The prognosis for patients diagnosed with an oligodendroglial tumor depends on the grade of the tumor. In most cases, grade III tumors, called anaplastic (or cancerous) oligodendrogliomas, are incurable. However, with treatment, these patients can continue living for years, in some cases. A recent study indicated that patients with anaplastic oligodendrogliomas or anaplastic mixed tumors who underwent a combination chemotherapy and radiation had a median survival rate of 4.8 years, and lived progression-free for 2.6 years; patients undergoing radiation therapy alone, meanwhile, had a median survival period of 4.5 years, and were progression-free for 1.9 years.
Patients with a lower-grade tumor have a better chance at surviving for several years. One study found that, among patients who had only received a biopsy or who’d had only part of their tumor removed, it took, on average, about five years for the disease to progress to a higher grade and 17 years until these patients died. A previous study found that among patients with supratentorial low-grade gliomas (including oligodendroglial tumors), 64 percent lived at least five years after diagnosis, and the median survival time was 7.3 years, with death coming after the tumor progressed to a higher grade.
This tumor offers a somewhat better prognosis than other parenchymal tumors, in part because it seems to be less aggressive and responds favorably to chemotherapy.