A re-analysis of clinical trial data shows that a combination of radiation and chemotherapy can double median survival time for some patients with a rare brain tumor, oligodendroglioma—from 7.3 to 14.7 years.

The affected patients are ones whose tumor has sections of chromosomes 1 and 19 deleted.
Principal Investigator Gregory Cairncross, MD, of the University of Calgary in Canada, says the re-analysis gives us “unequivocal evidence that the chromosomal structure of 1p and 19q co-deletion can be used as a marker to determine which patients will benefit from combined chemotherapy and radiation.” Dr. Cairncross has been an active advisor to the National Brain Tumor Society for several years.

An extra seven years would provide valuable family time for brain tumor patients. Moreover, such an increase in survival might be just enough time for researchers to develop a new therapy that could provide more time—or possibly a cure.

In the clinical trial, 286 patients with aggressive oligodendrogliomas received either radiotherapy alone or radiotherapy plus PCV chemotherapy (procarbazine, CCNU[lomustine], and vincristine).  In the first analysis (2006), when patients had been followed for three years, survival time amounted to 8.7 years for patients with the 1p19q deletion and 2.7 years for patients without the deletion.

In the re-analysis, after patients have now been followed more than 11 years, patients whose tumor has the deletion who received the combination treatment had overall survival times of 14.7 years compared to 7.3 years for the patients whose tumor did not have the co-deletion.

This news highlights the importance of Phase III clinical trials to produce actionable results. It also highlights the importance of tumor tissue collection and analysis for potential use in personalized medicine.