Autologous bone marrow transplantation in paediatric solid tumours

Massive therapy with ABMT is now an established treatment modality in paediatric oncology. The technical aspects and most treatment-related complications have been clarified and many phase II studies have shown encouraging results. In advanced neuroblastoma the poor outlook with conventional chemotherapy has stimulated extensive investigation of forms of massive therapy. Current results from several centres indicate that although the median survival is increased, long-term survival in an unselected group of stage IV patients is unlikely to exceed 30% with current regimens. In the future, management of this disease may involve the use of more intensive induction regimens to improve the quality of remission at the time of ABMT, which remains the single most important prognostic factor. Improved purging procedures involve the possible use of double massive therapy regimens and a combination of immunological and chemical treatments. In other paediatric tumours, the relative rarity and limited indications for ABMT make the evaluation of its role more difficult. Preliminary results in advanced rhabdomyosarcoma and Ewing's sarcoma are none the less encouraging and justify further investigation. The value of purging procedures remains controversial and their assessment has been hampered by the lack of sensitive clonogenic assays to detect residual tumour cells. However, neuroblastoma has provided a useful model for the investigation of physical, immunological and chemical procedures. Massive therapy is expensive, time consuming, and carries a high cost in patient morbidity and stress to the families involved. As with any new treatment, it must be adequately assessed in phase III, randomized studies. The ENSG and SIOP trials are a beginning and the future of massive therapy in the paediatric patient will, we hope, be based on a rigorous and scientific comparison with other treatment modalities.