The clinical value of the EpCAM biomarker and its association with immune cell infiltration in bladder cancer

Our plain-English summary of The clinical value of the EpCAM biomarker and its association with immune cell infiltration in bladder cancer, by T. Nedjadi, M.E. Ahmed, H.R. Ansari, et al (Diagnostic Pathology, 2025).

The study

• Authors: T. Nedjadi, M.E. Ahmed, H.R. Ansari, S. Aouabdi, A. Samkari, J. Al-Maghrabi
• Journal: Diagnostic Pathology
• Published: 2025;20(1):96
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Bladder cancer is characterized by its heterogeneous nature and high propensity for recurrence and progression. The absence of reliable diagnostic and prognostic biomarkers to accurately identify high-risk patients further complicates the clinical management of the disease. MOC-31, an antibody that targets epithelial cell adhesion molecule (EpCAM), is utilized to distinguish between mesothelioma and metastatic cancer, but its clinical utility, prognostic value and functional dynamics in bladder cancer have yet to be verified.

Methods: A comprehensive analysis of EpCAM expression and its associations with key clinicopathological parameters was performed via The Cancer Genome Atlas (TCGA). Additionally, we retrospectively assessed EpCAM expression in our bladder cancer cohort using MOC-31 antibody and examined its prognostic value and correlation with clinicopathological features. The cBioPortal, STRING and TIMER databases were used to explore the interactions between EpCAM expression, immune cell infiltration and immune checkpoint genes.

Results: The difference in EpCAM expression varied widely across various cancer types and was strongly correlated with advanced cancer stage. EpCAM staining with MOC-31 exhibited membranous positivity in 51.7% of the analysed cohort. Kaplan-Meier survival analysis revealed a discernible trend suggesting a poorer prognosis for patients with low EpCAM expression than for those with high EpCAM expression. Protein-protein interaction demonstrated that EFGR, HER2 and Claudin-7 are key EpCAM interactors. A strong association was observed between EpCAM expression and immune cell infiltration as well as immune-related genes.

Conclusion: This study highlights the prognostic value of EpCAM in bladder cancer, revealing a strong link between EpCAM expression and disease pathogenesis. These results underscore the need for further research to validate these findings and explore the significance of EpCAM as a therapeutic target in managing bladder cancer.

© 2025. The Author(s).

In plain English

This study is about bladder cancer, not asbestos. It looked at a protein called EpCAM, measured with an antibody called MOC-31, which the authors describe as used to tell mesothelioma apart from metastatic cancer. The authors stained stored tumour tissue from 182 bladder cancer patients (152 men, 30 women) who had bladder surgery at King Abdulaziz University Hospital in Jeddah, Saudi Arabia, between 2005 and 2010. They also analysed public cancer databases, including The Cancer Genome Atlas (TCGA). EpCAM staining was positive in 51.7% (94/182) of samples, and most positive samples stained weakly. Staining was not linked to most clinical features. For alive versus dead status the p value was 0.057. Patients with positive staining showed a trend toward better overall survival, but this did not reach statistical significance (p = 0.09). In TCGA data, low EpCAM tended to go with poorer outcomes (p = 0.18). In the databases, EpCAM was raised in 13 of 24 cancer types, including bladder cancer, and was associated with several immune cell types. The authors said the findings need verification in a larger multi-centre cohort. They noted that their study was small, retrospective and from one centre.

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: Retrospective single-centre study of stored tumour tissue (tissue microarray immunohistochemistry), combined with analysis of public cancer databases
• Who was studied: 182 bladder cancer patients (152 male, 30 female; median age 62) who had surgical resection of the bladder at King Abdulaziz University Hospital, Jeddah, Saudi Arabia, between 2005 and 2010; plus TCGA public database data
• Exposure: No asbestos or occupational exposure was studied. The factor examined was EpCAM protein in tumour tissue, detected with the MOC-31 antibody, which the authors describe as used to distinguish mesothelioma from metastatic cancer
• Main results:
  • In the in-house cohort, EpCAM (MOC-31) staining was positive in 51.7% (94/182) of samples
  • Among positive cases, staining was weak in 77%, moderate in 14% and strong in 9%
  • EpCAM staining did not correlate with most clinical and pathological features. The exception was alive/dead status, with p = 0.057
  • In-house cohort: there was a trend toward better overall survival with positive versus negative MOC-31 staining, but it was not statistically significant (log-rank p = 0.09)
  • TCGA data: low EpCAM expression tended to be associated with poor outcomes (log-rank p = 0.18)
  • TCGA data: EpCAM expression was significantly raised in 13 of 24 cancer types, including bladder cancer, compared with controls
  • TCGA data: high EpCAM expression was significantly associated with increased infiltration of several immune cell types
• The authors' conclusion: The authors concluded that their study highlights the prognostic value of EpCAM in bladder cancer. They added that its clinical usefulness in bladder cancer still needs to be verified in a larger multi-centre cohort
• Limitations the authors state:
  • The cohort analysed was small
  • The study was retrospective and from a single centre
  • The small tissue cores (1 mm) may not represent the whole tumour
  • Long-stored tissue blocks may lose antigenicity, which reduces staining intensity

Topics

Medical terms in this study, explained in our Lexicon: Biomarker, MOC-31, Mesothelioma, Prognosis, HER2.

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