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.