New strategies for the application of high-dose chemotherapy with haematopoietic support in paediatric solid tumours

Because paediatric solid tumours are usually highly chemosensitive, conventional-dose adjuvant chemotherapy has improved survival rates for the majority of paediatric patients. However, high-dose regimens are being explored for the treatment of tumours not curable by, or resistant to, conventional treatment. The use of high-dose melphalan and the BACT regime have produced encouraging results in neuroblastoma and Ewing's sarcoma, and non-Hodgkin's lymphoma respectively. Haematopoietic growth factors have also emerged as useful adjuncts both to conventional therapy and in megatherapy with bone marrow transplantation (BMT). Thus, granulocyte colony-stimulating factor (G-CSF) (filgrastim) given to children with disseminated neuroblastoma receiving intensive chemotherapy significantly reduced the duration of febrile neutropenia and led to significantly fewer cycles of chemotherapy requiring antibiotic support. Studies are currently underway to compare the use of autologous BMT with that of peripheral blood progenitor cell (PBPC) rescue in children with solid tumours receiving high-dose chemotherapy. The studies will explore the reduction in thrombocytopenia achievable with PBPC and also the effect of filgrastim on the duration of neutropenia and fever. It seems that haematopoietic growth factors have an important supportive role to play in the treatment of paediatric solid tumours.