Busulfan and Cyclophosphamide for Hemopoietic Stem Cell Transplantation from Related and Unrelated Donors in Patients with Myelodysplastic Syndrome

The myelodysplastic syndromes (MDS) are clonal hemopoietic disorders, characterized by ineffective hemopoiesis resulting in single or multilineage peripheral blood cytopenias, dysplastic morphology in single or multiple lineages, and, in many patients, clonal cytogenetic abnormalities. Hematopoietic stem cell transplantation is currently the only therapeutic modality that is potentially curative. A total of 17 patients (aged 16–40 years; median, 26 years) with MDS were treated with busulfan (BU 3.2 mg/kg/d, −7 d `−4 d,) plus cyclophosphamide (CY, 60 mg/kg, −3 d `−2 d)and hemopoietic stem cell (HSC) transplantation from related (n =5) or unrelated donors (n =12). At the time of transplantation, 13 patients had less than 5% myeloblasts in the marrow, and 4 patients had more advanced disease. Mycophenolate mofetil combined with cyclosporin A and methotrexate was used for prevention of acute graft-versus-host disease after transplantation. Lipo prostaglandin E1 was used in prophylactic regimen for hepatic venoocclusive disease. All but 2 evaluable patients had engraftment. Neutrophil count began to be higher than 0.5×10⁹/L on 15 days after BMT. Platelet count began to be higher than 20×10⁹/L on 18 days after BMT. The Kaplan-Meier estimates of 3-year relapse-free survival (RFS) were 57%, and only one patient relapsed after six months of transplantation. Non relapse mortality (NRM) at 100 days was 12%. Thus, a targeted BUCY regimen provided effective transplant conditioning for patients with MDS receiving transplants from HLA identical siblings or alternative donors.