Diagnostic value of BRCA1-associated protein-1, glucose transporter-1 and desmin expression in the discrimination between reactive mesothelial proliferation and malignant mesothelioma in tissues and effusions

Our plain-English summary of Diagnostic value of BRCA1-associated protein-1, glucose transporter-1 and desmin expression in the discrimination between reactive mesothelial proliferation and malignant mesothelioma in tissues and effusions, by S. Önder, E. Özogul, D. Koksal, et al (Cytopathology, 2019).

The study

• Authors: S. Önder, E. Özogul, D. Koksal, S. Sarinc Ulasli, P. Firat, S. Emri
• Journal: Cytopathology
• Published: 2019;30(6):592-600
• Cited by: 15 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: The aim of this study was to investigate the utility of BRCA1-associated protein-1 (BAP1), glucose transporter (GLUT)-1 and desmin expression by immunohistochemistry in the discrimination between reactive and malignant mesothelial proliferations.

Methods: A total of 88 biopsies and 30 effusions from mesothelioma cases were studied. Control groups were composed of 35 tissues and 30 cell blocks. The 88 mesothelioma cases were from 43 males and 45 females (mean age 56 years). Tumours were mostly localised to pleura (66/88, 75%) and of epithelioid histology (75/88, 85%). Cytology samples were from 17 males and 13 females (mean age 58 years), and 16 pleural and 14 peritoneal effusions. Twenty cytology cases had corresponding tissue biopsies.

Results: BAP1 loss was detected in 61/88 (69%) tissues and in 20/30 (67%) cytology samples from mesothelioma with a specificity of 100% for both sampling methods. BAP1 loss was observed more frequently in pleural and biphasic tumours. GLUT-1 immunoreactivity was identified in 54/81 (67%) and 23/25 (92%) malignant tissues and effusions, and in 6/33 (18%) and 6/30 (20%) benign tissues and effusions, respectively. Desmin loss was observed in 74/80 (92%) malignant biopsy samples, 16/21 (76%) malignant effusions and 10/34 (29%) of benign tissues, but in none of the reactive effusions. Concordance rate of results between biopsy and cytology was as follows: BAP1 20/20 (100%); GLUT-1 13/18 (72%); and desmin 10/14 (71%).

Conclusions: BAP1, GLUT-1 and desmin are useful markers in the discrimination between reactive and malignant mesothelial proliferations. BAP1 loss seems to be diagnostic for mesotheliomas both in biopsy and cytology samples.

© 2019 John Wiley & Sons Ltd.

In plain English

This study, from Hacettepe University in Ankara, Turkey, tested whether three laboratory stains (BAP1, GLUT-1 and desmin) help pathologists tell malignant mesothelioma apart from harmless, reactive growth of the lining cells. The authors examined 88 tissue biopsies and 30 fluid (effusion) samples from mesothelioma patients diagnosed between 2001 and 2018. They compared them with 35 biopsies and 30 fluid samples from patients without cancer. By clinical history, 84 biopsy patients lived in known environmental asbestos regions and four came from erionite villages in Cappadocia. Loss of BAP1 was seen in 61/88 mesothelioma tissues and 20/30 mesothelioma fluid samples, and in none of the control samples. GLUT-1 and desmin stains also separated the groups, but each also gave some results in controls that pointed toward mesothelioma. Differences in BAP1 loss by sex, tumour site, tumour type and asbestos or erionite region were not statistically significant. The authors concluded that BAP1 loss alone seems to be evidence in favour of mesothelioma. They advised that stain results be read together with clinical and imaging findings.

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 laboratory study of archived pathology samples (immunohistochemistry) comparing mesothelioma cases with non-cancer controls
• Who was studied: Mesothelioma cases diagnosed at Hacettepe University, Ankara, Turkey, 2001 to 2018: 88 tissue biopsies (43 male, 45 female; mostly pleural, mostly epithelioid) and 30 cytology samples (16 pleural, 14 peritoneal effusions). Controls were 35 biopsies and 30 cell blocks from patients sampled for non-neoplastic conditions. Cases were selected based on adequate sample being available.
• Exposure: Not an exposure study. By clinical history, 84 of the 88 biopsy patients lived in known environmental asbestos regions and 4 were from erionite villages in Cappadocia. Asbestos fiber types were not specified.
• Main results:
  • BAP1 loss was found in 61/88 (69.3%) mesothelioma tissue biopsies and in none of the 35 control tissues.
  • BAP1 loss was found in 20/30 (66.6%) mesothelioma cytology samples and in none of the control cytology samples.
  • In biopsies, BAP1 loss was more frequent in women, pleural tumours, biphasic tumours and erionite-village residents (75% vs 69% in asbestos regions), but these differences were not statistically significant.
  • GLUT-1 was positive in 54/81 (66.7%) mesothelioma biopsies and showed focal positivity in 6/33 (18.2%) control biopsies.
  • Desmin loss was seen in 74/80 (92.5%) mesothelioma biopsies and in 10/34 control biopsies.
  • In mesothelioma fluid samples, GLUT-1 was positive in 23 of 25 (92%) and desmin was lost in 16 of 21 (76.2%). In control fluid samples, GLUT-1 was positive in 6/30 and desmin was lost in 0/29 (per Table 2).
  • Agreement between matched biopsy and cytology results was 100% for BAP1 (20/20), 72% for GLUT-1 (13/18) and 71% for desmin (10/14).
  • Using the three stains together gave 100% sensitivity in both tissues and fluids. Specificity fell to 58% in tissues and 79% in cell blocks.
• The authors' conclusion: The authors concluded that BAP1, GLUT-1 and desmin are useful aids in telling reactive mesothelial proliferation from mesothelioma. In their view, BAP1 loss alone seems to be evidence in favour of mesothelioma, but stain results should always be correlated with clinical and radiological features.
• Limitations the authors state:
  • The authors called scoring GLUT-1 and desmin in cases with only a few staining cells a major drawback.
  • The lower agreement between biopsy and fluid results for desmin raised doubt about its reliability.
  • Interpreting BAP1 was difficult in some cell blocks made up mostly of inflammatory cells, especially macrophages.

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: Desmin, Malignant Mesothelioma, BAP1, Immunohistochemistry, Mesothelioma, Cell Block, Pleura, Epithelioid.

Related studies

• BAP1 (BRCA1-associated protein 1) is a highly specific marker for differentiating mesothelioma from reactive mesothelial proliferations — M. Cigognetti, S. Lonardi, et al. (2015)
• The value of BRCA-1-associated protein 1 expression and cyclin-dependent kinase inhibitor 2A deletion to distinguish peritoneal malignant mesothelioma from peritoneal location of carcinoma in effusion cytology specimens — W. Althakfi, S. Gazzo, et al. (2020)
• Practical utility of insulin-like growth factor II mRNA-binding protein 3, glucose transporter 1, and epithelial membrane antigen for distinguishing malignant mesotheliomas from benign mesothelial proliferations — S. Chang, M.H. Oh, et al. (2014)
• Distinguishing benign from malignant mesothelial cells in effusions by Glut-1, EMA, and Desmin expression: an evidence-based approach — M. Kuperman, R.R. Florence, et al. (2013)
• Loss of BRCA1-associated protein 1 (BAP1) expression is useful in diagnostic cytopathology of malignant mesothelioma in effusions — I. Cozzi, F.A. Oprescu, et al. (2018)
• Utility of BRCA1-associated protein 1 immunoperoxidase stain to differentiate benign versus malignant mesothelial proliferations in cytologic specimens — Z. McCroskey, G. Staerkel, et al. (2017)

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