Last edited 05/2019 and last reviewed 07/2023

The group of brain tumours called gliomas includes:

  • astrocytomas
  • glioblastoma multiforme
  • oligodendrogliomas
  • ependymomas

They are the most common primary tumour of the cerebral hemisphere in adults and children. They are usually highly malignant and carry a poor prognosis. The vast majority - approximately 90% - occur in either the frontal, parietal or temporal lobe. Other possible sites include the thalamus, corpus callosum or occipital lobe.

  • gliomas are graded according to their likely rate of growth, from grade 1 (slowest growing) to grade 4 (fastest growing)
    • grade 3 and 4 gliomas are considered high-grade gliomas
    • grade 3 gliomas include anaplastic astrocytoma, anaplastic ependymoma, anaplastic oligodendroglioma and anaplastic oligoastrocytoma
    • grade 4 gliomas are usually glioblastoma multiforme (GBM)

  • symptoms of high-grade glioma depend on the size, location and degree of infiltration of the tumour
    • possible symptoms include headache, nausea, vomiting, seizures, visual disturbance, speech and language problems, and changes in cognitive and/or functional ability

  • diagnosis of high-grade glioma is provisionally made through a computed tomography (CT) scan or MRI
    • diagnosis is then confirmed and the tumour classified histologically, either at the time of surgical resection or by a single-event biopsy if surgery is not possible

  • treatment usually consists of surgical resection where possible, followed by radiotherapy
    • surgery may achieve either complete resection or partial resection of the tumour
    • radiotherapy has been demonstrated to prolong survival and is usually recommended after surgery
    • adjuvant chemotherapy may be indicated

  • approximately 30% of adults with high-grade gliomas survive for at least 1 year, and 13% survive for 5 years
    • median survival of patients with anaplastic astrocytoma is around 2-3 years, and that of patients with GBM is approximately 1 year
    • age, performance status and tumour histology are indicators of pretreatment prognosis
      • patients with high-grade gliomas have a better prognosis if they are younger, have a better performance status, or have a grade 3 tumour


  • brain tumours account for fewer than 2% of all primary cancers.


  1. NICE (June 2007). Carmustine implants and temozolomide for the treatment of newly diagnosed high-grade glioma
  2. NICE (July 2018). Brain tumours (primary) and brain metastases in adults