Pleural mesothelioma

Our plain-English summary of Pleural mesothelioma, by P.A. Ruffie (Current Opinion in Oncology, 1991).

The study

• Author: P.A. Ruffie
• Journal: Current Opinion in Oncology
• Published: 1991;3(2):328-34
• Type of article: Review
• Cited by: 20 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Pleural mesotheliomas are uncommon tumors that can be classified as localized or diffuse. Diffuse pleural mesotheliomas are invariably malignant. Although the frequency is low in the general population, it is more common in persons with a heavy occupational exposure to asbestos, and is considered as a signal tumor to asbestos exposure with medicolegal consequences. Mesothelioma incidence has been steadily rising during the past two decades, reflecting the increase in asbestos exposure during and following World War II. Clinical features include initial complaints of nonpleuritic chest pain and dyspnea. Distinguishing malignant mesothelioma from metastatic adenocarcinoma can be difficult, and can require large tissue biopsy with special stains and electron microscopy. The median survival of about 9 to 12 months confirms the poor outcome of pleural mesothelioma. The clinical deterioration is primarily attributable to locoregional spread of tumors, but metastasis is not rare. Several factors seem to have a prognostic value: performance status, stage, platelet count, age, histologic subtype, and asbestos exposure. In spite of the different therapeutic modalities such as surgery, radiotherapy, and chemotherapy used alone or in combination, the median survival is fairly different from survival among untreated patients. Because of the uncommon occurrence of this tumor and the existence of several different prognostic categories, a cooperative effort will be necessary for future therapeutic trials. If these active new therapies are identified, it would be useful to compare them to a best supportive care regimen in order to demonstrate an advantage of the treatment.

In plain English

This article is a review of published research on pleural mesothelioma. It does not report a new study of its own. The review separated localized pleural tumors, described as not related to asbestos exposure, from diffuse malignant mesothelioma. Citing earlier data, it reported that male mesothelioma mortality had been rising by almost 10% per year, roughly in parallel with industrial asbestos use 30 to 40 years earlier. It stated that chrysotile is generally considered very weakly carcinogenic compared with amphiboles (crocidolite, amosite, and tremolite), while noting that the controversy over chrysotile continues. Drawing on cited studies, it reported that dyspnea and chest pain were the first symptoms in 90% of cases and that men outnumbered women 4 to 1. Median survival was 1 year or less from diagnosis, and about 6 months with supportive care only. It reported no differences in median survival between treated and untreated patients. Most chemotherapy agents tested in small studies had response rates below 10%. The author concluded that cure seems exceptional and that cooperative trials comparing new treatments against best supportive care are needed.

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: Review of published literature (Current Opinion in Oncology annual review); no original study
• Who was studied: Published studies on pleural mesothelioma, localized and diffuse forms, reviewed up to 1991
• Exposure: Occupational, household and environmental asbestos exposure. Fiber types discussed are chrysotile, the amphiboles (crocidolite, amosite, tremolite) and erionite.
• Main results:
  • The review described the localized form of pleural mesothelioma as not related to asbestos exposure.
  • Citing McDonald's data, the review reported that male mesothelioma mortality had risen by almost 10% per year since the 1950s, while the rate among women stayed relatively the same.
  • Citing studies of Quebec miners and millers, the review reported very low incidence of diffuse malignant mesothelioma in workers who used only chrysotile.
  • Citing studies, the review reported dyspnea and chest pain as the most common first symptoms, in 90% of cases.
  • The review reported a men-to-women ratio of 4 to 1, which it linked to occupational asbestos exposure of men.
  • Thrombocytosis (high platelet count) was reported in 41% of cases.
  • Median survival from diagnosis was 1 year or less.
  • For patients given supportive care only, median survival was about 6 months.
  • Citing studies, the review reported no differences in median survival between patients given various treatments and untreated patients.
  • Radical surgery (pleuropneumonectomy) was reported to have 24% morbidity and 14% mortality.
  • In chemotherapy, doxorubicin was reported as the most active single agent, with response rates of 15% to 20%.
  • In a Cancer and Leukemia Group B randomized trial, cisplatinum plus mitomycin had a response rate of 28%, compared with 13% for cisplatinum plus doxorubicin.
• The authors' conclusion: The author concluded that cure of mesothelioma seems exceptional. Because the tumor is uncommon and has several prognostic categories, the author called for cooperative future trials comparing treatments against best supportive care.
• Limitations the authors state:
  • The author noted that retrospective evaluation of treatment is difficult because patient groups differ at presentation and many combinations of treatment are used.
  • The author noted that projected mesothelioma mortality estimates vary widely, because questions such as low-level exposure, dose-response and individual susceptibility are unresolved.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Occupational Exposure, Signal Tumor, Asbestos Exposure, Mesothelioma, Dyspnea, Malignant Mesothelioma, Adenocarcinoma.

Browse more research in Current Opinion in Oncology, or return to medical research.