Treatment of spontaneous soft tissue sarcomas in cat

Preclinical experiments performed on mice clearly showed that electrochemotherapy can efficiently treat subcutaneous tumors of different histological types (1-4). However, the possibility of relevant clinical applications for electrochemotherapy requires the demonstration of its efficacy as a treatment of tumors larger than those encountered in mice. This necessitates the use of tumors growing in animals that are larger than mice. Since models for such tumors are rare and expensive, a convenient possibility is to test electrochemotherapy on spontaneous tumors that veterinarians have to treat in clinical presentations. Among them, cat soft-tissue sarcomas constitute a set of closely related tumors (fibrosarcoma of grade I or of grade II, and malignant fibrohistiocytoma) which are well suited for electrochemotherapy trials. Indeed, they are subcutaneous tumors, which always escape the conventional surgical treatment after a more or less long time, but which have only a local development for a long period of the disease evolution. Thus this carcinologic situation provides the possibility of testing the local efficiency of electrochemotherapy on animals having a good health status and bearing tumors for which no further conventional therapy can be proposed (5).