Survival of children with malignant brain tumors receiving valproate: a retrospective study

The treatment of pediatric patients with malignant brain tumors has evolved considerably in the past decades. However, results are still unsatisfactory for some patients. Valproate has been shown to positively affect the survival of adult glioblastoma patients. We have been giving prophylactic antiepileptic drugs to newly diagnosed children with brain tumors. Since then, we noted a trend towards a better survival from our patients. In order to study this, we performed a retrospective evaluation in our institution. Standard survival analysis was used, calculating survival until death by all causes or censoring. Comparisons were made by Cox's proportional hazards model regression. Between 2000 and 2010, 94 patients were treated (12 with high-grade gliomas, 56 medulloblastomas, and 26 ependymomas); median and mean ages were 7.7 and 7.8 years. Median follow-up was 60 months (35 for treated and 109 for untreated patients). Of these, 47 received valproate 10-15 mg/kg/day every 8-12 h and 47 did not. Patients who received valproate had a median survival of 34 months, whereas the other group had a median survival of 24 months (hazard ratios = 0.99, 0.57-1.75, p = 0.99). These results do not prove that valproate prophylactic treatment in pediatric patients with malignant brain tumors had an influence on their survival. However, our cohort showed an effect of higher size than the recent European Organization for Research and Treatment of Cancer trial analysis, even though not significant. Clinical trials with valproate in pediatric malignant brain tumors should be carefully planned, in order to detect a possible effect of this drug in survival.