A multi-institutional report of children with atypical teratoid rhabdoid tumor treated with intensive multimodal therapy

Atypical teratoid rhabdoid tumor (ATRT) is a rare pediatric central nervous system with little data on the efficacy of upfront treatment strategies. This study reports prognostic factors and survival of children with newly diagnosed ATRT at high volume centers treated as per Children’s Oncology Group trial ACNS0333. Data were collected retrospectively from 13 institutions. Included subjects were children with newly diagnosed ATRT, treated as per ACNS0333, a single-arm phase III trial of intensive chemotherapy and radiation therapy. Data were analyzed to assess prognostication of clinical variables and estimates of event-free (EFS) and overall survival (OS). Eighty subjects were included, with a median age at diagnosis of 18 months, 70% had localized disease, and 53% underwent complete tumor resection at the time of diagnosis. Fifty patients (63%) completed all therapy phases, while 12 patients (15%) experienced progression during treatment. Fifty-three patients (66%) received post-induction consolidation with high-dose chemotherapy and stem cell rescue (HDC/SCR), and 55 (69%) received radiation therapy (RT). The 4-year EFS and OS for the entire cohort were 49% and 53% respectively. Patients completing all therapy phases had superior outcomes (4-year EFS: 63%; OS: 67%) Absence of disease post-induction correlated with improved outcomes (4-year EFS: 64%; OS: 70%), and patients with primary spinal cord tumors had poor outcomes despite intensive therapy. Children with ATRT treated as per ACNS0333 with multi-modal therapy including HDC/SCR and RT have improved survival compared to those treated without RT and is higher than previously reported on study.