New research in the August Issue of Physics Today explains how low-intensity electric fields can disrupt the division of cancer cells and slow the growth of brain tumors. The team of researchers used alternating electric fields that shift electric particles in cells back and forth hundreds of thousands of times per second. These low-intensity alternating electric fields were once thought to only heat cells but after several years of experiments, the researchers have shown the fields to disrupt cell division in tumor cells placed on a glass dish.

After studying the effect of electricity in vitro and in labratory animals, the researchers began a small human clinical trial. The technique was applied to ten patients with glioblastoma multiforme, a type of brain cancer with a low survival rate. The researchers fitted the patients with electrodes that applied 200 kHz electric fields to the scalp at regular intervals for up to 18 hours a day. The cancer was observed to be progressing to advanced stages at a much slower rate (a median of 26 weeks) and in some cases even regressed. Typical time for tumor progression is 10 weeks and 3 of the 10 patients were still alive two years after the electrode therapy started.

Electric field therapy is found to have two effects on tumor cells. First, it slows down cell division by disrupting the formation and function of a key cell structure known as the mitotic spindle. Second, the electric field can sometimes cause the daughter cells to self destruct by forcing structures and molecules away from its infrastructure before the cell splits away from its partner . Electrode therapy poses little danger to normal brain tissue, because healthy brain cells do not divide. Researchers are now investigating the possibilities of combining electric fields with low-dose chemotherapy.