Abstract CT120: Radiotherapy in pediatric patients with atypical teratoid rhabdoid tumor of the central nervous system

Abstract

Abstract Atypical teratoid/rhabdoid tumor (ATRT) of the CNS is a rare, highly malignant tumor of early childhood. Current protocols favor multimodality treatment, but practice guidelines differ with regard to radiotherapy. The aim of this study was to evaluate outcomes and prognostic factors in pediatric ATRT receiving multimodality treatment including postoperative radiation. Pediatric subjects with CNS ATRT treated at our institution between 2000 and 2014 were evaluated. Kaplan Meier method was used to estimate progression free survival (PFS) and overall survival (OS) over time and log-rank tests were used to examine associations of demographic and treatment factors with PFS and OS. 20 pediatric subjects (median age 23.5 months; range 4-99 months) with CNS ATRT treated at our institution between 2000 and 2014 were retrospectively evaluated. All underwent surgical resection, adjuvant radiotherapy, and aggressive multi-agent chemotherapy. PFS at 1-year was 63.3% (95% CI, 38.1% - 80.6%) and 2-years was 46.1% (95% CI, 22.9% - 66.5%). OS at both 1- and 2-years was 73.0% (95% CI, 46.7% - 87.8%). Infratentorial disease, lack of metastatic disease at diagnosis, and gross total tumor resection were identified as beneficial prognostic factors in PFS and OS. Progressive disease after radiation was identified as a poor prognostic factor in OS. Radiation modality (proton versus x-ray) did not affect disease-related outcomes. Modern treatment for ATRT with aggressive multimodality therapy including radiotherapy results in a significant portion of subjects with long-term disease control. Prognosis appears to be improved in subjects with localized, completely resected disease. Citation Format: Melissa Frick, Jane Minturn, Yi-Mei Li, Christine Hill-Kayser. Radiotherapy in pediatric patients with atypical teratoid rhabdoid tumor of the central nervous system. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT120.