Local treatment of hepatic metastases with low-level direct electric current: experimental results.

BACKGROUND Several authors have recently reported encouraging results from low-level direct current therapy in easily accessible malignant tumors. However, antitumoral effects in colorectal metastases have not been investigated experimentally. METHODS Using an animal model with induced hepatic metastases, we analyzed the effectiveness and the tumor growth dynamics after direct current application. Three weeks after induction tumor volumes were estimated with magnetic resonance imaging (MRI). Then direct current (80 C/cm3) was applied in the treatment group by means of one anode in the tumor center and four cathodes peripherally. In the control group electrodes were placed without applying current. Tumor growth dynamics was analyzed with MRI after 3 and 5 weeks. After this all animals were killed, and the livers histologically examined. RESULTS After 5 weeks MRI showed a 1.6-fold tumor enlargement in the treatment group versus a 2.9-fold enlargement in the control group (Student t test, P=0.0051). The histopathologic analysis of the treated livers yielded a 21% complete response rate and a 78% partial response rate. No necroses were found in the control group. CONCLUSIONS These results confirm the effectiveness of low-level direct current application as a potential modality for the treatment of hepatic metastases.