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

Conductive Gel Increases the Small Tumor Treatment With Electrochemotherapy Using Needle Electrodes

“…Some authors use the gel to avoid empty spaces between plate electrodes and tissues (12,13). These authors used commercial gels (gels for electrocardiogram or ultrasonography) (14,15,26).…”

“…However, there are a few reports about this same treatment in dogs. The incidence of this tumor is higher in cats, accounting for 15-49% in cats and 2-15% of all cutaneous tumors in dogs (12).…”

“…Some works use conductive gel between plate electrodes and tumors to reduce the empty spaces. This methodology provides a homogeneous electric field inside the tumors of different sizes (12)(13)(14)(15). Ivorra et al (5) demonstrated that a good gel conductivity is about 0.5 S/ m with plate electrodes; the tumor diameter model was 4 mm.…”

“…The dog cutaneous SCC shows some clinical findings: the mean age affected is about 8 years; sunlight may induce tumors in unpigmented or lightly pigmented skin, such as the abdomen (18). There are studies of electrochemotherapy treatment of SCC in cats (12,(19)(20)(21). However, there are a few reports about this same treatment in dogs.…”

Electrochemotherapy in treatment of canine oral malignant melanoma and factors influencing treatment outcome

“…17 In veterinary medicine, ECT is a well-established therapy with multiple indications and proven efficacy. 18,19 It has been reported very good results for treating mast-cell tumors (OR 62.3-100%) [20][21][22] , sarcomas (OR 90%) 23 , perianal tumors (OR 94%) 24 , nasal duct tumors (OR 91%) 24,25 , among others, with minimum to absent side effects.…”