Introduction: Extracranial rhabdoid tumours are rare, highly aggressive malignancies
primarily affecting young children. The EU-RHAB registry was initiated in 2009 to
prospectively collect data of rhabdoid tumour patients treated according to the EU-RHAB
therapeutic framework. Methods: We evaluated 100 patients recruited within EU-RHAB
(2009-2018). Tumours and matching blood samples were examined for SMARCB1 mutations
by sequencing and cytogenetics. Results: A total of 70 patients presented with extracranial,
extrarenal tumours (eMRT) and 30 with renal rhabdoid tumours (RTK). Nine patients
demonstrated synchronous tumours. Distant metastases at diagnosis (M+) were present
in 35% (35/100), localised disease (M0) with (LN+) and without (LN-) loco-regional
lymph node involvement in 65% (65/100). SMARCB1 germline mutations (GLM) were detected
in 21% (17/81 evaluable) of patients. The 5-year overall survival (OS) and event-free
survival (EFS) rates were 45.8 +/- 5.4% and 35.2 +/- 5.1%, respectively. On univariate
analyses, age at diagnosis (>= 12 months), M0-stage, absence of synchronous tumours,
absence of a GLM, gross total resection (GTR), radiotherapy and achieving a CR were
significantly associated with favourable outcomes. In an adjusted multivariate model
presence of a GLM, M+ and lack of a GTR were the strongest significant negative predictors
of outcome. Conclusions: We suggest to stratify patients with localised disease (M0),
GTR+ and without proof of a GLM (5-year OS 72.2 +/- 9.9%) as 'standard risk'. Patients
presenting with one of the features M+ and/or GTR - and/ or GLM+ belong to a high
risk group (5-year, OS 32.5 +/- 6.2%). These patients need novel therapeutic strategies
such as combinations of targeted agents with conventional chemotherapy or novel experimental
approaches ideally within international phase I/II trials. (C) 2020 Elsevier Ltd.
All rights reserved.
