Cancer and epilepsy can intersect through brain tumours, brain metastases, treatment-related neurological injury and complex drug interactions. Seizure management must be coordinated with oncology rather than considered separately.
Brain tumours are a major link
Primary brain tumours and brain metastases can both cause seizures.
The likelihood varies by tumour type, location and biology.
Routine prophylaxis is not the same as treatment
Current neuro-oncology guidance generally does not support antiseizure medication simply because a brain tumour is present when no seizure has occurred.
Once a verified seizure occurs, treatment is usually indicated.
Drug interactions influence ASM choice
Enzyme-inducing antiseizure medicines can interact with systemic anticancer therapy and supportive medicines.
Modern practice often favours agents with fewer hepatic enzyme interactions when clinically appropriate.
Cancer treatment can change seizure control
Surgery, radiotherapy and systemic therapy may reduce or alter seizures by treating the tumour, while treatment complications can also provoke acute seizures.
Seizure trajectory therefore needs to be interpreted alongside tumour status.
Metastatic disease has its own evidence gaps
A 2025 systematic review found limited-quality evidence on seizure outcomes after treatment of brain metastases.
This uncertainty should be acknowledged rather than overstating expected seizure control.
Related reading
Sources and further reading
- Society for Neuro-Oncology consensus review
- Brain metastases and epilepsy systematic review, 2025
- Antiepileptic strategies in primary/metastatic brain tumours, 2024
Evidence checked: September 2026.