Glioblastomas or GBMs are the most devastating kind of cancer tumor found in the central nervous system in adults. Tumors of this type come in two forms, primary and secondary. Primary onset tumors are usually very aggressive and grow extremely fast. They are the most common form, accounting for about 90% of all GBM tumors. Secondary tumors grow a little slower over time but are still just as deadly.
About 15% of primary brain tumors in adults are GBMs and the prognosis is not usually very good
. Median survival for patients with this kind of tumor is about 14.6 months. Only 10% of patients will survive to the five year mark. As with most brain cancers, there is no known cause for GBM. In the last decade, every clinical trial or experimental treatment has failed to show any significant benefit when tested in widespread randomized trials. There might be something new on the horizon for this devastating brain cancer however.
published this week in the December 15 issue of JAMA shows promising results from a new type of electromagnetic field therapy called Tumor Treating Fields or TTFields. Patients who had been treated with a course of chemotherapy and radiation were split into two two groups. One had just the standard chemo and radiation, another group had the traditional therapy but also used a skull cap fitted with electrodes and the study results showed that those wearing the caps had prolonged periods where the disease did not progress along with longer overall survival times.
So how does this device work?
TTFields therapy involves disrupting the division of cells with low-intensity, intermediate-frequency alternating electric fields. The electric current is delivered through a transducer, across wires to discs placed on the cap, which is worn on a shaved head.
Roger Stupp, M.D., of University Hospital Zurich and the University of Zurich, Switzerland, and colleagues who conducted the study randomly assigned 695 patients with glioblastoma who had completed chemoradiotherapy to one group or another. 466 patients received maintenance treatment with TTFields plus the chemotherapy drug temozolomide and 229 patients were treated with temozolomide alone. The patients wearing the TTFields cap wore them for about 18 hours a day. The cap is powered by a portable power supply in a backpack like device and worn across the shoulders of the patients who then connect the cap to it..
Temozolomide was given for 5 days of each 28-day cycle. 83 medical centers in the United States, Europe, Canada, South Korea and Israel participated in the study.
The results were more than any of the study authors could have imagined. The median progression-free survival was 7.1 months in the TTFields plus temozolomide group compared with just 4 months in the temozolomide alone group. Median overall survival for the group wearing the cap was 20.5 months compared with 15.6 months in the temozolomide alone group.
An editorial in the JAMA
that was written by John H. Sampson, M.D., Ph.D., M.H.Sc., M.B.A., of Duke University, Durham, N.C. urged caution however. He In his editorial he stated, “Given the survival benefit reported in this study, it should now be a priority to understand the scientific basis for the efficacy of TTFields; achieving this may require the development of robust and widely available large animal models for glioblastoma, which do not currently exist. Perhaps most concerning, because of the study design chosen, doubts may remain as to the true efficacy of this therapy."
The video below shows a patient who used the cap. Check out her story to hear more about this novel approach to treating deadly brain tumors.