Increased EpCAM expression in malignant insulinoma: potential clinical implications.

Area of Science:

• Endocrinology
• Oncology
• Molecular Biology

Background:

• Epithelial cell adhesion molecule (EpCAM) is a morphoregulatory molecule involved in pancreatic island development.
• EpCAM overexpression is observed in fetal pancreatic progenitor cells.
• The role of EpCAM in adult insulinomas, pancreatic neuroendocrine tumors, is not well understood.

Purpose of the Study:

• To investigate whether EpCAM overexpression is reactivated in human insulinomas.
• To correlate EpCAM expression levels with tumor malignancy and patient survival.

Main Methods:

• Immunohistochemistry using anti-EpCAM antibody (Ber-Ep4) on 53 insulinomas (40 benign, 13 malignant) and 10 metastases.
• Analysis of EpCAM expression (0-3+ staining) in relation to tumor stage (ENETS TNM classification).
• Quantitative PCR for EpCAM mRNA and Kaplan-Meier survival analysis.

Main Results:

• Strong EpCAM expression (3+) was found in 38% of benign insulinomas.
• Malignant insulinomas (78%) and their metastases (80%) showed significantly higher rates of strong EpCAM expression (P<0.01).
• Quantitative PCR confirmed high EpCAM mRNA levels in malignant tumors; survival analysis showed a trend towards disadvantage for EpCAM 3+ tumors.

Conclusions:

• Reactivated strong EpCAM expression is associated with malignant insulinomas.
• EpCAM may serve as a biomarker for identifying patients at risk of malignant pancreatic neuroendocrine tumors.
• Targeting EpCAM with antibody-based therapies could be a potential treatment strategy for metastatic insulinoma.