Immunotherapy (sometimes called biologic therapy) is a form of cancer treatment that is still in its infancy in both humans and animals; however, great strides have been made in the last decade. The assumption is made that the growth of some cancers occurs because of a defect in the animal's immune system. Had the patient's immunity been normal, the tumor growth should have been suppressed very early, when only a few abnormal cells were present. For this reason, stimulation of the animal's immune system may be attempted as a part of cancer therapy, through the use of certain drugs and antibody treatments. For some tumors, monoclonal antibodies have been made that bind to tumor-associated antigens (special proteins) on the surface of the cell, sometimes causing the destruction of the tumor cell directly. These antibodies can also be designed to guide a chemotherapy medication or a radioisotope directly to the tumor, targeting its death. Great strides are being made in immunotherapeutic treatment at cancer research institutions for humans, and it is likely that veterinary oncologists will begin to be able to take advantage of some of these developments in the next few years.
