Busulfan/cyclophosphamide plus bone marrow transplantation is not sufficient to eradicate the malignant clone in juvenile chronic myelogenous leukemia.

Bone marrow transplantation plays an essential role in the successful treatment of both juvenile and adult chronic myelogenous leukemia. Recently, it has been reported that conditioning with high doses of busulfan can successfully replace total body irradiation (TBI), in patients with acute myelogenous leukemia as well as adult chronic myelogenous leukemia. We report here the case of a 29-month-old boy with juvenile chronic myelogenous leukemia (JCML) transplanted with HLA-identical bone marrow after conditioning with busulfan, etoposide and cyclophosphamide. Successful engraftment was followed by early relapse on day 67. A second HLA-identical transplant was performed following myeloablative treatment with TBI. Engraftment was once again successful and the patient remains free of disease more than 24 months after transplantation. We conclude that busulfan is insufficient in eradicating JCML and that TBI is required prior to transplantation.