AT-23
ENCOURAGING SURVIVAL OF PEDIATRIC CENTRAL NERVOUS SYSTEM (CNS) ATYPICAL TERATOID AND RHABDOID TUMOR (AT/RT) TREATED AS PER CHILDREN'S ONCOLOGY GROUP ACNS0333 STUDY: A SINGLE-INSTITUTION EXPERIENCE

AT/RT is a devastating malignant brain tumor affecting infants and young children. Therapy is multimodal but outcomes are still poor. A retrospective chart review was performed on CNS AT/RT patients diagnosed at Children's Hospital Los Angeles between 2006 and 2015 after obtaining institutional review board (IRB) approval. The Kaplan-Meier method and Log-Rank test was used for survival analysis. Twenty-eight patients with ATRT were identified. Between 2006 and 2009, all consecutive patients (n = 9) were treated on or as per Head Start III (HSIII) protocol. Since 2009, all consecutive patients (n = 16) have been treated on or as per ACNS0333 protocol. Four patients enrolled on ACNS0333 study have been excluded from analysis as study results have not yet been published. Families of three patients refused treatment after diagnosis. Median age at diagnosis was 1.5 years (range: 1-8 years). Eleven patients had disseminated disease and 12 had a gross total resection (GTR). Median follow-up is 37 months (range: 1-66 months). The 3-year PFS and OS was 30% (CI: 15-60%) 42% (CI: 25-71%) for all patients. All untreated patients died within 5 months. 3-year OS was significantly higher for patients treated as per ACNS0333 compared to HSIII patients (90% versus 11%, p < 0.01), and in patients who did or did not receive radiotherapy (74% versus 21%, p < 0.01). All patients who did not receive high-dose chemotherapy progressed prior to 5 months. Early institution of high-dose chemotherapy and/or irradiation, as administered on ACNS0333, seems to improve outcome in patients with CNS AT/RT.