Outcome of allogeneic stem cell transplantation with a conditioning regimen of busulfan, cyclophosphamide and low-dose etoposide for children with myelodysplastic syndrome.

Background And Objectives: Allogeneic stem cell transplantation (SCT) offers the best chance of cure and long-term survival for children with myelodysplastic syndromes (MDS).

Design And Setting: Retrospective analysis of pediatric patients with primary MDS treated with allogeneic SCT at a single institution treated between January 1993 and December 2008.

Patients And Methods: Of 16 consecutive children who received allogeneic SCT for treatment of MDS in our center, 14 patients met the criteria of MDS according WHO I and II criteria. The median age was 4.8 years (range, 1-14 years) and 64% were male. The median time from diagnosis to transplant was 6 months. MDS stage was refractory cytopenia (RC) in 9, refractory anemia with excess blasts (RAEB) in 5. Monosomy 7 was present in 35% of the patients. The majority of patients (11/14) were conditioned with a busulfan-based myeloablative (MA) regimen with addition of low-dose of etoposide (30 mg/kg). All but one received a bone marrow graft.

Results: Nine patients achieved complete remission (CR), and seven remain alive. At a median follow-up of 3 years (range, 2-14 years) the OS and EFS was 57% (95%CI, 0.28-0.78). Cumulative EFS at 10 years was 43% (95% CI, 0.14-0.70). Relapse-related mortality was 21.4%; nonrelapse mortality (NRM) was 28.57%. All the survivors had etoposide in their conditioning regimen. Patients younger than 10 years had better survival (P=.001).

Conclusion: Children with MDS achieve encouraging OS and EFS following allogeneic SCT. A busulfan-based regimen with a lower dose of etoposide is an effective and less toxic regimen. The outcomes are best in younger patients.