Researchers have developed a new clinical approach to increase the efficiency of treatment in glioblastomas that increased the median survival to 22 months. Patients diagnosed with this type of cancer, and who undergo current standard treatment, have a median survival of 16 months.
George Shenouda, radio-oncologist at the McGill University Health Centre and lead author of the study, says:
“Glioblastomas are very difficult to treat. These tumors grow and spread quickly throughout the brain, making it very difficult to completely remove with surgery.”
The standard treatment for glioblastomas includes removing as much of the tumor as possible with surgery and then eliminating what is left through radiotherapy combined with chemotherapy. After surgery, patients need at least four-to-five weeks of recovery before starting radiotherapy.
Unfortunately, during recovery, any remaining cancer cells will continue to grow. To make matters more complicated, remaining cancer cells, mainly cancer stem cells, can be more resistant to radiotherapy and chemotherapy.
The new approach adds chemotherapy with temozolomide prior to radiotherapy, a process known as neo-adjuvant chemotherapy. Giving neo-adjuvant chemotherapy prevented the tumor from progressing during recovery and increased survival.
After the neo-adjuvant chemotherapy, patients then received accelerated radiotherapy.
“We had better control over the tumor by giving patients the same overall dose of radiotherapy in fewer sessions and a shorter period of time. By doing this, we increased the efficacy of the treatment and we believe that in turn the treatment targeted the stem cells, which are the basis of recurrence,” Shenouda says. Reducing the radiotherapy sessions by one-third also alleviates the burden for patients. In addition, this represents a considerable cost reduction of delivery of treatment.”
Although additional research is required, the initial results are very promising, Shenouda says.
“Fifty percent of the patients in our study have survived two years since their diagnosis—this is very encouraging and we are very positive about the outcome.”
Shenouda, George et al. A Phase 2 Trial of Neoadjuvant Temozolomide Followed by Hypofractionated Accelerated Radiation Therapy With Concurrent and Adjuvant Temozolomide for Patients With Glioblastoma International Journal of Radiation Oncology • Biology • Physics , Volume 97 , Issue 3 , 487 - 494