Alterations in the laryngeal mucosa after exposure to asbestos (original) (raw)
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Modern Pathology, 2019
Asbestos describes a group of naturally occurring fibrous silicate mineral compounds that have been associated with a number of respiratory maladies, including mesothelioma and lung cancer. In addition, based primarily on epidemiologic studies, asbestos has been implicated as a risk factor for laryngeal and pharyngeal squamous cell carcinoma (SCC). The main objective of this work was to strengthen existing evidence via empirical demonstration of persistent asbestos fibers embedded in the tissue surrounding laryngeal and pharyngeal SCC, thus providing a more definitive biological link between exposure and disease. Six human papillomavirus (HPV)-negative laryngeal (n = 4) and pharyngeal (n = 2) SCC cases with a history working in an asbestos-exposed occupation were selected from a large population-based case-control study of head and neck cancer. A laryngeal SCC case with no history of occupational asbestos exposure was included as a control. Tissue cores were obtained from adjacent nonneoplastic tissue in tumor blocks from the initial primary tumor resection, and mineral fiber analysis was performed using a scanning electron microscope equipped with an energy dispersive X-ray analyzer (EDXA). Chrysotile asbestos fiber bundles were identified in 3/6 of evaluated cases with a history of occupational asbestos exposure. All three cases had tumors originating in the larynx. In addition, a wollastonite fiber of unclear significance was identified one of the HPV-negative pharyngeal SCC cases. No mineral fibers were identified in adjacent tissue of the case without occupational exposure. The presence of asbestos fibers in the epithelial tissue surrounding laryngeal SCC in cases with a history of occupational asbestos exposure adds a key line of physical evidence implicating asbestos as an etiologic factor.
Annals of Occupational Hygiene, 2007
The aim of this study was to assess the reliability of asbestos fibre concentration in bronchoalveolar lavage fluid (BALF) by carrying out the mineralogical analysis of BALF at different times in the same patient and comparing the results. Twenty two patients underwent diagnostic fibreoptic bronchoscopy twice: the first was to assess the past asbestos exposure and the second for different clinical reasons. Mineralogical analysis of BALF was carried out. In 16 patients (72.7%), a reduction of concentration in BALF of all asbestos fibres was observed. The concentrations of both chrysotile and amphiboles in the first bronchoalveolar lavage (BAL) were related to their concentrations in the second BAL and the observed differences were not statistically significant. A significant decrease in asbestos body concentration between the first and the second BAL was found (Wilcoxon test, P < 0.01). The reliability of the fibre concentration in BALF as a marker of past asbestos exposure seems quite good. In most cases, it allows us to distinguish workers in different classes of exposure and gives useful information on the pattern of exposure. Uncertainties related in general to lung residues and in particular to mineralogical analysis of BALF (mainly due to the high coefficient of variation (CV) at low fibre concentrations and the results of the statistical analysis on total fibres) suggest that this biomarker is more likely suitable for a qualitative/categorical approach to exposure assessment than a quantitative one.
Giornale italiano di medicina del lavoro ed ergonomia
Twenty-five subjects (24 males and 1 female, mean age 57.4 years) who have been exposed to asbestos underwent chest radiography, high resolution computed tomography (HRCT) of the chest, lung function tests and bronchoalveolar lavage (BAL) for evaluation of cell components (total cell count, percentages of macrophages, lymphocytes, neutrophil and eosinophil granulocytes and the lymphocyte subpopulations CD3+, CD4+, CD8+, CD19+ and HLADR+), soluble factors (IL-8, IL-10, IL-12 and MCP-1 in the supernatant) and concentration of asbestos fibre. The subjects were subdivided according to the degree of their exposure, to the concentration of asbestos fibres in the BAL and to chest X-ray findings using the I.L.O. classification (0/0pl, 0/1 and 1/0 and above). According to the exposure index, we showed statistically significant (p < 0.05) higher lymphocytes percentage in the BAL of subjects with moderate exposure and significantly higher levels of IL-10 (p < 0.05) in the supernatant of ...
Asbestosis, laryngeal carcinoma, and malignant peritoneal mesothelioma in an insulation worker
Occupational and Environmental Medicine, 1991
Asbestos associated diseases consist of both benign and malignant conditions. A rare constellation of asbestosis, laryngeal carcinoma, and malignant peritoneal mesothelioma occurring in a patient with long term occupational exposure to airborne asbestos fibres is presented. The observation illustrates the powerful disease-causing potential of occupational exposure to asbestos. A brief discussion of multiple primary neoplasms associated with exposure to asbestos is also presented. Asbestos associated diseases continue to pose a major public health problem in the United States.' They include both benign disorders, such as asbestosis and asbestos related pleural abnormalities, and malignant conditions. The malignant group of disorders is represented primarily by lung cancer and malignant pleural or peritoneal mesothelioma. Epidemiological investigations have suggested that other neoplasms may also be associated with a history of exposure to airborne asbestos fibres. These include certain gastrointestinal neoplasms as well as cancer of the larynx.2 The increased risk of developing lung cancer among people exposed to asbestos is widely considered to be a synergistic effect between cigarette smoking and exposure.3 In this context, multiple aetiological factors, such as cigarette smoking, alcohol intake, and exposure to asbestos have also been suggested for cancer of the larynx.4 We report on a patient with pulmonary asbestosis who developed cancer of the larynx followed three months later by the clinical onset of malignant
Airway function in lifetime-nonsmoking older asbestos workers
The American Journal of Medicine, 1983
Previous studies of lung function in asbestos workers have documented airflow limitation in many of the workers, but the specific influence of asbestos exposure could not be clearly differentiated from the effects of the cigarette smoking habit. In this study, airway function was evaluated in lifetime-nonsmoking, long-term workers of the mines and mills of Québec. The 17 asbestos workers in this study had worked for an average of 28 years in the mines and mills of the local asbestos industry and did not have any other respiratory industrial dust exposure. They did not have a history of previous pulmonary disease and did not meet the usual diagnostic criteria for chronic bronchitis, emphysema, or asthma. Seven of the workers met the diagnostic criteria for asbestosis and 10 workers did not. The latter group of workers did not differ from a matched control group except in terms of a higher isoflow volume (p less than 0.05). The workers with asbestosis, however, had a restrictive pattern of lung function, increased isoflow volume, and increased upstream resistance at low lung volumes (p less than 0.01). Lung biopsy in three of the patients with the disease demonstrated peribronchiolar alveolitis and fibrosis with obliteration and narrowing of the small airways. These data on lifetime-nonsmoking, long-term asbestos workers provide further evidence of small airway obstruction associated with asbestos exposure and independent of the smoking habit. This airflow limitation was observed predominantly in workers with a restrictive pattern of lung function associated with peribronchiolar alveolitis. The lifetime-nonsmoking asbestos workers without restrictive patterns of lung function had minimal dysfunction of the peripheral airways.
ASBESTOS DISEASE IN MAINTENANCE WORKERS OF THE CHEMICAL INDUSTRY
Annals of the New York Academy of Sciences, 1979
In several large groups of workers employed in chemical plants, chest x-ray abnormalities (small irregular opacities and/or pleural changes) of the type known to be induced by asbestos were found in a proportion of those examined. A cross-sectional study of maintenance workers in a large chemical plant was undertaken to evaluate the prevalence of asbestosis; 185 workers were examined. Radiologic evidence of parenchymal interstitial fibrosis was found in 24% of those examined; in 10% of workers, parenchymal fibrosis was the only abnormality. Pleural fibrosis and/or calcification was found in the absence of parenchymal fibrosis in 14% of cases; in another 14% of workers, both parenchymal and pleural abnormalities were detected. The prevalence was significantly higher in those employed 20 or more years. Pleural abnormalities were more prevalent than were parenchymal changes. The increased risk of lung cancer and mesothelioma remains to be studied.
Association Between Laryngeal Cancer and Asbestos Exposure
JAMA Otolaryngology–Head & Neck Surgery, 2016
IMPORTANCE It has been debated whether a link exists between laryngeal cancer and asbestos exposure. Prior systematic reviews have been conducted on this topic, but no updates have been performed on the most recent literature since 2000. OBJECTIVE To provide an updated systematic review of the association between laryngeal cancer and asbestos exposure. EVIDENCE ACQUISITION A search of electronic databases, including PubMed and the Cochrane Library, was performed for articles published between January 1, 2000, and April 30, 2016. Search terms, including laryngeal cancer and asbestos, were used to identify publications reviewing the risk of laryngeal cancer in association with asbestos exposure. Studies analyzing this association that were published in any language and translated reliably were included. Two independent reviewers assessed articles based on predetermined eligibility criteria. Each study was reviewed for quality using the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence and assessed for their findings of support for or against a correlation between asbestos exposure and laryngeal cancer. FINDINGS A total of 160 studies were retrieved from all databases, and 2 additional articles were identified by cross-references. Of the 162 articles screened, 15 articles comprising 438 376 study participants were included in this review. Of these 15 studies, 10 showed no correlation between asbestos exposure and laryngeal cancer. The remaining 5 studies claimed a correlation between asbestos exposure and incidence of laryngeal cancer, although only 1 accounted for smoking or alcohol exposure while 3 others did not, and 1 study included only 2 patients. CONCLUSIONS AND RELEVANCE Although asbestos is considered hazardous and carcinogenic, current evidence is lacking to support a correlation between asbestos exposure and laryngeal cancer. Few studies have been able to definitively conclude a causal association between asbestos exposure and laryngeal cancer, and those that found an association often did not account for the confounding factors of tobacco and alcohol exposure.
Histological type of lung carcinoma in asbestos cement workers and matched controls
Occupational and Environmental Medicine, 1992
Histological types of lung carcinoma were examined in a case series ofworkers exposed to asbestos cement dust (n = 29) and matched controls (n = 87). The proportion of adenocarcinomas was 31% among the exposed subjects and 15% among the controls (midp = 0O05). Among workers with high exposure the proportion of adenocarcinoma was even higher (45%, 5/11; mid-p = 0O03). The proportion of peripheral tumours tended to be higher among exposed cases than controls (24 v 12%, mid-p = 0 12). Lobe of origin did not differ, however, between exposed cases and controls. Thus the study indicates an association between the degree of exposure to asbestos and adenocarcinoma of the lung, and a peripheral rather than central localisation of the tumours, but with virtually the same distribution of lobe of origin as in the general population.