Prognostic significance of contrast-enhancing low-grade gliomas in adults and a review of the literature

Neurol Res. 2009 Nov;31(9):931-9. doi: 10.1179/174313209X395454. Epub 2009 Feb 12.


Objectives: Survival and tumor recurrence for patients with low-grade gliomas is heterogeneous, with reported survival and recurrence times varying by several months to years. The prognostic implications of a contrast-enhancing low-grade glioma remain less well understood.

Methods: We retrospectively reviewed all adult patients who underwent a craniotomy for a hemispheric low-grade glioma (WHO grade II) from 1996 to 2006 at a single institution. Multivariate proportional hazards regression analysis was used to identify independent associations with survival, recurrence and malignant degeneration. Furthermore, a review of the literature for all works on low-grade gliomas and contrast enhancement was conducted.

Results: One hundred eighty-nine patients (87 fibrillary astrocytomas, 89 oligodendrogliomas and 13 mixed gliomas) were available for analysis, with 64 (34%) and 125 (66%) contrast-enhancing and non-enhancing tumors, respectively. There were no significant differences in clinical and treatment-related variables between patients with and without contrast enhancement. After multivariate analysis, contrast enhancement was independently associated with decreased survival (p=0.006) and increased recurrence (p=0.04) and trended toward significance with malignant degeneration (p=0.15). Five-year overall survival, progression-free survival and malignancy-free survival rates for patients with enhancement versus patients without enhancement were 70 versus 85% (p=0.002), 32 versus 49% (p=0.008) and 74 versus 90% (p=0.002), respectively. The review of the literature identified 14 works that fit our criteria. The majority of these published works had design-related limitations including small population size as well as the inclusion of non-WHO grade II gliomas, pediatric patients and patient undergoing biopsy.

Discussion: This study may provide insights into risk stratifying patients with low-grade gliomas and most specifically those that contrast enhance.

MeSH terms

  • Adult
  • Astrocytoma / epidemiology
  • Astrocytoma / pathology
  • Brain Neoplasms / classification
  • Brain Neoplasms / epidemiology
  • Brain Neoplasms / pathology*
  • Contrast Media*
  • Craniotomy
  • Female
  • Glioma / classification
  • Glioma / epidemiology
  • Glioma / pathology*
  • Humans
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Neoplasm Invasiveness / pathology
  • Neoplasm Recurrence, Local
  • Oligodendroglioma / epidemiology
  • Oligodendroglioma / pathology
  • Predictive Value of Tests
  • Prognosis
  • Retrospective Studies
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Survival Rate


  • Contrast Media