Brain and central nervous system cancers - recognition and referral
Exam Tips
- Adult red flag for this pathway: progressive, subacute loss of central neurological function -> urgent direct-access MRI (or CT if MRI contraindicated) within 2 weeks.
- Paediatric red flag: newly abnormal cerebellar or other central neurological function -> very urgent specialist assessment within 48 hours.
- NICE timing language is examinable: immediate (hours), very urgent (48 h), urgent (2 weeks), suspected-cancer pathway aims diagnosis or exclusion within 28 days.
- Do not rely on isolated headache alone; pattern change plus focal deficits, seizures, cognitive/personality change, or reduced consciousness should escalate concern.
- In OSCE communication, explain urgent cancer referral clearly, provide written safety-net advice, and reassure that many urgent referrals are not cancer.
Definition
Brain and central nervous system (CNS) cancers are primary intracranial or intraspinal malignant tumours (for example gliomas, medulloblastoma, ependymoma) that present with progressive neurological disturbance from local tissue invasion and/or raised intracranial pressure. In UK primary care, this topic focuses on early recognition of suspicious symptom patterns and rapid referral or imaging, rather than definitive oncological treatment.
Pathophysiology
Primary brain/CNS tumours arise from uncontrolled proliferation of neural or glial lineage cells, causing mass effect, vasogenic oedema, disrupted neuronal signalling, and possible obstruction of cerebrospinal fluid pathways. These mechanisms produce focal deficits (by cortical or tract involvement), seizures (from cortical irritability), and global symptoms such as headache, nausea, drowsiness, and cognitive/personality change (from raised intracranial pressure). Tumour biology varies by histology and molecular subtype; high-grade lesions are more infiltrative, grow faster, and carry worse outcomes. For anatomy revision, correlate focal syndromes with lesion location (e. g, frontal personality/executive change, cerebellar ataxia); see standard neuro-oncology localisation diagrams in your core neurology text (brain lobe and posterior fossa figures).
Risk Factors
- Increasing age for many adult primary brain tumours
- Childhood/adolescence for specific CNS tumour subtypes (brain/CNS cancers are relatively common among cancers in children and young people)
- Previous cranial ionizing radiation exposure
- Inherited cancer-predisposition syndromes (e. g, neurofibromatosis type 1/2, Li-Fraumeni, tuberous sclerosis)
- Personal history of prior CNS tumour
Clinical Features
Symptoms
- New-onset seizure
- Headache (often progressive, may be worse on waking or with Valsalva)
- Nausea and/or vomiting
- Drowsiness or reduced alertness
- Visual change (e. g, blurred vision, field defect, diplopia)
- Personality or behavioural change
- Subacute progressive focal neurological symptoms (e. g, unilateral weakness, speech disturbance, sensory change)
- In children/young people: new cerebellar symptoms (ataxia, unsteadiness) or other new central neurological dysfunction
Signs
- Focal neurological deficit (motor, sensory, language, visual, cranial nerve)
- Cerebellar signs (ataxia, dysmetria, nystagmus)
- Features of raised intracranial pressure (papilloedema, reduced consciousness)
- Cognitive/executive dysfunction on bedside assessment
- Abnormal gait or coordination in children and young people
Investigations
Management
Lifestyle Modifications
- Safety-net clearly: advise urgent re-attendance for worsening headache, vomiting, seizures, confusion, reduced consciousness, or new focal deficit.
- Explain suspected-cancer referral pathway, expected timelines, and that many urgent referrals do not result in a cancer diagnosis.
- Arrange referral within 1 working day once decision is made; include urgency and key neurological findings in correspondence.
- If diagnostic uncertainty exists, discuss rapidly with a specialist service to avoid delay.
- After a first seizure, advise no driving and follow DVLA rules pending specialist assessment.
Pharmacological Treatment
Corticosteroid for tumour-related cerebral oedema
- Dexamethasone 8 mg to 16 mg daily in divided doses (or once daily), then titrate to lowest effective dose
Commonly initiated in secondary care for symptomatic mass effect/raised intracranial pressure. Use with gastroprotection where appropriate; monitor glucose, mood/psychosis, infection risk, proximal myopathy, and GI adverse effects. Avoid abrupt withdrawal after prolonged courses; taper according to clinical response.
Antiseizure therapy when seizures occur
- Levetiracetam 500 mg twice daily initially, increase by 500 mg twice daily every 2 weeks; usual maintenance 1 g to 1.5 g twice daily
- Sodium valproate (if specialist-selected and no suitable alternatives) 600 mg to 2.5 g daily in divided doses
Do not prescribe prophylactic antiepileptics routinely in seizure-naive patients with brain tumour. Levetiracetam is often preferred due to fewer enzyme interactions. Valproate has major teratogenic risk and safety restrictions in people who could become pregnant; follow MHRA pregnancy prevention requirements.
Analgesia and antiemetics for symptom control
- Paracetamol 1 g every 4-6 hours when required (maximum 4 g/day)
- Cyclizine 50 mg up to three times daily as needed
- Ondansetron 4 mg to 8 mg once or twice daily depending on route/need
Supportive only; avoid masking neurological deterioration. Check contraindications/interactions (e. g, QT prolongation risk with ondansetron; anticholinergic burden/sedation with cyclizine). Escalate urgently if red-flag progression despite symptom treatment.
Surgical / Interventional
- Neurosurgical biopsy or maximal safe resection for diagnosis and debulking
- CSF diversion procedures (e. g, ventriculoperitoneal shunt or endoscopic third ventriculostomy) if obstructive hydrocephalus
- Definitive multimodal treatment directed by MDT (surgery, radiotherapy, systemic anti-cancer therapy) according to tumour histology and molecular profile
Complications
- Raised intracranial pressure and risk of herniation
- Status epilepticus or recurrent seizures
- Progressive focal neurological disability
- Hydrocephalus
- Neurocognitive decline and personality change
- Venous thromboembolism
- Treatment-related complications (steroid toxicity, postoperative deficits, radionecrosis, endocrinopathy depending on site/therapy)
Prognosis
In the UK, about 9,000 new primary brain/CNS cancers are diagnosed annually. Overall outcomes remain guarded and vary strongly by age, tumour type, grade, molecular markers, and resectability; population-level data indicate roughly 15% survive 5 years or longer. Early recognition and rapid referral improve the chance of earlier diagnosis and timely specialist treatment.
Sources & References
✅NICE Guidelines(1)
📖Textbook References(20)
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 815, 816)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1443, 1444)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 379)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1445, 1446)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1550, 1551)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 376, 377)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 1570, 1571)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 815)[context]
- David Randall PhD MRCP (Editor), John Booth PhD MRCP (Editor), K - Kumar and Clark's Clinical Medicine (2025, American Elsevier Publishing Co.) - libgen.li.pdf(pp. 313)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 564)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 1025)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 1008, 1009)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 672)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 888)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 697)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 879)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 899)[context]
- Guyton and Hall Textbook of Medical Physiology (John E. Hall, Michael E. Hall) (Z-Library).pdf(pp. 673)[context]
- Netter F. Netter Atlas of Human Anatomy. Classic Regional Approach 8ed 2022.pdf(pp. 41)[context]
- [Williams, Bailey and Love's Short Practice of Surgery] Norman Williams, Christopher Bulstrode, P Ronan O'Connell - Bailey & Love's Short Practice of Surgery 26E (2013, CRC Press) - libgen.li.pdf(pp. 940)[context]