Intralesional and topical chemotherapy and immunotherapy

Surgery is the mainstay of treatment for equine tumors. Conservative treatm ent approaches which preserve function and appearance are increasingly used in clinical practice. This article covers the principles and applications of two conservative treatment modalities including local chemotherapy and i mmunotherapy. The therapeutic benefit of local chemotherapy is based on the direct drug delivery to tumor tissue, i.e., topical and intratumoral admin istration of cytotoxic agents in slow release formulation. This treatment m odality is very effective for cutaneous tumors and does not result in any p ermanent damage to normal tissue. Immunotherapy produces antitumor effects primarily through the action of natural host defense mechanisms against tum or cells. Although the use of immunotherapy is still under investigation th ere are many examples of its successful application to treatment of selecte d equine tumors.