Outcome in adult low-grade glioma

Low-grade gliomas (LGGs) represent a vexing clinical problem. Some patients present with readily controllable seizures and will enjoy years of freedom from tumor progression without intervention, whereas others progress rapidly with eventual neurologic decompensation and death. Both radiation and chemotherapy are helpful to many patients, but the optimal timing and sequencing of these therapies remain unknown. Recent studies have informed our understanding of clinical, histologic, and molecular prognostic factors and help provide guidance as to which patients require early intervention and when observation is feasible or warranted. We review contemporary knowledge regarding prognostic factors, our current evidence-based understanding of the roles and timing of radiation and chemotherapy, and ongoing clinical trials that will further elucidate management of LGGs. GLOSSARY: CCNU = lomustine; EORTC = European Organization for Research and Treatment of Cancer; FISH = fluorescence in situ hybridization; LGG = low-grade glioma; LOH = loss of heterozygosity; MGMT = O6-methylguanine-DNA methyltransferase; OS = overall survival; WHO = World Health Organization; PCV = procarbazine, CCNU, and vincristine; PFS = progression-free survival; QOL = quality of life; RT = radiation therapy.