What Do We Know about Grade 3 Intracranial Ependymoma in Adults?

Abstract

To investigate the long-term results of treatment for adults with primary grade 3 (G3) intracranial ependymoma and to identify the factors related to survival. A retrospective analysis of all consecutive patients (pts) older than 18 years old treated due to primary G3 intracranial ependymoma (EP) in years 1996-2018 was performed. Progression-free survival (PFS) and overall survival (OS) were calculated with Kaplan-Maier method. Log rank test and Cox regression model were used in univariate (UVA) and multivariate analysis (MVA). The group consisted of 41 pts (14 female, 27 male) with median age of 36 years (range 18-65). Infra- and supratentorial location was observed in 12 (29%) and 29 (71%) of cases, respectively. Most of the pts (93%) were in good performance status (ECOG 0 or 1). In 3 cases dissemination along craniospinal axis was diagnosed initially. All had surgery as primary treatment with R0, R1, R2 resection in 15, 9 and 15 cases, respectively. In 2pts no information regarding resection range was available. Adjuvant radiotherapy (RT) was performed in 38 pts (93%). Five patients received palliative RT and 33 radical irradiation. In 2 pts chemotherapy (CT) was administered (5%). In 3 cases no information regarding postoperative treatment was available. Among those who had RT: craniospinal irradiation was performed in 29 pts (median total dose, TD 36 Gy) with local boost (median TD 55.8 Gy, range 32.4 - 60 Gy) and 9 had local treatment (median TD 54 Gy, range 20 - 60 Gy). Median follow-up (FU) was 12.2 years. During that time 30 pts died, and 5- and 10-year overall survival (OS) was 39% and 26%. Local failure and metastases during the FU were diagnosed in 22 and 15 pts, respectively. Two- and 5-year PFS was 37% and 24%, respectively. In UVA younger age (p = 0.0001), infratentorial location of the tumor (p = 0.001) and adjuvant radical RT (p = 0.025) with high TD (p = 0.0433) positively impacted OS. In MVA only younger age (p = 0.01) confirmed positive impact on OS, however trend for better OS was observed in those who received higher RT TD (p = 0.08). Neither local nor distant recurrence had impact on OS. Younger age (p = 0.0026), infratentorial location of the tumor (p = 0.0011), extent of resection (p = 0.067), RT TD (p = 0.0396) and radical RT (p = 0.002) impacted positively PFS in UVA. In MVA younger age (p = 0.0009), extent of the resection (p = 0.00006) and radical RT (p = 0.027) confirmed positive impact on PFS. The outcome of adult patients with cranial G3 ependymoma is poor. Better survival (both OS and PFS) is observed in younger patients. Extent of surgical resection and adjuvant RT strongly impact PFS. In our analysis neither local nor distant recurrence impacted OS.