Epithelial cell adhesion molecule expression (CD326) in cancer: a short review

Epithelial cell adhesion molecule (EpCAM, CD326) is a pleiotropic molecule that potentially offers therapeutic applications in cancer treatment. Initially described as a dominant surface antigen on human colon carcinoma, it is a transmembrane glycoprotein mediating epithelial-specific intercellular cell-adhesion. Recent data suggest that EpCAM is also involved in cell signaling, migration, proliferation and differentiation. Since EpCAM is expressed exclusively in epithelia and epithelial-derived neoplasms, EpCAM can be used as diagnostic marker. Testing for EpCAM is based on morphology and phenotypical staining and can be performed with primary carcinoma tissue and cells harvested from malignant effusions. Stable or highly expressed EpCAM has been detected in most adenocarcinomas and has also been found in metastases, malignant effusions, and cancer stem cells. EpCAM may thus be an ideal tumor antigen candidate to detect circulating and metastasizing cancer cells by microchip technologies. In certain tumor types overexpression was linked to advanced stage of disease and worse overall survival, suggesting EpCAM as a potential prognostic marker. In addition to its diagnostic and prognostic role, EpCAM's broad expression and apparent involvement in tumorigenesis and metastasis point to its potential as a target for immunotherapeutic strategies. The first EpCAM targeting, trifunctional antibody catumaxomab (Removab®) has shown clear clinical benefits in treatment of malignant ascites associated with EpCAM positive carcinomas. Further research and clinical studies should unravel EpCAM's complex role in oncological processes, and expand potential therapeutic applications of EpCAM targeted strategies.