Staging childhood cancers in Europe: Application of the Toronto stage principles for neuroblastoma and Wilms tumour. The JARC pilot study.

Background The 'Toronto consensus principles and guidelines' (TG) provided paediatric-specific staging system affordable by population-based cancer registries (CRs). Within the European Rare Cancers Joint Action, a pilot study of the application of TG for childhood cancer (CC) was conducted to test the ability of CRs to reconstruct stage, describe stage across countries and assess survival by stage. Procedure Twenty-five CRs representing 15 countries contributed data on a representative sample of patients with neuroblastoma (NB) and Wilms tumour (WT) Results Stage was reconstructed for 95% of cases. Around half of the children had localised or locoregional disease at diagnosis. The proportion of metastatic cases was 38% for NB and 13% for WT. Three-year survival was >90% for locoregional cases both of NB and WT, 58% for NB M-stage and 77% for WT stage-IV. Older age was associated with more advanced stage. Conclusions European CRs were able to reconstruct stage according to the TG. Stage should be included in the routine collection of variables. Stage information had clear prognostic value and should be used to investigate survival variations between countries or over time.