Diffuse malignant mesothelioma: a review

Our plain-English summary of Diffuse malignant mesothelioma: a review, by W.N. Rom, J.E. Lockey (The Western Journal of Medicine, 1982).

The study

• Authors: W.N. Rom, J.E. Lockey
• Journal: The Western Journal of Medicine
• Published: 1982;137(6):548-54
• Type of article: Review
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Free full text
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 001801).

Abstract

Diffuse malignant mesothelioma is a signal tumor of asbestos exposure. Mesothelioma incidence has been steadily rising during the past two decades, reflecting the increases in asbestos use during and following World War II. The onset of the disease follows exposure by 25 to 40 years. The dose-response relationship appears to be much lower than that for asbestosis or lung cancer-it is not known whether current levels of exposure will entail a risk for disease 30 years hence. There is no synergistic or additive interaction with smoking for this tumor. Current knowledge indicates that pleural plaques, per se, do not increase the risk for this tumor beyond that of the previous asbestos exposure alone. Durable fibers with high aspect ratios, especially amphiboles, are associated with experimental tumor induction. Treatment modalities including surgical procedures and chemotherapy with doxorubicin and 5-azacytidine offer prospects for palliation.

In plain English

This 1982 article was a review of published research on diffuse malignant mesothelioma, not a new study. The authors summarized other researchers' work on how often the tumor occurs, its link to asbestos, symptoms, diagnosis, treatment, fiber type and animal experiments. They wrote that the tumor appears 25 to 40 years or more after asbestos exposure begins, that about three fourths of patients are men, and that 80 percent of cases affect the pleura. They cited annual rates for adults of two to three cases per million men and about 0.7 per million women. They stated that there is no synergistic or additive interaction with smoking for this tumor. They also stated that pleural plaques, per se, do not add risk beyond the asbestos exposure itself, though future studies may change that. They described a claimed ranking of risk by fiber: crocidolite, then amosite, then chrysotile. The authors concluded that the tumor appears to be caused by durable fibers with high length-to-width ratios. They also concluded that treatment has had little success, and that understanding the disease and prevention are likely to be more productive.

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: Narrative review of published literature
• Who was studied: No study population of its own. The authors reviewed published reports, case series, cohort and case-control studies, tissue-analysis studies and animal experiments on diffuse malignant mesothelioma, drawn from a literature of more than 175 scientific reports.
• Exposure: Occupational, household and environmental asbestos exposure. Fibers discussed include crocidolite, amosite, chrysotile, anthophyllite and tremolite, plus fibrous erionite (a zeolite).
• Main results:
  • The authors stated that the latency period for diffuse malignant mesothelioma after the start of asbestos exposure is 25 to 40 years or more.
  • Citing other data, the authors gave an annual incidence for adults of two to three cases per million for men and approximately 0.7 cases per million for women.
  • According to the review, three fourths of patients are men, and 80 percent of cases affect the pleura, with the remainder mostly in the peritoneum.
  • The authors stated that there is no synergistic or additive interaction with smoking for this tumor.
  • The authors stated that, on current knowledge, pleural plaques, per se, do not increase the risk of this tumor beyond that of the previous asbestos exposure alone.
  • The authors described a claimed gradation of risk by fiber type, with crocidolite greater than amosite greater than chrysotile. They noted that amphibole rather than chrysotile fibers are retained in lung tissue.
  • The authors noted that patients seldom live longer than 12 to 18 months after diagnosis.
  • Citing a prospective study by Chahinian and co-workers, the authors reported that 7 of 28 patients with pleural mesothelioma responded to doxorubicin and 5-azacytidine, with a median survival of 22.2 months from first treatment.
• The authors' conclusion: The authors concluded that diffuse malignant mesothelioma appears to be caused by durable fibers with high aspect ratios (length to width). They also concluded that treatment has had little success, so understanding the mechanisms of the disease and prevention are likely to be more productive from a public health perspective.
• Limitations the authors state:
  • The authors stated that it is not known whether current levels of exposure will carry a risk of disease 30 years later.
  • The authors stated that future epidemiologic studies may modify their statement that pleural plaques do not add risk.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Signal Tumor, Asbestos Exposure, Mesothelioma, Dose-response relationship, Lung Cancer, Pleural Plaques, Aspect Ratio (Length-to-diameter ratio).

Related studies

• Interaction of asbestos, age, and cigarette smoking in producing radiographic evidence of diffuse pulmonary fibrosis — K.H. Kilburn, R. Lilis, et al. (1986)
• Trends in mortality of diffuse malignant mesothelioma of pleura — V.E. Archer, W.N. Rom (1983)
• Diffuse pleural mesothelioma and asbestos exposure in the North Western Cape Province — J.C. Wagner, C.A. Sleggs, et al. (1960)
• Pleuropneumonectomy in the management of diffuse malignant mesothelioma of the pleura. Experience with 29 patients — E.G. Butchart, T. Ashcroft, et al. (1976)
• Diffuse malignant mesothelioma. Prospective evaluation of 69 patients — A.P. Chahinian, T.F. Pajak, et al. (1982)
• Diffuse malignant mesothelioma of the pleura in Ontario and Quebec: a retrospective study of 332 patients — P. Ruffie, R. Feld, et al. (1989)

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