ISSN: 2165-7092
Arlen M, Arlen P, Wang X, Saric O, Martin DA, Deutsch G and Sathyanaryana SA
One of the characteristics that defines many malignancies that metastasize via the circulatory system, is their ability to shed surface membrane proteins into the blood stream where they can be detected as tumor markers. The primary clinical application associated with defining these tumor markers, many representing carbohydrate antigens, has been in their use for specifically monitoring the status of the patient, in terms of their response to therapy. In the more than 40 years of the clinical measuring what we term tumor markers, none have been defined that are of value in their ability to help the clinician to diagnose the presence of an existing malignancy. Rather, their role has been assigned to that of a monitoring function. It appears essential that the ideal tumor marker, when defined, should be able detect the presence of an established tumor, as well as characterize the clinical state of such an existing neoplasm. This same marker should more importantly be expressed only in the malignant state and not be associated with inflammatory conditions developing in normal tissue adjacent to the tumor. In general, those markers presently available for clinical use are carbohydrate in origin, showing up in many conditions unrelated to the presence of cancer. Their use has been relegated to monitoring the clinical course of a known malignancy in terms of response or lack of to a therapeutic approach: that is radiation or chemotherapy. When the proper target proteins which are in the process of being defined and are detected by monoclonal antibodies directed against a specific epitope on the protein, the same monoclonal used for detection, when delivered intravenously can hunt, seek and destroy the existing neoplasm.