Pulse-mediated chemotherapy enhances local control and survival in a spontaneous canine model of primary mucosal melanoma

Mucosal melanomas account for 1% of all malignant melanomas in humans. Treatment options include surgery, chemotherapy, immunotherapy and radiation therapy; however, local recurrence and distant dissemination are still frequent. We treated locally aggressive spontaneous canine oral melanomas that, because of their advanced stage, were not treatable with conventional strategies. A cohort of 10 dogs with oral melanoma was enrolled over a 4-year period. The dogs received two sessions of local bleomycin, followed by the application of trains of biphasic pulses. The treatment was well tolerated and resulted in an overall response rate of 80% with 50% long-term control. Of interest, only one of the dogs died of metastatic disease, and four of the long-term survivors showed a vitiligo-like discoloration at the site of treatment, potentially suggesting a recruitment of the immune system by the therapy. Further studies are needed to characterize this approach and to determine its suitability for head and neck mucosal melanoma.