A phase 3 study presented at the annual meeting of the American Society of Clinical Oncology in June found that giving a combination of chemotherapy after standard radiotherapy delayed tumor growth and extended the lives of patients with a type of brain cancer known as anaplastic oligodendroglial tumors. In addition, researchers found that the survival benefit may be limited to patients whose tumors had specific deletions of genetic material in chromosomes 1 and 19 (1p/19q codeletions).
The current standard treatment for most patients with the disease is either chemotherapy or radiotherapy, rather than both. Lead author Martin Van Den Bent, MD, professor of neuro-oncology at Erasmus MC-Daniel den Hoed Cancer Center in Rotterdam, Netherlands, notes that the researchers have determined a better treatment as well as a way to assess which patients will and will not benefit from it.
For the study, 368 newly diagnosed patients were randomly assigned to receive either radiotherapy alone or radiotherapy followed by 6 cycles of chemotherapy with the drugs procarbazine, CCNU (lomustine), and vincristine, a regimen known as PCV. Progression-free survival was 24.3 months in the group treated with radiotherapy and PVC and 13.2 months in the group treated with radiotherapy only. Overall survival was 42.3 months in the radiotherapy and PVC group and 30.6 months in the radiotherapy-only group.
In the subset of 80 patients with known 1p/19q codeletions, treatment with the combination of radiotherapy and PVC reduced their risk of dying by 44% when compared with patients who received radiotherapy alone. The median overall survival in this group was 9 years in patients who received radiotherapy only; however, at the time of last follow-up, the endpoint had not yet been reached in the group receiving radiotherapy and PVC after a follow-up of nearly 12 years. Among 236 patients without these codeletions, the overall survival was not statistically different between the group treated with radiotherapy and PVC versus the group treated with radiotherapy alone (25 months vs 22 months, respectively).
Another study presented at the American Society of Clinical Oncology annual meeting by North American researchers found similar results.