423P - The impact of valproic acid in overall survival of patients with glioblastoma multiforme

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Supportive Care
Central Nervous System Malignancies
Presenter Sara Meireles
Authors S.R. Meireles1, M.L. Salgado2, D.P. Almeida3, L. Castro4, P. Linhares5, L. Osório6, A.S.A. Costa7, C. Caeiro1, M. Damasceno1
  • 1Medical Oncology Department, Hospital São João, 4200-319 - Porto/PT
  • 2Hospital São João, 4200-319 - Porto/PT
  • 3Medical Oncology Department, Hospital São João, Porto/PT
  • 4Histopathology Department, Hospital São João, 4200-319 - Porto/PT
  • 5Neurosurgery Department, Hospital São João, 4200-319 - Porto/PT
  • 6Radiotherapy Department, Hospital São João, 4200-319 - Porto/PT
  • 7Medical Oncology, Hospital São João, 4200-319 - Porto/PT

Abstract

Background

Seizures occur in up to 50% of patients with glioblastoma multiforme (GBM). Retrospective analysis of the pivotal European Organization for Research and Treatment of Cancer/National Cancer Institute of Canada clinical trial showed that the use of the antiepileptic (AED) valproic acid (VPA) may improve survival among patients with newly diagnosed glioblastoma receiving temozolamide compared to other AED or no treatment. We aimed to analyse the impact of VPA in overall survival (OS) of GBM patients submitted to Stupp's protocol.

Material and methods

Retrospective study of GBM patients who completed concomitant phase of Stupp's protocol from March 2004 until December 2011. Patients needing two AED to seizure control were excluded.

Results

One hundred thirty two patients were included. Median age at diagnosis was 61 years-old [24;79] and 68,2% were male. Seizures were present at diagnosis in 16,7% of cases. 55,3% were AED-free, 35,6% received VPA and 9,1% took another AED. Median OS was 15 months (95%CI: 13,3-16,7) and 2-year OS was 31,8%. Patients submitted to VPA had better median OS versus other AED or no treatment at all, although the difference was not statistically meaningful (16 vs 15 vs 14 months, p = 0.74). In univariate and multivariate analysis, ECOG PS ≥ 1 (HR: 1.58, 95% CI 1.01-2.47, p = 0.04), corticosteroid use (HR: 1.83, 95% CI 1.05-3.18, p = 0.03) and < 6 cycles of temozolamide in maintenance phase (HR: 3.15, 95% CI 2.05-4.85, p < 0.001) were the only independent factors with negative impact on OS. VPA treatment was not significantly correlated with OS (HR: 0.96, 95% CI 0.47-1.96, p = 0.90).

Conclusion

Opposite to the literature data, VPA didn't show any survival advantage in GBM patients. ECOG PS ≥1, corticosteroid use and < 6 cycles of temozolamide in maintenance phase were correlated with worst prognosis. Future studies are needed to confirm and understand which mechanisms justify any potencial survival benefit of VPA.

Disclosure

All authors have declared no conflicts of interest.