Successful treatment of equine sarcoids with cisplatin electrochemotherapy: a retrospective study of 48 cases.

The research investigates a new anti-cancer therapy, Electrochemotherapy (ECT), for treating the most common type of skin tumor in horses, the equine sarcoids. The study validates ECT, especially when used with the anti-cancer drug cisplatin, as a viable alternative treatment for equine sarcoids, based on its high nonrecurrence rate and the influence of tumor size and excision quality on treatment success.

Study Objectives and Methods

• This retrospective study’s primary goal was to validate ECT as an effective treatment for the most prevalent equine skin tumor type, known as sarcoids.
• ECT, an innovative anticancer therapy, operates by boosting cell membrane permeability to hydrophilic antitumor drugs like cisplatin via electrical pulses. This increased permeability results in a higher concentration of the therapeutic drug within the cells, yielding greater effects.
• The treatment process involved general anesthesia, whereby electric pulses were sent directly to the tumor location following intra-tumoral injections of a cisplatin solution.
• In the context of this study, the ECT treatments were implemented in two-week intervals, with or without prior tumor excision or debulking.

Results of the Study

• The ECT treatment was applied to 194 sarcoids across 34 horses, 2 ponies, 11 donkeys, and a mule, indicating a broad test sample.
• Successful outcomes were indicated by the high nonrecurrence rate, with 97.9% of the treated animals (47 out of 48) and 99.5% of the tumors (193 out of 194) showing no resurfacing after four years.
• The size of the tumor was found to significantly influence the number of treatments required for complete removal, especially when ECT was used as a singular treatment method.
• Moreover, when prior surgery was conducted, the quality of the excision and the healing mode significantly affected the number of treatments required.
• The most usual side effect was a mild oedematous response for lesions on thin skin areas.

Conclusion

• Overall, the findings demonstrate that ECT, irrespective of whether simultaneous tumor debulking was applied, is an effective substitute for traditional treatments of equine sarcoids.