The aim of our study was to assess the antitumor effect of electrochemicaltherapy (ECT) in the mice bearing advanced transplantable tumours. Mouse mammary cancer 16/C (group 1)and fibrosarcoma F69-3 (group 2) were transplanted subcutaneously (s.c.) into the C3H or BALB/c mice,respectively. Twenty animals in each group bearing measurable s.c. tumours were randomly divided intotwo subgroups (experimental and control). Two electrodes were inserted into tumours and low level directcurrent (6-7 V, 5-21 mA) was passed. The animals were observed and tumors were measured twice a week.The animals were sacrificed and autopsied when the tumor diameter reached 2.0 cm. Two animals of eachgroup (experimental and control) were sacrificed for histopathological tumor examination on the 1st and6th day after ECT. A significant inhibition of tumor growth in mice subjected to ECT was observed, bothin those with s.c. growing mammary cancer and with fibrosarcoma. This inhibition was associated withmarked prolongation of survival time of ECT-treated mice. It appeared that the mice with mammary cancerswere more susceptible to ECT therapy than those with growing s.c. fibrosarcoma. The histopathologicalstudies of tumor specimens from ECT-treated mice showed extensive foci of necrosis with shrinkage ofcell nuclei deprived of chromatin. In conclusion, the treatment which inhibits the growth of experimentalmammary and fibrosarcoma tumors was demonstrated. However, in no mice complete regression of tumourswas observed.

Keywords: Cell Division, Electric Stimulation Therapy, Electrochemistry, Fibrosarcoma, Mammary Neoplasms, Experimental, Mice, Inbred C3H, Neoplasm Transplantation, Time Factors