Chemotherapy Plus Radiation Improves Survival for Anaplastic Oligodendroglioma
Some patients with anaplastic oligodendroglioma live substantially longer if they are treated with a combination of chemotherapy and radiation instead of radiation alone, according to the long-term results of two studies published in the Journal of Clinical Oncology.
Gliomas are the most common type of cancerous brain tumors in adults and are the second leading cause of cancer deaths in young adults. Malignant gliomas refer to a group of cancers that develop in glial cells, which are the most abundant cells of the nervous system. These cells provide many supportive functions involved in the majority of processes conducted by neurons (cells that transmit impulses between the brain, spinal column, and nerves).
Anaplastic oliogodendroglioma (AO) is a fast growing type of malignant glioma and accounts for less than 10 percent of brain tumors. Historically AO has been treated with surgery and radiation, but some data indicates that the cancer may respond to chemotherapy as well.
About half of patients diagnosed with AO have missing or deleted parts of chromosomes 1 and 19. Both recent studies indicated that patients with these chromosomal co-deletions may benefit from combination radiation and chemotherapy treatment.
A study conducted by the Radiation Therapy Oncology Group (RTOG) included 299 patients who were randomly assigned to receive radiation alone or high-dose chemotherapy with procarbazine, lomustine, and vincristine (PCV) followed by radiation. Among patients whose tumors did not have the chromosomal deletions, median survival was less than 3 years for both treatment arms. The combination treatment, however, had a significant impact among patients with the chromosomal co-deletion—those treated with the combination therapy had a median survival of 14.7 years, whereas those treated with radiation alone had a median survival of 7.3 years.
The EORTC Brain Tumor Group Study included 368 patients with AO who were randomly assigned to radiation therapy or radiation followed by standard-dose PCV. After a median follow-up of 140 months, overall survival in the combination treatment arm was significantly longer—42.3 months, compared to 30.6 months in the radiation arm. Eighty patients have the chromosomal co-deletion and although median overall survival cannot yet be calculated for these patients, there is a trend toward improved survival with the combination therapy.
The results of both of these studies indicate that patients with AO who have chromosomal co-deletions may benefit from treatment with chemotherapy and radiation. Research will be ongoing to refine this treatment approach—but it will establish a new standard of care for these patients, as radiation alone is no longer considered adequate.
 Cairncross G, Wang M, Shaw E, et al. Phase III Trial of chemoradiotherapy for anaplastic oligodendroglioma: Long-term results of RTOG 9402. Journal of Clinical Oncology. Pulbished early online October 15, 2012. doi: 10.1200/JCO.2012.43.2674
 Van den Bent MJ, Brandes AA, Taphoorn MJB, et al. Adjuvant procarbazine, lomustine, and vincristine chemotherapy in newly diagnosed anaplastic oligodendroglioma: Long-term follow-up of EORTC Brain Tumor Group Study 26951. Journal of Clinical Oncology. Pulbished early online October 15, 2012. doi: 10.1200/JCO.2012.43.2229
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