Brain tumour (oligodendroglioma)

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

Notes:

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

Reference:

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