ELECTROCHEMICAL TREATMENT OF MOUSE AND RAT FIBROSARCOMAS WITH DIRECT-CURRENT

Electrochemical treatment (ECT) of cancer utilizes direct current to p roduce chemical changes in tumors. ECT has been suggested as an effect ive alternative local cancer therapy. However, a methodology is not es tablished, and mechanisms are not well studied. In vivo studies were c onducted to evaluate the effectiveness of ECT on animal tumor models. Radiation-induced fibrosarcomas were implanted subcutaneously in 157 f emale C3H/HeJ mice. Larger mt fibrosarcomas were implanted on 34 femal e Fisher 344 rats. When the spheroidal tumors reached 10 mm in the mic e, two to five platinum electrodes were inserted into the tumors at va rious spacings and orientations. Ten rats in a pilot group were treate d when their ellipsoidal tumors were about 25 mm long; electrode inser tion was similar to the later part of the mouse study, i.e., two at th e base and two at the center. A second group of 24 rats was treated wi th six or seven electrodes when their turners were about 20 mm long; a ll electrodes were inserted at the tumor base. Of the 24 rats, 12 of t hese were treated once, 10 were treated twice, and 2 were treated thri ce. All treated tumors showed necrosis and regression for both mice an d rats; however, later tumor recurrence reduced long-term survival. Wh en multiple treatments were implemented. the best 3 month mouse tumor cure rate was 59.3%, and the best 6 month rat tumor cure rate was 75.0 %. These preliminary results indicate that ECT is effective on the rad iation-induced fibrosarcoma (RIF-1) mouse tumor and rat fibrosarsoma. The effectiveness is dependent on electrode placement and dosage. (C) 1997 Wiley-Liss, Inc.