Unrelated Donor Bone Marrow Transplantation for Children With Acute Myeloid Leukemia Beyond First Remission or Refractory to Chemotherapy

Abstract

Purpose: Identify prognostic factors that influence outcome after unrelated donor bone marrow transplantation in children with acute myeloid leukemia (AML). Patients and Methods: Included are 268 patients (age ≤ 18 years) with AML in second complete remission (n = 142), relapse (n = 90), or primary induction failure (n = 36) at transplantation. All patients received bone marrow grafts from an unrelated donor and a myeloablative conditioning regimen. Cox regression models were constructed to identify risk factors that influence outcome after transplantation. Results: In this analysis, the only risk factor that predicted leukemia recurrence and overall and leukemia-free survival was disease status at transplantation. The 5-year probabilities of leukemia-free survival were 45%, 20%, and 12% for patients who underwent transplantation at second complete remission, relapse, and primary induction failure, respectively. As expected, risk of acute but not chronic graft-versus-host disease (GVHD) was lower with T-cell–depleted bone marrow grafts; T-cell–depleted grafts were not associated with higher risks of leukemia recurrence. We observed similar risks of leukemia relapse in patients with and without acute and chronic GVHD. Conclusion: Children who underwent transplantation in remission had a superior outcome compared with children who underwent transplantation during relapse or persistent disease. Nevertheless, 20% of children who underwent transplantation in relapse are long-term survivors, suggesting that unrelated donor bone marrow transplantation is an effective therapy in a significant proportion of children with recurrent or primary refractory AML.