High-dose busulfan and cyclophosphamide with autologous bone marrow transplantation support in advanced malignancies in children: a phase II study.

Twenty children with advanced, nonleukemic malignancies entered a phase II study of high-dose busulfan-cyclophosphamide followed by bone marrow transplantation (BMT). All had disease refractory to conventional and/or high-dose chemotherapy (HDC). There were ten neuroblastoma patients, six non-Hodgkin's lymphoma, three Ewing's sarcoma, and one rhabdomyosarcoma. Eight had primarily resistant disease, ten were in second progressive relapse, and two in third progressive relapse. One patient was not evaluable for response. Among the 19 evaluable patients the responses observed were complete response (CR), seven; partial response (PR), three; objective effect, five; and failure, four. However, survival was poor: 15 patients died, two are alive with disease, and three are alive with no evidence of disease (NED) at 8+, 11+, 14+ months post-BMT. Toxicity was high but considered as acceptable, taking into account the terminal state of these patients. Seven treatment-related deaths were observed. This combination therapy proved to be highly effective, with a response rate of 50%, and its value for eradication of residual disease in less advanced patients should be investigated.