Analysis of asbestos concentration in 20 cases of pseudomesotheliomatous lung cancer

Our plain-English summary of Analysis of asbestos concentration in 20 cases of pseudomesotheliomatous lung cancer, by R.F. Dodson, S.P. Hammar (Ultrastructural Pathology, 2015).

The study

• Authors: R.F. Dodson, S.P. Hammar
• Journal: Ultrastructural Pathology
• Published: 2015;39(1):13-22
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Mesothelioma is a rare neoplasm caused by asbestos exposure. The majority of mesotheliomas arise from the pleural lining of the thoracic cavity, but also involve the peritoneal and pericardial cavities. Another type of neoplasm referred to as pseudomesotheliomatous adenocarcinoma is rare. Most "pseudomesotheliomas" arise in the pleural tissue of the chest cavity and resemble pleural mesotheliomas, macroscopically and histologically. While most arise in the pleura, there are some that metastasize to the pleura from another site. We evaluated asbestos fiber concentrations in 20 cases of pseudomesotheliomatous lung cancer and found a significant number to contain an elevated concentration of asbestos in their lung tissue, which is similar with our study of 55 mesothelioma cases published in 1997. This would provide evidence that some pseudomesotheliomatous lung cancers are caused by asbestos.

In plain English

The authors measured asbestos in lung tissue from 20 men, aged 43 to 77, diagnosed with pseudomesotheliomatous lung cancer, a cancer involving the chest lining that resembles mesothelioma. The cases were randomly selected from cases referred to one author's laboratory as part of medical-legal work. Fourteen of the men had worked in jobs where asbestos exposure would be expected. Using light and electron microscopy, the authors counted asbestos (ferruginous) bodies and uncoated fibers. Seventeen cases had asbestos bodies. Fourteen had at least one sample above 20 per gram of wet tissue, while six were within the 0 to 20 per gram the authors expected in the general population. Uncoated asbestos was found in all 20 cases, most often tremolite and amosite. Five cases had over one million fibers per gram of dry tissue in both lungs. One case had no asbestos bodies but over a million fibers per gram, mostly chrysotile. The authors concluded that their data would suggest a causal relationship between asbestos exposure and this cancer in some people with past exposure. The role of smoking was not studied.

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 measuring asbestos bodies (light microscopy) and uncoated asbestos fibers (analytical transmission electron microscopy) in lung tissue, compared with the authors' earlier studies of mesothelioma cases and general-population tissue
• Who was studied: 20 males diagnosed with pseudomesotheliomatous lung cancer, aged 43 to 77, randomly selected from cases referred to Diagnostic Specialties Laboratory, Bremerton, Washington, as part of a medical-legal service; dates not stated
• Exposure: Asbestos exposure as reflected in lung tissue burden. Fourteen men worked in occupations where asbestos exposure would be expected, such as shipyard work, insulation, pipefitting and electrical work. Fiber types measured were amosite, crocidolite, tremolite, actinolite, anthophyllite and chrysotile.
• Main results:
  • 17 of the 20 cases (85%) were positive for ferruginous (asbestos) bodies
  • In 14 cases, at least one lung sample contained over 20 asbestos bodies per gram wet weight
  • Six men (30%) had asbestos body levels in both samples at the level the authors expected in the general population (0 to 20 per gram wet tissue), compared with four cases (7.3%) in the authors' earlier mesothelioma study
  • Of 128 asbestos bodies examined by electron microscopy, 124 had amosite cores, 3 had crocidolite cores and 1 had a tremolite core
  • Uncoated asbestos fibers were found in both lung samples in 18 cases and in one of two samples in the other 2 cases (Cases 18 and 19)
  • Five cases had over one million uncoated asbestos fibers per gram of dry tissue in both lung samples
  • By case, 17 of 20 (85%) were positive for amosite and 18 (90%) for tremolite
  • 12 cases (60%) had at least one sample positive for chrysotile
  • Case 6 had no detectable asbestos bodies but over a million uncoated asbestos fibers per gram dry weight in both samples, mostly chrysotile
  • Eight cases (40%) had at least one sample with over one million asbestos fibers per gram dry weight, compared with 21 of 55 cases (38.2%) in the earlier mesothelioma study
  • The four highest tissue burdens in the earlier mesothelioma study were higher than any sample in this study
  • The authors stated that the combined asbestos body and uncoated fiber data confirmed past asbestos exposure in all cases
  • The longest survival from diagnosis was 20 months; the average was six months
• The authors' conclusion: The authors concluded that their data would suggest a causal relationship between asbestos exposure and pseudomesotheliomatous lung cancer in some persons with this disease and past asbestos exposure
• Limitations the authors state:
  • Whether smoking and asbestos act together in causing this cancer was not studied
  • Smoking and other history data were not available for some cases
  • Chrysotile is reported to clear from lung tissue more readily than amphiboles, so tissue measurements may understate chrysotile exposure

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Mesothelioma, Neoplasm, Asbestos Exposure, Pericardial, Pseudomesotheliomatous Adenocarcinoma, Pleural Mesothelioma, Pleura.

Related studies

• 'Pseudomesotheliomatous' carcinomas of the pleura: a 10-year analysis of cases from the Environmental Lung Disease Research Group, Cardiff — R.L. Attanoos, A.R. Gibbs (2003)
• Case reports of primary pulmonary adenocarcinoma with pleural spread: so-called pseudomesotheliomatous adenocarcinoma — R. Saito, A. Kasajima, et al. (2012)
• Local recurrence of lung adenocarcinoma 10 years after left upper lobectomy resembling pseudomesotheliomatous adenocarcinoma: a case report — J. Okamoto, H. Kubokura, et al. (2014)
• The forensic significance of pseudomesotheliomatous adenocarcinoma of the lung — J.M. Kennedy (2019)
• Pseudomesotheliomatous adenocarcinoma of the lung with rhabdoid features — J.H. Attems, F. Lintner (2001)
• A technical comparison of evaluating asbestos concentration by phase-contrast microscopy (PCM), scanning electron microscopy (SEM), and analytical transmission electron microscopy (ATEM) as illustrated from data generated from a case report — R.F. Dodson, S.P. Hammar, et al. (2008)

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