Lee HE, Kim HR.

Occupational Safety and Health Research Institute, KOSHA, Inchoen, Korea.

Abstract

Malignant mesothelioma and lung cancer are representative examples of occupational cancer. Lung cancer is the leading cause of cancer death, and the incidence of malignant mesothelioma is expected to increase sharply in the near future. Although information about lung carcinogen exposure is limited, it is estimated that the number of workers exposed to carcinogens has declined. The first official case of occupational cancer was malignant mesothelioma caused by asbestos exposure in the asbestos textile industry in 1992. Since then, compensation for occupational respiratory cancer has increased. The majority of compensated lung cancer was due to underlying pneumoconiosis. Other main causative agents of occupational lung cancer included asbestos, hexavalent chromium, and crystalline silica. Related jobs included welders, foundry workers, platers, plumbers, and vehicle maintenance workers. Compensated malignant mesotheliomas were associated with asbestos exposure. Epidemiologic studies conducted in Korea have indicated an elevated risk of lung cancer in pneumoconiosis patients, foundry workers, and asbestos textile workers. Occupational respiratory cancer has increased during the last 10 to 20 yr though carcinogen-exposed population has declined in the same period. More efforts to advance the systems for the investigation, prevention and management of occupational respiratory cancer are needed.

Park EK, Hannaford-Turner KM, Hyland RA, Johnson AR, Yates DH.

Research and Education Unit, Workers’ Compensation Dust Diseases Board of NSW, Sydney, Australia.

Abstract

Asbestos is a fibrous silicate which is recognized as causing a variety of lung disorders including malignant mesothelioma of the pleura, lung cancer and asbestosis. Asbestos use has been banned in most developed countries but exposure still occurs under strict regulation in occupational settings and also occasionally in domestic settings. Although the hazards of asbestos are well known in developed countries, awareness of its adverse health effects is less in other parts of the world, particularly when exposure occurs in non-occupational settings. Experience of asbestos use and its adverse heath effects in developed countries such as Australia have resulted in development of expertise in the diagnosis and treatment of asbestos-related diseases as well as in screening and this can be used to help developing countries facing the issue of asbestos exposure.

Keywords: Asbestos, Mesothelioma, Asbestos-related diseases, Occupational exposure, Public health

Kashanskii SV, Zhetpisbaev BA, Il’derbaev OZ, Ermenbai OT.

Abstract

The paper presents the results of a review of 69 reports published by Kazakhstan scientists over 50 years. For this period, mesotheliomas were diagnosed in 5 of 14 areas of the country. The basic clinical, demographic, medical, and statistical data are concordant with those published elsewhere on this pathology.

Nishikawa K, Takahashi K, Karjalainen A, Wen CP, Furuya S, Hoshuyama T, Todoroki M, Kiyomoto Y, Wilson D, Higashi T, Ohtaki M, Pan G, Wagner G.

Department of Environmental Epidemiology, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu City, Japan.

Abstract

Background: In response to the health risks posed by asbestos exposure, some countries have imposed strict regulations and adopted bans, whereas other countries have intervened less and continue to use varying quantities of asbestos.

Objectives: This study was designed to assess, on a global scale, national experiences of recent mortality from pleural mesothelioma, historical trends in asbestos use, adoption of bans, and their possible interrelationships.

Methods: For 31 countries with available data, we analyzed recent pleural mesothelioma (International Classification of Diseases, 10th Revision) mortality rates (MRs) using age-adjusted period MRs (deaths/million/year) from 1996 to 2005. We calculated annual percent changes (APCs) in age-adjusted MRs to characterize trends during the period. We characterized historical patterns of asbestos use by per capita asbestos use (kilograms per capita/year) and the status of national bans.

Results: Period MRs increased with statistical significance in five countries, with marginal significance in two countries, and were equivocal in 24 countries (five countries in Northern and Western Europe recorded negative APC values). Countries adopting asbestos bans reduced use rates about twice as fast as those not adopting bans. Turning points in use preceded bans. Change in asbestos use during 1970-1985 was a significant predictor of APC in mortality for pleural mesothelioma, with an adjusted R(2) value of 0.47 (p < 0.0001).

Conclusions: The observed disparities in global mesothelioma trends likely relate to country-to-country disparities in asbestos use trends.

Pairon JC, Andujar P, Matrat M, Ameille J.

INSERM Unité 841, Créteil, France. JC.Pairon@chicreteil.fr

Abstract

Lung cancer and pleural mesothelioma are the most common occupational cancers.

Recent epidemiological studies have estimated that the fraction attributable to occupational factors varies from 13 to 29% for lung cancer in men and is about 85% for pleural mesothelioma in men. Previous occupational exposure to asbestos is the most common occupational exposure in these cancers. Mesothelioma immediately leads the clinician to look for past asbestos exposure. In contrast, the search for an occupational exposure that should be routine in all cases of lung cancer, is generally more difficult because of the number of occupational aetiological factors and the absence of criteria that allow distinction of an occupational cancer from a tobacco related one.

Therefore attention should be paid to the identification of occupational exposure in order to set up primary prevention programmes to prevent exposure still present in the working environment and, on the other hand, to identify the subjects entitled to the acknowledgement of occupational disease and/or to obtain the compensation available to asbestos victims.

Keywords: Asbestos, Silicon dioxide, Occupational diseases, Lung, Carcinogens

Ugolini D, Neri M, Canessa PA, Casilli C, Catrambone G, Ivaldi GP, Lando C, Marroni P, Paganuzzi M, Parodi B, Visconti P, Puntoni R, Bonassi S.

Department of Oncology, Biology and Genetics, University of Genoa, National Cancer Research Institute, Largo R. Benzi, 10-16132 Genoa, Italy. donatella.ugolini@istge.it

Abstract

Objectives: The Cancer of RESpiratory Tract (CREST) biorepository was established to investigate biological mechanisms and to develop tools and strategies for primary and secondary prevention of respiratory tract cancer. The CREST biorepository is focused on pleural malignant mesothelioma, a rare and severe cancer linked to asbestos exposure whose incidence is particularly high in the Ligurian region.

Methods: The CREST biorepository includes biological specimens from (a) patients with pleural malignant mesothelioma and lung cancer, (b) patients with nonneoplastic respiratory conditions, and (c) control subjects. Whole blood, plasma, serum, lymphocytes, pleural fluid, saliva, and biopsies are collected, and a questionnaire is administered. Collection, transportation, and storage are done according to international standards.

Results: As of January 31, 2008, the overall number of subjects recruited was 1,590 (446 lung cancer, 209 pleural malignant mesothelioma, and 935 controls). The biorepository includes a total of 10,055 aliquots (4,741 serum; 3,082 plasma; 1,599 whole blood; 633 pleural fluid; and 561 lymphocytes) and 107 biopsies. Demographic, clinical, and epidemiologic information is collected for each subject and processed in a dedicated database.

Conclusions: The CREST biorepository is a valuable tool for molecular epidemiology and translational studies. This structure relies on a network of contacts with local health districts that allows for an active search for patients. This is a particularly efficient approach, especially when the object of the study is a rare cancer type. The CREST experience suggests that the presence of limited resources can be overcome by the biorepository specialization, the high quality of the epidemiologic information, and the variety of samples.

Reid A, Heyworth J, de Klerk N, Musk AW.

Occupational Respiratory Epidemiology, School of Population Health, M431, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia. Alison.Reid@uwa.edu.au

Abstract

Objectives: Knowledge of mortality patterns following exposure to asbestos has been determined mostly from cohort studies of men who were exposed to asbestos in their workplace. Women are more likely to have obtained their asbestos exposure domestically or from their environment.

Methods: 2552 women and girls are documented to have lived in the blue asbestos mining and milling township of Wittenoom between 1943 and 1992 and were not involved in asbestos mining or milling. Quantitative asbestos exposure measurements were derived from periodic dust surveys undertaken in the industry and around the township. Death records were obtained for the period 1950–2004. Standardised mortality ratios (SMRs) were calculated to compare the Wittenoom women’s mortality with that of the Western Australian female population.

Results: There were 425 deaths, including 30 from malignant mesothelioma. There was excess mortality for all causes of death (SMR = 1.13), all neoplasms (SMR = 1.42), symptoms, signs and ill defined conditions (SMR = 6.35), lung cancer (SMR = 2.15) and pneumoconiosis (SMR = 11.8). Mortality from cancer of the ovary (SMR = 1.52), upper aerodigestive cancers (SMR = 2.70) and tuberculosis (SMR = 5.38) was increased but not significantly. The risk of death from mesothelioma was increased, but not significantly, in residents known to have lived with or washed the clothes of an Australian Blue Asbestos Company asbestos worker (HR = 2.67, 95% CI 0.77 to 9.21; HR = 2.61, 95% CI 0.85 to 7.99, respectively).

Conclusion: Women who were former residents of Wittenoom, exposed to asbestos in their environment or in their home, have excess cancer mortality, including mesothelioma, compared with the Western Australian female population.

Teta MJ, Mink PJ, Lau E, Sceurman BK, Foster ED.

Exponent Inc., Health Sciences Practice, New York, New York, USA. jteta@exponent.com

Abstract

Mesothelioma rates are declining toward background levels, although estimates of the background rate have varied. We expanded upon earlier analyses and provided a data-based estimate of the background rate. We analyzed US male and female patterns for five age groups using the National Cancer Institute’s Surveillance Epidemiology and End Results registry data from 1973 to 2002. Age-specific and age-adjusted incidence rates per 1 000 000 persons per year, standardized to the 2000 US population, were calculated for total, pleural, and peritoneal mesothelioma. We also calculated rates for persons who attained working age after the US Occupational Safety and Health Administration asbestos exposure limits took effect. Mesothelioma rates observed among young males and females varied little over time. We observed a decline and convergence of recent male and female rates in older age groups, except those who are between the age of 60 and above, for whom the 2002 male rate was approximately five times greater than that of females. As expected, rates were higher in major shipyard areas on the West coast. Rates for persons with little or no opportunity for occupational asbestos exposure were 1.15 (95% confidence interval: 0.90-1.45) for men and 0.94 (95% confidence interval: 0.87-1.24) for women. Mesothelioma is rare in younger age groups, and rates have been relatively stable and similar for both sexes. Rates continue to decline in older age groups, but remain high for males at 60 years or older. Rates among females at older ages suggest an impact of occupational exposure. The background rate for persons below age 50 is approximately one per million, independent of sex. Future data are needed to estimate this rate for older age groups.

Rodríguez D, Cheung MC, Housri N, Koniaris LG.

Division of Surgical Oncology, DeWitt Daughtry Family Department of Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.

Abstract

Objective: Determine the role of surgery for patients with malignant abdominal mesotheliomas (MAMs).

Methods: The Surveillance, Epidemiology, and End Results (SEER) database (1973-2005) was queried.

Results: Overall, 10,589 cases of malignant mesotheliomas were identified. Of these, 9,211 cases were thoracic (TM) and 1,112 cases were MAM (10.5%). Patients with TM presented with more localized disease than those patients with MAM (P < 0.001). MAM more often affected younger patients (63 years vs. 71 years) (P < 0.001). The annual incidence of MAM was approximately 1.00 case per 100,000 in 2005. Overall median survival for MAM patients was 8 months, with a significant difference between women and men (13 months vs. 6 months, respectively) (P < 0.001). Patients who successfully underwent surgical resection had a considerably longer median survival (20 months vs. 4 months, P < 0.001) as well as a significantly higher 5-year survival (28% vs. 12%, P < 0.001). Multivariate analysis identified that a poorly differentiated tumor grade, failure to undertake surgical resection, advanced age, and male gender were all independent predictors of poorer outcome.

Conclusion: Surgical extirpation of MAM may be associated with significantly improved survival. All patients with MAM should be evaluated for potential surgical resection.

Keywords: malignancy, cancer, survival, surgery, peritoneal mesothelioma, thoracic mesothelioma, pleural mesothelioma, SEER, abdominal mesothelioma, outcomes

Berry G, Pooley F, Gibbs A, Harris JM, McDonald JC.

School of Public Health, University of Sydney, Sydney, Australia. geoffb@health.usyd.edu.au

Abstract

A cohort of 1,154 employees, mainly women, who had worked 1940-1945 on the manufacture of military gas masks using filter pads containing 20% crocidolite, was traced through 2003, by which time 65 were known to have died from mesothelioma. The last known death with mesothelioma was in 1994, whereas a further 5 cases would have been expected in those with known duration of exposure. Lung tissue samples, from 50 deaths from mesothelioma and 20 other causes, had been analyzed for mineral fiber content. For ten of the mesothelioma cases data on fiber size were collected. Crocidolite fiber concentrations were analyzed in relation to exposure by time and duration. Fiber concentrations overall fell fairly steadily by decade of death, and increased with length of exposure up to 36 months and then fell sharply. The annual rate of elimination estimated by regression was 7.5% corresponding to a half life of 9.2 years. The proportion of fibers longer than 6 μm increased over time implying that the shorter fibers were eliminated more rapidly than the longer ones. The decline in concentrations with time confirms the hypothesis that crocidolite and, by inference, other amphibole fibers are slowly removed from the lung, but since the longer more carcinogenic fibers were cleared more slowly it is unclear to what extent this clearance explains the slowing down of the increase in mesothelioma mortality from about 40 years from the most recent exposure. The exact biostatistical models which most closely conform with the data remain open to question.