Bone marrow transplantation in pediatric patients with therapy-related myelodysplasia and leukemia

Eleven children underwent BMT for therapy-related MDS or leukemia, four fro m HLA-identical siblings and seven from unrelated donors. Ten of the 11 wer e conditioned with busulfan and cyclophosphamide as the majority had receiv ed prior irradiation to the chest and/or abdomen. All patients engrafted. R egime-related toxicity was more common when compared to historical controls . Eight patients developed acute GVHD and four of eight who survived 100 da ys post transplant developed extensive chronic GVHD, Nonrelapse related mor tality occurred in three patients. Five patients developed recurrent malign ancy: one died from recurrence of osteosarcoma, three died of recurrent leu kemia or MDS and another developed two subsequent malignancies (duodenal ca rcinoma and anaplastic astrocytoma), Three survive disease-free at 14+, 22 and 43+ months for a 2 year actuarial cancer-free survival of 24% (95% con fidence interval = 5-53%), Although allogeneic BMT can be curative, regimen -related toxicity is frequent and recurrent malignancy remains the major ob stacle.