Evaluation of the pleural malignant mesothelioma patients with the relation of asbestos exposure

Our plain-English summary of Evaluation of the pleural malignant mesothelioma patients with the relation of asbestos exposure, by T. Kishimoto, K. Okada, T. Sato, et al (Environmental Research, 1989).

The study

• Authors: T. Kishimoto, K. Okada, T. Sato, T. Ono, H. Ito
• Journal: Environmental Research
• Published: 1989;48(1):42-8
• Cited by: 6 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000107).

Abstract

There has been a recent increase in the number of patients with malignant mesothelioma in parts of Japan where Naval shipyards were located during World War II. This can be attributed to asbestos exposure during work in the shipyard. We have studied eight patients who were seen between 1984 and 1986 in Kure Kyosai Hospital. All had a history of asbestos exposure, seven in a Naval shipyard. In these seven cases, the latent period between exposure and the appearance of mesothelioma was 43-49 years. Quantification of asbestos bodies in the lung indicated a high concentration in all patients, giving further weight to the concept that asbestos is an etiologic factor in the genesis of mesothelioma. The major types of asbestos fibers were crocidolite and amosite. The study of structural features of these two types may provide a clue to the pathogenesis of the disease.

In plain English

This was a report on eight patients with pleural malignant mesothelioma who were autopsied between 1984 and 1986 at Kure Kyosai Hospital in Kure, Japan. Seven were men, and the average age was 72.9 years. All had a history of longstanding asbestos exposure: seven worked in a Naval shipyard and one was a steel company crane operator. The time from exposure to disease ranged from 25 to 49 years. The authors counted asbestos bodies in lung tissue free of tumor and compared these counts with those of 100 autopsied patients who had died of diseases other than cancer. Every mesothelioma patient had more than 500 asbestos bodies per 5 g of lung, while 93% of the comparison patients had fewer than 500. The authors reported the difference as significant (P < 0.01). Three patients had calcified pleural plaques, and the authors noted that higher asbestos body counts went with more extensive plaques. The main fibers found were crocidolite and amosite, with some chrysotile. The authors concluded that their findings added weight to the concept that asbestos exposure is etiologically related to malignant mesothelioma.

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 of eight autopsied patients, with asbestos body counts compared against 100 noncancer autopsy controls
• Who was studied: Eight patients with pleural malignant mesothelioma autopsied between 1984 and 1986 at Kure Kyosai Hospital, Kure, Japan. Seven were male, six were over 70, and the average age was 72.9 years. Controls were 100 noncancer patients whose occupations were not related to asbestos exposure.
• Exposure: Longstanding asbestos exposure. Seven patients worked at the Kure Naval shipyard (as a laborer, carpenter, welder and in other jobs), mostly during World War II. One patient was a steel company crane operator from 1960 to 1965.
• Main results:
  • Across all eight patients, the latency from exposure to disease ranged from 25 to 49 years. The 25-year case was the steel company worker.
  • All eight mesothelioma cases had more than 500 asbestos bodies per 5 g of lung tissue. Among the 100 noncancer controls, 93% had fewer than 500.
  • The difference in asbestos body counts between the mesothelioma cases and the noncancer controls was reported as significant (P < 0.01).
  • Asbestos body counts in the mesothelioma cases ranged from 522 per 5 g of lung tissue to the highest count, which is printed as 141,960 in the text but as 149,160 in Table 3.
  • On chest X-rays, three cases (4, 7 and 8) had pleural plaques with calcification, two cases (1 and 2) had definite plaques, and three had probable plaques.
  • Among the eight cases, higher asbestos body counts went with more extensive pleural plaques.
  • The main asbestos fibers found were crocidolite and amosite. Some chrysotile was also observed by analytic electron microscopy.
  • By tumor type, three of the eight tumors were epithelioid, one was sarcomatous and four were biphasic.
  • Six of the eight patients had a history of smoking and two were nonsmokers.
• The authors' conclusion: The authors concluded that the high asbestos body concentrations in lung tissue not involved by tumor added weight to the concept that asbestos exposure is etiologically related to malignant mesothelioma. They also suggested that structural characteristics of crocidolite and amosite may be related to mesothelioma induction, although the exact nature of this relationship is not clear.
• Limitations the authors state:
  • The counting method could not count uncoated asbestos fibers.

Topics

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

Medical terms in this study, explained in our Lexicon: Mesothelioma, Asbestos Exposure, Asbestos Bodies, Crocidolite, Amosite.

Related studies

• Malignant mesotheliomas in Kure City, Japan: the relationship of asbestos exposure — T. Kishimoto, T. Sato, et al. (1989)
• Relationship between number of asbestos bodies in autopsy lung and pleural plaques on chest X-ray film — T. Kishimoto, T. Ono, et al. (1989)
• Fatal pleural mesothelioma in Japan (2003-2008): evaluation of computed tomography findings — K. Kato, K. Gemba, et al. (2016)
• Acute myelocytic leukemia after exposure to asbestos — T. Kishimoto, T. Ono, et al. (1988)
• Synchronous double malignancy: adenocarcinoma of lung and malignant astrocytoma induced by asbestos exposure — T. Kishimoto, H. Hashimoto, et al. (1992)
• Diffuse malignant mesothelioma. Prospective evaluation of 69 patients — A.P. Chahinian, T.F. Pajak, et al. (1982)

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