Donor Peripheral Stem Cell Transplant in Treating Patients With Advanced Hematologic Cancer or Other Disorders

OBJECTIVES: Primary * To evaluate hematopoietic recovery, using neutrophil and platelet engraftment as the primary criterion, in patients with advanced hematologic malignancies or other disorders undergoing allogeneic peripheral blood stem cell (PBSC) transplantation from matched unrelated donors. * To evaluate the incidence of acute and chronic graft-versus-host-disease (GVHD) in patients undergoing allogeneic PBSC transplantation from matched unrelated donors. Secondary * To evaluate the impact of HLA class I and class II allele-matching on the incidence of GVHD and on the survival outcome of these patients. * To evaluate overall survival, disease-free survival, and relapse in these patients. OUTLINE: Patients are stratified according to type of conditioning regimen (myeloablative vs reduced-intensity myeloablative). Patients are assigned to a conditioning regimen according to diagnosis, age, disease status, prior radiotherapy, and prior autologous stem cell transplantation. * Conditioning regimen: * Regimen I: Patients undergo total body irradiation (TBI) on days -7 to -4 and receive cyclophosphamide IV on days -3 and -2. Alternatively, patients may receive cyclophosphamide on days -7 and -6 and undergo TBI on days -4 to -1. * Regimen II: Patients receive busulfan IV over 2 hours once on day -8 and then every 6 hours on days -7 to -4. Patients also receive cyclophosphamide IV on days -3 and -2. * Regimen III: Patients undergo TBI on days -7 to -4 and receive etoposide IV on day -3. * Regimen IV: Patients receive fludarabine phosphate IV over 30 minutes on days -7 to -3 and melphalan IV on day -2. * Regimen V: Patients receive fludarabine phosphate IV over 30 minutes on days -4 to -2 and undergo TBI on day 0. * Regimen VI: Patients receive busulfan IV over 3 hours and fludarabine phosphate IV over 30 minutes on days -5 to -2. * Allogeneic peripheral blood stem cell (PBSC) transplantation: All patients undergo allogeneic PBSC transplantation on day 0. * Graft-versus-host disease (GVHD) prophylaxis: Patients receive one of the following GVHD prophylaxis regimens: * Regimen A: Patients receive tacrolimus IV or orally on days -1 to 180 and methotrexate IV on days 1, 3, 6, and 11. * Regimen B: Patients receive cyclosporine IV or orally twice daily on days -1 to 180, mycophenolate mofetil IV over 2 hours or orally twice daily on days 0-27, and methotrexate IV on days 1, 3, and 6. * Regimen C: Patients receive tacrolimus IV continuously or orally, and oral sirolimus beginning on day -3. Patients also receive methotrexate IV on days 1, 3, and 6. After completion of study therapy, patients are followed periodically.