In the early 1990s, apart from the European Neuroblastoma Study Group (ENSG) which involved six northern European countries, all countries in Europe organised their own clinical trials for neuroblastoma.

The numbers of patients in many of these trials were very small. It was appreciated that much faster progress in improving the treatment of neuroblastoma could be achieved with more countries working together in clinical trials. Therefore steps were started to bring many European countries together.

Daniel Beck, Bruno de Bernardi and Jean Michon proposed a pan European trial for localised neuroblastoma (Localised Neuroblastoma European Group – LNESG1). The principal objectives of this study were to confirm that surgery alone suffices in all stage 1 children and to assess whether the same is true for stage 2 with no amplification of MYCN. LNESG1 was successfully launched in 1995.

Jean Michon and Andy Pearson then worked on creating a pan European neuroblastoma clinical trial group for all stages of neuroblastoma. The International Society of Paediatric Oncology Europe Neuroblastoma Group (SIOPEN) was officially created at the Advances in Neuroblastoma Research Meeting in Bath, England in June 1998.

The first clinical trial of SIOPEN was Infant Neuroblastoma European Study (INES), which four trials and opened in 1999. The Study was led by Mary Gerrard, Bruno de Bernard, Jean Michon, Herve Rubie and Adela Canete and recruited patients from nine countries.

The SIOPEN High Risk Neuroblastoma Study (HR -NBL1) was opened in February 2002 with Ruth Ladenstein as the Principal Investigator recruiting patients from 12 countries. In parallel to HR-NBL 1 being designed, speciality committees, for example for biology and surgery, were created. Furthermore funding from the European Union was obtained allowing creation of SIOPEN R-Net.