INTRATUMORAL CISPLATIN ADMINISTRATION IN ELECTROCHEMOTHERAPY - ANTITUMOR EFFECTIVENESS, SEQUENCE DEPENDENCE AND PLATINUM CONTENT

Electrochemotherapy using intratumoral cisplatin administration was te sted on EAT tumors in mice. Mice were treated with eight electric puls es (100 mu s, 1 Hz, 1040 V) and/or cisplatin (1, 2, 4 and 8 mg/kg). Ci splatin treatment resulted in up to 20 days of tumor growth delay. Ele ctrochemotherapy resulted in tumor cures; local tumor control reached a plateau at 4 mg/kg in 67% of tumor cures. The maximal effect of elec trochemotherapy was achieved when cisplatin was injected 5 min before or simultaneously with electric pulses application. Approximately two times more platinum was bound to DNA in electrochemotherapy than in ci splatin treated tumors at all time points tested. Our study shows that electrochemotherapy with intratumoral cisplatin administration is a v ery effective local treatment of EAT tumors with high curability rate. [(C) 1998 Lippincott-Raven Publishers.].