Electrochemotherapy in Canine and Feline Clinical Oncology Practice

Electrochemotherapy (ECT) is an innovative antineoplastic treatment based on local application of short and intense electrical pulses, inducing reversible permeabilization of cell membranes (electroporation) to facilitate the transport of chemotherapeutic drugs (CTDs) into cells. There is an intrinsic antitumor efficacy locally at low doses of CTDs without systemic toxicity, sparing tissues not exposed to pulses. Canine and feline patients were subjected to different protocols of ECT, to evaluate the effectiveness of this treatment. In this study 22 dogs and 7 cats (both sexes) were enrolled presenting skin, subcutaneous tissue or mucous membranes tumours, both benign and malignant. Dogs (many elderly animals, range 2–15 years old): skull osteochondrosarcoma #1, perianal adenoma or adenocarcinoma #11, schwannoma #4, skin mast cell tumour (MCT) #2, oral squamous cell carcinoma (SCC) #1, or epulides #1, or melanoma #1, and nares carcinoma #1; Cats (8–16 years old): injection-site sarcoma #2, oral carcinoma or fibrosarcoma #3, skin SCC #2). Cliniporator (IGEA S.p.a., Modena, Italy) was the instrument used, connecting different electrodes (hexagonal or linear) with needles of different length. The current delivery was preset by the manufacturer. Bleomicin (10 mg/mq IV or IntraTumoral 3 mg/sqcm, IT) or (Cisplatin 2 mg/sqcm IT) were CTDs used. ECT was used as single approach or in combination after or with surgery. The cases were monitored for local relapse, partial or complete remission, overall survival times (OST), and side effects. All the cases treated show a good or very good grade of responsiveness depending on type of tumour, site, burden and use of surgical combination. No particular side effects were noticed. In dogs, worse results were obtained in canine MCTs, nares carcinoma, and oral melanoma, while best results were seen in perianal tumours (complete remission locally but distant metastasis occurred), oral SCC, schwannoma, and epulides. In cats, worse results were seen in injection-site sarcoma, skin SCC, while best results were seen in oral carcinoma or fibrosarcoma. Electrochemotherapy (ECT) is an applicable and effective treatment and it has several advantages over other antitumour procedures (i.e., improving quality of life as massive surgery was avoided, or lacking any side effects). If the ECT is applied when the tumour burden is low, there is a high chance for complete remission, depending on the tumour type. In case of high-burden tumours, ECT is often used as last resource and a partial remission should be expected.