106. Recurrent Infratentorial Ependymomas: A Systematic Review and Meta-Analysis on Outcomes and Molecular Classification

Authors: Eric Montgomery

The prognosis of recurrent ependymomas differs based on location and molecular signature, but the difference in survival of PFA and PFB recurrent ependymomas remains poorly defined in the pediatric population.Methods: We searched PubMed, Scopus, Embase, and Ovid for studies on recurrent infratentorial ependymomas in patients < 25 years old. Exclusion criteria were case series of less than 5 patients and studies that did not provide individualized patient data or averages with sample size and standard deviation/error. Tumors were characterized based on WHO grade and multi-omic molecular classification. Survival was quantified as overall survival after the first recurrence of the primary tumor.
Our database search yielded 472 unique articles, of which 13 were included in the final analysis. There was a total of 287 recurrent infratentorial pediatric ependymomas reported, with 163 grade II tumors (57.0%) and 123 grade III (43.0%) on histology. One hundred and sixty-one patients were male (56.1%). In the studies that provided molecular classification, there were 109 PFA tumors (90.8%) and 11 PFB (9.2%). The overall mortality for recurrent infratentorial pediatric ependymomas was 58.5% (168/287). Of the studies with individualized molecular data, mortality for recurrent PFA tumors was 44.0% (11/25) and for recurrent PFB tumors 12.5% (1/8). The pooled median survival was 23.53 months after recurrence (95% CI: 11.75-35.31). Ninety-eight patients received initial subtotal resection of the primary tumor (40.7%). Thirty-seven patients received radiation for their recurrence and 30 received chemotherapy. Twenty-one experienced metastasis along with their local recurrence.
The overall mortality rate of recurrent infratentorial ependymomas was found to be 58.5%, with a pooled median survival of 23.5 months in the sample population. Most of the recurrent infratentorial ependymomas were of the PFA molecular subtype, which also demonstrated a worse survival with recurrence.