gms | German Medical Science

68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

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The Impact of extent of resection and MGMT-promotor methylation in newly diagnosed IDH1R non mutated glioblastoma

Meeting Abstract

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  • Florian Geßler - Department of Neurosurgery, Goethe University Frankfurt, Frankfurt am Main, Deutschland
  • Peter Baumgarten - Frankfurt, Deutschland
  • Anne Braczynski - Frankfurt, Deutschland
  • Michel Mittelbronn - Frankfurt, Deutschland
  • Volker Seifert - Frankfurt, Deutschland
  • Christian Senft - Frankfurt, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocMO.22.01

doi: 10.3205/17dgnc128, urn:nbn:de:0183-17dgnc1280

Published: June 9, 2017

© 2017 Geßler et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.

Outline

Text

Purpose: The purpose of this prospective single-center analysis was the incorporation of molecular diagnostics in the assessment of extent of resection (EOR) as a progrostic factor for patients with glioblastoma (GBM).

Patients and Methods: Histology, MGMT promoter methylation status, isocitrate dehydrogenase 1 (IDH-1)R132H-mutation status, EOR and clinical data were prospectively added to a glioma patient database. We analyzed patients with newly diagnosed WHO grade IV glioblastomas and excluded those with IDH-1 R132H mutations. Survival analyses were performed using the Kaplan-Meier method. Prognostic factors were calculated by proportional hazard models.

Results: 176 patients were included in the analysis. 104 patients (59.4%) had gross total resection (GTR), 71 patients (40.6 %) had subtotal or partial resection. 80 patients (45.7%) displayed MGMT-promoter methylation, 95 patients (54.3%) showed no MGMT-promoter methylation. In Cox regression analysis, both MGMT-promoter methylation (HR 1.55; 95% CI, 1.01-2.19; p=0.0133) and GTR (HR 1.48; 95% CI, 1.06-2.07; p=0.0206) were significantly associated with favorable progression free survival (PFS). Furthermore, both MGMT-promoter methylation (HR 2.13; 95% CI, 1.45-3.12; p=0.0001) and GTR (HR 1.81; 95% CI, 1.24-2.63; p=0.0020) were even associated with favorable overall survival (OS). Of other risk factors analyzed, only age ( > 60 vs. <=60 years) was significantly associated with PFS (HR 1.60; 95% CI, 1.14-2.24; p=0.006) and OS (HR 2.19; 95% CI, 1.51-3.19; p<0.0001). No significant difference was observed between GTR, MGMT-non-methylated and non-GTR, MGMT-methylated GBM patients (PFS p=0.726; OS p=0.477).

Conclusion: GTR and MGMT-promoter methylation are independent prognostic factors for improved OS and PFS in a homogeneous cohort of non-IDH-1 mutant, newly diagnosed glioblastomas. If achieved, GTR compensates the biological disadvantage of lacking methylation of the MGMT-promoter region in primary GBM.