Previously, GBM patients only typically lived between six to 12 months after diagnosis, and there were almost no survivors beyond two years. This type of cancer accounts for 20 percent to 25 percent of all primary brain tumors.
"A substantial number of patients with glioblastoma now have a good chance of surviving at least a few years now and of enjoying a productive life during this time, which was almost unthinkable less than a decade ago," said Rene-Olivier Mirimanoff, M.D., lead author of the study and a radiation oncologist at the Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland. "Considering how quickly this type of cancer grows, patients who live four or five years after diagnosis are indeed considered long-term cancer survivors."
Early results of the Phase III trial published by Stupp in the New England Journal of Medicine in 2005 showed for the first time that twice as many GBM patients who were treated with TMZ and radiation therapy survived two years after diagnosis, compared to those who received radiation alone. The trial involved 573 patients who were randomized to receive TMZ during and after radiation therapy or radiation alone. This treatment immediately became the standard treatment for GBM patients worldwide.
Researchers extended the study to find out if patients with GBM who had this treatment plan could live more than two years. Updated results show that 12 percent of patients who added TMZ during and after radiation treatment lived for four years compared to three percent of those who received radiation alone and survived the same amount of time.
Findings also show that the main group of patients who survived for four years after diagnosis was less than 50 years old and in otherwise good health without any prior major medical condition (categorized as in RPA Class III). Over one-quarter (28 percent) of these patients who were treated with TMZ and radiation lived for four years, versus only 7 percent of patients who received only radiation therapy.
"Since GBM patients can now live longer, oncologists are monitoring them more closely and a substantial proportion of these patients are being actively treated when their cancer returns through a combination of treatment options," said Mirimanoff. "This new management approach was extremely unlikely 10 years ago."