Electrochemotherapy compared to surgery for treatment of canine mast cell tumours.

UNLABELLED: The aim of this study was to evaluate the effectiveness of local treatment electrochemotherapy (ECT) with cisplatin and to compare it with effectiveness of surgery for treatment of mast cell tumours (MCT) in dogs. MATERIALS AND METHODS: In the present retrospective study, 25 dogs of different breeds with MCT were divided into two treatment groups: surgery (16 dogs with 16 tumours) and those whose owners refused surgery being included into the ECT group (9 dogs with 12 tumours). Response rate and duration of response to the treatment were evaluated and comparison between groups was made. RESULTS: The clinical stages of the tumours were stage I in 4 (45%) and stage III in 5 (55%) dogs treated by ECT; 12 (75%) dogs treated by surgery were stage I and 4 (25%) dogs were in clinical stage III. The median size of the tumours was 5.2 cm3 and 2.9 cm3 of tumours treated by surgery and ECT, respectively. ECT resulted in as comparable antitumor effectiveness as surgical treatment. However, the estimated median duration of response in dogs treated with complete surgical excision was 31.5 months, while it was not reached for the ECT group at the time of writing. CLINICAL SIGNIFICANCE: ECT is an easy, effective and safe local treatment of MCT. It can be an alternative treatment to surgery, specifically for smaller nodules in which a complete response with long duration can be obtained after only one treatment session, or when the nodule is unresectable because of the location.

Effective treatment of perianal tumors in dogs with electrochemotherapy.

BACKGROUND: Electrochemotherapy is an antitumor therapy that utilizes locally-delivered, short intense direct current electric pulse to the tumor nodule plus chemotherapy. The aim of the present study was to evaluate the electrochemotherapy treatment of perianal tumors of different sizes in dogs. MATERIALS AND METHODS: In 12 dogs, 26 tumor nodules of perianal tumors of different size, and clinically expected to be of different histological type, were treated with electrochemotherapy. Electrochemotherapy consisted of intratumoral injection of cisplatin (1 mg/cm3) or bleomycin (3 mg/cm3), followed by application of electric pulses (8 electric pulses; amplitude, 910 V, duration, 100 micros, frequency, 1 Hz) to the tumor nodule. RESULTS: Responses to treatment were assessed 4 weeks after the therapy; 82% of all tumors treated with electrochemotherapy responded with objective response (OR) (complete response (CR)=41%, partial response (PR)=41%), 16% responded with no change (NC) and 1 tumor (2%) went to progressive disease (PD). At the end of the observation period for each tumor, ranging from 1 to 34 months, 92% OR (CR=65%, PR=27%), 8% NC and no PD were obtained. No major local or general side-effects were noted. CONCLUSION: Electrochemotherapy with cisplatin or bleomycin is an effective treatment of perianal tumors in dogs. The advantages of this therapy are its simplicity, short duration of treatment sessions, low chemotherapeutic doses and insignificant side-effects, as well as the fact that the subject does not have to stay in hospital.