Extent of resection and survival for oligodendroglioma: a U.S. population-based study

J Neurooncol. 2019 Sep;144(3):591-601. doi: 10.1007/s11060-019-03261-5. Epub 2019 Aug 12.

Abstract

Background: National guidelines recommend maximal safe resection of low-grade and high-grade oligodendrogliomas. However, there is no level 1 evidence to support these guidelines, and recent retrospective studies on the topic have yielded mixed results.

Objective: To assess the association between extent of resection (EOR) and survival for oligodendrogliomas in the general U.S.

Methods: Cases diagnosed between 2004 and 2013 were selected from the Surveillance, Epidemiology, and End-Results (SEER) Program and retrospectively analyzed for treatment, prognostic factors, and survival times. Cases that did not undergo tumor de-bulking surgery (e.g. no surgery or biopsy alone) were compared to subtotal resection (resection) and gross-total resection (GTR). The primary end-points were overall survival (OS) and cause-specific survival (CSS). An external validation cohort with 1p/19q-codeleted tumors was creating using the TCGA and GSE16011 datasets.

Results: 3135 Cases were included in the final analysis. The 75% survival time (75ST) and 5-year survival rates were 47 months and 70.8%, respectively. Subtotal resection (STR, 75ST = 50 months) and GTR (75ST = 61 months) were associated with improved survival times compared to cases that did not undergo surgical debulking (75ST = 20 months, P < 0.001 for both), with reduced hazard ratios (HRs) after controlling for other factors (HR 0.81 [0.68-0.97] and HR 0.65 [0.54-0.79], respectively). GTR was associated with improved OS in both low-grade and anaplastic oligodendroglioma subgroups (HR 0.74 [0.58-0.95], HR 0.60 [0.44-0.82], respectively) while STR fell short of significance in the subgroup analysis. All findings were corroborated by multivariable analysis of CSS and externally validated in a cohort of patients with 1p19q-codeleted tumors.

Conclusion: Greater EOR is associated with improved survival in oligodendrogliomas. Our findings in this U.S. population-based cohort support national guidelines.

Keywords: Extent of resection; Gross-total resection; Oligodendroglioma; Surgery.

MeSH terms

  • Adolescent
  • Adult
  • Brain Neoplasms / epidemiology
  • Brain Neoplasms / mortality*
  • Brain Neoplasms / pathology
  • Brain Neoplasms / surgery
  • Child
  • Child, Preschool
  • Female
  • Follow-Up Studies
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Middle Aged
  • Neurosurgical Procedures / methods
  • Neurosurgical Procedures / mortality*
  • Oligodendroglioma / epidemiology
  • Oligodendroglioma / mortality*
  • Oligodendroglioma / pathology
  • Oligodendroglioma / surgery
  • Prognosis
  • Retrospective Studies
  • Survival Rate
  • United States / epidemiology
  • Young Adult