Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan

Abstract

BACKGROUND AND OBJECTIVES: Ependymoma is the most common spinal intramedullary tumor. Although clinical outcomes have been described in the literature, most of the reports were based on limited numbers of cases or been confined to institutional experience. The objective of this study was to analyze more detailed characteristics of spinal intramedullary ependymoma (SIE) and provide clinical factors associated with progression-free survival (PFS). METHODS: This retrospective observational multicenter study included consecutive patients with SIE in the cervical or thoracic spine treated surgically at a total of 58 institutions between 2009 and 2020. The results of pathological diagnosis at each institute were confirmed, and patients with myxopapillary ependymoma, subependymoma, or unverified histopathology were strictly excluded from this study. Outcome measures included surgical data, surgery-related complications, postoperative systemic adverse events, postoperative adjuvant treatment, postoperative functional condition, and presence of recurrence. RESULTS: This study included 324 cases of World Health Organization grade II (96.4%) and 12 cases of World Health Organization grade III (3.6%). Gross total resection (GTR) was achieved in 76.5% of cases. Radiation therapy (RT) was applied after surgery in 16 cases (4.8%), all of which received local RT and 5 of which underwent chemotherapy in combination. Functional outcomes were significantly affected by preoperative neurological symptoms, tumor location, extent of tumor resection, and recurrence. Multivariate regression analysis suggested that limited extent of tumor resection or recurrence resulted in poor functional outcomes. Multiple comparisons among the groups undergoing GTR, subtotal resection and biopsy, or partial resection of the tumor showed that the probability of PFS differed significantly between GTR and other extents of resection. CONCLUSION: When GTR can be safely obtained in the surgery for SIE, functional maintenance and longer PFS can be expected.

Clinical presentation and extent of resection impacts progression-free survival in spinal ependymomas

“…An extensive body of literature exists investigating clinical and treatment characteristics that portend improvements in overall survival (OS) and progression-free survival (PFS) metrics in spinal ependymoma patients [ 2 , 4 , 5 , 7 – 15 ]. Furthermore, a number of authors have demonstrated the benefits of gross total resection (GTR) over subtotal resection (STR) as a principal treatment for spinal ependymomas using both OS and PFS as primary outcome criteria [ 4 , 7 , 9 , 15 ]. Abdel-Wahab et al conducted one of the largest retrospective reviews of 120 spinal ependymoma patients undergoing primary surgical treatment with or without adjuvant radiation from 1953 to 2000.…”

Letter: Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan

“…We eagerly read the recent publication by Naito et al 1 Although ependymomas are the most common spinal intramedullary tumor, previous studies outlining disease progression and functional outcomes after treatment have been limited in case numbers and also biased by the inclusion of nonintramedullary subtypes. Naito et al performed a retrospective multicenter study with more exclusive histological inclusion criteria as well as a large sample size to attain a more complete analysis on the predictors of progression-free survival and functional outcomes in spinal intramedullary ependymoma (SIE) treatment.…”

In Reply: Predictors of Progression-Free Survival in Patients With Spinal Intramedullary Ependymoma: A Multicenter Retrospective Study by the Neurospinal Society of Japan

“…We are also well aware of their importance. However, because this study 2 is retrospective observational multicenter analysis, it is true that there are many research limitations for tumor characteristics, tumor axial location, operative variables, intraoperative neuromonitoring, and gene analysis. Of course, we also understand that more detailed analysis is ideal, especially for gene analysis.…”