Understanding low-grade glioma A decade of progress

A decade ago, neuro-oncologists began asking important questions about the optimal management of patients with low-grade gliomas of the cerebral hemispheres.1 Should all patients be exposed to the risks of surgery, simply for diagnosis? Does radiotherapy prolong tumor control and patient survival? Is early radiotherapy preferable to delayed treatment? Will better tumor control by radiation be negated by cognitive impairment or other toxicities? Is high-dose radiotherapy more effective than lower dose treatment? Is there a role for chemotherapy in the treatment of low-grade glioma? In this issue of Neurology , Olson et al.2 address many of these important questions as they pertain to patients with oligodendrogliomas and oligoastrocytomas, two subtypes of hemispheric low-grade glioma with similar clinical features and molecular origins. Their analysis shows that patients with oligodendrogliomas and oligoastrocytomas have remarkably favorable prognoses. The median progression-free survival time in this series was 5 years, and the median overall survival time was 16.3 years. These good outcomes, among the best “on-record,” attest to the slow growth of oligodendrogliomas and mixed gliomas and to earlier diagnosis in the era of modern neuroimaging. Since the introduction of CT and …