Anti-tumor effect of electrotherapy alone or in combination with interleukin-2 in mice with sarcoma and melanoma tumors

Electrotherapy with direct current (DC) was performed on two murine tumor models, fibrosarcoma SA-1 and melanoma B16. Three Pt/lr cathodes were inserted directly into the subcutaneous tumors and two anodes subcutaneously in the vicinity of the tumor. Significant tumor growth delay was achieved after electrotherapy and was dependent on DC intensity (0.6, 1.0, 1.4 and 1.8 mA). Melanoma B16 tumors were more sensitive to electrotherapy than SA-1 tumors. In order to enhance the antitumor effect of electrotherapy, combined treatment with interleukin-2 (IL-2) was performed. When both therapies were combined significant tumor growth delay and also higher curability rate was achieved. The results imply that electrotherapy can be an effective antitumor therapy and that the effects can be enhanced with additional IL-2 therapy.