Implant delivery system: Intralesional delivery of chemotherapeutic agents for treatment of spontaneous skin tumors in veterinary patients

Anew approach to targeted drug administration using intralesional chemotherapy delivered via therapeutic implant (TI) technology was evaluated in a wide variety of spontaneously occurring skin and subcutaneous tumors in veterinary patients. Many of these animal tumors show similarities in histology and biologic behavior to human epitheliomas and neoplasms and, therefore, serve as appropriate preclinical models for human studies. These animal studies provided valuable insight into this method of local chemotherapy which is now under evaluation with 5-fluorouracil, methotrexate, and cisplatin for treatment of human skin diseases as well as cancer. Administration of free drugs directly into tumors has met with some success in the treatment of superficial lesions including keratoacanthoma, 1 basal cell carcinoma, 2,3 verruca plantaris, 4–6 condyloma acuminatum, 6–8 and Kaposi's sarcoma. 9 In an effort to improve the response to local chemotherapy we used the therapeutic implant to increase the dose and duration of exposure of selected drugs to tumors, thereby maximizing the therapeutic response while minimizing toxicity to normal tissue.