ABSTRACT
AIM: Mast cell tumours (MCT) are common skin tumours in dogs. If complete surgical removal of the tumours is not possible, then another therapy is needed. In the current study we tested the therapeutic effect of intratumoural injection of interleukin-2 (IL-2). MATERIALS AND METHODS: Seven dogs had non-resectable cutaneous MCT. The tumours were injected with 4.5×10(6) IU IL-2. RESULTS: The early clinical effects in the seven dogs with cutaneous MCT were: complete regression (CR) in two dogs; partial regression (PR) in four, and stable disease (SD) in one dog. The final clinical effects were CR in three dogs, PR in two dogs, and PD in two dogs. CONCLUSION: This pilot study shows that intratumoural IL-2 application can exert an anti-MCT effect. A larger study would be required to precisely establish the magnitude of the therapeutic effect against MCT. A single application of IL-2 in cases of non-resectable MCT has no observable side-effects.