Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)

Oligodendroglial

Oligodendrogliomas (World Health Organization grade II) behave like diffuse astrocytomas. (Refer to the Oligodendroglial tumors section in the Classification section of this summary for more information.)

STANDARD TREATMENT OPTIONS:

• Surgery plus radiation therapy; however, some controversy exists concerning the timing of radiation therapy. A study of 300 patients who had surgery were randomized to either radiation therapy or watch and wait.[1] There was no difference in overall survival (OS) in the two groups.[1][Level of evidence: 1iiA] Median progression-free survival was 5.3 years in the radiation therapy group and 3.4 years in the control group.[1][Level of evidence 1iiDii]

TREATMENT OPTIONS UNDER CLINICAL EVALUATION:

1. Clinical trials are evaluating the effect of adding drugs to local therapy, e.g., radiation therapy with or without chemotherapy for incompletely resected tumors.
2. Chemotherapy. Temozolomide appears to have activity in patients with low-grade oligodendrogliomas with a 1p allelic loss. Clinical improvement was noted in 51% of patients, and the radiologic response rate was 31%.[2][Level of evidence: 3iiiDiii]
3. Patients with newly diagnosed and recurrent low-grade oligodendrogliomas and oligoastrocytomas respond to procarbazine, lomustine, and vincristine (PCV) therapy. In 3 of 5 patients recurrent disease was found, and 13 of 16 newly diagnosed patients responded to PCV. Median time to progression was 24 months.[3][Level of evidence: 3iiiDiii]

Anaplastic Oligodendroglioma

Anaplastic oligodendrogliomas (WHO grade III) have a low cure rate with standard local treatment.[4] These patients are appropriate candidates for clinical trials designed to improve local control by adding newer forms of treatment. (Refer to the Oligodendroglial tumors section in the Classification section of this summary for more information.)

STANDARD TREATMENT OPTIONS:

1. Surgery plus radiation therapy.[5,6,7,8]
2. Surgery plus radiation therapy plus chemotherapy.[9,10]
3. Patients with an allelic loss at 1p and 19q have a higher than average response rate to PCV chemotherapy.[11,12][Level of evidence: 3iiiDiii]
4. A recent phase III study compared radiation therapy alone with chemotherapy plus radiation therapy. Progression-free survival was increased but overall survival was not.[13][Level of evidence: 1iiDii] This was true in the 1p and 19q allelic deletion group as well. These studies are ongoing.

TREATMENT OPTIONS UNDER CLINICAL EVALUATION:

• Patients with brain tumors that are either infrequently curable or unresectable should be considered candidates for clinical trials. Information about ongoing clinical trials is available from the NCI Web site.

References:

1. van den Bent MJ, Afra D, de Witte O, et al.: Long-term efficacy of early versus delayed radiotherapy for low-grade astrocytoma and oligodendroglioma in adults: the EORTC 22845 randomised trial. Lancet 366 (9490): 985-90, 2005.
2. Hoang-Xuan K, Capelle L, Kujas M, et al.: Temozolomide as initial treatment for adults with low-grade oligodendrogliomas or oligoastrocytomas and correlation with chromosome 1p deletions. J Clin Oncol 22 (15): 3133-8, 2004.
3. Stege EM, Kros JM, de Bruin HG, et al.: Successful treatment of low-grade oligodendroglial tumors with a chemotherapy regimen of procarbazine, lomustine, and vincristine. Cancer 103 (4): 802-9, 2005.
4. Kyritsis AP, Yung WK, Bruner J, et al.: The treatment of anaplastic oligodendrogliomas and mixed gliomas. Neurosurgery 32 (3): 365-70; discussion 371, 1993.
5. Bullard DE, Rawlings CE 3rd, Phillips B, et al.: Oligodendroglioma. An analysis of the value of radiation therapy. Cancer 60 (9): 2179-88, 1987.
6. Burger PC, Rawlings CE, Cox EB, et al.: Clinicopathologic correlations in the oligodendroglioma. Cancer 59 (7): 1345-52, 1987.
7. Lindegaard KF, Mørk SJ, Eide GE, et al.: Statistical analysis of clinicopathological features, radiotherapy, and survival in 170 cases of oligodendroglioma. J Neurosurg 67 (2): 224-30, 1987.
8. Wallner KE, Gonzales M, Sheline GE: Treatment of oligodendrogliomas with or without postoperative irradiation. J Neurosurg 68 (5): 684-8, 1988.
9. Cairncross JG, Macdonald DR: Successful chemotherapy for recurrent malignant oligodendroglioma. Ann Neurol 23 (4): 360-4, 1988.
10. van den Bent MJ, Chinot O, Boogerd W, et al.: Second-line chemotherapy with temozolomide in recurrent oligodendroglioma after PCV (procarbazine, lomustine and vincristine) chemotherapy: EORTC Brain Tumor Group phase II study 26972. Ann Oncol 14 (4): 599-602, 2003.
11. Cairncross JG, Ueki K, Zlatescu MC, et al.: Specific genetic predictors of chemotherapeutic response and survival in patients with anaplastic oligodendrogliomas. J Natl Cancer Inst 90 (19): 1473-9, 1998.
12. Brandes AA, Tosoni A, Vastola F, et al.: Efficacy and feasibility of standard procarbazine, lomustine, and vincristine chemotherapy in anaplastic oligodendroglioma and oligoastrocytoma recurrent after radiotherapy. A Phase II study. Cancer 101 (9): 2079-85, 2004.
13. van den Bent MJ, Carpentier AF, Brandes AA, et al.: Adjuvant procarbazine, lomustine, and vincristine improves progression-free survival but not overall survival in newly diagnosed anaplastic oligodendrogliomas and oligoastrocytomas: a randomized European Organisation for Research and Treatment of Cancer phase III trial. J Clin Oncol 24 (18): 2715-22, 2006.