Primary prevention carried out today can reduce the disease incidence in the future decades. The present disease panorama is the consequence of past asbestos exposure mainly before the 1970s. The peak incidence of asbestos-induced diseases will be reached around 2010 in Finland. The number of asbestos-related premature deaths is at present annually about 150 which exceeds the figure of fatal work accidents. Asbestos-related cancer will increase still for 15-20 years and reach its maximum, about 300 cases, in 2010, and will start to decrease after that. More than 20,000 asbestos-exposed workers have participated in the medical screening and follow-up. The termination of exposure, antismoking campaigns, improved diagnostics and careful attention to compensation issues, as well as other potentials for prevention, were the central issue of the Asbestos Program of the Finnish Institute of Occupational Health. An important objective of research work is to improve early diagnostics, and thereby treatment prospects, in case of asbestos-induced cancers.
The natural history and etiology of malignant mesothelioma (MM) is already thoroughly described in the literature, but there is still debate on prognostic factors, and details of asbestos exposure and possible context with clinical and demographic data, have not been investigated comprehensively.
Description of patients with MM, focusing on exposure, occupation, survival and prognostic factors.
Review of medical records of patients with MM from 1984 to 2010 from a Danish Occupational clinic. Survival was estimated using Kaplan-Meier survival analysis and prognostic factors were identified by Cox regression analysis.
110 (90.2%) patients were male, and 12 (9.8%) were female. The median (interquartile rang [IQR]) age was 65 (13) years. Pleural MM was seen in 101 (82.8%) patients, and peritoneal in 11 (9.0%); two (1.6%) had MM to tunica vaginalis testis, and eight (6.6%) to multiple serosal surfaces. We found 68 (55.7%) epithelial tumors, 26 (21.3%) biphasic, and 6 (4.9%) sarcomatoid. 12 (9.8%) patients received tri-modal therapy, 66 (54.1%) received one-/two-modality treatment, and 36 (29.5%) received palliative care. Asbestos exposure was confirmed in 107 (91.0%) patients, probable in four (3.3%), and unidentifiable in 11 (9.0%). The median (IQR) latency was 42 (12.5) years. Exposure predominantly occurred in shipyards. The median overall survival was 1.05 (95% CI: 0.96-1.39) years; 5-year survival was 5.0% (95% CI: 2.0%-13.0%). Female sex, good WHO performance status (PS), epithelial histology and tri-modal treatment were associated with a favorable prognosis.
MM continuously presents a difficult task diagnostically and therapeutically, and challenges occupational physicians with regard to identification and characterization of asbestos exposure.
OBJECTIVES: The aim of this study was to analyze the incidence of pleural tumors among various categories of Swedish construction workers and to determine to what extent its change over time differs from that of the general male population. METHODS: Traditional methods have been used to study cancer incidence through 1998 in a cohort comprising 370 165 male workers examined in 1971-1992 by Bygghälsan, an organization at the time providing nationwide occupational health service. Incidence was assessed by linkage to the national cancer register. RESULTS: Swedish construction workers, particularly those heavily exposed to asbestos, had an excess incidence of pleural tumors in 1975-1998 [standardized incidence ratio (SIR) 3.16, 95% confidence interval (95% CI) 2.55-3.88]. The excess declined with subsequent follow-up periods and birth cohorts with the exception of the most recent period (SIR 3.83, 95% CI 2.64-5.38) and those borne in the 1930s. CONCLUSIONS: A possible decline in pleural tumors among men following the cessation of asbestos use 25 years earlier in the population at large may not be applicable to an end-user sector like construction work. In occupations charged with repairing and refurbishing work, there may even have been an increase lately.
INTRODUCTION: This study focus on the incidence of asbestos-related cancers among 28,300 officers and enlisted servicemen in the Royal Norwegian Navy. Until 1987, asbestos aboard the vessels potentially caused exposure to 11,500 crew members. METHODS: Standardized incidence ratios (SIR) were calculated for malignant mesothelioma, lung cancer, and laryngeal, pharyngeal, stomach, and colorectal cancers according to service aboard between 1950 and 1987 and in other Navy personnel. RESULTS: Increased risk of mesothelioma was seen among engine room crews, with SIRs of 6.23 (95% CI = 2.51-12.8) and 6.49 (95% CI = 2.11-15.1) for personnel who served less than 2 years and those with longer service, respectively. Lung cancer was nearly 20% higher than expected among both engine crews and non-engine crews. An excess of colorectal cancer bordering on statistical significance was seen among non-engine crews (SIR = 1.14; 95% CI = 0.98-1.32). Land-based personnel and personnel who served aboard after 1987 had lower lung cancer incidence than expected (SIR = 0.77; 95% CI = 0.64-0.92). No elevated risk of laryngeal, pharyngeal, or stomach cancers was seen. CONCLUSION: The overall increase (65%) in mesotheliomas among military Navy servicemen was confined to marine engine crews only. The mesothelioma incidence can be taken as an indicator of the presence or absence of asbestos exposure, but it offered no consistent explanation to the variation in incidence of other asbestos-related cancers.
Despite international efforts to block Canada's export of asbestos, the Canadian federal government continues to defend the economic interests of the asbestos industry. Ironically, Canadian asbestos miners, mill workers, and those engaged in a wide range of other occupations continue to suffer asbestos-related disease and premature death. Although there is an employer-funded compensation system in each province, many workers with mesothelioma and other asbestos-related diseases remain uncompensated. The export of Canadian asbestos to developing countries sets the stage for another preventable occupational disease epidemic that will manifest over the coming decades. There is growing support from the Canadian labor movement for an end to asbestos exportation and for a just transition strategy for the asbestos workers and their communities.
Comment In: Int J Occup Environ Health. 2007 Oct-Dec;13(4):45118085060
Comment In: Int J Occup Environ Health. 2008 Apr-Jun;14(2):157-818507297
A review of 398 pleural and peritoneal tumours suggests that diffuse mesothelioma was probably present in 50-60%. However, objective assessment was frequently impeded by serious deficiencies in data or material, which affect the diagnostic grading of cases seen by panels. Observer variation in diagnosis also remains a significant problem. The value of panels for diagnosis could be greatly increased by the provision of adequate data/material and by meetings.