Use of cisplatin-containing biodegradable beads for treatment of cutaneous neoplasia in equidae: 59 cases (2000–2004)

OBJECTIVE: To determine outcome for equids with cutaneous neoplasms treated with cisplatin-containing biodegradable beads, alone or in conjunction with debulking. DESIGN: Retrospective case series. ANIMALS: 56 horses, 1 zebra, 1 donkey, and 1 mule. PROCEDURES: Medical records were reviewed. Follow-up information was obtained through telephone conversations with owners and trainers of the animals. RESULTS: 22 tumors were sarcoids, 6 were fibrosarcomas, 1 was a fibroma, 2 were peripheral nerve sheath tumors, 11 were squamous cell carcinomas, 14 were melanomas (13 gray horses and 1 bay horse), 1 was a lymphosarcoma, 1 was an adenocarcinoma, and 1 was a basal cell tumor. Forty-five (76%) animals underwent conventional or laser debulking of the tumor prior to bead implantation. Forty of 48 (83%) animals for which long-term follow-up information was available were relapse free 2 years after treatment. This included 20 of 22 animals with spindle cell tumors (including 11/13 horses with sarcoids), 6 of 10 animals with squamous cell carcinomas, 13 of 14 animals with melanomas, and 2 of 3 animals with other tumor types. Adverse effects were minimal. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that implantation of cisplatin-containing biodegradable beads, with or without tumor debulking, may be an effective treatment for equidae with various cutaneous neoplasms.