Nonexpandable Lung: More Than Just a Call from Radiology

Our plain-English summary of Nonexpandable Lung: More Than Just a Call from Radiology, by D. Feller-Kopman (Annals of the American Thoracic Society, 2019).

The study

• Author: D. Feller-Kopman
• Journal: Annals of the American Thoracic Society
• Published: 2019;16(10):1240-1242
• Type of article: Editorial, Comment
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

This editorial commented on a study by Bibby and colleagues, published in the same issue, of nonexpandable lung (NEL) in patients with malignant pleural mesothelioma (MPM). The author first reviewed the background. Malignant pleural effusions account for more than 120,000 US hospital admissions each year. NEL can be seen in at least 30% of patients with malignant pleural effusion, but its incidence in MPM had not been described. He noted that identifying NEL matters when pleurodesis is being considered. He described the Bibby study as the first prospective evaluation of NEL in MPM. In a cohort of 229 patients, 33% had NEL, defined radiographically. NEL was an independent predictor of poor survival (hazard ratio 1.80; 95% confidence interval 1.16–2.80), independent of pleural effusion and tumor stage. Breathlessness was more common in patients with NEL than in those with effusion and expandable lung. More than half of patients with NEL were managed without pleural intervention. The author discussed possible mechanisms of breathlessness, including more negative pleural pressure reducing diaphragm efficiency. He identified as a limitation the radiologic rather than pressure-based definition of NEL, and the lack of data on volumes of fluid drained. He suggested that future studies use ultrasound and pleural pressure measurement, report causes of death, and examine whether pleurectomy might reduce deaths from respiratory failure.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This is a short editorial, not a research study. The author commented on a separate study by Bibby and colleagues, published in the same journal issue, about nonexpandable lung in people with malignant pleural mesothelioma. Nonexpandable lung is a lung that cannot fully re-expand, often because its pleural covering has thickened. As the editorial describes it, that study prospectively evaluated 229 patients and found that 33% had nonexpandable lung, judged from imaging. After adjusting for other factors, nonexpandable lung was linked to higher mortality (hazard ratio 1.80; 95% confidence interval 1.16 to 2.80), independent of pleural effusion or tumor stage. No link was found between the degree of nonexpandable lung and survival. The author noted that only 64 patients were in that analysis, likely too few to detect one. Breathlessness was more common in patients with nonexpandable lung, and more than half of them were managed without pleural procedures. The author pointed out that the study defined nonexpandable lung by imaging rather than by pleural pressure, and suggested that future studies use ultrasound and pressure measurements. The editorial does not discuss asbestos exposure.

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: Editorial commenting on a separate prospective cohort study by Bibby and colleagues; the editorial reports no data of its own
• Who was studied: The study discussed (Bibby and colleagues) included 229 patients with malignant pleural mesothelioma; histology was 64% epithelioid, 20% sarcomatoid or desmoplastic, and 8% biphasic
• Main results:
  • In the Bibby study, as reported by the editorial, 33% of the 229 patients with malignant pleural mesothelioma had nonexpandable lung
  • In the Bibby study's multivariable model, nonexpandable lung was an independent predictor of increased mortality (hazard ratio 1.80; 95% confidence interval 1.16 to 2.80)
  • The association between nonexpandable lung and survival was independent of pleural effusion and tumor stage
  • No association was found between the degree of nonexpandable lung and survival, in a subgroup of 64 patients
  • In the Bibby study, 80% of patients presented with breathlessness and 84% had pleural effusion at presentation
  • Breathlessness was more common in patients with nonexpandable lung than in patients with pleural effusion and expandable lung
  • More than half of the patients with nonexpandable lung were managed without pleural intervention
• The authors' conclusion: The author wrote that the Bibby study provides new understanding and raises many questions for further study. The author suggested that future studies use ultrasound to define and quantify nonexpandable lung, and measure pleural pressures.
• Limitations the authors state:
  • The editorial author noted that the Bibby study defined nonexpandable lung radiologically rather than by pleural pressures
  • The editorial author noted that the Bibby study did not report the volume of fluid drained, the volume remaining, or why fluid removal was stopped
  • The editorial author noted that the subgroup analysis of degree of nonexpandable lung likely lacked statistical power

Topics

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

Medical terms in this study, explained in our Lexicon: Trapped Lung, Pleural Mesothelioma, Pleural Effusion, Pleurodesis, Hazard Ratio, confidence interval, Diaphragm, Ultrasound.

Related studies

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• Endemic malignant mesothelioma: exposure to erionite is more important than genetic factors — M. Metintas, G. Hillerdal, et al. (2010)
• Screening for mesothelioma: more harm than good? — J.P. van Meerbeeck, G. Hillerdal (2008)
• MAGE-A is More Highly Expressed Than NY-ESO-1 in a Systematic Immunohistochemical Analysis of 3668 Cases — S.P. Kerkar, Z.F. Wang, et al. (2016)
• The clinical diagnosis of asbestosis in this century requires more than a chest radiograph — R.M. Ross (2003)
• The Prevalence and Clinical Relevance of Nonexpandable Lung in Malignant Pleural Mesothelioma. A Prospective, Single-Center Cohort Study of 229 Patients — A.C. Bibby, P. Halford, et al. (2019)

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