Asbestos-related cancer and the amphibole hypothesis. The hypothesis is still supported by scientists and scientific data

Our plain-English summary of Asbestos-related cancer and the amphibole hypothesis. The hypothesis is still supported by scientists and scientific data, by B.T. Mossman, J.B. Gee (American Journal of Public Health, 1997).

The study

• Authors: B.T. Mossman, J.B. Gee
• Journal: American Journal of Public Health
• Published: 1997;87(4):689-90; author reply 690-1
• Type of article: Comment, Letter
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Summary of the article

In this letter, Mossman and Gee responded to an annotation by Cullen, and a review by Stayner and colleagues, that had questioned the amphibole hypothesis of mesothelioma advanced in their 1990 Science article. They stated that the hypothesis rested on Wagner's 1960 study, since updated, and on studies of crocidolite-exposed cohorts such as gas mask workers and cigarette filter manufacturers. They argued that it was wrong to call their article the first introduction of the hypothesis, and that its thrust was mesothelioma, not lung cancer. They noted that they had suggested chrysotile may be less pathogenic than crocidolite for lung cancer, but that smoking made fiber-type roles harder to define. They criticized the review for omitting recent conference and panel conclusions: of its 72 references, only 12 were published after 1991, and half of these supported the hypothesis. They also cited mechanistic studies, including rat inhalation studies in which crocidolite, unlike chrysotile at identical airborne concentrations, induced protooncogene expression and sustained mesothelial cell proliferation. They concluded that the hypothesis remained viable. In his reply, Cullen welcomed the narrowing to mesothelioma. He held that a strong dose-response between cancer and chrysotile was proven, with a slope not differing from other fibers. He agreed that chrysotile is of lower pathogenicity for mesothelioma, though this remains unproven, and noted that 100 lung cancers occur for every mesothelioma in developed countries.

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 was a letter to the editor, not a research study, and it reported no new data. The authors responded to what they called errors in an annotation by Cullen and in a review by Stayner and colleagues, both of which questioned the amphibole hypothesis of mesothelioma. They argued that the hypothesis rests on a 1960 study by Wagner and on later studies showing increased mesothelioma risks in cohorts exposed to crocidolite asbestos, such as gas mask workers and cigarette filter manufacturers. They stressed that the hypothesis concerns mesothelioma, not lung cancer. They noted that because smoking is a more powerful factor in lung cancer than asbestos, the roles of different fiber types in lung cancer are harder to define. They stated that only 12 of the 72 references in the Stayner review were published after 1991. They also argued that two mesothelioma cases in Zimbabwe did not show that "pure" chrysotile was the cause. They cited rat inhalation research in which crocidolite, unlike chrysotile, increased cell changes in the lungs and mesothelial tissue. The authors concluded that the hypothesis "is still viable."

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: Letter to the editor responding to an annotation by Cullen and a review by Stayner and colleagues; no original data
• Who was studied: No study population. The letter discussed published studies and reviews on asbestos fiber type and cancer.
• Exposure: Crocidolite (an amphibole) compared with chrysotile asbestos. The authors stated that the amphibole hypothesis concerns mesothelioma rather than lung cancer.
• Main results:
  • The authors stated that the foundation of the amphibole hypothesis is a 1960 study by Wagner.
  • The authors stated that the hypothesis is supported by studies showing increased mesothelioma risks in crocidolite-exposed cohorts, including gas mask workers and cigarette filter manufacturers.
  • The authors quoted the Stayner review as acknowledging that the proportion of mesothelioma deaths is much lower in chrysotile-exposed miners and millers than in crocidolite miners.
  • On lung cancer, the authors stated that smoking is a more powerful factor than asbestos exposure, which makes the roles of different fiber types harder to define.
  • The authors stated that of the 72 references cited in the Stayner review, only 12 were published after 1991.
  • The authors argued that two mesothelioma cases in Zimbabwe did not show that "pure" chrysotile was the cause, especially since no lung fiber burden studies were done.
  • The authors cited laboratory studies, including a rat inhalation study, which they described as showing that crocidolite, in contrast to chrysotile at identical airborne concentrations, induced protooncogene expression in the lungs and sustained proliferation of mesothelial cells.
• The authors' conclusion: The authors concluded that, contrary to Cullen's annotation, the amphibole hypothesis of mesothelioma was not dead on arrival in 1990 and remains viable.

Topics

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

Medical terms in this study, explained in our Lexicon: amphibole hypothesis, Mesothelioma, Crocidolite, Lung Cancer, Chrysotile, Mesothelial Cells, Dose-response relationship.

Related studies

• The amphibole hypothesis of asbestos-related cancer--gone but not forgotten — M.R. Cullen (1996)
• Asbestos-related cancer and the amphibole hypothesis. The first documentation of the association — J.C. Wagner (1997)
• Asbestos-related cancer and the amphibole hypothesis. The amphibole hypothesis: neither gone nor forgotten — A.M. Langer, R.P. Nolan (1997)
• Mechanisms of asbestos carcinogenesis and toxicity: the amphibole hypothesis revisited — B.T. Mossman (1993)
• Occupational exposure to chrysotile asbestos and cancer risk: a review of the amphibole hypothesis — L.T. Stayner, D.A. Dankovic, et al. (1996)
• A review of scientific literature examining the mining history, geology, mineralogy, and amphibole asbestos health effects of the Rainy Creek igneous complex, Libby, Montana, USA — B.R. Bandli, M.E. Gunter (2006)

Browse more research in American Journal of Public Health, or return to medical research.