Asbestos, an extrinsic factor in the pathogenesis of bronchogenic carcinoma and mesothelioma

Our plain-English summary of Asbestos, an extrinsic factor in the pathogenesis of bronchogenic carcinoma and mesothelioma, by W.M. O'Donnell, R.H. Mann, J.L. Grosh (Cancer, 1966).

The study

• Authors: W.M. O'Donnell, R.H. Mann, J.L. Grosh
• Journal: Cancer
• Published: 1966;19(8):1143-8
• Cited by: 17 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. 001510).

In plain English

This was a retrospective report on 55 patients with pathologically proven pulmonary asbestosis seen at Lancaster General Hospital, Pennsylvania, between 1940 and 1965. All but one had worked in the same asbestos textile plant, which carded, spun and wove asbestos and used chrysotile almost exclusively. Of the 55, 23 had bronchogenic carcinoma (lung cancer) and 5 had mesothelioma: 3 in the peritoneum only, 1 in both peritoneum and pleura, and 1 in the pleura. In 22 of the 23 lung cancers, the tumor began in a lower lobe. Among the patients with cancer, mean exposure was 20 years. For the 25 patients whose records gave this information, the time from first exposure to diagnosis was 20 to 44 years in the results (20 to 40 years elsewhere in the article), averaging about 30 years. Smoking histories were mostly unavailable. The authors could not link cancer to the severity of asbestosis. They said their patients were a selected hospital group and that they did not aim to measure incidence. The authors concluded that the frequent association could be explained only by a causal relationship.

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: Retrospective case series of hospital patients with asbestosis, confirmed at autopsy or surgery
• Who was studied: 55 patients with pathologically proven pulmonary asbestosis seen at Lancaster General Hospital, Lancaster, Pennsylvania, 1940 to 1965. All but one had worked in the same asbestos textile plant. The report focuses on the 28 who had cancer: 25 men and 3 women, aged 37 to 69.
• Exposure: Work in an asbestos textile plant (carding, spinning and weaving) that used chrysotile asbestos almost exclusively. Most workers were exposed before effective industrial hygiene was achieved between 1935 and 1940.
• Main results:
  • Among the 55 patients with asbestosis, 28 had malignant tumors: 23 bronchogenic carcinomas and 5 mesotheliomas of the peritoneum or pleura. The remaining 27 died of pulmonary insufficiency or of an unrelated disease.
  • The authors reported the association of asbestosis with bronchogenic carcinoma as 42% and with mesothelioma as 8% in this series.
  • Of the 5 mesotheliomas, 3 arose in the peritoneum and stayed in the abdominal cavity, 1 involved both peritoneum and pleura, and 1 (described separately) was limited to the pleura.
  • In 22 of the 23 lung carcinomas, the tumor arose in a lower lobe. In the remaining patient it was considered multicentric.
  • Lung carcinoma types: 10 squamous cell, 7 anaplastic, 5 adenocarcinoma, 1 bronchiolar.
  • Of the 28 patients with tumors, 25 were men and 3 were women. Ages ranged from 37 to 69, with a median of 54 years.
  • Mean duration of exposure was 20 years among those who developed a tumor.
  • For the 25 patients with available information, the time from first exposure to clinical recognition of the tumor ranged from 20 to 44 years, averaging about 30 years.
  • Eleven workers were still employed at the plant when the cancer was found. For those who had left, the tumor was recognized on average 21 years after leaving.
  • Two individuals developed asbestosis and a tumor after about a year of exposure.
  • Five of the patients had a recorded history of smoking more than one pack of cigarettes a day.
  • The authors could not relate the occurrence of lung carcinoma or mesothelioma to how extensive or severe the asbestosis was.
• The authors' conclusion: The authors concluded that bronchogenic carcinoma and mesothelioma are endemic occupational diseases of asbestos textile workers. In their view, the frequent (50%) association of these tumors with asbestosis can be explained only by a causal relationship.
• Limitations the authors state:
  • The study was not designed to measure the incidence of lung cancer or mesothelioma in asbestos workers.
  • The patients were a selected group, admitted to hospital because of advanced pneumoconiosis or cancer.
  • The study was retrospective, and the dust levels these patients experienced no longer existed to the same degree.
  • Asbestos workers share the general population's non-occupational risk of lung cancer.
  • Detailed smoking histories were missing for most patients.
  • The exposure history of at least one patient, recorded as 4 months, was considered possibly incomplete.

Topics

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

Medical terms in this study, explained in our Lexicon: Bronchogenic Carcinoma, Mesothelioma.

Related studies

• Morphology of bronchogenic carcinoma in workers formerly exposed to crocidolite at Wittenoom Gorge in Western Australia — J.E. Baker, D.C. Reutens, et al. (1986)
• Association of asbestos and bronchogenic carcinoma in a population with low asbestos exposure — M.L. Warnock, A.M. Churg (1975)
• Asbestosis associated with bronchogenic carcinoma — R. Stoll, R. Bass, et al. (1951)
• Occupational and environmental causes of bronchogenic carcinoma — B.M. Haus, H. Razavi, et al. (2001)
• Biomarker assessments in asbestos-exposed workers as indicators for selective prevention of mesothelioma or bronchogenic carcinoma: rationale and practical implementations — E. Pluygers, P. Baldewyns, et al. (1992)
• Biomarker assessments in asbestos-exposed workers as indicators for selective prevention of mesothelioma or bronchogenic carcinoma: rationale and practical implementations — E. Pluygers, P. Baldewyns, et al. (1991)

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