Neurosurgery Resident University of Toronto Toronto, Ontario, Canada
Introduction: Pediatric posterior fossa ependymoma is associated with morbidity and premature mortality among affected children. There is a known risk of recurrence even among long-term 5-year survivors undergoing initial gross total resection (GTR). The overall survival and dissemination patterns of multiply recurrent pediatric posterior fossa ependymoma are not well understood. We therefore aimed to study outcomes following primary and recurrent ependymoma in a molecularly defined cohort.
Methods: We queried an institutional database for primary diagnosis of posterior fossa ependymoma from January 2000 to December 2019. Patients with histologically confirmed posterior fossa ependymoma from birth to age 18 at time of primary resection were included. Patients were excluded if files were incomplete or missing data and rightward censoring was employed. Descriptive statistics and survival analyses were performed to delineate the relationship between treatment, extent of resection and overall survival.
Results: There were 60 patients with posterior fossa ependymoma identified, of which 49 were PF-A ependymoma cases (87.5%) and 7 were PF-B ependymoma cases (12.5%). Overall recurrence rate in the cohort was 48%; median cohort 50% survival was 12.3 years and only 3.3 years following diagnosis of first relapsed disease. After adjusted analysis, primary ependymoma GTR was associated with improved overall survival with hazard ratio 0.373 (95% CI 0.14-0.96). Presence of recurrent disease was significantly associated with worse survival (p < 0.0001). At recurrent disease diagnosis, disseminated disease was a negative factor portending worse prognosis in the cohort with hazard ratio 11.0 (95% CI 2.7-4.4). Surgery compared to no surgery for recurrent disease was significantly favorable for recurrent ependymoma survival 0.154 (95% CI 0.035-0.68).
Conclusion : We present a large series of molecularly characterized posterior fossa ependymoma and demonstrated that disseminated disease at recurrence and relapsed cases managed without surgery had poor overall survival compared to the remainder of the cohort.
