Diffuse Pleural Mesotheliomas In South Africa

Our plain-English summary of Diffuse Pleural Mesotheliomas In South Africa, by C.A. Sleggs, P. Marchand, J.C. Wagner (1961).

The study

• Authors: C.A. Sleggs, P. Marchand, J.C. Wagner
• Published: South African Medical Journal 35(2):28-34, January 14 (1961)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 001590. The article is still under copyright, so we describe it here rather than post it.

In plain English

This article described the clinical and X-ray findings in 34 people with diffuse pleural mesothelioma whom the authors investigated in South Africa. Only cases confirmed by tissue examination were included. There were 24 men and 10 women. Thirty-three gave a history of exposure to crocidolite (Cape blue asbestos) mined in the North West Cape, either through work or through living near the mines and mills. One woman, a nursing sister, apparently had no contact with asbestos. The time from first apparent exposure to first symptoms was 20 to 60 years. About a third of cases showed X-ray signs of asbestosis, and 27 of the 34 had right-sided disease. Of the 28 patients who had died, 17 (61%) died within a year of symptoms and all within 48 months. The authors reported disappointing results from nitrogen mustard, deep X-ray therapy and radioactive gold. Separately, asbestos bodies and fibres were found in the sputum of 115 patients with no definite mining exposure. The authors concluded that the findings justified further epidemiological and laboratory investigation.

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: Case series: a description of the clinical and radiological (X-ray) findings in patients with diffuse pleural mesothelioma. Only cases confirmed histologically (by tissue examination on biopsy or at necropsy) were included. It supplements the authors' earlier paper on 33 cases.
• Who was studied: 34 patients with diffuse pleural mesothelioma investigated by the authors in South Africa (24 males and 10 females), diagnosed mainly during the 4 years before publication.
• Exposure: Crocidolite (Cape blue asbestos) mined in the North West Cape. Patients were exposed through mining, milling and transport of asbestos; through industrial work such as lagging locomotive boilers; through cobbing asbestos in their homes; or through living near mines and mills and playing on dumps.
• Main results:
  • One of the 34 patients, a woman who worked as a nursing sister and had never lived in the North West Cape, apparently had no contact with asbestos.
  • In this series, the latent period between first apparent exposure to asbestos dust and the first symptoms was between 20 and 60 years.
  • Six men who had lived all their lives near the asbestos mines were the only patients under 40 at diagnosis. Four of them had been miners.
  • In about a third of the cases, X-rays showed signs of asbestosis.
  • 27 of the 34 cases had right-sided lesions. In no case was the mesothelioma initially on both sides, although the X-rays of 10 patients showed changes on both sides due to asbestosis.
  • Of the 34 patients, 28 had died: 17 (61%) within a year of developing symptoms, 7 during the second year and 2 (7%) during the third year. All 28 were dead within 48 months.
  • Two patients given repeated injections of nitrogen mustard into the chest cavity both died within 6 months.
  • Four patients with seemingly localized disease who were given deep X-ray therapy were all dead within a year.
  • Of 6 patients given radioactive gold instillations, 4 died within 13 months of starting the injections. The other 2 were alive, but their treatment was recent.
  • Sputum samples sent from the West End Hospital, Kimberley, showed asbestos bodies and fibres in 115 patients who had no definite mining exposure.
  • Asbestos bodies were found in the lung tissue of 30% of the cases.
  • In one family, both the father and a daughter died of histologically proved mesotheliomas.
• The authors' conclusion: The authors concluded that the findings of this paper and their earlier paper were striking enough to justify further epidemiological and laboratory investigations. These would try to determine causative and correlative factors, including a possible relationship with asbestos or other elements.
• Limitations the authors state:
  • Even when lung tissue was available, histological evidence of asbestosis was not obtained in every case.
  • Thoracoscopy, the usual diagnostic procedure in the early stages, restricted the choice of biopsy area. A representative specimen could not be obtained, and the authors felt a great deal of information was missed.
  • In some patients the exposure had been so brief that it was quickly forgotten, which made exposure histories harder to establish.
  • Asbestos bodies and fibres in sputum show only exposure to asbestos dust. They are not evidence of asbestosis without clinical and radiological support.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Crocidolite, Cape Blue, Asbestos Bodies, Sputum.

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