safety cap.
A patient glioblastoma door NovoTTF-100A.
www.novocuretrial.com
For years, the electric fields have been rumored to cause cancer. Now, there is reason to believe they could fight - and in some cases even destroy it. The researchers used low intensity, intermediate frequency electric fields to fight against an aggressive brain cancer known as glioblastoma multiforme (GBM). The strategy highlights the tumors without invasive brain surgery and more than doubled survival time in preliminary studies.
The new approach exploits a cog in the way of cell division. When cells divide, a molecular motor called the axis of microtubules helps separate the chromosomes into daughter cells resulting. Resembling a set of strings, the pin is made of electrically polar macromolecules that are sensitive to electrical fields. Previous work has shown that if a field of 0 kHz is applied to these macromolecules, the spindle can not form correctly. Consequently, cells stop dividing and eventually die.
Because cancer results from uncontrolled cell division, a team of researchers from NovoCure Limited, a biotechnology company located in Haifa, Israel, and other institutes in Israel and Europe began a clinical trial with 10 patients with GBM who was not helped by standard therapies. They gave each patient a lightweight, battery operated, called NovoTTF-100A, which generates fields 0 kHz. (Power lines, for comparison, generate about 60 Hz fields.) Then, doctors glued four sets of isolated electrodes on the scalp so as to focus the field on the tumor. The patients wore the device on the head 24 hours a day for 18 months or until the disease worsened.
In eight cases, the electric fields increased life expectancy. Although there is no control group, the researchers compared the results of volunteers in historical studies testing GBM. The median overall survival for all patients was 62 weeks compared to the average of 29 weeks of more than 800 patients at a similar stage of the disease which had been treated with chemotherapy. The tumors stopped growing in four patients and decreased in four. In one case, a patient's tumor disappeared completely and the patient remained for 2.5 years after the trial without tumor; entering the study she had an expected survival time of about six months, the doctor said Eilon Kirson of NovoCure. Tumors continued to grow in two other patients.
The device is ideal for those who GBM because it only acts on the brain and has no systemic side effects of chemotherapy, says Eric Wong, a neuro-oncologist at Beth Israel Deaconess Medical Center in Boston, Massachusetts. Because tumor cells in the brain often divide, normal brain cells are not affected by electric fields, reports online this week in the team Proceedings of the National Academy of Sciences . However, brain stimulation electric field produced seizures in laboratory rats, a phenomenon known as kindling, Wong noted, so "I would be worried if most with there would be crises [in humans]." Yet he said, no increase in foreclosures rates were observed in 10 patients.
Wong was not involved in the study, but it is part of a research team currently testing the device in a III clinical trial phase, which includes over 0 patients with glioblastoma in the United States and Europe. If it works, the researchers hope to apply the electric field therapy to other types of cancer, such as breast cancer and lung cancer non-small cell.
Related Sites
- Video of malignant melanoma cell explodes following an electrical field of 100 kHz
- More information on glioblastoma
- More information about cell division
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