Pulmonary Asbestosis: V. A Report Of Bronchial Carcinoma And Epithelial Metaplasia

Our plain-English summary of Pulmonary Asbestosis: V. A Report Of Bronchial Carcinoma And Epithelial Metaplasia, by K.M. Lynch, W.A. Smith (1939).

The study

• Authors: K.M. Lynch, W.A. Smith
• Published: American Journal Of Cancer 36(4):567-573, August (1939)
• Type of article: Journal article
• Our copy: from Johns-Manville's own medical library, J-M no. 002903. The article is still under copyright, so we describe it here rather than post it.

In plain English

This 1939 article from the Medical College of the State of South Carolina reported a second case of lung cancer in a person with pulmonary asbestosis, following the authors' first such report in 1935. The patient, a white man, had worked as a weaver in an asbestos mill, with thirteen years of exposure to asbestos dust, and died at about fifty. The examination after death was limited to the chest. It found widespread lung scarring (fibrosis) with asbestos bodies, thick nodular pleura (the lining around the lungs), and a mixed squamous-cell and glandular carcinoma. The cancer probably began in the lower right lobe and had spread through the lungs, mediastinum and pleura. The authors also described a man, called in the article a Negro man, whose asbestos exposure was not known. He had asbestosis, and the lining of his airways had changed to a squamous (flattened, layered) form. Over twelve years of 2343 necropsies, 35 showed some asbestosis, and 2 of these had lung cancer, about 6 per cent. The authors called the significance of this questionable because the series was small.

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 report of a second lung cancer in asbestosis, plus a second case showing bronchial epithelial metaplasia and a count from the authors' necropsy records
• Who was studied: Main case: a white man first seen at age forty-two who had worked as a weaver in an asbestos mill. Second case: a man the article describes as Negro, ill with a diagnosis of asthma. Necropsy series: 2343 consecutive necropsies over twelve years, 35 of them with some degree of asbestosis
• Exposure: Asbestos dust from work as a weaver in an asbestos mill, thirteen years in total (main case). No fiber type is named. The second man's asbestos exposure was not known
• Main results:
  • Main case: a carcinoma of mixed squamous-cell and glandular type, with asbestos bodies nearby
  • Main case: the primary growth was probably in the lower right lobe, with wide spread into the lungs, mediastinum and pleura
  • Main case: both lungs showed widespread old but still progressive fibrosis
  • Main case: both the visceral and parietal pleura were thick, nodular and almost cartilaginous
  • Main case: sputum examinations showed no asbestos bodies
  • Main case: death occurred at about fifty years of age
  • Second case: squamous metaplasia of the bronchial epithelium had occurred
  • Among the 35 necropsies showing asbestosis, 2 had lung carcinoma, about 6 per cent
  • By the authors' count, this case brought the number of recorded cases of lung cancer in asbestosis to 8
• The authors' conclusion: The authors called the significance of the 6 per cent figure questionable. They wished to record the observation that advanced asbestosis may lead to metaplasia of the bronchial epithelium
• Limitations the authors state:
  • The series of asbestos cases was small, and whether the 6 per cent figure was significant was questionable
  • The duration of the carcinoma could not be estimated accurately
  • The main case's necropsy was limited to the chest
  • The second man's exposure to asbestos dust was not known

Topics

Medical terms in this study, explained in our Lexicon: Asbestosis, Carcinoma, Lung Cancer, Fibrosis, Asbestos Bodies, Pleura, Mediastinum, Asbestos Exposure.

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