EPN-14
PEDIATRIC EPENDYMOMA: MULTI-INSTITUTIONAL EXPERIENCE REVEALS POOR LONG-TERM OVERALL SURVIVAL DESPITE FAVORABLE FIVE-YEAR OUTCOMES

BACKGROUND: Current understanding of prognosis and treatment of pediatric ependymoma has historically been guided by 5-year survival outcomes. There is a paucity of large studies with long-term follow-up, and factors influencing prognosis remain unclear. Studies with longer follow-up are needed to understand the long-term survival and recurrence patterns of this disease. PROCEDURE: Detailed outcome analyses were performed on 113 pediatric patients with WHO Grades II/III intracranial ependymoma, treated between 1985-2008, at Dana Farber/Boston Children's Hospital and Lurie Children's Hospital of Chicago. Actuarial overall survival (OS) and progression-free survival (PFS) were determined by the Kaplan-Meier method. Univariate and multivariate analyses were performed using the log-rank test and Cox proportional-hazards models to evaluate the prognostic significance of 13 clinical and histopathologic variables. RESULTS: The 5- and 10-year OS rates were 64% ± 5% and 49% ± 6%, respectively (median follow-up 7.1 years, range 0.2-28 years). The 5- and 10-year PFS were 37% ± 5% and 28% ± 5%, respectively. Seventy-three patients (65%) displayed radiographic evidence of recurrent disease at a median of 1.8 years (0-19.4) post-operatively. Relapses were local in 49 cases (67%), distant in 11 (15%), combined local and distant in 9 (12%) and unknown in 4 (5%). Among the prognostic factors analyzed, only low Topo-II alpha expression (<9.4%) was found to be statistically predictive of improved OS. CONCLUSIONS: We show that 5-year OS overestimates long-term outcomes in children with ependymoma. Control at the primary site remains the major positive predictor of long-term survival. Our data support ongoing investigations evaluating the role of maintenance therapy to reduce late recurrences.