A systematic review of outcome in intramedullary ependymoma and astrocytoma

Abstract

The objective was to determine the impact of surgical resection and adjuvant therapies on survival in intramedullary ependymoma and astrocytoma. Secondary goals were to determine predictors of survival in surgical patients including histological grading, age and gender. Searching of Medline, Embase and Clinicaltrials.gov databases were performed. Multivariate analyses were performed for overall survival (OS) and progression-free survival (PFS) through Monte Carlo methods and Maximum Likelihood Estimation. 57 articles detail results for 3022 patients. Meta-analysis revealed the following factors to have a statistically significant effect on OS. Patients undergoing gross-total resection (GTR) are 5.37 times more likely to survive than patients with lesser volumes of tumor resected (HR for OS 1.68, p < 0.01). High-grade tumors were associated with a 14 times risk of death over low-grade tumors (HR for OS 2.64, p < 0.01). Radiation increased the risk of mortality in low-grade tumors (HR for OS 5.20, p < 0.01), but decreased mortality in high-grade lesions (HR for OS 2.46, p < 0.01). Adult patients were more likely to die from disease compared with pediatric patients by a factor of 1.6 (HR for OS 0.47, p < 0.01). In PFS, radiotherapy was associated with a reduced time to recurrence (HR for PFS 1.90, p < 0.01). There was a male predominance of 58%. Gender did not influence survival. 79% of patients demonstrated stable or improved functional neurological outcomes six months post-operatively. Our data indicates GTR improves OS in all tumor grades. Radiation improves OS only in the presence of high-grade histology. Advancing age and high-grade histology are negative prognostic indicators.

Keywords: Astrocytoma; Ependymoma; Intramedullary tumor; Radiotherapy; Spine.