Abstract
Electrochemotherapy (ECT) is a new technique that enhances the antitumor effect of various anticancer agents by delivering high-voltage electrical impulses to the tumor. In the present study, ECT was used in the treatment of oral cancer using SCC158 cell, a rat squamous cell carcinoma, which was transplanted into the tongue. These tumors were subjected to high-voltage electrical impulses (1200V/cm, 0.1msec, 8 pulses) 30 minutes after the injection of bleomycin. The antitumor effect of ECT on these tumors was then evaluated, as were histological changes in the damaged tumor, and healing of the surrounding damaged tissue. In a further experiment, to determine the optimum voltage of electrical impulse histologically, these tumors received various electrical pulses (125-1200V/cm, 0.1msec, 8 pulses) in ECT.
As a result, the tongue tumors were no longer visible from the 3rd day after ECT, and histological examination revealed complete regression. The healing following ECT proceeded in an almost uneventful manner, but the normal tissue within the electrical field was necrotic. In addition, the antitumor effect of ECT appeared most strongly when the voltage was more than 1000V/cm ; however, the surrounding normal tissue within the electrical field was seriously damaged.
In conclusion, ECT was shown to be an efficient therapy for treating tumors of the tongue, and it is expected to be applied to human oral cancer. It is hoped that problems related to damage to normal tissue and the inducement of metastasis will soon be resolved as a result of future investigations.
