The Pathology And Mineral Content Of Lungs In Cases Of Mesothelioma In The United Kingdom In 1976

Our plain-English summary of The Pathology And Mineral Content Of Lungs In Cases Of Mesothelioma In The United Kingdom In 1976, by J.S.P. Jones, F.D. Pooley, G.H. Roberts, et al (1980).

The study

• Authors: J.S.P. Jones, F.D. Pooley, G.H. Roberts, N.J. Clark, P.G. Smith, W.G. Owen, J.C. Wagner, G. Berry, D.J. Pollock
• Published: Biological Effects Of Mineral Fibres (J.C. Wagner, Editor), Lyon: Iarc Scientific Publications, Volume 30, Pp. 187-199 (1980)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library, J-M no. 002581. The article is still under copyright, so we describe it here rather than post it.

In plain English

This study examined people who died of mesothelioma in the United Kingdom in 1976. Pathologists and coroners were invited to notify a mesothelioma panel of these deaths; participating pathologists were asked to send tissue. The panel confirmed mesothelioma in 93 of 117 submitted cases: 54 pleural, 6 peritoneal and 33 of unknown site. Lung tissue from 86 confirmed cases was examined with electron microscopy for asbestos fibres. So was tissue from 27 matched controls with bronchial carcinoma and 29 with cerebrovascular disease. Mesothelioma cases contained more amosite and crocidolite than the controls combined (P less than 0.001), about 10 times as much on average. Chrysotile was similar in cases and controls. No chrysotile was found in 30 of the 86 mesothelioma cases or in 12 of the 56 controls. Four mesothelioma cases had no amosite or crocidolite. Nine of the cerebrovascular controls had more than 1000 amphibole fibres per mg. The authors concluded the study gave no evidence implicating chrysotile in mesothelioma. They noted that fewer cases and controls were collected than intended, and that the controls' work histories were not known in detail.

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: Survey of mesothelioma deaths with panel review of tumour tissue, and lung fibre analysis of cases compared with matched control patients (bronchial carcinoma and cerebrovascular disease)
• Who was studied: Deaths from pleural or peritoneal mesothelioma in the United Kingdom in 1976. Of 117 cases submitted, 93 were confirmed as mesothelioma (86 with adequate lung tissue) and 24 were not confirmed. Controls were 28 bronchial carcinoma cases (27 adequate) and 30 cerebrovascular disease cases (29 adequate). The confirmed cases were 72 males, 16 females and 5 of unknown sex. Sites were 54 pleural, 6 peritoneal and 33 unknown.
• Exposure: Asbestos and other mineral fibres in lung tissue, counted as fibres per mg of lung tissue using electron microscopy and X-ray microprobe techniques: chrysotile, amosite and crocidolite, plus anthophyllite, tremolite and actinolite
• Main results:
  • Mesothelioma cases contained more amosite and more crocidolite than the two control groups combined (P < 0.001)
  • For each of the two amphiboles (amosite and crocidolite), mesothelioma cases had on average about 10 times as much as the controls
  • Chrysotile was present no more frequently, and not in greater amounts, in mesothelioma cases than in controls
  • No chrysotile was found in 30 (35%) of the 86 mesothelioma cases analysed, nor in 12 (21%) of the 56 controls
  • Four of the mesothelioma cases had no amphibole fibres in their lungs. Two of these had chrysotile fibres and the other two had no asbestos fibres.
  • Nine (31%) of the cerebrovascular disease controls had more than 1000 amphibole fibres per mg, but only one had more than 2000 fibres per mg
  • Controls with cerebrovascular disease had significantly more chrysotile than controls with lung cancer (P < 0.05). The authors described this difference as small.
  • Confirmed mesothelioma cases showed no evidence of differences in fibre content from the other submitted cases that were not confirmed as mesothelioma
  • Anthophyllite, tremolite and actinolite were rare and showed no marked differences between groups, so they were not considered further
  • All three mesothelioma patients with a negative history of asbestos exposure had some asbestos fibres in their lungs. The authors said this was possibly due to environmental dust.
  • Three tumours first diagnosed as mesothelioma showed differentiation toward muscle, bone and cartilage and were excluded from the mesothelioma group. Their occupational histories and lung asbestos levels were similar to those of asbestos-induced mesotheliomas.
• The authors' conclusion: The authors concluded that the study provided no evidence to implicate chrysotile in the cause of mesothelioma. Amosite and crocidolite were more frequent and more abundant in mesothelioma cases. The study gave no evidence on the relative hazards of amosite and crocidolite.
• Limitations the authors state:
  • Only 93 confirmed cases were referred, about two-thirds of the number expected
  • 209 deaths in that year were certified as malignant neoplasm of the pleura, so only about half were available to the survey
  • Only 58 control samples were obtained for the 117 index cases. The authors said the control design was too restrictive.
  • The occupational histories of the controls were not known in detail. Some of the amphibole in controls may have come from environmental exposure.
  • Controls were matched by area, so there is no information on control lung fibre content in areas where mesotheliomas did not occur or were not submitted

Topics

Medical terms in this study, explained in our Lexicon: Pathology, Mesothelioma, Carcinoma, Amosite, Crocidolite, Chrysotile, Amphibole Group.

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