Mesothelioma in man and experimental animals

Our plain-English summary of Mesothelioma in man and experimental animals, by M. Kannerstein, J. Churg (Environmental Health Perspectives, 1980).

The study

• Authors: M. Kannerstein, J. Churg
• Journal: Environmental Health Perspectives
• Published: 1980;34:31-6
• Type of article: Review
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Asbestos has been established as the cause of most cases of diffuse malignant mesothelioma occurring in the industrialized world. The morphology of mesothelioma may be complex, and the employment of chemical, histochemical and ultrastructural studies are often helpful in identification. Diagnostic difficulties may to some degree blur the extent of its prevalence and reliance on exposure history may not reveal its association with asbestos. Reference panels can be useful in assessing the former and analysis of lung tissue asbestos content may help to clarify the latter, especially in the low dose range. Electron microscopy may prove to be of assistance in this respect, possibly with particular attention to the peripheral areas of the lung. Animal experimentation has supported epidemiologic conclusions and revealed the phenomenon of fiber carcinogenesis. The morphology of mesothelioma in experimental animals is very similar to that in humans, including ultrastructural and biochemical features.

In plain English

This article was a review of diffuse malignant mesothelioma of the pleura and peritoneum in humans and experimental animals. It reported no new patient series or animal experiment; apart from a brief mention of the authors' personal experience, its findings came from other studies. The authors described diagnostic difficulties, citing a US expert panel that accepted 70% of submitted cases as definite or probable mesothelioma and fully rejected 14%. In cited case series, the share of patients with a known asbestos exposure history ranged from 22% to almost 100%. In one cited lung-tissue study by Whitwell and colleagues, 78% of mesothelioma patients had more than 100,000 asbestos fibers per gram of dried lung, while 71% of controls had fewer than 20,000. The reviewed animal experiments showed that all commercial varieties of asbestos, and also glass fibers and aluminum oxide, produced mesotheliomas. The authors judged it probable that the fibers' physical form, not their chemistry, was responsible. The authors concluded that asbestos has been established as the cause of most mesotheliomas in the industrialized world and that animal tumors closely resemble human ones.

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 of published human and animal research, with a brief reference to the authors' personal experience; no new patient series or animal experiment
• Who was studied: Published reports on diffuse malignant mesothelioma of the pleura and peritoneum in humans, and on mesothelioma in experimental animals (mainly rats and hamsters)
• Exposure: Human exposure: occupational and environmental asbestos. Animal exposure: all commercial varieties of asbestos (including chrysotile, crocidolite and other amphiboles), given by injection into the body cavities, by intratracheal injection, or by inhalation. Also reviewed: zeolites in Turkey, glass fibers, aluminum oxide and some non-fibrous chemicals
• Main results:
  • In a cited US study by an experienced diagnostic panel, 70% of submitted cases were accepted as definite or probable mesothelioma and 14% were entirely rejected
  • In the case series cited, the proportion of mesothelioma patients with a positive asbestos exposure history ranged from 22% to almost 100%
  • In the cited study by Whitwell et al., 78% of mesothelioma patients had more than 100,000 asbestos fibers per gram of dried lung tissue, while 71% of a control series had fewer than 20,000
  • Whitwell et al. estimated that about 15% of mesothelioma cases in their industrial and shipyard area were spontaneous, meaning not associated with asbestos. The reviewing authors noted that only an optical counting method was used
  • In cited rat experiments, Stanton found that fibrous materials (asbestos, glass fibers and aluminum oxide) produced mesotheliomas, and Pott et al. found that chemically similar but non-fibrous material produced few or no tumors. The authors judged it probable that physical form, not chemistry, was responsible
  • In cited rat inhalation experiments by Wagner et al., two of 11 mesotheliomas occurred after only one day's exposure to asbestos, and chrysotile proved as carcinogenic and fibrogenic as the amphiboles
  • Mesotheliomas in experimental animals resembled human mesotheliomas under the microscope, in their fine structure, and in producing hyaluronic acid. However, many authors described a predominance of sarcomatous tumors in animals
• The authors' conclusion: The authors concluded that asbestos has been established as the cause of most cases of diffuse malignant mesothelioma in the industrialized world. They also concluded that animal experiments confirmed this and revealed fiber carcinogenesis, and that animal mesothelioma closely resembles the human tumor
• Limitations the authors state:
  • The authors noted that mesothelioma cases attributed to other causes may be missed, and that no definitive study of this problem had been reported
  • The authors acknowledged that introducing asbestos directly into the body cavities of animals does not match how humans are exposed

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Malignant Mesothelioma, Exposure History, Carcinogenesis.

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• The relationship between fibrosis and cancer in experimental animals exposed to asbestos and other fibers — J.M. Davis, H.A. Cowie (1990)
• Epithelial outgrowths from lung tissue following intrapleural injection of asbestos dust in experimental animals — J.M. Davis (1971)
• Tumorigenic effect of fibrous dusts in experimental animals — F. Pott, F. Huth, et al. (1974)
• Asbestosis in experimental animals — J.C. Wagner (1963)
• The long term fibrogenic effects of chrysotile and crocidolite asbestos dust injected into the pleural cavity of experimental animals — J.M. Davis (1970)

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