New treatment paradigm for patients with anaplastic oligodendroglial tumors

Abstract

Oligodendrogliomas are uncommon tumors in neurooncology that represent about 5% of primary brain malignancies. Their high sensitivity to radiotherapy and chemotherapy was observed a long time ago. Nonetheless, the evidence-based proof of the significantly longer survival in patients with oligodendrogliomas treated with combined chemotherapy and radiotherapy in comparison to radiotherapy-alone did not exist. The long-term follow-up of two landmark phase III clinical trials: RTOG 9402 and EORTC 26951, recently demonstrated favorable effects of combined radiotherapy and chemotherapy (procarbazine, lomustine and vincristine) in patients with anaplastic oligodendrogliomas and anaplastic oligoastrocytomas carrying the chromosomal mutation of co-deletion of 1p/19q. There is also an increasing role of other molecular biomarkers, such as mutations in the metabolic enzyme isocitrate dehydrogenase 1/2, O6-methylguanine DNA methyltransferase gene promoter methylation, or glioma genome cytosine-phosphate-guanine islands methylator phenotype. The analysis of molecular genetics in oligodendrogliomas is now recommended as an important part of the management of these tumors and together with the novel chemotherapeutic regimens means a paradigm shift in current clinical practice in neurooncology.

Keywords: IDH1/2 mutations; MGMT promoter methylation; Oligodendroglioma; co-deletion 1p/19q; novel treatment; personalized medicine; review.