Research Article Variations of dose and electrode spacing for rat breast cancer electrochemical treatment Ru-Long Ren 1, Nayana Vora 2, Frank Yang 3, Jeff Longmate 4, Warner Wang 1, Helen Sun 3, Jian-Ren Li 1, Lawrence Weiss 3, Cecil Staud 2, John A. McDougall 1, Chung-Kwang Chou 1 * 1Department of Radiation Research, City of Hope National Medical Center, Duarte, California 2Division of Radiation Oncology, City of Hope National Medical Center, Duarte, California 3Division of Pathology, City of Hope National Medical Center, Duarte, California 4Department of Biostatistics, City of Hope National Medical Center, Duarte, California
email: Chung-Kwang Chou (ck.c...@motorola.com) *Correspondence to Chung-Kwang Chou, Motorola Florida Research Laboratories, 8000 West Sunrise Blvd., Plantation, Florida 33322. Funded by: U.S. Army Medical Research and Material Command; Grant Number: DAMD 17-96-1-6184 Keywords tumor; alternative therapy; necrosis; survival; direct current; EChT Abstract Electrochemical treatment (EChT) with direct current delivered through implanted electrodes has been used for local control of solid tumors in humans. This study tested the hypothesis that rat breast cancer responses to EChT are dependent on electrode spacing and dose, and explored suitable parameters for treating breast cancers with EChT. Rat breast cancers were initiated by injecting 1 × 106 MTF-7 cells to the right mammary gland fat pad of Fisher 344 female rats. The rats were randomly divided into designated experimental groups when the tumors grew to approximately 2 × 2 × 2 cm. One hundred and thirty rats were used for a survival study and 129 for a pathology study. A 4-channel EChT machine was used to administer coulometric doses. The survival study indicated that local tumor control rate is less than 40% in the 40 coulomb (C) and 60 C groups and more than 70% in the 80 and 100 C groups. Sixty six rats died of primary tumors, including all 10 rats in the control group. Once a rat's primary tumor was controlled, no recurrence was found. The main reason for terminating the primary tumor-free rats (51) was lymph node metastasis. Thirteen tumor-free rats survived for more than 6 months. The pathology study showed a significant dose effect on EChT induced tumor necrosis. At 10, 20, 40, and 80 C, the fraction showing necrosis were 39.7, 52.3, 62, and 77.7%, respectively (P 0.001). Electrodes spacing was not an important factor within a given range. At 5, 10, and 15 mm spacing, the fraction showing the necrosis were 54.1, 60.4, and 59.2%, respectively (P = 0.552). The overlap rate of necroses was similar in the 5 and 10 mm groups (82.5 and 85%) and lower in the 15 mm group (65%). We conclude that the tumor responses to EChT, local control, survival rates, and necrosis percentages were significantly increased with increasing dose. The changes in electrode spacing (3, 5, and 10 mm) did not significantly affect the tumor responses to EChT within the same dose. For a diameter of 2.0-2.5 cm rat breast cancer, EChT should be applied with 5-10 mm spacing and a minimum dosage of 80 C. Bioelectromagnetics 22:205-211, 2001. © 2001 Wiley-Liss, Inc. ------------------------------------------------------------------------ -------- Received: 2 August 1999; Revised: 17 May 2000 -- The silver-list is a moderated forum for discussion of colloidal silver. To join or quit silver-list or silver-digest send an e-mail message to: silver-list-requ...@eskimo.com -or- silver-digest-requ...@eskimo.com with the word subscribe or unsubscribe in the SUBJECT line. To post, address your message to: silver-list@eskimo.com Silver-list archive: http://escribe.com/health/thesilverlist/index.html List maintainer: Mike Devour <mdev...@eskimo.com>
