Malignant Pleural Mesothelioma: Accuracy of CT Against Immunohistochemical Test Among the Mexican Population

Our plain-English summary of Malignant Pleural Mesothelioma: Accuracy of CT Against Immunohistochemical Test Among the Mexican Population, by R. Gopar-Nieto, G. Aguilar-Madrid, L. Sotelo-Martínez, et al (Archives of Medical Research, 2015).

The study

• Authors: R. Gopar-Nieto, G. Aguilar-Madrid, L. Sotelo-Martínez, C.A. Juárez-Pérez, J. Kelly-García, L. Argote-Greene, M.D. Ochoa-Vázquez, E.M. García-Bazán, J. Ramírez-Pérez, L. Haro-García, C. Jiménez-Ramírez, A. Cabello-López
• Journal: Archives of Medical Research
• Published: 2015;46(2):107-11
• Cited by: 2 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background And Aims: Malignant pleural mesothelioma (MPM) is associated with occupational and environmental exposure to asbestos. The incidence is expected to increase as the use of asbestos is not prohibited in many countries, such as in Mexico. We undertook this study to determine sensitivity, specificity, predictive values and likelihood ratios of computed tomography (CT) in a sample from Mexican population with suspected MPM and other pleuropulmonary diseases.

Methods: CT films of 38 patients suspected of having MPM were analyzed. A single observer was blinded to MPM diagnoses. The frequencies of ten CT findings were identified. A cut-off point of ≥5 CT findings was established to determine high MPM probability. Sensitivity, specificity, predictive values and likelihood ratio of the CT against biopsy using immunohistochemical testing (IHC) for MPM were calculated.

Results: Of the 38 patients, 31 had MPM and seven had lung adenocarcinoma. The five key findings were mediastinal pleural thickening 96.7% (n = 30), nodular pleural thickening 93.3% (n = 29), pleural mass 83.9% (n = 26), diminished lung 70.9% (n = 22) and contracted hemithorax 70.9% (n = 22). Sensitivity 96.8% (83.2-99.4), specificity 85.7% (42.2-97.6), positive likelihood ratio 6.7 (1.1-41.6), and negative likelihood ratio of 0.04 (0.01-0.2) were reported.

Conclusions: Sensitivity and specificity in this study was greater than previously reported, 96.8% and 85.7 vs. 93.2 and 65.6%, respectively. CT is an easily accessible and useful tool that should be incorporated into the medical education of general physicians to improve MPM diagnosis of suspected cases.

Copyright © 2015 IMSS. Published by Elsevier Inc. All rights reserved.

In plain English

This Mexico City study tested how well chest computed tomography (CT) flagged malignant pleural mesothelioma (MPM), compared with biopsy examined by immunohistochemical (IHC) staining. The authors used a convenience sample of 38 patients from an ongoing study at a Mexican Institute of Social Security hospital. Of these, 31 had MPM and seven had lung adenocarcinoma. All 31 MPM patients had asbestos exposure, mostly work-related. One trained observer, blind to the diagnoses, checked each scan for ten CT signs. Five or more signs counted as a high probability of MPM. Among MPM patients, the most common signs were mediastinal pleural thickening (96.7%) and nodular pleural thickening (93.5%). Measured against IHC, CT correctly flagged 30 of 31 MPM patients, a sensitivity of 96.8% (confidence interval 83.2 to 99.4%). It correctly ruled out 6 of 7 other patients, a specificity of 85.7% (confidence interval 42.2 to 97.6%). The authors concluded these figures exceeded an earlier study's and that CT should be part of general physicians' training. They listed as limitations a retrospective design, one hospital, one observer and a small sample.

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: Diagnostic accuracy study using a convenience sample, described by the authors as retrospective. A single trained, blinded observer read CT scans and compared them with biopsy and immunohistochemistry (IHC) diagnoses.
• Who was studied: 38 patients suspected of having MPM, lung adenocarcinoma and/or pleural disease, drawn from an ongoing biomarker study (October 2011 to March 2014) at the Occupational Health Research Unit with the Oncology Hospital, Centro Medico Nacional Siglo XXI, Mexican Institute of Social Security, Mexico City. CT scans were collected from patients recruited between November 2011 and July 2012. Of the 38, 31 had MPM and 7 had lung adenocarcinoma.
• Exposure: The test studied was chest CT, read for ten signs from guidelines by Zhou et al., with five or more signs taken as high probability of MPM. All MPM patients had asbestos exposure: 67.7% (n = 21) definitely work-related, 16.1% (n = 5) probably work-related, 12.9% (n = 4) environmental (living close to the asbestos industry) and 3.2% (n = 1) indirect (e.g., wives of asbestos workers). Fiber types are not specified.
• Main results:
  • Of the 38 patients with CT, 31 were incident cases of MPM and seven had lung adenocarcinoma. Diagnoses were confirmed by IHC testing with two positive and two negative markers for MPM.
  • The five most common CT signs among MPM patients were mediastinal pleural thickening (96.7%), nodular pleural thickening (93.5%), pleural mass (83.9%), diminished lung (70.9%) and contracted hemithorax (70.9%).
  • Pleural effusion was found in only 32.2% of MPM patients. The authors attribute this to earlier fluid drainage or pleurodesis at referring hospitals.
  • With a cut-off of five or more signs, compared with IHC, CT had a sensitivity of 96.8% (83.2 to 99.4; 30 of 31 MPM patients) and a specificity of 85.7% (42.2 to 97.6; 6 of 7 non-MPM patients).
  • Positive predictive value was 96.8% and negative predictive value was 85.7%.
  • Positive likelihood ratio was 6.7 (1.1 to 41.6) and negative likelihood ratio was 0.04 (0.01 to 0.2).
  • Tumors were mainly on the right side (64.5%, n = 20 of the MPM patients); one patient had bilateral cancer.
• The authors' conclusion: The authors concluded that sensitivity and specificity in this study (96.8% and 85.7%) were greater than previously reported by Zhou et al. (93.2% and 65.6%). They also concluded that CT is an easily accessible and useful tool that should be incorporated into the medical education of general physicians to improve MPM diagnosis of suspected cases.
• Limitations the authors state:
  • The retrospective nature of the study means selection bias must be considered.
  • The study was done at a single hospital, had only one differential diagnosis for lung and pleural tumors, used a single observer, and had a small sample size.
  • There was no inter-observer analysis, unlike the Zhou et al. study.

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: Pleural Mesothelioma, Environmental Exposure, Biopsy, Lung Adenocarcinoma, Pleural Thickening, Hemithorax.

Related studies

• Biomarkers for Predicting Malignant Pleural Mesothelioma in a Mexican Population — G. Aguilar-Madrid, B. Pesch, et al. (2018)
• Evaluation of androgen receptor and GATA binding protein 3 as immunohistochemical markers in the diagnosis of metastatic breast carcinoma to the lung — Y. Hattori, A. Yoshida, et al. (2015)
• An immunohistochemical comparison of two TTF-1 monoclonal antibodies in atypical squamous lesions and sarcomatoid carcinoma of the lung, and pleural malignant mesothelioma — S. Klebe, A. Swalling, et al. (2016)
• Identification of DAB2 and Intelectin-1 as Novel Positive Immunohistochemical Markers of Epithelioid Mesothelioma by Transcriptome Microarray Analysis for Its Differentiation From Pulmonary Adenocarcinoma — M. Kuraoka, V.J. Amatya, et al. (2017)
• Diagnostic accuracy and safety of semirigid thoracoscopy in exudative pleural effusions in Denmark — F. Willendrup, U. Bodtger, et al. (2014)
• Monoclonal antibody SM047 as an immunohistochemical marker of ovarian adenocarcinoma — W.G. McCluggage, P. Maxwell, et al. (2001)

Browse return to medical research.