Ep-CAM expression in squamous cell carcinoma of the esophagus: a potential therapeutic target and prognostic marker
1 Klinik für Allgemein- und Viszeralchirurgie, Universitätsklinikum Düsseldorf, D-40225 Düsseldorf, Germany
2 Klinik für Allgemein-, Viszeral- und Thoraxchirugie, Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany
3 Institut für Pathologie, Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany
4 Koordinierungszentrum für klinische Studien, Universitätsklinikum Düsseldorf, D-40225 Düsseldorf, Germany
5 Chirurgische Klinik, Universitätsklinikum Hamburg-Eppendorf, D-20246 Hamburg, Germany
BMC Cancer 2006, 6:165 doi:10.1186/1471-2407-6-165Published: 23 June 2006
To evaluate the expression and test the clinical significance of the epithelial cellular adhesion molecule (Ep-CAM) in esophageal squamous cell carcinoma (SCC) to check the suitability of esophageal SCC patients for Ep-CAM directed targeted therapies.
The Ep-CAM expression was immunohistochemically investigated in 70 primary esophageal SCCs using the monoclonal antibody Ber-EP4. For the interpretation of the staining results, we used a standardized scoring system ranging from 0 to 3+. The survival analysis was calculated from 53 patients without distant metastasis, with R0 resection and at least 2 months of clinical follow-up.
Ep-CAM neo-expression was observed in 79% of the tumors with three expression levels, 1+ (26%), 2+ (11%) and 3+ (41%). Heterogeneous expression was observed at all expression levels. Interestingly, tumors with 3+ Ep-CAM expression conferred a significantly decreased median relapse-free survival period (log rank, p = 0.0001) and median overall survival (log rank, p = 0.0003). Multivariate survival analysis disclosed Ep-CAM 3+ expression as independent prognostic factor.
Our results suggest Ep-CAM as an attractive molecule for targeted therapy in esophageal SCC. Considering the discontenting results of the current adjuvant concepts for esophageal SCC patients, Ep-CAM might provide a promising target for an adjuvant immunotherapeutic intervention.