Brain Tumour

Definition/ diagnostic criteria Brain tumours encompass a variety of neoplasms originating in the brain or its surrounding structures, including primary tumours, which originate in the brain, and secondary (metastatic) tumours, which spread to the brain from other sites. The World Health Organization (WHO) classifies brain tumours into different types based on histological characteristics. Diagnosis is confirmed by neuroimaging, primarily MRI, and biopsy for histopathological examination.

Epidemiology Brain tumours account for 85 to 90% of all primary central nervous system (CNS) tumours. In the UK, around 11,700 new cases of brain, other CNS, and intracranial tumours are diagnosed each year. Malignant brain tumours represent a small proportion of these but are significant due to their poor prognosis.

Diagnosis
Clinical features:

• Symptoms of brain tumours vary based on the tumour’s location and size but often include headaches (especially upon waking), seizures, persistent nausea, cognitive or personality changes, sensory or motor deficits and visual disturbances.
• Red flags for GPs include new-onset seizures in adults, neurological deficits and rapid progression of symptoms.

NICE Cancer guidance states:

• In adults, consider an urgent direct access, MRI scan of the brain (or CT scan if MRI is contraindicated; to be done within two weeks) to assess for brain or central nervous system cancer in adults with progressive, sub‑acute loss of central neurological function.
• In children and young people, consider a very urgent referral (for an appointment within 48 hours) for suspected brain or central nervous system cancer in children and young people with newly abnormal cerebellar or other central neurological function.

Investigations: Diagnostic imaging is crucial, with MRI being the gold standard. MRI can provide detailed information on tumour size, location, and potential impact on surrounding structures. CT scans are used when MRI is contraindicated.

• Typical abnormalities found in imaging include mass effect, contrast enhancement, and specific features suggestive of tumour type (e.g., ring-enhancing lesions in high-grade gliomas).
• Referral to a neurologist or neurosurgeon for further evaluation, including possible biopsy, is indicated when imaging suggests a brain tumour.

Treatment Treatment depends on the type, size, and location of the tumour, and the patient’s general health. Options include surgery, radiotherapy, and chemotherapy.

• Surgery aims to remove as much of the tumour as possible while preserving neurological function.
• Radiotherapy and chemotherapy are used for treating high-grade tumours or in cases where complete surgical removal is impossible.
• Corticosteroids (e.g., dexamethasone) are often prescribed to reduce cerebral oedema. Antiepileptic drugs may be required for seizure control.

Prognosis The prognosis of a brain tumour depends on various factors, including the type and grade of tumour, patient age, and overall health.

High-grade tumours, such as glioblastomas, have a poor prognosis, with median survival times of 12-18 months despite treatment. Lower-grade tumours, particularly in younger patients, often have a better prognosis. Long-term effects of brain tumours and their treatment can include cognitive and physical impairments, necessitating multidisciplinary rehabilitation and support.