Survival of brain tumour patients with epilepsy.

Pro-tumorigenic electrochemical synapses between neurons and brain tumour cells in preclinical studies suggest unfavourable effects of epilepsy on patient survival. We investigated associations of epilepsy and survival in three cohorts of brain tumour patients (meningioma, glioblastoma and brain metastases). Cohorts were segregated into three groups for comparative analyses: (i) no epilepsy; (ii) epilepsy without status epilepticus; and (iii) status epilepticus. Status epilepticus was considered a surrogate of extensive neuronal hyperexcitability. The main outcome was progression-free survival (meningioma) and overall survival (glioblastoma and brain metastases), adjusted for established prognostic factors and onset of epilepsy by time-dependent multivariate Cox modelling. The primary analysis population comprised 1792 patients (742 meningioma, 249 glioblastoma, 801 brain metastases). Epilepsy was associated with favourable prognostic factors. However, on multivariate analyses, status epilepticus was associated with inferior overall survival of patients with glioblastoma [status epilepticus versus no epilepsy multivariate hazard ratio (HR) 3.72, confidence interval (CI) 1.78-7.76, P < 0.001] and brain metastases (status epilepticus versus no epilepsy HR 2.30, CI 1.10-4.79, P = 0.026). Among brain metastases patients, but not among patients with meningioma or glioblastoma, epilepsy was similarly associated with inferior overall survival (epilepsy versus no epilepsy HR 2.16, CI 1.60-2.93, P < 0.001). We conclude that epilepsy may convey inferior survival of patients with malignant brain tumours.