Central nervous system atypical teratoid rhabdoid tumours: The Canadian Paediatric Brain Tumour Consortium experience

Background: Atypical teratoid rhabdoid tumours (ATRT) are aggressive brain tumours mostly occurring in early childhood. Largest published series arise from registries and institutional experiences (1-4). The aim of this report is to provide population-based data to further characterise this rare entity and to delineate prognostic factors. Patients and methods: A national retrospective study of children 618 years diagnosed with a central nervous system (CNS) ATRT between 1995 and 2007 was undertaken. All cases underwent central pathology review. Results: There were 50 patients (31 males; median age at diagnosis of 16.7 months). Twelve patients were >36 months. Infratentorial location accounted for 52% of all cases. Nineteen patients (38%) had metastatic disease. Fifteen (30%) underwent gross total resection (GTR). Ten patients (20%) underwent palliation. Among the 40 remaining patients, 22 received conventional chemotherapy and 18 received high dose chemotherapy regimens (HDC); nine received intrathecal chemotherapy and 15 received adjuvant radiation. Thirty of the 40 treated patients relapsed/progressed at a median time of 5.5 months (0-32). The median survival time of the entire cohort was 13.5 months (1-117.5 months).Age, tumour location and metastatic status were not prognostic. Patients with GTR had a better survival (2 years overall survival (OS): 60% +/- 12.6 versus 21.7% +/- 8.5, p = 0.03). HDC conferred better outcome (2 years OS 47.9% +/- 12.1 versus 27.3% +/- 9.5, p = 0.036). Upfront radiation did not provide survival benefit. Six of the 12 survivors (50%) did not receive radiation. Conclusion: The outcome of CNS ATRT remains poor. However, the use of HDC provides encouraging results. GTR is a significant prognostic factor. The role of adjuvant radiation remains unclear. (C) 2011 Elsevier Ltd. All rights reserved.