The high seizure burden seen in WHO grade 2 gliomas is well documented. This study aims to identify factors which influence the probability of seizure freedom (12 months of seizure remission) and treatment failure (ASM cessation or introduction of an alternative) in patients with WHO grade 2 glioma.
This is a retrospective observational analysis of patients from a regional UK neurosurgical centre with histologically proven (n=146) WHO grade 2 glioma and brain tumour related epilepsy. Statistical analyses using both Kaplan-Meier and Cox-proportional hazards models were undertaken, with a particular focus on treatment outcomes when the commonly prescribed ASM levetiracetam (n=101) is used first line.
Treatment with levetiracetam as a first line ASM resulted in a significant increase in the probability of seizure freedom (p<0.05) at 2 years compared with treatment with an alternative ASM. Individuals presenting with focal seizures without bilateral tonic-clonic progression were between 39-42% significantly less likely to reach seizure freedom within 10 years (p<0.05) and 132% more likely to fail treatment by 5 years (p<0.01) when compared to those that had seizures with progression to bilateral tonic-clonic activity. ASM choice did not significantly affect treatment failure rates.
Over two-thirds of WHO grade 2 glioma patients treated with levetiracetam first line achieve seizure freedom within 2 years and it is a reasonable first choice agent. Experiencing mainly focal seizures without progression infers a significant long-term reduction in the chance of seizure freedom. Further studies are needed to inform ASM selection.