No abstract

EphB4 is a receptor tyrosine kinas e that is expressed on epithelial cells during fe tal life. It is also expressed on some venous endothelial cells. We conducted a study of six men with primary squamous cell carcinoma of the head and neck (HNSC C) that had metastasized to the cervical lymph nodes. Our goal was to determine ifEphB4 is aberrantly expressed in cases ofHNSCC and to determine if there is a qualitati ve difference between the expression of EphB4 on primary and metastatic tumors and its expression on normal mucosa adja cent to primary tumors. From each patient, we obtained speci mens ofthe prima ry tumor, the nodal metastasis, and the adj acent normal mucosa, and weperform ed immunocytochemistry on each. We obse rved EphB4 expres sion in all primary and metastatic tumors and no expression in the normal tissue. In each of the six pat ients, expres sion was greater in the metastatic tumor than in the primary tumor. We conclude that EphB4 is a novel target in the treatment of HNSCC.