occupationally exposed to lung carcinogens, published in France in 2015, recommended the setting up of a trial of low-dose chest CT lung cancer screening in subjects at high risk of lung cancer.

OBJECTIVE

To evaluate the organisation of low-dose chest CT lung cancer screening in subjects occupationally exposed to lung carcinogens and at high risk of lung cancer.

METHODS AND ANALYSIS

This trial will be conducted in eight French departments by six specialised reference centres (SRCs) in occupational health. In view of the exploratory nature of this trial, it is proposed to test initially the feasibility and acceptability over the first 2 years in only two SRCs then in four other SRCs to evaluate the organisation. The target population is current or former smokers with more than 30 pack-years (who have quit smoking for less than 15 years), currently or previously exposed to International Agency for Research on Cancer group 1 lung carcinogens, and between the ages of 55 and 74 years. The trial will be conducted in the following steps: (1) identification of subjects by a screening invitation letter; (2) evaluation of occupational exposure to lung carcinogens; (3) evaluation of the lung cancer risk level and verification of eligibility; (4) screening procedure: annual chest CT scans performed by specialised centres and (5) follow-up of CT scan abnormalities.

ETHICS AND DISSEMINATION

This protocol study has been approved by the French Committee for the Protection of Persons. The results from this study will be submitted to peer-reviewed journals and reported at suitable national and international meetings.

TRIAL REGISTRATION NUMBER

NCT03562052; Pre-results.

Cancer incidence and all-cause mortality among civilian men and women employed by the Royal Norwegian Navy between 1950 and 2005

OBJECTIVE

We aimed to investigate cancer incidence and all-cause mortality in a cohort of 8358 civilians (5134 men and 3224 women) employed by the Royal Norwegian Navy at any time between 1950 and 2005.

METHODS

The cohort was followed for cancer incidence and all-cause mortality from 1960 through 2015. Standardised incidence ratios (SIR) and mortality ratios (SMR) were calculated from national rates. Separate SIRs were calculated for a subgroup of male workshop workers and another of female cleaners.

RESULTS

Overall cancer incidence among men was similar to the reference rate; male breast cancer was more frequent (SIR = 3.23). Male workshop workers showed a SIR of 1.77 for stomach cancer, while their incidence of lympho-haematopoietic cancers was half that of the reference rates. Women had increased risks of overall cancer (SIR = 1.11), lung cancer (SIR = 1.35), and ovarian cancer (SIR = 1.39). Female cleaners showed a SIR of 2.33 for bladder cancer and a lowered incidence of brain cancer (SIR = 0.18). In the overall cohort, all-cause mortality was lower than expected for men (SMR = 0.92) and closer to the reference rate for women (SMR = 0.95).

CONCLUSION

In men, we observed a lowered all-cause mortality and an excess of stomach cancer in workshop workers. In women, increased risks of overall cancer, lung cancer and ovarian cancer was seen. An increased risk of bladder cancer and a lowered incidence of brain cancer was observed among female cleaners.

Lung cancer risk and occupational exposures in crop farming: results from the AGRIculture and CANcer (AGRICAN) cohort

Objectives

Farmers are considered at lower risk of lung cancer. However, specific tasks can expose them to hazardous air contaminants such as pesticides, diesel exhaust and mineral dust. This study aimed to assess the associations between various crops and related tasks and the risk of lung cancer, overall and by histological subtypes.

Methods

AGRIculture and CANcer is a prospective French cohort of individuals affiliated to the agricultural health insurance scheme. Incident lung cancers (n=897) were identified by cancer registries from enrolment (2005–2007) to 2013. Data on crop and livestock exposure during lifetime were obtained from the enrolment questionnaire. We used a Cox model with attained age as timescale, adjusted for gender, smoking history and exposure to cattle and horses. Effects of duration and surface were assessed and analyses stratified on gender and smoking status were performed.

Results

Winegrowers were at higher risk of adenocarcinoma (HR=1.27 (95% CI 0.94 to 1.72)). We also found an association between pea growing and small cell lung cancer: significant effect of duration (ptrend=0.04) and the suggestion of a surface–effect relationship (ptrend=0.06); increased risk (HR=2.38 (95% CI 1.07 to 5.28)) for pesticide users; and significant effect of duration (ptrend=0.01) for harvesters. The risk of squamous cell carcinoma was increased for sunflower growing (HR=1.59 (95% CI 0.97 to 2.62), fruit-tree pruning (HR=1.44 (95% CI 0.92 to 2.27)) and pesticide use on beets (HR=1.47 (95% CI 0.92 to 2.34)). Corn and/or wheat/barley growers were at lower risk of lung cancer.

Conclusions

Our results suggest associations between lung cancer and several crop-related tasks, even if we cannot rule out some chance findings due to multiple comparisons.

[Respiratory cancers attributable to occupational exposures: what is the cost to society in France]

OBJECTIVE

To estimate the social cost of respiratory cancers attributable to occupational risk factors in France in 2010.

METHODS

We estimated the number of cases of respiratory cancers attributable to each identified occupational risk factor according to the attributable fractions method. We also estimated direct (costs of hospital stays, drugs, outpatient care) and indirect costs (production losses) related to morbidity (absenteeism and presenteeism) and mortality (years of lost production). Production losses for paid work and unpaid domestic activities were taken into account.

RESULTS

The social cost of respiratory cancers (lung, larynx, sinonasal, pleural mesothelioma) attributable to exposure to asbestos, chromium, diesel engine exhaust, polycyclic aromatic hydrocarbons, painting occupations (unidentified carcinogen), crystalline silica, wood and leather dust in France in 2010 was estimated to be between €960 and 1,866 million. The cost of lung cancer represents between €804 and 1,617 million. The three risk factors with the greatest impact are asbestos (€530 to 890 million), diesel engine exhaust (€227 to 394 million), and crystalline silica (€116 to 268 million).

CONCLUSION

These results provide a conservative estimate of the public health and economic burden of respiratory cancers attributable to occupational risk factors from a societal perspective.

Women Epidemiology Lung Cancer (WELCA) study: reproductive, hormonal, occupational risk factors and biobank

Background

Lung cancer aetiology and clinical aspects have been mainly studied in men, although specific risk factors probably exist in women. Here we present the rationale, design and organization of the WELCA study (Women Epidemiology Lung CAncer) that has been launched to investigate lung cancer in women, focusing particularly on hormonal and occupational factors.

Methods/Design

WELCA is a population based case-control study and planned to recruit 1000 cases and 1000 controls in three years, based on study power calculation. Eligible cases are female patients newly diagnosed with lung cancer, living in Paris and the Ile de France area and aged up to 75 years. Almost all Parisian pneumology and oncology clinical departments are involved. The control group is a random sample of the population living in the same area, frequency-matched on age and additionally stratified on the distribution of socio-professional categories of women residing there. After acquisition of written consent, research nurses administer standardized computer assisted questionnaires to all the subjects in face-to-face interviews and acquire anthropometric measures. Besides usual socio-demographic characteristics, information is gathered about menstrual and reproductive factors, hormonal treatments, lifestyle and leisure characteristics, occupational history, personal and familial medical history. Biological samples are also collected, in order to establish a biobank for molecular epidemiology studies. Molecular characteristics of the tumours will be obtained and patients will be followed up for five years.

Discussion

The WELCA study aims to answer key questions in lung cancer aetiology and clinical characteristics specifically in women. The role of hormonal impregnation is investigated, and the interactions with cigarette smoking or body mass index (BMI) will be analyzed in detail. The occupational history of the subjects is carefully reconstructed, focusing in particular on the service sector. The creation of a biobank for collection of serum, plasma, DNA and tumour tissue will allow the genetic and biochemical characterization of both the subjets and the tumours. The follow-up of the patients will help in disentangling the role of hormonal factors and tumour molecular characteristics in survival.

The time-dependent health and biochemical effects in rats exposed to stainless steel welding dust and its soluble form

Welding processes that generate fumes containing toxic metals, such as hexavalent chromium (Cr(VI)), manganese (Mn), and nickel (Ni), have been implicated in lung injury, inflammation, and lung tumor promotion in animal models. The principal objective of this study was to determine the dynamics of toxic effects of inhalation exposure to morphologically rated welding dust from stainless steel welding and its soluble form in TSE System with a dynamic airflow. We assessed the pulmonary toxicity of welding dust in Wistar rats exposed to 60.0 mg/m³ of respirable-size welding dust (mean diameter 1.17 µm) for 2 weeks (6 h/day, 5 days/week); the aerosols were generated in the nose-only exposure chambers (NOEC). An additional aim included the study of the effect of betaine supplementation on oxidative deterioration in rat lung during 2 weeks of exposure to welding dust or water-soluble dust form. The animals were divided into eight groups (n = 8 per group): control, dust, betaine, betaine + dust, soluble-form dust, soluble-form dust + betaine, saline and saline + betaine groups. Rats were euthanized 1 or 2 weeks after the last exposure for assessment of pulmonary toxicity. Differential cell counts, total protein concentrations and cellular enzyme (lactate dehydrogenase-LDH) activities were determined in bronchoalveolar lavage (BAL) fluid, and corticosterone and thiobarbituric acid reactive substances (TBARS) concentrations were assessed in serum. The increase in polymorphonuclear (PMN) leukocytes in BAL fluid (a cytological index of inflammatory responses of the lung) is believed to reflect pulmonary toxicity of heavy metals. Biomarkers of toxicity assessed in bronchoalveolar fluids indicate that the level of the toxic effect depends mainly on the solubility of studied metal compounds; biomarkers that showed treatment effects included: total cell, neutrophil and lymphocyte counts, total protein concentrations, and cellular enzyme (lactate dehydrogenase) activity. Betaine supplementation at 250 mg/kg/day in all study rats groups attenuated stress indices, and corticosterone and TBARS serum levels, and simultaneously stimulated increase of polymorphonuclear cells in BALF of rats. The study confirmed deleterious effect of transitory metals and particles during experimental inhalation exposure to welding dusts, evidenced in the lungs and brain by increased levels of total protein, higher cellular influx, rise of LDH in BALF, elevated TBARS and increased corticosterone in serum of rats. Our result confirm also the hypothesis about the effect of the welding dusts on the oxidative stress responsible for disturbed systemic homeostasis and impairment of calcium regulation.

Occupational phthalate exposure and health outcomes among hairdressing apprentices

We studied occupational exposure to phthalates from first-morning-void urine sample of hairdressing apprentices by HPLC-MS/MS analyses and association with health status. Metabolites of mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono ethyl phthalate (MEP), mono- n-butyl phthalate (MnBP) and mono-iso-butyl phthalate (MiBP) were detected in all urine samples, followed by metabolites mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and mono(2-etylhexyl) phthalate (MEHP) occurring in 97.06% and 86.76% of samples, respectively. Positive associations for females were observed between MnBP and fat-free mass index (FFMI) and age; negative associations were found between MEHP, MEOHP, MEHHP, sum of MEHP, MEHHP, MEOHP and vital capacity and also between MEHP and forced vital capacity (FVC of predicted value (PV)). Lengths of exposure were associated to MnBP, MEHHP, and MEP. We also documented positive associations between anthropometry (body mass index, waist-to-height ratio (WHtR), FFMI, fat mass index) and pulmonary function FVC% of PV for females and negative associations between WHtR, waist-to-hip ratio, FFMI and ratio of forced expiratory volume in 1 s (FEV₁) to FVC (FEV₁/FVC). We assume that factors of occupational environment of hairdressing apprentices are affected by phthalates and resulted in negative outcomes in breathing mechanism and influence of body composition. Adipose tissue could play role as confounding factor in urine excretion of phthalates because of their lipid solubility and accumulation.

Lung Cancer Among Firefighters: Smoking-Adjusted Risk Estimates in a Pooled Analysis of Case-Control Studies

OBJECTIVES

The aim of this study was to explore lung cancer risk among firefighters, with adjustment for smoking.

METHODS

We used pooled information from the SYNERGY project including 14 case-control studies conducted in Europe, Canada, New Zealand, and China, with lifetime work histories and smoking habits for 14,748 cases of lung cancer and 17,543 controls. We estimated odds ratios by unconditional logistic regression with adjustment for smoking and having ever been employed in a job known to present an excess risk of lung cancer.

RESULTS

There was no increased lung cancer risk overall or by specific cell type among firefighters (n = 190), neither before nor after smoking adjustment. We observed no significant exposure-response relationship in terms of work duration.

CONCLUSIONS

We found no evidence of an excess lung cancer risk related to occupational exposure as a firefighter.

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.

Lung cancer risk among workers in the construction industry: results from two case-control studies in Montreal

BACKGROUND

Given the large number of workers in the construction industry, it is important to derive accurate and valid estimates of cancer risk, and in particular lung cancer risk. In most previous studies, risks among construction workers were compared with general populations including blue and white collar workers. The main objectives of this study were to assess whether construction workers experience excess lung cancer risk, and whether exposure to selected construction industry exposures carries excess risks. We wished to address these objectives within the sub-population of blue collar workers.

METHODS

Two case-control studies were conducted in Montreal. Combined, they included 1593 lung cancer cases and 1427 controls, of whom 1304 cases and 1081 controls had been blue collar workers. Detailed lifetime job histories were obtained and translated by experts into histories of exposure to chemical agents. The two key analyses were to estimate odds ratio (OR) estimates of lung cancer risk: a) for all blue-collar construction workers compared with other blue-collar workers, and b) for construction workers exposed to each of 20 exposure agents found in the construction industry compared with construction workers unexposed to those agents. All analyses were conducted using unconditional logistic regression adjusted for socio-demographic factors and smoking history.

RESULTS

The OR for all construction workers combined was 1.11 (95 % CI: 0.90-1.38), based on 381 blue collar construction workers. Analyses of specific exposures were hampered by small numbers and imprecise estimates. While none of 20 occupational agents examined was significantly associated with lung cancer, the following agents manifested non-significantly elevated ORs: asbestos, silica, Portland cement, soil dust, calcium oxide and calcium sulfate.

CONCLUSIONS

Compared with other blue collar workers, there was only a slight increased risk of lung cancer for subjects who ever held an occupation in the construction industry. The analyses of agents within the construction industry produced imprecise estimates of risk, but nevertheless pointed to some plausible associations. Excess risks for asbestos and silica were in line with previous knowledge. The possible excess risks with the other inorganic dusts require further corroboration.

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.

Lung cancer risk among cooks when accounting for tobacco smoking: a pooled analysis of case-control studies from Europe, Canada, New Zealand, and China

OBJECTIVES

To investigate the risk of lung cancer among cooks, while controlling for smoking habits.

METHODS

We used data from the SYNERGY project including pooled information on lifetime work histories and smoking habits from 16 case-control studies conducted in Europe, Canada, New Zealand, and China.

RESULTS

Before adjustment for smoking, we observed an increased risk of lung cancer in male cooks, but not in female cooks. After adjusting, there was no increased risk and no significant exposure-response relationship. Nevertheless, subgroup analyses highlighted some possible excess risks of squamous cell carcinoma and small cell carcinoma in female cooks.

CONCLUSIONS

There is evidence that lung cancer risks among cooks may be confounded by smoking. After adjustment, cooks did not experience an increased risk of lung cancer overall. The subgroup analyses showing some excess risks among female cooks require cautious interpretation.

Lung cancer risk among bricklayers in a pooled analysis of case-control studies

Bricklayers may be exposed to several lung carcinogens, including crystalline silica and asbestos. Previous studies that analyzed lung cancer risk among these workers had several study design limitations. We examined lung cancer risk among bricklayers within SYNERGY, a large international pooled analysis of case-control studies on lung cancer and the joint effects of occupational carcinogens. For men ever employed as bricklayers we estimated odds ratios (OR) and 95% confidence intervals (CI) adjusted for study center, age, lifetime smoking history and employment in occupations with exposures to known or suspected lung carcinogens. Among 15,608 cases and 18,531 controls, there were 695 cases and 469 controls who had ever worked as bricklayers (OR: 1.47; 95% CI: 1.28-1.68). In studies using population controls the OR was 1.55 (95% CI: 1.32-1.81, 540/349 cases/controls), while it was 1.24 (95% CI: 0.93-1.64, 155/120 cases/controls) in hospital-based studies. There was a clear positive trend with length of employment (p < 0.001). The relative risk was higher for squamous (OR: 1.68, 95% CI: 1.42-1.98, 309 cases) and small cell carcinomas (OR: 1.78, 95% CI: 1.44-2.20, 140 cases), than for adenocarcinoma (OR: 1.17, 95% CI: 0.95-1.43, 150 cases) (p-homogeneity: 0.0007). ORs were still elevated after additional adjustment for education and in analyses using blue collar workers as referents. This study provided robust evidence of increased lung cancer risk in bricklayers. Although non-causal explanations cannot be completely ruled out, the association is plausible in view of the potential for exposure to several carcinogens, notably crystalline silica and to a lesser extent asbestos.

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.

Heavy smoking and lung cancer: are women at higher risk? Result of the ICARE study

Background:

Whether women are more or equally susceptible to the carcinogenic effects of cigarette smoke on the lungs compared with men is a matter of controversy. Using a large French population-based case–control study, we compared the lung cancer risk associated with cigarette smoking by gender.

Methods:

The study included 2276 male and 650 female cases and 2780 male and 775 female controls. Lifetime smoking exposure was represented by the comprehensive smoking index (CSI), which combines the duration, intensity and time since cessation of smoking habits. The analysis was conducted among the ever smokers. All of the models were adjusted for age, department (a regional administrative unit), education and occupational exposures.

Results:

Overall, we found that the lung cancer risk was similar among men and women. However, we found that women had a two-fold greater risk associated with a one-unit increase in CSI than men of developing either small cell carcinoma (OR=15.9, 95% confidence interval (95% CI) 7.6, 33.3 and 6.6, 95% CI 5.1, 8.5, respectively; P<0.05) or squamous cell carcinoma (OR=13.1, 95% CI 6.3, 27.3 and 6.1, 95% CI 5.0, 7.3, respectively; P<0.05). The association was similar between men and women for adenocarcinoma.

Conclusion:

Our findings suggest that heavy smoking might confer to women a higher risk of lung cancer as compared with men.

Welding and lung cancer in a pooled analysis of case-control studies

Several epidemiologic studies have indicated an increased risk of lung cancer among welders. We used the SYNERGY project database to assess welding as a risk factor for developing lung cancer. The database includes data on 15,483 male lung cancer cases and 18,388 male controls from 16 studies in Europe, Canada, China, and New Zealand conducted between 1985 and 2010. Odds ratios and 95% confidence intervals between regular or occasional welding and lung cancer were estimated, with adjustment for smoking, age, study center, and employment in other occupations associated with lung cancer risk. Overall, 568 cases and 427 controls had ever worked as welders and had an odds ratio of developing lung cancer of 1.44 (95% confidence interval: 1.25, 1.67) with the odds ratio increasing for longer duration of welding. In never and light smokers, the odds ratio was 1.96 (95% confidence interval: 1.37, 2.79). The odds ratios were somewhat higher for squamous and small cell lung cancers than for adenocarcinoma. Another 1,994 cases and 1,930 controls had ever worked in occupations with occasional welding. Work in any of these occupations was associated with some elevation of risk, though not as much as observed in regular welders. Our findings lend further support to the hypothesis that welding is associated with an increased risk of lung cancer.

Rotating night-shift work and lung cancer risk among female nurses in the United States

The risk of lung cancer among night-shift workers is unknown. Over 20 years of follow-up (1988-2008), we documented 1,455 incident lung cancers among 78,612 women in the Nurses' Health Study. To examine the relationship between rotating night-shift work and lung cancer risk, we used multivariate Cox proportional hazard models adjusted for detailed smoking characteristics and other risk factors. We observed a 28% increased risk of lung cancer among women with 15 or more years spent working rotating night shifts (multivariate relative risk (RR) = 1.28, 95% confidence interval (CI): 1.07, 1.53; Ptrend = 0.03) compared with women who did not work any night shifts. This association was strongest for small-cell lung carcinomas (multivariate RR = 1.56, 95% CI: 0.99, 2.47; Ptrend = 0.03) and was not observed for adenocarcinomas of the lung (multivariate RR = 0.91, 95% CI: 0.67, 1.24; Ptrend = 0.40). Further, the increased risk associated with 15 or more years of rotating night-shift work was limited to current smokers (RR = 1.61, 95% CI: 1.21, 2.13; Ptrend < 0.001), with no association seen in nonsmokers (Pinteraction = 0.03). These results suggest that there are modestly increased risks of lung cancer associated with extended periods of night-shift work among smokers but not among nonsmokers. Though it is possible that this observation was residually confounded by smoking, our findings could also provide evidence of circadian disruption as a "second hit" in the etiology of smoking-related lung tumors.

Lung cancer risk among hairdressers: a pooled analysis of case-control studies conducted between 1985 and 2010

Increased lung cancer risks among hairdressers were observed in large registry-based cohort studies from Scandinavia, but these studies could not adjust for smoking. Our objective was to evaluate the lung cancer risk among hairdressers while adjusting for smoking and other confounders in a pooled database of 16 case-control studies conducted in Europe, Canada, China, and New Zealand between 1985 and 2010 (the Pooled Analysis of Case-Control Studies on the Joint Effects of Occupational Carcinogens in the Development of Lung Cancer). Lifetime occupational and smoking information was collected through interviews with 19,369 cases of lung cancer and 23,674 matched population or hospital controls. Overall, 170 cases and 167 controls had ever worked as hairdresser or barber. The odds ratios for lung cancer in women were 1.65 (95% confidence interval (CI): 1.16, 2.35) without adjustment for smoking and 1.12 (95% CI: 0.75, 1.68) with adjustment for smoking; however, women employed before 1954 also experienced an increased lung cancer risk after adjustment for smoking (odds ratio = 2.66, 95% CI: 1.09, 6.47). The odds ratios in male hairdressers/barbers were generally not elevated, except for an increased odds ratio for adenocarcinoma in long-term barbers (odds ratio = 2.20, 95% CI: 1.02, 4.77). Our results suggest that the increased lung cancer risks among hairdressers are due to their smoking behavior; single elevated risk estimates should be interpreted with caution and need replication in other studies.

Occupational exposure and thoracic malignancies, is there a relationship?

OBJECTIVES

The aim of this study was to evaluate the effect of occupational exposure in the occurrence of lung cancer.

METHOD

Three-hundred lung cancer cases diagnosed between September 1, 1999, and September 31, 2007, and 300 healthy controls were enrolled in this case-control study. Life-long occupational history, gender, age, exposure to asbestos, comorbidities, and smoking status were collected.

RESULTS

The mean age of the 300 lung cancer cases was 60.3 ± 9.9 year (91.7% male and 8.3% female), and the mean age of healthy control group was 60.4 ± 10.5 year (95.0% male and 5.0% female). The most frequent histological types were squamous (172, 57.3%), adeno (69, 23.1%), and small cell (37, 12.3%). There was an increased risk of lung cancer occurrence among agriculture workers (OR=1.89, 95% Cl=1.17-2.98) (p=0.009). Inorganic dust exposure (OR=1.81, 95% Cl=1.0-3.25) (p=0.049) and organic dust exposure (OR=1.89, 95% Cl=1.0-3.59) (p=0.05) were found to be related with high frequency of having lung cancer.

CONCLUSION

Workers who had occupational exposure to organic and inorganic dust, especially in the agricultural field, had higher risk of lung cancer occurrence when compared with office workers.

Lung cancer epidemiology, risk factors, and prevention

The greatest risk by far for developing lung cancer is cigarette smoking, but age, radon exposure, environmental pollution, occupational exposures, gender, race, and pre-existing lung disease also are important contributors. However, not all people with these risk factors develop lung cancer, and some without any known risk factor do, indicating the importance of genetic influences. Future advances in understanding and treating lung cancer will be based on genetic analysis. The most effective preventive measure is to never start or to stop cigarette smoking.

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.

Impact of occupational carcinogens on lung cancer risk in a general population

BACKGROUND

Exposure to occupational carcinogens is an important preventable cause of lung cancer. Most of the previous studies were in highly exposed industrial cohorts. Our aim was to quantify lung cancer burden attributable to occupational carcinogens in a general population.

METHODS

We applied a new job-exposure matrix (JEM) to translate lifetime work histories, collected by personal interview and coded into standard job titles, into never, low and high exposure levels for six known/suspected occupational lung carcinogens in the Environment and Genetics in Lung cancer Etiology (EAGLE) population-based case-control study, conducted in Lombardy region, Italy, in 2002-05. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated in men (1537 cases and 1617 controls), by logistic regression adjusted for potential confounders, including smoking and co-exposure to JEM carcinogens. The population attributable fraction (PAF) was estimated as impact measure.

RESULTS

Men showed an increased lung cancer risk even at low exposure to asbestos (OR: 1.76; 95% CI: 1.42-2.18), crystalline silica (OR: 1.31; 95% CI: 1.00-1.71) and nickel-chromium (OR: 1.18; 95% CI: 0.90-1.53); risk increased with exposure level. For polycyclic aromatic hydrocarbons, an increased risk (OR: 1.64; 95% CI: 0.99-2.70) was found only for high exposures. The PAFs for any exposure to asbestos, silica and nickel-chromium were 18.1, 5.7 and 7.0%, respectively, equivalent to an overall PAF of 22.5% (95% CI: 14.1-30.0). This corresponds to about 1016 (95% CI: 637-1355) male lung cancer cases/year in Lombardy.

CONCLUSIONS

These findings support the substantial role of selected occupational carcinogens on lung cancer burden, even at low exposures, in a general population.