Glioblastoma multiforme (GBM) is the most common and most aggressive malignant primary brain tumor in humans, involving glial cells and accounting for 52% of all functional tissue brain tumor cases and 20% of all intracranial tumors. Despite being the most prevalent form of primary brain tumor, GBMs occur in only 2–3 cases per 100,000 people in Europe and North America. According to the WHO classification of the tumors of the central nervous system, the standard name for this brain tumor is "glioblastoma"; it presents two variants: giant cell glioblastoma and gliosarcoma. Glioblastomas are also an important brain tumor in canines, and research continues to use this as a model for developing treatments in humans.
Treatment can involve chemotherapy, radiation, radiosurgery, corticosteroids, antiangiogenic therapy, surgery and experimental approaches such as gene transfer.
With the exception of the brainstem gliomas, glioblastoma has the worst prognosis of any central nervous system (CNS) malignancy, despite multimodality treatment consisting of open craniotomy with surgical resection of as much of the tumor as possible, followed by concurrent or sequential chemoradiotherapy, antiangiogenic therapy with bevacizumab, gamma knife radiosurgery, and symptomatic management with corticosteroids. Prognosis is poor, with a median survival time of approximately 14 months.