RARE-08. MULTI-INSTITUTIONAL ANALYSIS OF PEDIATRIC RELAPSED/REFRACTORY CENTRAL NERVOUS SYSTEM GERMINOMA

Abstract

Abstract BACKGROUND Relapsed central nervous system (CNS) germinomas are rare with no universal agreement regarding management. We explore prognostic factors that may impact the treatment of patients with relapsed CNS germinoma. METHODS An international multi-institutional retrospective study of relapsed/progressive CNS germinomas was conducted. Data was summarized using descriptive statistics. Overall survival (OS) was evaluated using Kaplan-Meier and Fischer’s exact test to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS Analysis included 21 patients (Male 71.4%) with relapsed/progressive germinomas from 7 sites. Median age at diagnosis was 15 years (interquartile range (IQR): 9.9-19) with 5% presenting with metastatic disease. Twelve patients (57.1%) achieved complete remission (CR) after initial therapy. Nineteen children (90.5%) suffered relapse. One (4.8%) suffered progression. The median time from diagnosis to relapse/progression was 21 months (range: 10-56 months) with 90.5% occurring within 24 months. 19 (90.5%) underwent chemotherapy, 9 (42.9%) bone marrow ablative therapy (HDCx), and 13 (61.9%) radiotherapy. At last follow-up, 88.9% of HDCx and 92.3% of radiotherapy recipients were alive. Of patients receiving radiation, 45% received whole ventricular irradiation, 25% craniospinal irradiation, and 5% focal irradiation (remainder unreported). Eleven children (52.4%) achieved CR after relapse/progression therapy and 16 (76.2%) were alive at last follow-up. Median time to last follow-up was 39 months (IQR: 18.43–89.50). Re-irradiation at relapse (OR=16, 95% CI: 1.27-200.9) and achieving complete response (CR) at relapse/progression (OR=4, 95% CI: 1.04-1.78) were associated with improved OS. CR after initial therapy (OR=0.857, 95%CI: 0.11-6.62) and HDCx at relapse/progression (OR=4, 95%CI: 0.36-44.13) were not associated with improved OS. CONCLUSIONS Relapsed CNS germinomas are radiosensitive and salvageable by re-irradiation at relapse. This ongoing multi-institutional study will contribute to existing knowledge about relapsed/progressive CNS germinomas and inform prospective clinical trials to improve outcomes for children with relapsed/progressive disease.