OBJECTIVES:
* Examine the impact of the use of killer cell immunoglobulin-like receptor (KIR)-mismatched umbilical cord blood as a source of hematopoietic stem cells, after busulfan, melphalan, and anti-thymocyte globulin in pediatric patients with relapsed or refractory solid tumors.
* Determine the toxicity of this regimen, in terms of incidence of grade 3-4 acute graft-versus-host disease, donor/host chimerism, and cellular immunity against tumor cell lines, in these patients.
OUTLINE:
* Transplantation: Patients receive busulfan orally or IV every 6 hours on days -8 to -5, anti-thymocyte globulin IV over 6 hours on days -4 to -1, and melphalan IV over 15-20 minutes on days -4 to -2. Patients undergo allogeneic umbilical cord blood stem cell infusion on day 0. Patients receive sargramostim (GM-CSF) subcutaneously beginning on day 7 and continuing until blood counts recover.
* Graft-vs-host disease prophylaxis: Patients receive cyclosporine IV over 1 hour or orally twice daily on days -1 to 180 and methylprednisolone IV or orally once or twice daily on days 5 - 49.
Blood samples are collected periodically for immunophenotyping and flow cytometric analysis (including interferon gamma and other TH1 and TH2 cytokines).
After completion of study treatment, patients are followed periodically.
PROJECTED ACCRUAL: A total of 20 patients will be accrued for this study.
