Use of Anti-Epileptic Drugs During Adjuvant Chemo-Radiotherapy is Associated with Increased Mortality in Patients with Glioblastoma: A Nationwide Population-Based Cohort Study

Abstract

BackgroundThere are emerging but inconsistent evidences about anti-epileptic drugs (AEDs) as radiosensitizers to improve survival in glioblastoma (GBM) patients. We conducted a population-based study to evaluate the impact of concurrent AED during post-operative chemo-radiotherapy (CCRT) on outcome.Methods1057 GBM patients were identified by National Health Insurance Research Database and Cancer Registry in 2008-2015. Eligible criteria included those receiving surgery, adjuvant RT and temozolomide (TMZ), and without other cancer diagnoses. Survival between patients taking concurrent AED for 14 days or more during CCRT (AED group) and those who did not (non-AED group) were compared, and subgroup analyses for valproic acid (VPA), levetiracetam (LEV), and phenytoin were performed. Multivariate analyses were used to adjust for confounding factors. ResultsThere were 642 patients in the AED group while 415 in the non-AED group. The demographic data was balanced except trend of more patients in the AED group had previous drug history of AEDs. (22.6% vs 18%, p=0.078). Overall, the AED group had significantly increased risk of mortality (HR=1.18, p=0.016). In subgroup analyses, the significant detrimental effect was demonstrated in VPA (HR=1.29, p=0.0002), but not in LEV (HR=1.18, p=0.079) and phenytoin (HR = 0.98, p=0.862). When stratified by sex and age, this detrimental effect was seen in male and patients less than 65 years old in the VPA group.Conclusion:Survival was not improved and even worse in patients with AEDs during CCRT in this nationwide population-based study. Our real-world data did not support prophylactic use of AEDs for GBM.