<h4>Background</h4>EpAb3-5, an anti-EpCAM (epithelial cell adhesion molecule) neutralizing antibody, enhances circulating tumor cell (CTC) detection, but its clinical and prognostic relevance in head and neck squamous cell carcinoma (HNSCC) remains unclear.<h4>Methods</h4>We retrospectively analyzed 66 HNSCC patients. Here, EPCAM is linked to neoplasm.