Purpose: In an effort to evaluate the usefulness of bone marrow transplantation, the Childrens Cancer Group (CCG) initiated a multiinstitutional study comparing bone marrow transplantation versus chemotherapy after successful induction of remission for previously untreated children and young adults with acute myeloid leukemia.
Patients and methods: From 1979 to 1983, 508 patients were entered onto this study and 490 were treated. After induction, patients with an HLA mixed leukocyte culture (MLC)-compatible sibling underwent bone marrow transplantation. Patients not eligible for bone marrow transplantation were eligible for randomization to two chemotherapy maintenance regimens. All patients undergoing bone marrow transplantation were conditioned with cyclophosphamide and total-body irradiation (TBI). Methotrexate was used to prevent or modify graft-versus-host disease (GVHD).
Results: Three hundred eighty-one patients achieved bone marrow remission (78%). Eighty-nine patients had an HLA/MLC-compatible sibling donor and were eligible for bone marrow transplantation, and 252 had no match. Comparison of survival estimates for patients eligible for transplantation versus not eligible at 3 years (52% v 41%), 5 years (50% v 36%), and 8 years (47% v 34%) showed a significant difference in favor of bone marrow transplantation (P < .05). Disease-free survival (DFS) demonstrated similar results. Application of a cure model to the results showed a better outcome for those eligible for transplantation (P = .04). Patients randomized between the two chemotherapy regimens did not show any significant difference between those treated with a continuous maintenance versus a cyclic regimen (P = .16).
Conclusion: Children and young adults who successfully achieved a remission with multiple-agent chemotherapy who had an HLA/MLC-compatible donor and were thus eligible for an allogeneic bone marrow transplant had better survival than those not eligible for transplantation.