The epidemiology and pathogenesis of malignant mesothelioma

Our plain-English summary of The epidemiology and pathogenesis of malignant mesothelioma, by J.E. Craighead (Chest, 1989).

The study

• Author: J.E. Craighead
• Journal: Chest
• Published: 1989;96(1 Suppl):92S-93S
• Type of article: Review
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000063).

Summary of the article

In this brief review, the author set out to describe the general epidemiologic features of malignant mesothelioma of the pleura and peritoneum and to summarize understanding of how these tumors develop. He stated that, apart from therapeutic irradiation, amphibole asbestos (crocidolite and amosite) was the only established cause. He traced the history of the association: early German reports during the Second World War, the South African study by Wagner and colleagues of cases among miners and nearby residents, and later cases in shipbuilding communities such as Liverpool, heavy industry and the insulation trade. He predicted that excess cases would continue into the next century. On chrysotile, he noted the rare cases (fewer than 100 reported) among Canadian chrysotile miners and millers. He attributed these possibly to tremolite contaminants or to residual amphiboles, and stated that workers exposed only to processed chrysotile did not appear to have excess mesothelioma. He considered this to have major public health implications for the removal of chrysotile-containing materials from US buildings. He proposed a multistage mechanism. In this model, retained amphibole fibers are taken up by macrophages, which produce oxygen radicals and growth substances, and DNA damage combined with stimulated cell proliferation leads to neoplastic transformation. He contrasted this with chrysotile, which breaks down and is cleared from the lung. He concluded that research should aim at preventive approaches, such as altering macrophage activity.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This article was a brief narrative survey, not a new study. It summarized earlier published work on the epidemiology and causes of malignant mesothelioma of the pleura and peritoneum. The author wrote that, apart from therapeutic irradiation, no specific cause other than amphibole asbestos had been established. The amphibole types named were crocidolite and amosite. The author also wrote that epidemiologic studies had shown amphibole responsible for almost all, if not all, asbestos-attributable mesotheliomas. Among heavily exposed Canadian chrysotile miners and millers, the author noted sporadic cases (fewer than 100 reported) and that many authorities suggested tremolite contaminants may be responsible. The author saw no good evidence that 'pure' chrysotile causes the tumor. The author also stated that, aside from these rare cases, among worker groups exposed to processed chrysotile, mesotheliomas did not appear to occur as a result of that exposure in excess of what would be expected in the general population. The author proposed that macrophages taking up fibers release oxygen radicals and growth substances that may damage DNA and drive cell growth. The author called this plausible but probably not provable, and suggested research on altering macrophages and their products.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Narrative review (brief survey) of published epidemiologic and experimental literature, with the author's proposed hypothesis of how the tumor develops; no new data were collected
• Who was studied: No study population; the article discussed previously published studies (for example South African miners and nearby residents, shipyard and insulation workers, Canadian chrysotile miners and millers, and rats in animal experiments)
• Exposure: Amphibole asbestos (crocidolite and amosite) compared with chrysotile asbestos, including tremolite contaminants in chrysotile ore
• Main results:
  • The author stated that, apart from therapeutic irradiation, no specific cause of mesothelioma other than amphibole asbestos had been established (a review statement, not a finding of this article)
  • The author stated that epidemiologic studies had shown amphibole to be responsible for almost all, if not all, mesotheliomas attributable to asbestos
  • Regarding Canadian chrysotile miners and millers, the author noted that mesotheliomas occur sporadically (fewer than 100 cases reported), but that there was no good evidence that 'pure' chrysotile itself causes the tumor
  • The author reported that many authorities suggest tremolite contaminants in the ore may be responsible for the Canadian miner and miller cases
  • The author stated that, aside from the rare and sporadic Canadian cases, among worker groups exposed to processed chrysotile, mesotheliomas did not appear to occur as a result of that exposure in excess of what would be expected in the general population
  • The author described earlier studies indicating that chrysotile fibers break down in lung tissue and do not accumulate in large quantities in the lungs of occupationally exposed people
  • The author cited animal work by Stanton and Wrench indicating that fiber length and breadth are probably critical to inducing the disease
• The authors' conclusion: The author concluded that a multistage process, in which fibers taken up by macrophages lead to DNA damage and the growth of damaged cells, is a plausible explanation consistent with existing evidence. The author also concluded that whatever factors cause tumors in Canadian miners and millers do not cause disease in workers exposed exclusively to chrysotile after it has been purified by milling. The author suggested that future research might focus on altering macrophages and their products.
• Limitations the authors state:
  • The author stated that the proposed mechanism most probably cannot be proved definitively, and that the idea that amphibole-burdened individuals would invariably develop mesothelioma if they lived long enough is a hypothesis that cannot be proved

Topics

The National Library of Medicine indexes this study under subjects our site covers: Mesothelioma.

Medical terms in this study, explained in our Lexicon: Epidemiology, Malignant Mesothelioma, Pleura, Peritoneum, Amphibole Asbestos, Crocidolite, Amosite, Chrysotile.

Related studies

• Mesothelioma epidemiology, carcinogenesis, and pathogenesis — H. Yang, J.R. Testa, et al. (2008)
• Mechanisms in the pathogenesis of asbestosis and silicosis — B.T. Mossman, A. Churg (1998)
• Current concepts about the pathogenesis of silicosis and asbestosis — R.D. deShazo (1982)
• Pathogenesis of mesothelial reactions to asbestos fibers. Monocyte recruitment and macrophage activation — R.M. Branchaud, L.J. Garant, et al. (1993)
• The two-stage clonal expansion model in occupational cancer epidemiology: results from three cohort studies — A. Zeka, R. Gore, et al. (2011)
• The epidemiology of mesothelioma in historical context — J.C. McDonald, A.D. McDonald (1996)

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