Ep-CAM - A marker for the detection of disseminated tumor cells in patients suffering from SCCHN

Disseminated tumor cells are considered as the origin of metastases. Since the number of circulating tumor cells in the bone marrow or the peripheral blood of patients correlates well with the tumor stage, their early detection is an important feature for the identification of high risk patients. We therefore investigated the pan-carcinoma antigen Ep-CAM for its suitability to serve as a specific marker for disseminated tumor cells in patient with squamous cell carcinoma of the head and neck (SCCHN). In order to detect small numbers of tumor cells in early tumor stages, we developed and describe here a RT-PCR assay that detects a single tumor cell within 10⁵ normal cells. We examined bone marrows from patients and healthy donors and demonstrate that Ep-CAM can be used as a tumor marker for the diagnosis of single tumor cells in patients with SCCHN.