CD24: a potential new marker in differentiating malignant mesothelioma from pulmonary adenocarcinoma

Our plain-English summary of CD24: a potential new marker in differentiating malignant mesothelioma from pulmonary adenocarcinoma, by D.J. Pinato, P. Nya, R. Sharma, et al (Journal of Clinical Pathology, 2013).

The study

• Authors: D.J. Pinato, P. Nya, R. Sharma, F.A. Mauri
• Journal: Journal of Clinical Pathology
• Published: 2013;66(3):256-9
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background: The differential diagnosis between malignant mesothelioma (MM) and metastatic lung adenocarcinoma (MLA) often relies on immunohistochemical studies, with no individual immunomarker holding satisfactory discrimination ability.

Methods: We investigated the diagnostic accuracy of CD24 immunoreactivity on 134 patients including 69 cases of MM and 65 MLA.

Results: The expression of CD24 favoured MLA, with 57/65 cases showing positive cytoplasmic staining compared with 9/69 MM (p<0.001), whose immunopositivity pattern was prevalently membranous (7/9 cases).

Conclusions: CD24 positivity can accurately discriminate MM from MLA. Prospective studies are warranted to clarify whether CD24 could integrate with other immunomarkers to facilitate the diagnosis of mesothelial malignancies.

In plain English

This short report from Imperial College London tested whether staining tissue for a protein called CD24 could help pathologists tell malignant mesothelioma (MM) apart from lung adenocarcinoma. The two cancers can look alike under the microscope. The authors called it a pilot study. They stained tissue samples from 69 mesotheliomas (56 epithelioid, four sarcomatoid, nine biphasic) and 65 lung adenocarcinomas. The article does not discuss asbestos or patients' exposures. CD24 staining was found in 9 of 69 mesotheliomas (13%), mostly at the cell membrane (7 cases). It was found in 57 of 65 adenocarcinomas (88%), consistently inside the cell (p less than 0.001). Counting any staining, CD24 was 88% sensitive and specific for adenocarcinoma (95% CI 83 to 93). Counting only staining inside the cell, specificity was 89% (95% CI 84 to 94) and positive predictive value 96% (95% CI 93 to 99). The authors concluded that CD24 may be useful in telling the two cancers apart, and that larger studies are needed to combine it with other markers. They noted that they did not compare CD24 with markers already in use.

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: Pilot diagnostic accuracy study using immunohistochemical staining (tissue staining for a protein) on tissue microarrays of stored tumour samples
• Who was studied: 134 tumour samples. 69 were malignant mesotheliomas: 49 from commercial tissue microarrays and 20 consecutive cases diagnosed at Hammersmith Hospital, London, between 2007 and 2009. Of the 69, 56 were epithelioid, four sarcomatoid and nine biphasic. The other 65 were lung adenocarcinomas from commercial tissue microarrays.
• Exposure: Not an exposure study. Asbestos and other exposures are not discussed. The factor examined was CD24 staining in tumour tissue, detected with an anti-CD24 monoclonal antibody (clone SN3b).
• Main results:
  • CD24 staining was seen in 9/69 (13%) of mesotheliomas: seven with staining at the cell membrane and two with staining inside the cell (cytoplasmic).
  • All mesotheliomas with cytoplasmic staining were epithelioid. Membranous staining was seen in six epithelioid tumours and one biphasic tumour.
  • 57/65 (88%) of the lung adenocarcinomas were CD24 positive, with a consistently cytoplasmic pattern. The difference from mesothelioma had p less than 0.001.
  • Counting all staining patterns, CD24 was 88% sensitive and specific for diagnosing lung adenocarcinoma (95% CI 83 to 93), with a positive predictive value of 86% (95% CI 80 to 92) and a negative predictive value of 88% (95% CI 83 to 93).
  • Counting cytoplasmic staining only, specificity rose to 89% (95% CI 84 to 94), positive predictive value to 96% (95% CI 93 to 99) and negative predictive value to 89% (95% CI 84 to 94).
  • Five mesothelioma samples that were CD24 negative on the tissue microarrays were restained on full diagnostic sections. The results fully matched.
• The authors' conclusion: The authors concluded that the study suggests CD24 may be useful in distinguishing malignant mesothelioma from lung adenocarcinoma in tissue specimens, and that larger studies are needed to combine CD24 with other markers.
• Limitations the authors state:
  • The authors did not compare how well CD24 performed against other markers already in use.

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: Malignant Mesothelioma, Adenocarcinoma, Differential Diagnosis, Lung Adenocarcinoma.

Related studies

• CD24 is highly useful in differentiating high-grade serous carcinoma from benign and malignant mesothelial cells — B. Davidson (2016)
• Calretinin, thrombomodulin, CEA, and CD15: a useful combination of immunohistochemical markers for differentiating pleural epithelial mesothelioma from peripheral pulmonary adenocarcinoma — C.E. Comin, L. Novelli, et al. (2001)
• Value of Glut-1 and Koc markers in the differential diagnosis of reactive mesothelial hyperplasia, malignant mesothelioma and pulmonary adenocarcinoma — Ö. Üçer, A.F. Dağli, et al. (2013)
• Identification of cancer stem cell markers in human malignant mesothelioma cells — F.I. Ghani, H. Yamazaki, et al. (2011)
• E-cadherin, E-selectin and vascular cell adhesion molecule: immunohistochemical markers for differentiation between mesothelioma and metastatic pulmonary adenocarcinoma? — A.M. Müller, A. Weichert, et al. (2002)
• E-cadherin and calretinin: a useful combination of immunochemical markers for differentiation between mesothelioma and metastatic adenocarcinoma — M.P. Leers, M.M. Aarts, et al. (1998)

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