Infratentorial ependymomas: prognostic factors and outcome analysis in a multi-center retrospective series of 106 adult patients

This study was undertaken to analyze outcomes and to assess the prognostic impact of age, location, surgery, radiotherapy (RT), and histopathology in a series of adult infratentorial ependymomas. This was a retrospective study of a population of 106 adult patients with infratentorial ependymomas diagnosed between 1990 and 2004. A central pathological review of all cases was performed. Grading was according to the WHO and Marseille's neograding classifications. The series consisted of 58 males (54.7%) and 48 females (45.3%) in the age range of 18-82 years. Using the WHO classification, 88 patients (83.0%) had grade II and 18 patients (17.0%) grade III ependymomas. Using the Marseille's neograding system, 91 patients were low-grade and 15 high-grade. Gross total resection was achieved in 66 patients (62.3%). Thirty-seven patients (35.0%) received adjuvant RT. The 5- and 10-year overall survival rates for the entire cohort were 86.1% and 80.5%, respectively. On multivariate analysis, a preoperative Karnofski performance status score > 80, no recessus lateral extension and a low histological grade (Marseille's grading) were associated with a longer overall survival. The 5- and 10-year progression-free survival rates for the entire cohort were 70.8% and 57.7%, respectively. On multivariate analysis, no recessus lateral extension, gross total resection and a low histological grade (Marseille's grading) were associated with a longer progression-free survival. Adjuvant RT was significantly associated with a better overall and progression-free survival in incompletely resected WHO grade II ependymomas. This study highlights the key role of histology in the clinical outcome and the fact that gross total resection is a main prognostic factor and the treatment of choice for posterior fossa ependymomas. The use of adjuvant RT in patients with incompletely resected WHO grade II ependymomas appears beneficial, but its effect on high-grade tumors remains to be determined.