Anaplastic Glioma: Treatment Approaches in the Era of Molecular Diagnostics.

OPINION STATEMENT: The treatment paradigm for anaplastic glioma has shifted, owing to new diagnostic criteria and new phase III clinical trial evidence. In 2016, the WHO classification of brain tumors including diffuse gliomas was redefined to include molecular criteria, often supplanting the morphological appearance of the tumor cells. This was necessary as prognosis is more closely associated with molecular diagnosis than with morphology and grade. Recently, the benefit of adjuvant chemotherapy in addition to radiotherapy has been demonstrated in both anaplastic oligodendroglioma and anaplastic astrocytoma, as well as lower grade gliomas with the most marked benefit evident in IDH-mutated (astrocytoma) and 1p/19q co-deleted (oligodendroglial) tumors. The defining principle of recent breakthroughs has been the benefit of combinatorial therapy (chemo-radiation) as opposed to treatment in series or treatment of either modality after a period of observation upon evidence of progression.