gms | German Medical Science

62nd Annual Meeting of the German Society of Neurosurgery (DGNC)
Joint Meeting with the Polish Society of Neurosurgeons (PNCH)

German Society of Neurosurgery (DGNC)

7 - 11 May 2011, Hamburg

Studying the prognostic role of the extent of resection in a retrospective cohort of supratentorial infiltrative low grade gliomas: analysis of treatment bias

Meeting Abstract

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  • K. Gousias - Abteilung für Neurochirurgie, Universitätsklinikum Bonn
  • J. Schramm - Abteilung für Neurochirurgie, Universitätsklinikum Bonn
  • M. Simon - Abteilung für Neurochirurgie, Universitätsklinikum Bonn

Deutsche Gesellschaft für Neurochirurgie. Polnische Gesellschaft für Neurochirurgen. 62. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), Joint Meeting mit der Polnischen Gesellschaft für Neurochirurgen (PNCH). Hamburg, 07.-11.05.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocMI.03.04

doi: 10.3205/11dgnc191, urn:nbn:de:0183-11dgnc1911

Published: April 28, 2011

© 2011 Gousias et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: The prognostic impact of the extent of resection in supratentorial low grade gliomas (LGG) remains controversial. Prognostic factors might not only influence survival but also the surgical strategy, i.e. patients with a presumably better prognosis may have more aggressive resections on the average (or vice versa). In the present study we attempt to analyze this potential treatment bias.

Methods: We conducted a retrospective study including all 125 patients >18 years with a histologically confirmed diagnosis of a primary infiltrative LGG undergoing surgery in our institution from 1996-2007. Potential prognostic factors were analyzed in order to identify and adjust for treatment bias.

Results: Median follow-up was 66 months. Tumor recurrence was observed in 91 patients (72.8%), 87 of whom underwent a second operation. The rate of malignant transformation was 78.2%. Median PFS (progression free survival) after partial resections/biopsies vs gross total resections was estimated to be 55 vs 125 months (p > 0.01). Preoperative presence of a neurological deficit, tumor size and extent of resection were shown to be independent predictors of recurrence and malignant progression (Cox regression, p < 0.01). Younger patients with a non-eloquent tumor, a high KPI and no neurological deficit were more likely to have a complete resection (p < 0.05). After stratification for these parameters, the extent of resection still proved to be a significant prognostic factor.

Conclusions: Surgical treatment for LGG is often biased. However, this does not account for the correlation between the extent of resection and survival observed in our series. The extent of resection remained an important predictor of survival after adjustment for eloquent tumor location, KPI, presence of neurological deficits and age.