High-dose chemotherapy followed by peripheral blood stem cell rescue for metastatic rhabdomyosarcoma: The experience at Chicago Children's Memorial Hospital

Background. Because outcome for metastatic rhabdomyosarcoma remains poor wi th standard therapy, and because some patients with extensive unresectable metastatic rhabdomyosarcoma are unable to tolerate standard therapy with th e associated large radiation fields, peripheral blood stem cell rescue (PBS CR) following high-dose chemotherapy was offered as consolidative therapy f or patients with Stage 4/Group IV rhabdomyosarcoma. Patients and Methods. E ight patients with Stage 4/Group IV rhabdomyosarcoma were diagnosed from Ma y, 1992, through November, 1994. Consolidative PBSCR following thiotepa 300 mg/M-2 on days -7, -6, and -5; cyclophosphamide 1,500 mg/M-2 on days -5, - 4, -3, and -2; and carboplatin 600 mg/M-2 on days -3 and -2 was offered to those patients who achieved a complete remission with multimodality therapy . Patients with extensive metastatic disease who did not receive full doses of radiation to all sites of disease remained eligible for high-dose chemo therapy and PBSCR. Results. Five of eight patients achieved a complete resp onse. Four patients underwent PBSCR. One of the four patients is alive with out evidence of disease 53 months post-PBSCR. All other patients died of pr ogressive disease. Conclusions. These results, along with the existing lite rature, show no advantage of high-dose chemotherapy followed by PBSCR as co nsolidative therapy for patients with Stage 4/Group IV rhabdomyosarcoma ove r standard dose chemotherapy, radiation, and surgery. For patients with ext ensive, unresectable disease at diagnosis who cannot receive radiation to a ll areas of disease based on concerns of marrow reserve, high-dose chemothe rapy followed by PBSCR does not appear to provide adequate local control an d cannot be offered as curative therapy. Med. Pediatr. Oncol. 32:88-92, 199 9. (C) 1999 Wiley-Liss, Inc.