Low-grade glioma: supratentorial astrocytoma, oligodendroglioma, and oligoastrocytoma in adults.

Low-grade glioma is not a single diagnosis but a category of biologically diverse neoplasms. They are indolent, progressive, and, following anaplastic transformation, invariably fatal. Neuro-oncologists have not established a treatment standard for these tumors. However, it is clear that "low-grade" is not synonymous with "benign," and treatment is required sometime in the course of the disease. Previously, achieving a consensus had been limited by a lack of class I evidence. Physicians treated patients based on retrospective series and personal experience. Currently, results from prospective clinical trials are becoming available. These studies have provided data that may serve as treatment guidelines. Additional results regarding the identification of prognostic variables have raised more questions to be answered. Attention is now directed to the importance of translational research to better define these neoplasms. In the future, it will be necessary to distinguish among low-grade gliomas and identify therapies that may differ between them.