Occupational exposure to carcinogens and risk of lung cancer: results from The Netherlands cohort study

Lung Cancer in Never Smokers: Delving into Epidemiology, Genomic and Immune Landscape, Prognosis, Treatment, and Screening

Lung cancer in never smokers (LCINS) represents a growing and distinct entity within the broader landscape of lung malignancies. This review provides a comprehensive overview of LCINS, encompassing its epidemiologic trends, risk factors, distinct genomic alterations, clinical outcomes and the ongoing initiative aimed at formulating screening guidelines tailored to this unique population. As LCINS continues to gain prominence, understanding its intricate genomic landscape has become pivotal for tailoring effective therapeutic strategies. Moreover, LCINS does not meet the criteria for lung cancer screening as per the current guidelines. Hence, there is an urgent need to explore its heterogeneity in order to devise optimal screening guidelines conducive to early-stage detection. This review underscores the vital importance of detailed research to elucidate the multifaceted nature of LCINS, with the potential to shape future clinical management and screening recommendations for this unique and growing patient cohort.

Second Primary Lung Cancer Among Lung Cancer Survivors Who Never Smoked

Importance

Lung cancer among never-smokers accounts for 25% of all lung cancers in the US; recent therapeutic advances have improved survival among patients with initial primary lung cancer (IPLC), who are now at high risk of developing second primary lung cancer (SPLC). As smoking rates continue to decline in the US, it is critical to examine more closely the epidemiology of lung cancer among patients who never smoked, including their risk for SPLC.

Objective

To estimate and compare the cumulative SPLC incidence among lung cancer survivors who have never smoked vs those who have ever smoked.

Design, Setting, and Participants

This population-based prospective cohort study used data from the Multiethnic Cohort Study (MEC), which enrolled participants between April 18, 1993, and December 31, 1996, with follow-up through July 1, 2017. Eligible individuals for this study were aged 45 to 75 years and had complete smoking data at baseline. These participants were followed up for IPLC and further SPLC development through the Surveillance, Epidemiology, and End Results registry. The data were analyzed from July 1, 2022, to January 31, 2023.

Exposures

Never-smoking vs ever-smoking exposure at MEC enrollment.

Main Outcomes and Measures

The study had 2 primary outcomes: (1) 10-year cumulative incidence of IPLC in the entire study cohort and 10-year cumulative incidence of SPLC among patients with IPLC and (2) standardized incidence ratio (SIR) (calculated as the SPLC incidence divided by the IPLC incidence) by smoking history.

Results

Among 211 414 MEC participants, 7161 (3.96%) developed IPLC over 4 038 007 person-years, and 163 (2.28%) developed SPLC over 16 470 person-years. Of the participants with IPLC, the mean (SD) age at cohort enrollment was 63.6 (7.7) years, 4031 (56.3%) were male, and 3131 (43.7%) were female. The 10-year cumulative IPLC incidence was 2.40% (95% CI, 2.31%-2.49%) among ever-smokers, which was 7 times higher than never-smokers (0.34%; 95% CI, 0.30%-0.37%). However, the 10-year cumulative SPLC incidence following IPLC was as high among never-smokers (2.84%; 95% CI, 1.50%-4.18%) as ever-smokers (2.72%; 95% CI, 2.24%-3.20%), which led to a substantially higher SIR for never-smokers (14.50; 95% CI, 8.73-22.65) vs ever-smokers (3.50; 95% CI, 2.95-4.12).

Conclusions and Relevance

The findings indicate that SPLC risk among lung cancer survivors who never smoked is as high as among those with IPLC who ever-smoked, highlighting the need to identify risk factors for SPLC among patients who never smoked and to develop a targeted surveillance strategy.

Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer

Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.

Proceedings from the CIHLMU occupational safety and health symposium 2019 "Protecting workers' health: global challenges and opportunities in work-related respiratory diseases"

The international CIH^LMU Occupational Safety and Health Symposium 2019 was held on 16th March, 2019 at the Ludwig-Maximilians-Universität Munich, Germany. About 60 participants from around the world representing occupational health and safety professionals, students, instructors from several institutions in Germany and abroad, attended the symposium.

The main objective of the symposium was to create awareness on global challenges and opportunities in work-related respiratory diseases. One keynote lecture and six presentations were made. While the keynote lecture addressed issues on occupational diseases in the twenty-first century, the six presentations were centered on: Prevention and control of work-related respiratory diseases, considerations; Occupational health and safety in Mining: Respiratory diseases; The prevention of TB among health workers is our collective responsibility; Compensation and prevention of occupational diseases and discussion on how artificial intelligence can support them: Overview of international approaches; Work-related Asthma: Evidence from high-income countries; and The role of imaging in the diagnosis of work- related respiratory diseases. A panel discussion was conducted following the presentations on the importance and challenges of data acquisition which is needed to have a realistic picture of the occupational safety and health status of workers at different levels. The current summary is an attempt to share the proceedings of the symposium.

Welding fumes and lung cancer: a meta-analysis of case-control and cohort studies

BACKGROUND

An estimated 110 million workers are exposed to welding fumes worldwide. Welding fumes are classified by the International Agency for Research on Cancer as carcinogenic to humans (group 1), based on sufficient evidence of lung cancer from epidemiological studies.

OBJECTIVE

To conduct a meta-analysis of case-control and cohort studies on welding or exposure to welding fumes and risk of lung cancer, accounting for confounding by exposure to asbestos and tobacco smoking.

METHODS

The literature was searched comprehensively in PubMed, reference lists of relevant publications and additional databases. Overlapping populations were removed. Meta-relative risks (mRRs) were calculated using random effects models. Publication bias was assessed using funnel plot, Eggers's test and Begg's test.

RESULTS

Forty-five studies met the inclusion criteria (20 case-control, 25 cohort/nested case-control), which reduced to 37 when overlapping study populations were removed. For 'ever' compared with 'never' being a welder or exposed to welding fumes, mRRs and 95% CIs were 1.29 (1.20 to 1.39; I2=26.4%; 22 studies) for cohort studies, 1.87 (1.53 to 2.29; I2=44.1%; 15 studies) for case-control studies and 1.17 (1.04 to 1.38; I2=41.2%) for 8 case-control studies that adjusted for smoking and asbestos exposure. The mRRs were 1.32 (95% CI 1.20 to 1.45; I2=6.3%; 15 studies) among 'shipyard welders', 1.44 (95% CI 1.07 to 1.95; I2=35.8%; 3 studies) for 'mild steel welders' and 1.38 (95% CI 0.89 to 2.13; I2=68.1%; 5 studies) among 'stainless steel welders'. Increased risks persisted regardless of time period, geographic location, study design, occupational setting, exposure assessment method and histological subtype.

CONCLUSIONS

These results support the conclusion that exposure to welding fumes increases the risk of lung cancer, regardless of the type of steel welded, the welding method (arc vs gas welding) and independent of exposure to asbestos or tobacco smoking.

Clinical study of asbestos-related lung cancer diagnosed by asbestos medical examination

AIM

People with occupational exposure to asbestos demonstrate a high incidence of lung cancer. Asbestos medical examination for those at risk was implemented as a national policy in Japan. This study aimed to characterize patients with asbestos-related lung cancer who were diagnosed by these examinations.

METHODS

We retrospectively investigated 120 individuals exposed to asbestos who were examined from 2008 to 2016 at our institution. Clinical data, including CT findings and time-related exposure variables, were evaluated. Each asbestos-related change was assigned 1 point if present, and the scores were compared between patients with and without asbestos-related lung cancer using the Mann-Whitney U test and Fisher's exact test.

RESULTS

Five patients were diagnosed with lung cancer, and four underwent surgical treatment. At the time of writing, three of four operated patients were alive without recurrence, with a similar prognosis to patients with lung cancer unrelated to asbestos. Average scores for asbestos-related findings on CT Scan were 1.8 (9/5) for patients with lung cancer and 0.79 (91/115) for those without lung cancer.

CONCLUSION

Patients with lung cancer had significantly more asbestos-related changes on CT scan than those without lung cancer. Concurrent calcified plaque and interstitial changes might be a predictor of lung cancer incidence. Although further investigation with a larger study group is needed, regular medical examination and CT scan every 6 months might contribute to the early detection of lung cancer with asbestos-related changes on CT.

Autochthonous murine models for the study of smoker and never-smoker associated lung cancers

Lung cancer accounts for the greatest number of cancer deaths in the world. Tobacco smoke-associated cancers constitute the majority of lung cancer cases but never-smoker cancers comprise a significant and increasing fraction of cases. Recent genomic and transcriptomic sequencing efforts of lung cancers have revealed distinct sets of genetic aberrations of smoker and never-smoker lung cancers that implicate disparate biology and therapeutic strategies. Autochthonous mouse models have contributed greatly to our understanding of lung cancer biology and identified novel therapeutic targets and strategies in the era of targeted therapy. With the emergence of immuno-oncology, mouse models may continue to serve as valuable platforms for novel biological insights and therapeutic strategies. Here, we will review the variety of available autochthonous mouse models of lung cancer, their relation to human smoker and never-smoker lung cancers, and their application to immuno-oncology and immune checkpoint blockade that is revolutionizing lung cancer therapy.

Current and new challenges in occupational lung diseases

Occupational lung diseases are an important public health issue and are avoidable through preventive interventions in the workplace. Up-to-date knowledge about changes in exposure to occupational hazards as a result of technological and industrial developments is essential to the design and implementation of efficient and effective workplace preventive measures. New occupational agents with unknown respiratory health effects are constantly introduced to the market and require periodic health surveillance among exposed workers to detect early signs of adverse respiratory effects. In addition, the ageing workforce, many of whom have pre-existing respiratory conditions, poses new challenges in terms of the diagnosis and management of occupational lung diseases. Primary preventive interventions aimed to reduce exposure levels in the workplace remain pivotal for elimination of the occupational lung disease burden. To achieve this goal there is still a clear need for setting standard occupational exposure limits based on transparent evidence-based methodology, in particular for carcinogens and sensitising agents that expose large working populations to risk. The present overview, focused on the occupational lung disease burden in Europe, proposes directions for all parties involved in the prevention of occupational lung disease, from researchers and occupational and respiratory health professionals to workers and employers.

The Global Burden of Occupational Disease

PURPOSE OF REVIEW

Burden of occupational disease estimation contributes to understanding of both magnitude and relative importance of different occupational hazards and provides essential information for targeting risk reduction. This review summarises recent key findings and discusses their impact on occupational regulation and practice.

RECENT FINDINGS

New methods have been developed to estimate burden of occupational disease that take account of the latency of many chronic diseases and allow for exposure trends and workforce turnover. Results from these studies have shown in several countries and globally that, in spite of improvements in workplace technology, practices and exposures over the last decades, occupational hazards remain an important cause of ill health and mortality worldwide. Major data gaps have been identified particularly regarding exposure information. Reliable data on employment and disease are also lacking especially in developing countries. Burden of occupational disease estimates form an important part of decision-making processes.

Non-small cell lung cancer: current treatment and future advances

Lung cancer has a poor prognosis; over half of people diagnosed with lung cancer die within one year of diagnosis and the 5-year survival is less than 18%. Non-small cell lung cancer (NSCLC) accounts for the majority of all lung cancer cases. Risk factors for developing NSCLC have been identified, with cigarette smoking being a major factor along with other environmental and genetic risk factors. Depending on the staging of lung cancer, patients are eligible for certain treatments ranging from surgery to radiation to chemotherapy as well as targeted therapy. With the advancement of genetics and biomarkers testing, specific mutations have been identified to better target treatment for individual patients. This review discusses current treatments including surgery, chemotherapy, radiotherapy, and immunotherapy as well as how biomarker testing has helped improve survival in patients with NSCLC.

Non-small cell lung cancer: current treatment and future advances

Lung cancer has a poor prognosis; over half of people diagnosed with lung cancer die within one year of diagnosis and the 5-year survival is less than 18%. Non-small cell lung cancer (NSCLC) accounts for the majority of all lung cancer cases. Risk factors for developing NSCLC have been identified, with cigarette smoking being a major factor along with other environmental and genetic risk factors. Depending on the staging of lung cancer, patients are eligible for certain treatments ranging from surgery to radiation to chemotherapy as well as targeted therapy. With the advancement of genetics and biomarkers testing, specific mutations have been identified to better target treatment for individual patients. This review discusses current treatments including surgery, chemotherapy, radiotherapy, and immunotherapy as well as how biomarker testing has helped improve survival in patients with NSCLC.

Lung Cancer in Never Smokers

Lung cancer is predominantly associated with cigarette smoking; however, a substantial minority of patients with the disease have never smoked. In the US it is estimated there are 17,000-26,000 annual deaths from lung cancer in never smokers, which as a separate entity would be the seventh leading cause of cancer mortality. Controversy surrounds the question of whether or not the incidence of lung cancer in never-smokers is increasing, with more data to support this observation in Asia. There are several factors associated with an increased risk of developing lung cancer in never smokers including second hand smoke, indoor air pollution, occupational exposures, and genetic susceptibility among others. Adenocarcinoma is the most common histology of lung cancer in never smokers and in comparison to lung cancer in smokers appears less complex with a higher likelihood to have targetable driver mutations.

Expected number of asbestos-related lung cancers in the Netherlands in the next two decades: a comparison of methods

OBJECTIVES

Exposure to asbestos fibres increases the risk of mesothelioma and lung cancer. Although the vast majority of mesothelioma cases are caused by asbestos exposure, the number of asbestos-related lung cancers is less clear. This number cannot be determined directly as lung cancer causes are not clinically distinguishable but may be estimated using varying modelling methods.

METHODS

We applied three different modelling methods to the Dutch population supplemented with uncertainty ranges (UR) due to uncertainty in model input values. The first method estimated asbestos-related lung cancer cases directly from observed and predicted mesothelioma cases in an age-period-cohort analysis. The second method used evidence on the fraction of lung cancer cases attributable (population attributable risk (PAR)) to asbestos exposure. The third method incorporated risk estimates and population exposure estimates to perform a life table analysis.

RESULTS

The three methods varied substantially in incorporated evidence. Moreover, the estimated number of asbestos-related lung cancer cases in the Netherlands between 2011 and 2030 depended crucially on the actual method applied, as the mesothelioma method predicts 17 500 expected cases (UR 7000-57 000), the PAR method predicts 12 150 cases (UR 6700-19 000), and the life table analysis predicts 6800 cases (UR 6800-33 850).

CONCLUSIONS

The three different methods described resulted in absolute estimates varying by a factor of ∼2.5. These results show that accurate estimation of the impact of asbestos exposure on the lung cancer burden remains a challenge.

Elevated expression of TGIF is involved in lung carcinogenesis

The purpose of this study was to explore the expression of TG-interacting factor (TGIF) in lung carcinogenesis. Malignant transformation of human bronchial epithelial (16HBE) cell was established by benzo(a)pyrene (BaP) treatment. Soft agar assay and tumor formation assay in nude mice were applied. Tumorigenesis experiment in vivo was done by BaP treatment. Western blotting, immunohistochemistry, and quantitative polymerase chain reaction were used to detect TGIF expression. We observed a higher level of TGIF messenger RNA (mRNA) in lung cancer tissues than that in paracancerous tissues. We observed significantly higher levels of TGIF mRNA and protein in A549 and H1299 cell lines than that in 16HBE cell. Increased expressions of TGIF protein and mRNA were observed in 16HBE cells induced by BaP treatment as compared to those in solvent control group. We observed significantly higher levels of TGIF mRNA and protein in 16HBE-BaP cells than that in 16HBE-control cells. We observed significantly higher levels of TGIF mRNA and protein in mice lung tissues treated with BaP than that in control group. Our results suggested that elevated expression of TGIF was involved in lung carcinogenesis.

Night shift work and lung cancer risk among female textile workers in Shanghai, China

In 2007, the International Agency for Research on Cancer classified shift work that involves circadian disruption as a probable human carcinogen. Suppression of the anti-neoplastic hormone, melatonin, is a presumed mechanism of action. We conducted a case-cohort study nested within a cohort of 267,400 female textile workers in Shanghai, China. Newly diagnosed lung cancer cases (n = 1451) identified during the study period (1989-2006) were compared with an age-stratified subcohort (n = 3040). Adjusting for age, smoking, parity, and endotoxin exposure, relative risks [hazard ratios (HRs)] were estimated by Cox regression modeling to assess associations with cumulative years and nights of rotating shift work. Results did not consistently reveal any increased risk of lung cancer among rotating shift work or statistically significant trends for both cumulative years (HR 0.82, 95% CI 0.66 to 1.02; P(trend) = 0.294) and nights (HR 0.81, 95% CI 0.65 to 1.00; P(trend) = 0.415). Further analyses imposing 10- and 20-year lag times for disease latency also revealed similar results. Contrary to the initial hypothesis, rotating nighttime shift work appears to be associated with a relatively reduced lung cancer risk although the magnitude of the effect was modest and not statistically significant.

Occupational asbestos exposure and risk of pleural mesothelioma, lung cancer, and laryngeal cancer in the prospective Netherlands cohort study

OBJECTIVE

To study the association between occupational asbestos exposure and pleural mesothelioma, lung cancer, and laryngeal cancer, specifically addressing risk associated with the lower end of the exposure distribution, risk of cancer subtypes, and the interaction between asbestos and smoking.

METHODS

Using the Netherlands Cohort Study (n = 58,279 men, aged 55 to 69 years), asbestos exposure was estimated by linkage to job-exposure matrices. After 17.3 years of follow-up, 132 pleural mesothelioma, 2324 lung cancer, and 166 laryngeal cancer cases were available.

RESULTS

The multivariable-adjusted model showed overall positive associations between all levels of asbestos exposure and mesothelioma, lung cancer, and laryngeal cancer. Lung adenocarcinoma and glottis cancer showed only a positive association after prolonged higher asbestos exposure (hazard ratio per 10 years increment, 1.43 [95% confidence interval, 1.06 to 1.93] and 1.95 [95% confidence interval, 1.36 to 2.80], respectively). There was no statistically significant interaction between asbestos and smoking.

CONCLUSIONS

Asbestos levels encountered at the lower end of the exposure distribution may be associated with an increased risk of pleural mesothelioma, lung cancer, and laryngeal cancer.

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.

A comparison of exposure assessment approaches: lung cancer and occupational asbestos exposure in a population-based case-control study

OBJECTIVES

In attempts to overcome the limitations of self-reported data in occupational health research, job-exposure matrices, which assign exposure by occupation, have emerged as an objective approach for assessing occupational exposures. On the basis of a lung cancer case-control study conducted in the Greater Toronto Area, 1997-2002, assessment of occupational exposure to asbestos was compared using self-reports and a general population job-exposure matrix (DOM-JEM).

METHODS

Cases and frequency matched controls provided life-time job histories and self-reported exposures to potential lung carcinogens including asbestos through a detailed questionnaire. Exposure to asbestos was also assigned to each job by linking occupational histories with DOM-JEM. Agreement in classification of exposed and unexposed jobs according to self-reports and DOM-JEM was evaluated using Cohen's κ. Risks for lung cancer were estimated using unconditional logistic regression for each exposure assessment approach.

RESULTS

The prevalence of occupational asbestos exposure was greater when based on DOM-JEM than when based on self-reports. Agreement in classifying exposure to jobs between the two assessment approaches was poor. The risk of lung cancer was not elevated among workers who self-reported asbestos exposure, whereas workers considered exposed on the basis of DOM-JEM were almost twice as likely as unexposed workers to be diagnosed with lung cancer (OR 1.9, 95% CI 1.3 to 2.7).

CONCLUSIONS

It is generally assumed by epidemiologists that self-reported exposure assessments result in inflated risk estimates. In this study, self-reports found no association with a well-established risk factor, whereas a high-quality job-exposure matrix revealed relative risk estimates that are more consistent with previous findings.

Lung cancer risk at low cumulative asbestos exposure: meta-regression of the exposure-response relationship

PURPOSE

Existing estimated lung cancer risks per unit of asbestos exposure are mainly based on, and applicable to, high exposure levels. To assess the risk at low cumulative asbestos exposure, we provide new evidence by fitting flexible meta-regression models, a notably new and more robust method.

METHODS

Studies were selected if lung cancer risk per cumulative asbestos exposure in at least two exposure categories was reported. From these studies (n = 19), we extracted 104 risk estimates over a cumulative exposure range of 0.11-4,710 f-y/ml. We fitted linear and natural spline meta-regression models to these risk estimates. A natural spline allows risks to vary nonlinearly with exposure, such that estimates at low exposure are less affected by estimates in the upper exposure categories. Associated relative risks (RRs) were calculated for several low cumulative asbestos exposures.

RESULTS

A natural spline model fitted our data best. With this model, the relative lung cancer risk for cumulative exposure levels of 4 and 40 f-y/ml was estimated between 1.013 and 1.027, and 1.13 and 1.30, respectively. After stratification by fiber type, a non-significant three- to fourfold difference in RRs between chrysotile and amphibole fibers was found for exposures below 40 f-y/ml. Fiber-type-specific risk estimates were strongly influenced by a few studies.

CONCLUSIONS

The natural spline regression model indicates that at lower asbestos exposure levels, the increase in RR of lung cancer due to asbestos exposure may be larger than expected from previous meta-analyses. Observed potency differences between different fiber types are lower than the generally held consensus. Low-exposed industrial or population-based cohorts with quantitative estimates of asbestos exposure a required to substantiate the risk estimates at low exposure levels from our new, flexible meta-regression.

Arsenic, asbestos and radon: emerging players in lung tumorigenesis

The cause of lung cancer is generally attributed to tobacco smoking. However lung cancer in never smokers accounts for 10 to 25% of all lung cancer cases. Arsenic, asbestos and radon are three prominent non-tobacco carcinogens strongly associated with lung cancer. Exposure to these agents can lead to genetic and epigenetic alterations in tumor genomes, impacting genes and pathways involved in lung cancer development. Moreover, these agents not only exhibit unique mechanisms in causing genomic alterations, but also exert deleterious effects through common mechanisms, such as oxidative stress, commonly associated with carcinogenesis. This article provides a comprehensive review of arsenic, asbestos, and radon induced molecular mechanisms responsible for the generation of genetic and epigenetic alterations in lung cancer. A better understanding of the mode of action of these carcinogens will facilitate the prevention and management of lung cancer related to such environmental hazards.

Exposure to welding fumes increases lung cancer risk among light smokers but not among heavy smokers: evidence from two case-control studies in Montreal

We investigated relationships between occupational exposure to gas and arc welding fumes and the risk of lung cancer among workers exposed to these agents throughout the spectrum of industries. Two population-based case-control studies were conducted in Montreal. Study I (1979-1986) included 857 cases and 1066 controls, and Study II (1996-2001) comprised 736 cases and 894 controls. Detailed job histories were obtained by interview and evaluated by an expert team of chemist-hygienists to estimate degree of exposure to approximately 300 substances for each job. Gas and arc welding fumes were among the agents evaluated. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) of lung cancer using logistic regression, adjusting for smoking history and other covariates. The two studies provided similar results, so a pooled analysis was conducted. Among all subjects, no significant association was found between lung cancer and gas welding fumes (OR = 1.1; 95% CI = 0.9-1.4) or arc welding fumes (OR = 1.0; 95% CI = 0.8-1.2). However, when restricting attention to light smokers, there was an increased risk of lung cancer in relation to gas welding fumes (OR = 2.9; 95% CI = 1.7-4.8) and arc welding fumes (OR = 2.3; 95% CI = 1.3-3.8), with even higher OR estimates among workers with the highest cumulative exposures. In conclusion, there was no detectable excess risk of lung cancer due to welding fumes among moderate to heavy smokers; but among light smokers we found an excess risk related to both types of welding fumes.

Welding and lung cancer in Central and Eastern Europe and the United Kingdom

Occupation as a welder has been associated with a 25%-40% increase in lung cancer risk. This study aims to elucidate to what extent confounding by smoking and asbestos drives this association and to evaluate the role of welding-related exposures such as chromium. The study included 2,197 male incident lung cancer cases and 2,295 controls from Romania, Hungary, Poland, Russia, Slovakia, the Czech Republic, and the United Kingdom from 1998 to 2001. Information on risk factors was collected through face-to-face interviews. Experts assessed exposure to 70 agents, and risk estimates were adjusted for smoking and occupational exposures. Occupation as a welder/flame cutter (prevalence controls: 3.7%) was associated with an odds ratio of 1.36 (95% confidence interval (CI): 1.00, 1.86) after adjustment for smoking and occupational exposures including asbestos. An odds ratio of 1.18 (95% CI: 1.01, 1.38) was found for welding fumes (prevalence controls: 22.8%), increasing to 1.38 for more than 25 exposure years (95% CI: 1.09, 1.75). A duration-response association was also observed for mild steel welding without chromium exposure. In this population, occupational exposure to welding fumes accounted for approximately 4% of lung cancer cases, to which both stainless and mild steel welding contributed equally. Given that welding remains a common task for many workers, exposure to welding fumes represents an important risk factor for lung cancer.

Occupational risks and lung cancer burden for Chinese men: a population-based case-referent study

OBJECTIVE

We aimed to fill in the gap of knowledge on the lung cancer burden resulting from occupational exposures among Chinese men through a population-based case-referent study.

METHODS

Detailed information on lifestyle and full occupational histories of 1,208 male lung cancer incident cases and 1,069 age-matched male community referents were obtained through interviews during 2004-2006. The associations between lung cancer risk and exposures to specific or group of agents that were confirmed or suspected occupational carcinogens were analyzed.

RESULTS

After adjustment of smoking and other potential confounding factors, significant odds ratio of lung cancer was observed for workers employed in major industrial divisions of "construction" (1.37, 95% CI: 1.00-1.89) and "financing, insurance, real estate, and business services" (0.48, 95% CI: 0.23-0.97), as well as in the occupational groups of "bricklayers, carpenters, and other construction workers" (1.49, 95% CI: 1.07-2.06). Significantly elevated odds ratios were found for occupational exposures to silica dust (1.75, 95% CI: 1.16-2.62), welding fumes (1.74, 95% CI: 1.13-2.68), diesel exhaust (2.18, 95% CI: 1.23-3.84), and man-made mineral fibers (7.45, 95% CI: 1.63-34.00), while a significantly reduced risk (OR = 0.67, 95% CI: 0.47-0.95) was linked to cotton dust. The population attributable fraction of lung cancer was 3.2% (95% CI: 0.1-7.3%) for construction workers and 9.5% (95% CI: 4.8-15.1%) for the four significant specific exposures.

CONCLUSIONS

Our study indicates that previous exposure to occupational carcinogens remains an important determinant of lung cancer burden for Hong Kong Chinese men. However, results obtained from this study should be confirmed by future analyses based on job exposure matrix.

Lung cancer risk in painters: a meta-analysis

We conducted a meta-analysis to quantitatively compare the association between occupation as a painter and the incidence or mortality from lung cancer. PubMed and the reference lists of pertinent publications were searched and reviewed. For the meta-analysis, we used data from 47 independent cohort, record linkage, and case-control studies (from a total of 74 reports), including > 11,000 incident cases or deaths from lung cancer among painters. Three authors independently abstracted data and assessed study quality. The summary relative risk (meta-RR, random effects) for lung cancer in paint-ers was 1.35 [95% confidence interval (CI), 1.29-1.41; 47 studies] and 1.35 (95% CI, 1.21-1.51; 27 studies) after controlling for smoking. The relative risk was higher in never-smokers (meta-RR = 2.00; 95% CI, 1.09-3.67; 3studies) and persisted when restricted to studies that adjusted for other occupational exposures (meta-RR = 1.57; 95% CI, 1.21-2.04; 5 studies). These results support the conclusion that occupational exposures in painters are causally associated with the risk of lung cancer.

Clinical study of asbestos-related lung cancer in Japan with special reference to occupational history

A total of 152 patients with asbestos-related lung cancer recognized by the criteria of Japanese compensation law for asbestos-related diseases were examined and compared with 431 patients with non-asbestos-related lung cancer. Male comprised 96% of patients. Ages ranged from 50 to 91 years with a median of 72 years. Eighty-nine percent were smokers or ex-smokers. Almost all patients had occupational histories of asbestos exposure. The median duration of asbestos exposure was 31 years and the median latency period was 47 years. Thirty-four percent of patients exhibited asbestosis and 81% exhibited pleural plaques by radiography. Regarding asbestos particles in the lung for 73 operated or autopsied patients, 62% had more than 5,000 particles per gram. On the other hand, 100% of non-asbestos-related lung cancer patients had <5000 particles per gram with a median of 554 particles. The number of asbestos bodies in the lung, male gender, absence of symptoms, smoking index, and early stage of cancer were significantly much more than those of non-asbestos-related lung cancer. In this study, a diagnosis of asbestos-related lung cancer was made in 34% of patients by asbestosis, in 62% by presence of both pleural plaques and more than 10 years' occupational asbestos exposure, and in 4% by more than 5000 asbestos particles per gram of lung tissue. Occupational histories, duration of asbestos exposure, and pleural plaques are common categories for the recognition of asbestos-related lung cancer in Japan.

Meta-analyses of occupational exposure as a painter and lung and bladder cancer morbidity and mortality 1950-2008

The International Agency for Research on Cancer (IARC) classified occupational painting as a human carcinogen based on lung and bladder cancers; however, no specific exposures were implicated. The authors conducted comprehensive meta-analyses of the epidemiological literature on occupational painting and these cancers. The authors abstracted study results and confounder information, and used quantile plots and regression models to evaluate heterogeneity and publication bias. Summary risk estimates were derived and sensitivity analyses performed to evaluate smoking, socioeconomic status (SES), and exposure variables. Where applicable, a Bayesian approach was used to externally adjust for smoking, a major risk factor for both cancers. For lung cancer cohort mortality studies, publication bias and heterogeneity were seen, and earlier studies reported higher risk estimates than later studies. Overall lung cancer summary risk estimates were 1.29 for case-control and 1.22 and 1.36 for cohort morbidity and mortality studies, respectively, and risk estimates for bladder cancer were 1.28 for case-control and 1.14 and 1.27 for cohort morbidity and mortality studies, respectively (all statistically significant). Risks did not differ between painters and mixed occupations. Nonsignificant summary estimates resulted for lung and bladder cancers when controlling for SES, or externally adjusting for smoking in lung cancer studies. Summary risks varied by control source for case-control studies. Residual confounding by smoking and SES, lack of exposure group effect, and publication bias limit the ability of the meta-analyses to explain associations observed between occupational painting and lung and bladder cancers. Given the long latencies for lung and bladder cancers, these weak associations, if real, may not be elucidated through studies of occupational painting today.

Lung cancer risk in painters: a meta-analysis

OBJECTIVE

We conducted a meta-analysis to quantitatively compare the association between occupation as a painter and the incidence or mortality from lung cancer.

DATA SOURCES

PubMed and the reference lists of pertinent publications were searched and reviewed. For the meta-analysis, we used data from 47 independent cohort, record linkage, and case control studies (from a total of 74 reports), including > 11,000 incident cases or deaths from lung cancer among painters.

DATA EXTRACTION

Three authors independently abstracted data and assessed study quality.

DATA SYNTHESIS

The summary relative risk (meta-RR, random effects) for lung cancer in painters was 1.35 [95% confidence interval (CI), 1.291.41; 47 studies] and 1.35 (95% CI, 1.211.51; 27 studies) after controlling for smoking. The relative risk was higher in never-smokers (meta-RR = 2.00; 95% CI, 1.093.67; 3 studies) and persisted when restricted to studies that adjusted for other occupational exposures (meta-RR = 1.57; 95% CI, 1.212.04; 5 studies). The results remained robust when stratified by study design, sex, and study location and are therefore unlikely due to chance or bias. Furthermore, exposure response analyses suggested that the risk increased with duration of employment.

CONCLUSION

These results support the conclusion that occupational exposures in painters are causally associated with the risk of lung cancer.

Platinum versus non-platinum chemotherapy regimens for small cell lung cancer

BACKGROUND

Small cell lung cancer (SCLC) is a very fast growing form of cancer and is characterised by early metastasis. As a result, chemotherapy is the mainstay of treatment. A number of different platinum-based chemotherapy regimens and non-platinum-based chemotherapy regimens have been used for the treatment of SCLC, with varying results. This review was conducted to analyse the data from these trials in order to compare their effectiveness.

OBJECTIVES

To determine the effectiveness of platinum chemotherapy regimens compared with non-platinum chemotherapy regimens in the treatment of SCLC with respect to survival, tumour response, toxicity and quality of life.

SEARCH STRATEGY

We searched the biomedical literature databases CENTRAL (The Cochrane Library 2007, Issue 2), MEDLINE, EMBASE and CINAHL from 1966 to April 2007. In addition, we handsearched reference lists from relevant resources.

SELECTION CRITERIA

All randomised controlled trials involving patients with pathologically confirmed (cytological or histological) SCLC and the use of a platinum-based chemotherapy regimen in at least one treatment arm and a non-platinum-based chemotherapy regimen in a separate arm.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed search results. We assessed included studies for methodological quality and recorded the following outcome data: survival, tumour response, toxicity and quality of life. We combined the results of the survival, tumour response and toxicity data in a meta-analysis.

MAIN RESULTS

A total of 29 trials involving 5530 patients were included in this systematic review. There was no statistically significant difference between treatment groups in terms of survival at 6 months, 12 months and 24 months. There was also no statistically significant difference in terms of overall tumour response. However, platinum-based treatment regimens did have a significantly higher rate of complete response. Platinum-based chemotherapy regimens had significantly higher rates of nausea and vomiting, anaemia and thrombocytopenia toxicity. Three trials presented quality of life data but the data presented were not complete and therefore could not be combined in a meta-analysis.

AUTHORS' CONCLUSIONS

Platinum-based chemotherapy regimens did not offer a statistically significant benefit in survival or overall tumour response compared with non-platinum-based regimens. However, platinum-based chemotherapy regimens did increase complete response rates, at the cost of higher adverse events including nausea and vomiting, anaemia and thrombocytopenia toxicity. These data suggest non-platinum chemotherapy regimens have a more advantageous risk-benefit profile. This systematic review highlights the lack of quality of life data in trials involving chemotherapy treatment for SCLC. With poor long-term survival associated with both treatment groups, the issue of the quality of the survival period takes on even more significance. It would be beneficial for future trials in this area to include a quality of life assessment.

Expert assessment of exposure to carcinogens in Norway's offshore petroleum industry

This study presents and evaluates an expert group's assessment of exposure to carcinogens for defined job categories in Norway's offshore petroleum industry, 1970-2005, to provide exposure information for a planned cohort study on cancer. Three university and five industry experts in occupational hygiene individually assessed the likelihood of exposure to 1836 combinations of carcinogens (n=17), job categories (n=27) and time periods (n=4). In subsequent plenary discussions, the experts agreed on exposed combinations. Agreement between the individual and the panel assessments was calculated by Cohen's kappa index. Using the panel assessment as reference, sensitivity and specificity were estimated. The eight experts assessed 63% of the 1836 combinations in plenary, resulting in 265 (14%) convened exposed combinations. Chlorinated hydrocarbons, benzene and inhalation of mineral oils had the highest number of exposed job categories (n=14, 9 and 10, respectively). The job categories classified as exposed to the highest numbers of carcinogens were the mechanics (n=10), derrick workers (n=6) and process technicians (n=5). The agreement between the experts' individual assessments and the panel assessment was kappa=0.53-0.74. The sensitivity was 0.55-0.86 and specificity 0.91-0.97. For these parameters, there were no apparent differences between the university experts and the industry experts. The resulting 265 of 1836 possible exposure combinations convened as "exposed" by expert assessment is presented in this study. The experts' individual ratings highly agreed with the succeeding panel assessment. Correlation was found between years of experience of the raters and agreement with the panel. The university experts and the industry experts' assessments had no apparent differences. Further validation of the exposure assessment is suggested, such as by new sampling data or observational studies.

Factores etiológicos del cáncer de pulmón: fumador activo, fumador pasivo, carcinógenos medioambientales y factores genéticos

Every year, in Spain 18,000 new cases of lung cancer (LC) are diagnosed. Approximately, 80-90% LC in men and women are directly attributable to tobacco abuse. Cigarette smoke contains over 300 chemicals, 40 of which are known to be potent carcinogens. In the last decade, as in Spain, prevalence of smoking in women has generally increased in the European Union. LC risk can be substantially reduced after smoking cessation, yet never reaches baseline. On the other hand, environmental tobacco smoke exposure (passive smoking) in nonsmokers appears to have a significantly increased risk of LC. An updated of etiology factors of LC, risk related to duration as well as intensity of smoking, relationship between environmental tobacco smoke exposure and LC risk, genetic predisposition and a variety of occupational and environmental exposures implicated as potential risk factors for the development of LC will be reviewed here.

Lung Cancer in Never Smokers: A Review

Lung cancer is the leading cause of cancer-related death in the United States. Although tobacco smoking accounts for the majority of lung cancer, approximately 10% of patients with lung cancer in the United States are lifelong never smokers. Lung cancer in the never smokers (LCINS) affects women disproportionately more often than men. Only limited data are available on the etiopathogenesis, molecular abnormalities, and prognosis of LCINS. Several etiologic factors have been proposed for the development of LCINS, including exposure to radon, cooking fumes, asbestos, heavy metals, and environmental tobacco smoke, human papillomavirus infection, and inherited genetic susceptibility. However, the relative significance of these individual factors among different ethnic populations in the development of LCINS has not been well-characterized. Adenocarcinoma is the predominant histologic subtype reported with LCINS. Striking differences in response rates and outcomes are seen when patients with advanced non–small-cell lung cancer (NSCLC) who are lifelong never smokers are treated with epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors such as gefitinib or erlotinib compared with the outcomes with these agents in patients with tobacco-associated lung cancer. Interestingly, the activating mutations in the EGFR-TK inhibitors have been reported significantly more frequently in LCINS than in patients with tobacco-related NSCLC. This review will summarize available data on the epidemiology, risk factors, molecular genetics, management options, and outcomes of LCINS.

The influence of occupational exposure to pesticides, polycyclic aromatic hydrocarbons, diesel exhaust, metal dust, metal fumes, and mineral oil on prostate cancer: a prospective cohort study

AIMS

To investigate the relation between exposure to pesticides, polycyclic aromatic hydrocarbons (PAHs), diesel exhaust, metal dust, metal fumes, and mineral oil in relation to prostate cancer incidence in a large prospective study.

METHODS

This cohort study was conducted among 58,279 men in the Netherlands. In September 1986, cohort members (55-69 years) completed a self-administered questionnaire on potential cancer risk factors, including job history. Follow up for prostate cancer incidence was established by linkage to cancer registries until December 1995 (9.3 years of follow up). The analyses included 1386 cases of prostate cancer and 2335 subcohort members. A blinded case-by-case expert exposure assessment was carried out to assign cases and subcohort members a cumulative probability of exposure for each potential carcinogenic exposure.

RESULTS

In multivariate analyses there was a significant negative association for pesticides (RR 0.60; 95% CI 0.37 to 0.95) when comparing the highest tertile of exposure to pesticides with no exposure. No association was found for occupational exposure to PAHs (RR 0.75; 95% CI 0.42 to 1.31), diesel exhaust (RR 0.81; 95% CI 0.62 to 1.06), metal dust (RR 1.01; 95% CI 0.72 to 1.40), metal fumes (RR 1.11; 95% CI 0.80 to 1.54), or mineral oil (RR 0.99; 95% CI 0.66 to 1.48) when comparing the highest tertile of exposure with no exposure. In subgroup analysis, with respect to tumour invasiveness and morphology, null results were found for occupational exposure to pesticides, PAH, diesel exhaust, metal dust, metal fumes, and mineral oil.

CONCLUSIONS

These results suggest a negative association between occupational exposure to pesticides and prostate cancer. For other carcinogenic exposures results suggest no association between occupational exposure to PAHs, diesel exhaust, metal dust, metal fumes, or mineral oil and prostate cancer.

After Helsinki: a multidisciplinary review of the relationship between asbestos exposure and lung cancer, with emphasis on studies published during 1997-2004

Despite an extensive literature, the relationship between asbestos exposure and lung cancer remains the subject of controversy, related to the fact that most asbestos-associated lung cancers occur in those who are also cigarette smokers: because smoking represents the strongest identifiable lung cancer risk factor among many others, and lung cancer is not uncommon across industrialised societies, analysis of the combined (synergistic) effects of smoking and asbestos on lung cancer risk is a more complex exercise than the relationship between asbestos inhalation and mesothelioma. As a follow-on from previous reviews of prevailing evidence, this review critically evaluates more recent studies on this relationship--concentrating on those published between 1997 and 2004--including lung cancer to mesothelioma ratios, the interactive effects of cigarette smoke and asbestos in combination, and the cumulative exposure model for lung cancer induction as set forth in The Helsinki Criteria and The AWARD Criteria (as opposed to the asbestosis-->cancer model), together with discussion of differential genetic susceptibility/resistance factors for lung carcinogenesis by both cigarette smoke and asbestos. The authors conclude that: (i) the prevailing evidence strongly supports the cumulative exposure model; (ii) the criteria for probabilistic attribution of lung cancer to mixed asbestos exposures as a consequence of the production and end-use of asbestos-containing products such as insulation and asbestos-cement building materials--as embodied in The Helsinki and AWARD Criteria--conform to, and are further consolidated by, the new evidence discussed in this review; (iii) different attribution criteria (e.g., greater cumulative exposures) are appropriate for chrysotile mining/milling and perhaps for other chrysotile-only exposures, such as friction products manufacture, than for amphibole-only exposures or mixed asbestos exposures; and (iv) emerging evidence on genetic susceptibility/resistance factors for lung cancer risk as a consequence of cigarette smoking, and potentially also asbestos exposure, suggests that genotypic variation may represent an additional confounding factor potentially affecting the strength of association and hence the probability of causal contribution in the individual subject, but at present there is insufficient evidence to draw any meaningful conclusions concerning variation in asbestos-mediated lung cancer risk relative to such resistance/susceptibility factors.

Epidemiology, etiology, and prevention of lung cancer

Over the past century, lung cancer has gone from an obscure disease to the leading cause of cancer death worldwide. Initially an epidemic disease among men in industrialized nations, lung cancer now has become the leading cancer killer in both sexes in the United States and an increasingly common disease of both sexes in developing countries. Lung cancer incidence largely mirrors smoking prevalence, with a latency period of several decades. Other important risk factors for the development of lung cancer include environmental exposure to tobacco smoke, radon, occupational carcinogens, and pre-existing nonmalignant lung disease. Studies in molecular biology have elucidated the role that genetic factors play in modifying an individual's risk for lung cancer. Although chemopreventive agents may be developed to prevent lung cancer, prevention of smoking initiation and promotion of smoking cessation are currently the best weapons to fight lung cancer. No other malignancy has been shown to have such a strong epidemiologic relation between a preventable behavior and incidence of disease. Despite this knowledge, more than 20% of all Americans smoke, and tobacco use is exploding in developing countries. Based on current and projected smoking patterns, it is anticipated that lung cancer will remain the leading cause of cancer death in the world for decades to come.

Occupational risk factors for male bladder cancer: results from a population based case cohort study in the Netherlands

OBJECTIVES

This study was conducted to estimate risk of bladder cancer associated with occupational exposures to paint components, polycyclic aromatic hydrocarbons (PAHs), diesel exhausts, and aromatic amines among the general population in The Netherlands.

METHODS

A prospective cohort study was conducted among 58,279 men. In September 1986, the cohort members (55-69 years) completed a self administered questionnaire on risk factors for cancer including job history. Follow up for incident bladder cancer was established by linkage to cancer registries until December 1992. A case-cohort approach was used based on 532 cases and 1630 subcohort members. A case by case expert assessment was carried out to assign to the cases and subcohort members a cumulative probability of occupational exposure for each carcinogenic exposure.

RESULTS

Men in the highest tertiles of occupational exposure to paint components, PAHs, aromatic amines, and diesel exhaust had non-significantly higher age and smoking adjusted incident rate ratios (RRs) of bladder cancer than men with no exposure: 1.29 (95% confidence interval (95% CI) 0.71 to 2.33), 1.24 (95% CI 0.68 to 2.27), 1.32 (95% CI 0.41 to 4.23) and 1.21 (95% CI 0.78 to 1.88), respectively. The associations between paint components and PAHs and risk of bladder cancer were most pronounced for current smokers. Among former smokers it seemed that for cumulative probability of exposure to paint components and PAHs, men who had smoked more than 15 cigarettes a day had RRs below unity compared with men who had smoked less than 15 cigarettes a day, whereas among current smokers the opposite was found. Exposure to diesel exhaust was positively associated with risk of bladder cancer among current and former smokers who had smoked more than 15 cigarettes a day.

CONCLUSIONS

This study provided only marginal evidence for an association between occupational exposure to paint components, PAHs, aromatic amines, and bladder cancer. Despite the small proportion of exposed subjects, an interaction with cigarette smoking was found, specifically for paint components, suggesting that the carcinogenic effect on the bladder might decrease after stopping smoking.

Occupational exposure and lung cancer risk: a population-based case-referent study in Sweden

This case-referent study investigated the lung cancer risk from occupational exposure to diesel exhaust, mixed motor exhaust, other combustion products, asbestos, metals, oil mist, and welding fumes. All cases of lung cancer in males aged 40-75 years among stable residents of Stockholm County, Sweden, were identified from 1985 to 1990. Referents were selected as a stratified (age, inclusion year) random sample. Information on lifetime occupational history, residency, and tobacco smoking was obtained from the study subjects or from next of kin. Response rates of 87% and 85% resulted in 1,042 cases and 2,364 referents, respectively. Occupational exposures were assessed by an occupational hygienist who coded the intensity and probability of each exposure. Risk estimates were adjusted for tobacco smoking, other occupational exposures, residential radon, and environmental exposure to traffic-related air pollution. For the highest quartile of cumulative exposure versus no exposure, the relative risk was 1.63 (95% confidence interval (CI): 1.14, 2.33) for diesel exhaust, 1.60 (95% CI: 1.09, 2.34) for combustion products, and 1.68 (95% CI: 1.15, 2.46) for asbestos. Dose-response analyses indicated an increase in lung cancer risk of 14% per fiber-year/ml for asbestos exposure. No increased risk was found for the other exposure factors. An overall attributable proportion of 9.5% (95% CI: 5.5, 13.9) was estimated for lung cancer related to diesel exhaust, other combustion products, and asbestos.

Asbestos exposure in lung carcinoma: a necropsy-based study of 414 cases

BACKGROUND

The prerequisites necessary for attributing lung carcinoma to asbestos, represent a controversial issue.

METHODS

Three parameters (occupational history, pleural plaques, and lung asbestos bodies) were investigated in 414 consecutive cases of lung carcinoma, examined at necropsy at the Hospital of Monfalcone, Italy. Occupational data were obtained from the patients' relatives by personal or telephone interviews. Pleural plaques were classified into three classes (small, moderate, large). Routine lung sections were examined for asbestos bodies in all cases; isolation and counting were performed in 408 cases.

RESULTS

The series included 353 men, and 61 women, aged between 38 and 97 years. The male patients had worked in industries in 74% of cases (60% in shipbuilding). Men showed pleural plaques in 82% of cases (moderate or large plaques in 58.7%). Asbestos bodies were observed in routine lung sections in 34.8%, and in 31% exceeded the value of 5,000 bodies per gram of dried tissue. Among women the principal features were: history or domestic exposure to asbestos in 36% of the cases, prevalence of pleural plaques 34% (moderate or large plaques 15%), asbestos bodies in routine lung sections in 3.3% and there was no case with an asbestos body burden over 5,000/g. The fraction of asbestos-related carcinomas among male patients varied between 24.7 and 61%, depending on the criteria used for attribution.

CONCLUSIONS

Different criteria indicated about 60% of the present lung carcinomas among men as plausibly attributable to asbestos.

Rheumatic syndromes: clues to occult neoplasia

OBJECTIVES

Rheumatic disorders associated with cancer include a variety of conditions, most of which have no features distinguishing them from idiopathic rheumatic disorders. It is generally held that an extensive search for occult malignancy in most rheumatic syndromes is not recommended unless accompanied by specific findings suggestive of malignancy. The objective of this review are to identify rheumatic syndromes associated with cancer, to call attention to features that may suggest the presence of a hidden cancer, and to examine the role to additional clinical and laboratory data as clues to the possible neoplastic cause of those syndromes.

METHODS

A MEDLINE search of the literature dealing with cancer-associated rheumatic syndromes was conducted.

RESULTS

Review of the literature identified significant progress in this area. First, the association of malignancy with certain rheumatic syndromes was convincingly established, such as asymmetric polyarthritis presenting in the elderly with an explosive onset, rheumatoid arthritis with monoclonal gammopathy, Sjögren's syndrome with monoclonality, hypertrophic osteoarthropathy, dermatomyositis, polymyalgia rheumatica with atypical features, Lambert-Eaton myasthenic syndrome, palmar fasciitis and arthritis, eosinophilic fasciitis poorly responsive to corticosteroid therapy, erythema nodosum lasting more than 6 months, and onset of Raynaud's phenomenon or cutaneous leukocytoclastic vasculitis after age 50 years. Second, the list of cancer-associated rheumatic syndromes was extended by including additional entities such as benign edematous polysynovitis, sacroiliitis, adult-onset Still's disease, dermatomyositis sine myositis, systemic sclerosis, Sweet's syndrome, osteomalacia, skeletal hyperostosis, antiphospholipid syndrome, and essential mixed cryoglobulinemia. Third, evidence was provided substantiating that certain long-standing rheumatic syndromes, in particular rheumatoid arthritis, Felty's syndrome, Sjögren's syndrome, dermatomyositis, systemic sclerosis, systemic lupus erythematosus, and temporal arteritis behave like "premalignant conditions." Fourth, it was shown that the recognized tumor markers alpha-fetoprotein, prostate-specific antigen, CA-125, CA 19-9, and CA-3 have low sensitivity and specificity in screening for occult cancer in a population of rheumatic patients, whereas the presence of a monoclonal gammopathy in rheumatoid arthritis and the monoclonal antibody 17-109 in Sjögren's syndrome are reliable signs of malignant transformation.

CONCLUSIONS

The presence of specific rheumatic syndromes and certain clinical and laboratory findings may justify a workup for hidden cancer. Studies of the epidemiology of the cancer-associated rheumatic syndromes and evaluation of the validity of aforementioned clues in prospective studies are goals for future investigations.

Asbestos and cancer: An overview of current trends in Europe

This review assesses the contribution of occupational asbestos exposure to the occurrence of mesothelioma and lung cancer in Europe. Available information on national asbestos consumption, proportions of the population exposed, and exposure levels is summarized. Population-based studies from various European regions on occupational asbestos exposure, mesothelioma, and lung cancer are reviewed. Asbestos consumption in 1994 ranged, per capita, between 0. 004 kg in northern Europe and 2.4 kg in the former Soviet Union. Population surveys from northern Europe indicate that 15 to 30% of the male (and a few percent of the female) population has ever had occupational exposure to asbestos, mainly in construction (75% in Finland) or in shipyards. Studies on mesothelioma combining occupational history with biologic exposure indices indicate occupational asbestos exposure in 62 to 85% of the cases. Population attributable risks for lung cancer among males range between 2 and 50% for definite asbestos exposure. After exclusion of the most extreme values because of methodologic aspects, most of the remaining estimates are within the range of 10 to 20%. Estimates of women are lower. Extrapolation of the results to national figures would decrease the estimates. Norwegian estimates indicate that one-third of expected asbestos-related lung cancers might be avoided if former asbestos workers quit smoking. The combination of a current high asbestos consumption per capita, high exposure levels, and high underlying lung cancer rates in Central Europe and the former Soviet Union suggests that the lung cancers will arise from the smoking-asbestos interaction should be a major concern.