Inhibition of SA-1 tumor growth in mice by human leukocyte interferon alpha combined with low-level direct current.

A preliminary study of the antitumor effect of partially purified human interferon alpha (IFN-alpha) and low-level direct current (DC) was carried out using a murine subcutaneous SA-1 experimental tumor model. Tumor-bearing animals were treated with 5 x 10(4) IU IFN-alpha peritumorally, or with 0.6 mA DC current for 15 minutes daily, for 6 consecutive days. Antitumor effect was manifested 2 days after the beginning of each treatment modality. Combined treatment with DC current applied immediately after IFN-alpha application was more effective than IFN-alpha treatment alone (P less than 0.005), but not significantly better than DC current treatment (P less than 0.5). The results indicate that the combined treatment with IFN-alpha and DC current can be effective in tumor therapy; however, further work is required to determine optimal scheduling.