High-dose therapy with stem cell rescue for pediatric solid tumors: rationale and results.

Metastatic and recurrent pediatric solid tumors usually respond to chemotherapy but are likely to recur. Because of steep dose-response relationships, HDT requiring hematopoietic rescue may improve outcome. This strategy has recently been shown to be effective for metastatic neuroblastoma. Metastatic Ewing's sarcoma appears to be a closely analogous situation, and promising phase II studies suggest that a definitive trial of efficacy would be appropriate. Phase I or II trials remain appropriate and are needed to define further the efficacy of HDT for most other poor prognosis pediatric solid tumors.