An isolated monoclonal antibody or an antigen-binding fragment thereof is disclosed. The antibody or the antigen-binding fragment is characterized by: (a) having a specific binding affinity to epithelial cell adhesion molecule (EpCAM) comprising the amino acid sequence of SEQ ID NO: 1; (b) having a specific binding affinity to cancer cells expressing EpCAM said cancer cells being selected from the group consisting of oral cancer cells, nasopharyngeal cancer cells (NPC), colorectal cancer cells, and ovarian cancer cells; and (c) having no binding affinity to human umbilical vein endothelial cell (HUVEC) and normal nasal mucosal epithelia (NNM). Also disclosed is an isolated monoclonal antibody or an antigen-binding fragment thereof that has a specific binding affinity to an epitope within the sequence of KPEGALQNNDGLYDPDCDE (SEQ ID NO: 63) located within the EGF-like domain II of epithelial cell adhesion molecule (EpCAM). Methods of using the same are also disclosed.