There was a time not too long ago when the idea of zapping body parts with electric current was the stuff of science fiction, quackery or worse. Anyone who has seen or read "One Flew Over the Cuckoo's Nest" probably has a hard time considering electroconvulsive therapy as a legitimate medical practice, yet it is now used as a last-resort treatment for symptoms of severe mental illness, including depression, mania and catatonia.
I have to admit I had the same bias toward the idea of using electric current on tumors until I learned of research that will be presented at this week's annual meeting of the American Society of Clinical Oncology. At 130 neuro-oncology centers around the United States, doctors are using an electric device, approved in 2011 by the Food and Drug Administration, on a highly aggressive and very lethal form of brain tumor, glioblastomas. When they recur after therapy, glioblastomas kill 90 percent of their victims within a year.
Patients treated with the relatively new device, which sends a weak electric field through the tumors, have somewhat better survival rates, according to the study that will be presented at the conference. But the major benefit for people with this form of cancer is that the therapy has few side-effects, in contrast to the debilitating problems associated with chemotherapy and radiation, according to Eilon Kirson, chief scientific officer for NovoCure, which markets the device.
It "allows them to live at home, to continue normal, daily life," Kirson said. "They don't have to be in the hospital. They don't have to be connected to it all the time."
The current interferes with the replication of the cancer cells, which die when they can't divide and grow (cell mitosis, for those of you who remember high school biology.). Patients can take the laptop-sized device home and wear it as much as they want — even 24 hours a day, Kirson said. Eighteen hours a day seems to be the critical threshold that helps extend lives, he said. The current, one to three volts per centimeter at a frequency of 200 kilohertz, is delivered through wires that are taped to the patient's head.
The most common side-effect was skin irritation, though about 10 percent of the 457 patients studied experienced neurological disorders and smaller groups had sensations of heat, electricity or a headache, according to a summary of the research. Animal studies showed no long-term side-effects, Kirson said.
Perhaps more promising, Kirson said, 14 percent saw their tumors shrink by half, and in 3 percent, the tumors disappeared. Twenty percent survived for a year, he said. This has led the company to begin experimenting with use of the device in newly-diagnosed glioblastomas and a common form of lung cancer, both in combination with chemotherapy.
The use of electric fields on tumors is the brainchild of Yoram Palti, a former physiologist at the Technion-Israel Institute of Technology, who founded NovoCure to market the device. Palti theorized that at a critical time in cell division, the electric field could interrupt the process without harming healthy tissue or stimulating nerves, Kirson said.
Recurrent glioblastomas were a good choice for the first application of the device because those cancer patients have no other options besides surgery, the cancer rarely spreads beyond the brain and regulatory agencies like to try out new therapies on diseases that will otherwise soon result in death.
"The aim," Kirson said, "is to lengthen life."