Electrochemotherapy is highly effective for the treatment of canine perianal hepatoid adenoma and epithelioma

Abstract

Perianal tumors are common in older male dogs. The usefulness of electrochemotherapy in veterinary oncology has already been demonstrated by clinical studies on different malignancies in companion animals. In a prospective non-randomized study, we evaluated the effectiveness of electrochemotherapy in 5 male dogs with 26 perianal adenocarcinomas and 16 male dogs with 40 benign tumors. After premedication and under general anesthesia, the dogs were treated with intratumoral administration of a chemotherapeutic drug (cisplatin or bleomycin) and exposure of tumors to electric pulses, delivered by two different electroporation protocols (Protocol 1 or Protocol 2). At the end of the observation time (median 14 months), an objective response (OR) was obtained in 62/66 tumors (94%) with 87.9% complete responses (CR). No statistically significant difference in OR rate was observed based on histological type (p = 0.110), previous castration (p = 0.088), chemotherapeutic drug used (p = 0.657), and electroporation protocol (p = 0.337). Tumor size at the beginning of the treatment was the only parameter that influenced the treatment outcome (p = 0.04). No major local or general side-effects were noted. We can conclude that electrochemotherapy is an easy, highly effective, safe and cost-effective local approach for the treatment of primary perianal tumors of dogs, especially hepatoid adenoma and epithelioma.