Effective Treatment of Transmissible Venereal Tumors in Dogs with Vincristine and IL2.

AIM: To improve treatment of inoperable transmissible venereal tumors (TVTs) in dogs. Recently, we showed that TVT is sensitive to intratumoral treatment with interleukin-2 (IL2). In addition it is known that TVT is sensitive to intravenous treatment with vincristine. In the present study we tried to establish the therapeutic effect of intratumoral treatment with vincristine and IL2. PATIENTS AND METHODS: We treated 12 dogs with TVT with 1-4 intratumoral treatments with vincristine and IL-2. Per treatment we used vincristine (0.5-0.7 mg/m(2)) and IL2 (2×10(6) units). The injections were given at weekly intervals. RESULTS: Early therapeutic effects were: three complete regressions, four partial regressions, three stable disease, and two progressive disease. Late therapeutic effects were established 45-60 months after the first presentation; there were five complete regressions, no partial regressions, nor stable or progressive diseases. Interestingly, all five dogs with late therapeutic effects were in good health. No tumor recurrence was noted. CONCLUSION: Intratumoral treatment of TVT with vincristine and IL2 appears to have impressive therapeutic effects.

Treatment of transmissible venereal tumors in dogs with intratumoral interleukin-2 (IL-2). A pilot study.

AIM: To improve the treatment of transmissible venereal tumors (TVTs) in dogs with intratumoral injections of interleukin-2 (IL-2). PATIENTS AND METHODS: We treated 13 dogs with 18 natural TVTs with IL-2. The tumors were treated with intratumoral application of 2×10(6) units IL-2. RESULTS: Three months after injection of IL-2, the tumors in 2/13 dogs had regressed completely, those in 1/13 had regressed partially, and 4/13 dogs had stable disease. CONCLUSIONS: Local IL-2 treatment of TVT is therapeutically effective, as indicated by complete regression (CR), partial regression (PR) and stable disease (SD) of the tumors of 7 out of 13 dogs. In addition, we observed that the intratumoral treatment with IL-2 did not cause any toxic side-effects.

Intratumoural interleukin-2 therapy can induce regression of non-resectable mastocytoma in dogs.

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.