Imaging of malignant pleural mesothelioma: it is possible a screening or early diagnosis program?-a systematic review about the use of screening programs in a population of asbestos exposed workers

Our plain-English summary of Imaging of malignant pleural mesothelioma: it is possible a screening or early diagnosis program?-a systematic review about the use of screening programs in a population of asbestos exposed workers, by F. Falaschi, C. Romei, S. Fiorini, et al (Journal of Thoracic Disease, 2018).

The study

• Authors: F. Falaschi, C. Romei, S. Fiorini, M. Lucchi
• Journal: Journal of Thoracic Disease
• Published: 2018;10(Suppl 2):S262-S268
• Type of article: Review
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant pleural mesothelioma (MPM) in an uncommon neoplasia with high mortality rate, mostly related to professional asbestos exposure. Clinical manifestations are not specific so that diagnosis is performed at advanced stage and screening protocols are not feasible now. On the other hand, asbestos-exposed workers have a high incidence of developing lung cancer. Low-dose computed tomography (LDCT) is a volumetric acquisition technique with high spatial resolution and a low dose exposure; it is used in many trials to detect lung tumours at an early stage in screening protocols, reducing mortality rate in smoker subjects. In recent papers, the possibly role of lung cancer screening was evaluated and recommended also in subjects exposed to asbestos. This article summarizes previous and present clinical trials validated for lung cancer screening, to discuss the possibility of early diagnosis or screening programs in a population of asbestos exposed workers by LDCT.

In plain English

This was a review article by authors from radiology and thoracic surgery departments in Pisa, Italy. It is titled a systematic review, but the text does not describe how studies were searched for or chosen. The authors described how malignant pleural mesothelioma is diagnosed and staged with imaging. They then discussed earlier studies of low-dose CT (LDCT) screening for lung cancer, including trials in asbestos-exposed workers. Among the studies they cited, a meta-analysis by Ollier et al. reported 49 lung tumours among 5,074 asymptomatic asbestos-exposed subjects, a prevalence of 1.1%. Two Italian screening studies were also cited. One, of 1,045 exposed workers, found no mesothelioma at baseline. The other, of over 1,119 exposed subjects, found no mesothelioma. In their own unpublished clinical data, the authors reported 21 lung tumours (1.38%) and 2 mesotheliomas (0.13%) among 1,513 patients. They wrote that mesothelioma grows so fast that it escapes screening intervals, and that differences between the trials made their results hard to compare. The authors concluded that mesothelioma screening is currently not feasible. In their view, lung cancer screening in asbestos-exposed people, with careful evaluation of risk factors, is possible and desirable.

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 article (titled a systematic review; the text does not describe a literature search or study-selection method). It also includes the authors' unpublished clinical data and one illustrative case figure.
• Who was studied: Asbestos-exposed workers studied in published LDCT lung cancer screening trials (results published 2002 to 2009), plus lung screening trials in heavy smokers. The authors' own unpublished data covered 1,513 patients.
• Exposure: Occupational ("professional") asbestos exposure, with fiber types not specified in general. Imaging methods discussed were chest X-ray, CT, HRCT, LDCT, MRI and PET/CT.
• Main results:
  • Authors' own unpublished clinical data: 21 lung tumours (1.38%) and 2 malignant pleural mesotheliomas (0.13%) among 1,513 patients.
  • Cited meta-analysis by Ollier et al. of seven lung screening studies in asbestos-exposed workers: 49 lung tumours among 5,074 asymptomatic subjects (prevalence 1.1%). Of these, 18 tumours (36.7%) were stage I and underwent radical surgery.
  • Cited study by Fasola et al. (Udine) of 1,045 asbestos-exposed workers: 9 lung cancers found (detection rate 1%), 8 at stage 1, and no mesothelioma at baseline.
  • Cited study by Mastrangelo et al. (Padova) of over 1,119 exposed subjects: 5 lung cancers found (detection rate 0.4%), 1 at stage 1, and no mesothelioma. That study did not consider LDCT screening cost-effective.
  • The authors explained that mesothelioma, like small cell lung cancer, grows very rapidly and escapes screening intervals. Such tumours are occasionally found and reported as interval cancers.
• The authors' conclusion: The authors concluded that, in the current view, screening for malignant pleural mesothelioma is not feasible. In their view, lung cancer screening in asbestos-exposed subjects, with careful evaluation of risk factors, is possible and desirable.
• Limitations the authors state:
  • The screening trials in asbestos-exposed workers used different CT techniques and different criteria for a positive test, which made their results difficult to compare.

Topics

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Systematic Review, Asbestos Exposure, Lung Cancer, Low-Dose CT Screening, Clinical Trial.

Related studies

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• The National Sheet Metal Worker Asbestos Disease Screening Program: radiologic findings. National Sheet Metal Examination Group — L.S. Welch, D. Michaels, et al. (1994)
• Mortality among sheet metal workers participating in a respiratory screening program — L. Welch, J. Dement, et al. (2015)
• Asbestos-related disease among sheet-metal workers. Preliminary results of the National Sheet Metal Worker Asbestos Disease Screening Program — L.S. Welch, D. Michaels, et al. (1991)
• Experiences of a state-sponsored notification and screening program for asbestos workers — A.P. Bender, A.N. Williams, et al. (1993)
• Low-dose CT: a useful and accessible tool for the early diagnosis of lung cancer in selected populations — L. Callol, F. Roig, et al. (2007)

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