Supratentorial extraventricular ependymomas: A retrospective study focused on long-term outcomes and prognostic factors

Objective: Supratentorial extraventricular ependymomas are relatively rare. Long-term outcomes and prognostic factor for this rare tumor have not been well established. The purpose of this study was to demonstrate progression-freesurvival (PFS),overall survival (OS), and prognostic factors of such tumor. Patients and methods: Fifty-five patients with supratentorial extraventricular ependymomas from our hospital were included in this study. Epidemiological characteristics, clinical features, treatment,long-term outcomes, and prognostic factors for PFS and OS were reviewed retrospectively. Results: The patients consisted of 30 males and 25 females with mean age of 30.0 +/- 23.6 years (range, 1-74 years). Twenty-nine tumors were located in the right hemisphere, and 26 in the left side. The 2 most common tumor locations were the frontal (n = 19; 35%) and parietal lobe (n = 11; 20%). All patients underwent surgical resection. Gross-total resection (GTR) was achieved in 42 cases (76%) and subtotal resection (STR) was performed in 13 patients (24%). According to the WHO classification system, 38 tumors (69%) were Grade III (anaplastic ependymoma), and 17 (31%) were Grade II (ependymoma). Three-,5-, and 10 year PFS rates were 60%, 49%, and 36%, respectively. Three-,5-, and 10 year OS rates were 79%, 64%, and 49%, respectively. EOR and tumor grade were identified as prognostic factors for PFS and OS on univariate analysis, multivariate analysis, and Kaplan-Meierlog-rank testing. Subtotal resection (STR) predicted a worse PFS (HR = 4.808; 95%, 1.942-11.905; P=.001) and OS (HR = 5.650; 95%, 2.114-15.152; P=.001). WHO Grade III tumors also had worse PFS (HR = 3.922; 95%, 1.429-18.182; P=.012) and OS (HR = 6.329; 95%, 1.328-30.303; P =0.021). For patients with tumor recurrence, reoperation was significant prognostic factors for OS (HR = 2.091; 95%, 0.939-4.654; p=.000). Age, sex, tumor side, and postoperativeradiotherapy were not prognostic factors for PFS and OS. Conclusions: Most supratentorial extraventricular ependymomas are WHO grade III tumors. STR and WHO Grade III pathology predicted worse PFS and OS. Gross-total resection remains the optimal treatment for patients with supratentorial extraventricular ependymoma. Reoperation should be considered first in cases of recurrence. The role of postoperative radiotherapy as an adjuvant treatment for supratentorial extraventricular ependymoma needs further investigation.