Analysis of asbestos fiber burden in lung tissue from mesothelioma patients

Our plain-English summary of Analysis of asbestos fiber burden in lung tissue from mesothelioma patients, by R.F. Dodson, M. O'Sullivan, C.J. Corn, et al (Ultrastructural Pathology, 1997).

The study

• Authors: R.F. Dodson, M. O'Sullivan, C.J. Corn, J.W. McLarty, S.P. Hammar
• Journal: Ultrastructural Pathology
• Published: 1997;21(4):321-36
• Cited by: 50 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Mesothelioma is a rare neoplasm that occurs most frequently in individuals with previous asbestos exposure. Differences for risk of development of asbestos-related mesothelioma and lung cancer have been attributed to the various types of asbestos, as well as to the dimension of the inhaled fibers. In the present study, 55 individuals with the pathological diagnosis of mesothelioma were evaluated as to ferruginous body and fiber content in lung tissue. The procedures used in the analysis included tissue digestion and analysis of the collected material for ferruginous bodies by light microscopy and for uncoated fibers by analytical transmission electron microscopy. Forty-six of the samples had ferruginous body concentrations of over 1000/per gram dry weight of lung tissue. The majority of the cores of these ferruginous bodies were amosite. Likewise, the most common uncoated asbestos fiber in the tissue was amosite. Only a small percentage of each type of asbestos would have been visible by light microscopy or even potentially by electron microscopy if the magnification was not sufficient to detect those with thin (< 0.2 micron) diameters. The consistent finding in most of the cases was a considerable presence of asbestos, often of mixed types.

In plain English

This study measured asbestos in lung tissue from 55 people diagnosed with mesothelioma. All were from the Pacific Northwest, and most had shipyard-related work. Ferruginous bodies (coated fibers that looked like asbestos bodies) were counted by light microscopy, and uncoated fibers were identified by analytical transmission electron microscopy. Forty-six of the 55 patients (83.6%) had more than 1,000 ferruginous bodies per gram of dry lung tissue. Of 841 ferruginous bodies found by electron microscopy, 781 (92.9%) had formed on amosite and 11 (1.3%) on nonasbestos fibers. Uncoated amosite was detected in 53 cases (96.4%), tremolite in 33 (60.0%), crocidolite in 22 (40.0%), and anthophyllite in 21 (38.2%). No chrysotile was detected in 24 cases (43.6%). One patient had no asbestos fibers detected. Patients with pathologic asbestosis had a higher median fiber level than those without, but the authors found the ranges too wide to predict asbestosis from fiber counts. The authors concluded that most patients had a confirmed asbestos burden above general population levels, often of mixed types. They also concluded that their data could not support differing mesothelioma risks between asbestos types.

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 analyzing asbestos burden in lung tissue: tissue digestion, light microscopy for ferruginous bodies, and analytical transmission electron microscopy (ATEM) for uncoated fibers and ferruginous body cores; no comparison group
• Who was studied: 55 people with a pathological diagnosis of mesothelioma, all from the Pacific Northwest (USA), most with shipyard-related exposures
• Exposure: Occupational asbestos exposures, mostly shipyard work, with some other trades. Lung tissue was measured for amosite, crocidolite, chrysotile, tremolite, actinolite and anthophyllite
• Main results:
  • The group was 53 men and 2 women; mean age at death 69.5 years (range 43 to 87)
  • The authors counted as ferruginous bodies the structures whose appearance was consistent with an asbestos body
  • 46 of the 55 patients (83.6%) had an average of more than 1,000 ferruginous bodies per gram of dry lung tissue
  • Of 841 ferruginous bodies found by ATEM, 781 (92.9%) were formed on amosite, 24 (2.9%) on crocidolite, 8 (1.0%) on tremolite, and 1 (0.1%) on chrysotile
  • Of the 841 ferruginous bodies, 11 (1.3%) were formed on nonasbestos fibers, and the cores of 10 (1.2%) were totally coated or could not be analyzed
  • Total uncoated asbestos ranged from 68,950,000 to 22,096 fibers per gram of dry lung tissue across patients
  • One patient (case L-13) had no asbestos fibers detected within the study's detection limits
  • Amosite was detected in 53 of the 55 cases (96.4%)
  • Crocidolite was found in 22 cases (40.0%)
  • No chrysotile was detected in 24 cases (43.6%)
  • Tremolite was found in 33 cases (60.0%) and anthophyllite in 21 cases (38.2%)
  • Among the 29 cases with pathologic asbestosis, median total asbestos fibers was 1,045,300 per gram of dry lung (mean 5,426,123)
  • Among the 26 cases without pathologic asbestosis, median total asbestos fibers was 505,556 per gram of dry lung (mean 3,258,705)
  • Fiber and body concentrations varied widely in patients both with and without asbestosis
  • Survival from diagnosis ranged from 1 week to 26 months (mean 8.3 months)
  • Latency (diagnosis minus first exposure) ranged from 25 to 71 years (mean 45 years)
• The authors' conclusion: The authors concluded that, in most cases, people with mesothelioma had a confirmed asbestos burden above general population levels. They said their data could not support differing levels of mesothelioma risk for the various asbestos types.
• Limitations the authors state:
  • The authors noted that the number of cases is small and that results (stated for the comparison of histologic types) could differ with a larger sample
  • The authors noted that uncoated fiber counts can vary with the counting technique used

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: Fiber Burden, Mesothelioma, Neoplasm, Asbestos Exposure, Lung Cancer, Ferruginous body, Tissue Digestion, Ferruginous Bodies.

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• Relationships between ferruginous bodies and uncoated asbestos fibers in lung tissue — R.F. Dodson, M. O'Sullivan, et al. (1996)
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