Antemortem diagnosis of asbestosis by screening chest radiograph correlated with postmortem histologic features of asbestosis: a study of 273 cases

Our plain-English summary of Antemortem diagnosis of asbestosis by screening chest radiograph correlated with postmortem histologic features of asbestosis: a study of 273 cases, by K.N. Mizell, C.G. Morris, J.E. Carter (Journal of Occupational Medicine and Toxicology, 2009).

The study

• Authors: K.N. Mizell, C.G. Morris, J.E. Carter
• Journal: Journal of Occupational Medicine and Toxicology
• Published: 2009;4:14
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Accuracy in the clinical diagnosis of asbestosis has significant implications for the future health of affected patients as well as serious medicolegal implications for both patients and asbestos-associated industries. The radiographic gold-standard for diagnosis of asbestosis has been the plain chest radiograph, and in many asbestosis-screening clinics, chest radiograph abnormalities in conjunction with a history of asbestos exposure have been the mainstay of diagnosis. No studies have yet compared the antemortem chest radiographic diagnosis of asbestosis with the subsequent presence of pulmonary fibrosis and lung tissue ferruginous bodies at autopsy.

Methods: Records were reviewed from 273 autopsies performed to investigate asbestosis over an 11-year period. Accrued data included age and gender as well as the presence or absence of the following: occupational exposure to asbestos, antemortem clinical diagnosis of asbestosis by chest radiograph, fibrous pleural plaques, peribronchiolar or interstitial pulmonary fibrosis, ferruginous bodies in histologic sections of lung tissue, and ferruginous bodies in digested lung tissue.

Results: 242 cases with the antemortem radiographic diagnosis of asbestosis (study group) were identified. 31 additional autopsies had been requested based on history of asbestos exposure without radiographic documentation of asbestosis (control group). Comparison of the two groups showed a statistically significant increase in the association of chest radiograph-diagnosed asbestosis and the presence at autopsy of pleural plaques (p = 0.0109), peribronchiolar or interstitial pulmonary fibrosis (p = 0.0472), and histologically-diagnostic asbestosis (p = 0.0021). At autopsy, histologically-diagnostic asbestosis was confirmed in only 90 of the 243 study group cases. Comparison of individual parameters within the 242 study group cases showed a statistically significant correlation between the presence of fibrous pleural plaques and histologically-proven pulmonary fibrosis (p = 0.0025) as well as the subsequent histologic diagnosis of asbestosis (p < 0.0001).

Conclusion: Clinical diagnosis of asbestosis by screening chest radiograph is more predictive of the postmortem presence of fibrous pleural plaques, pulmonary fibrosis, and histologically-proven asbestosis than is occupational exposure history alone. However, chest radiograph-based diagnosis of asbestosis significantly overpredicts the subsequent histologic diagnosis of asbestosis.

In plain English

This retrospective review covered autopsy records from the University of South Alabama Medical Center in Mobile, Alabama, from January 1990 to December 2001. The authors compared 242 people diagnosed with asbestosis by chest X-ray before death with 31 people with a history of asbestos exposure but no X-ray diagnosis. Most cases were referred by a local law firm. At autopsy, the X-ray group more often had pleural plaques (61.1% vs. 35.4%), peribronchiolar or interstitial lung fibrosis (64.8% vs. 45.1%), and asbestosis confirmed under the microscope (36.8% vs. 9.7%). All of these differences were statistically significant. Microscope-confirmed asbestosis meant peribronchiolar fibrosis plus multiple ferruginous bodies in lung tissue sections. The results table counts it in 89 of 242 X-ray group cases, though the article elsewhere gives slightly different counts. The authors concluded that an X-ray diagnosis combined with exposure history predicted autopsy-confirmed asbestosis better than exposure history alone. They also concluded that X-rays over-predicted the diagnosis by a wide margin. They did not know the X-ray grades. Because the control group mixed negative X-rays and no X-rays, the study could not estimate X-ray sensitivity or specificity.

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 review of autopsy records comparing a chest X-ray-diagnosed group with a control group
• Who was studied: 273 autopsies performed to investigate asbestosis at the University of South Alabama Medical Center, Mobile, Alabama, January 1990 to December 2001. The study group was 242 cases with a pre-death chest X-ray diagnosis of asbestosis (ages 38 to 91, mean 70.7 years). The control group was 31 cases with a history of asbestos exposure but no X-ray diagnosis of asbestosis (ages 42 to 86, mean 70.2 years). Most cases were referred by a local law firm.
• Exposure: A history of asbestos exposure. The authors note the local shipbuilding industry and a law firm in legal action against these companies. Fiber types were not specified.
• Main results:
  • Pleural plaques at autopsy were found in 61.1% of the X-ray-positive group vs. 35.4% of the control group (p = 0.0109).
  • Peribronchiolar or interstitial pulmonary fibrosis was found in 64.8% of the X-ray group vs. 45.1% of controls (p = 0.0472).
  • Ferruginous bodies in lung tissue sections were found in 41.3% of the X-ray group vs. 12.9% of controls (p = 0.0016). Ferruginous bodies in digested lung tissue were found in 75.5% vs. 46.4% (p = 0.0028); digestion was not done or documented in all cases.
  • Histologically proven asbestosis was found in 36.8% of the X-ray group vs. 9.7% of controls (p = 0.0021). All compared findings differed significantly between the groups.
  • Histologically proven asbestosis, defined as both peribronchiolar fibrosis and multiple ferruginous bodies in histologic sections, was confirmed in 89 study group cases. The table gives 89 of 242; the Results text says 89 of 243 and the abstract says 90 of 243.
  • Within the 242 study group cases, pleural plaques were significantly correlated with histologically proven pulmonary fibrosis (p = 0.0025) and with the histologic diagnosis of asbestosis (p less than 0.0001).
• The authors' conclusion: The authors concluded that a chest X-ray suggestive of asbestosis combined with an exposure history is more predictive of histologically proven asbestosis at autopsy than exposure history alone. They also concluded that chest radiography over-predicts the histologic diagnosis of asbestosis by a wide margin.
• Limitations the authors state:
  • Clinical information was limited; often only age, sex, cause of death and the presence or absence of an X-ray diagnosis were provided.
  • The ILO classification of the X-rays was unknown, so autopsy findings could not be correlated with it.
  • The control group mixed people with negative X-rays and people with no X-rays, so sensitivity and specificity of chest radiography cannot be inferred.
  • Lung digestion methods changed during the period, so fiber counts were not comparable; cases were only classed by presence or absence of ferruginous bodies.
  • Because most patients were referred by law firms, the authors assumed radiologists likely knew of possible exposure, which previous studies link to over-reading.

Topics

Medical terms in this study, explained in our Lexicon: Chest X-Ray, Asbestos Exposure, Pulmonary Fibrosis, Ferruginous body, Autopsy, Occupational Exposure, Pleural Plaques, Interstitial.

Related studies

• The clinical diagnosis of asbestosis in this century requires more than a chest radiograph — R.M. Ross (2003)
• Performance of chest radiograph and CT scan for lung cancer screening in asbestos-exposed workers — B. Clin, F. Morlais, et al. (2009)
• Incremental value of oblique chest radiographs in the diagnosis of asbestos-induced pleural disease — E.L. Baker, R. Greene (1982)
• Antemortem diagnosis in two cases of malignant peritoneal mesothelioma — B. Eslami, C.L. Lutcher (1974)
• Effect of tobacco smoking on the presence of asbestosis at postmortem and on the reading of irregular opacities on roentgenograms in asbestos-exposed workers — E. Hnizdo, G.K. Sluis-Cremer (1988)
• Effect of tobacco smoking on the presence of asbestosis at postmortem and on the reading of irregular opacities on roentgenograms in asbestos-exposed workers — A. Kraut, J. Godbold, et al. (1989)

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