Electrochemical Treatment of Breast Cancer with Direct Current.

Abstract

Abstract : To test two hypotheses of using electrochemical treatment (EChT) for cancer therapy: (1) both anodes and cathodes should be inserted inside the tumor; (2) tumor responses are dependent on electrode spacing and dose. Rat breast cancers were initiated by injecting 1 x 10(exp 6) MTF-7 cells to the rat right mammary gland fat pad. Rats were randomly divided into experimental groups when the tumors were grown to 2 x 2 x 2 cu cm. 69 rats were used for hypothesis 1 study, 130 for hypothesis 2 - survival study arid 129 for hypothesis 2 - pathological study. The tissues around electrodes were necrosis after EChT. The effects of EChT are non-specific since it destroys both tumor and normal tissues. The survival study indicated that the tumor control and rat survival rates significantly increased with increasing dose regardless of the spacing. The local control rate is less than 40% in 40 C and 60 C groups and more than 70%-in 80 C and 100 C groups. 66 rats died of primary tumor including 10 rats in control group. Once the primary tumor is controlled, no recurrence was found in this study. The main reason to terminate the primary tumor-free rats (51 rats) was lymph node metastasis. 13 rats survived over six months tumor free. Pathological study showed that there was a significant dose effect on the EChT induced tumor necrosis. At 10 C, 20 C, 40 C, and 80 C, the percent of the necrosis were 39.7%, 52.3%, 62%, and 77.7%, respectively (p < 0.00001). Spacing is not an important factor within a given range. At 5, 10, and 15 mm spacing, the percent of the necrosis were 54.1%, 60.4%, and 59.2%, respectively (p = 0.552). The necrosis overlap rate was similar at 5 mm and 10 mm groups (82.5% and 85%), while lower in 15 mm group (65%). The effects of EChT are non-specific, the cathodes should not be inserted into the normal tissues. For a diameter of 2.0 to 2.5 cm rat breast cancer, EChT with 5 - 10 mm spacing and at least 80 C are the best parameter combinations.