Purpose: This study compares outcomes of autologous bone marrow transplantation (ABMT) in patients with acute myeloid leukemia (AML) in untreated first relapse (REL1) or in second complete remission (REM2).
Patients and methods: Forty-seven patients with AML in REL1 (n = 21) or in REM2 (n = 26) were treated with busulfan (BU) and cyclophosphamide (CY) with or without total-body irradiation (TBI) followed by ABMT. All REL1 patients and four REM2 patients had marrow stored during first remission (REM1). Twenty-seven had marrow stored with and 20 without treatment in vitro with 4-hydroperoxycyclophosphamide (4-HC). Eighteen patients received BU and CY and 29 received BU, CY, and TBI. REL1 patients relapsed within a median of 9 months (range, 2 to 26) after marrow harvest and were transplanted a median of 30 days (range, 9 to 87) from detection of relapse.
Results: With a median follow-up of 2.1 years (range, 0.4 to 5.3), 19 patients survive in remission (10 of 21 in REL1; nine of 26 in REM2). The actuarial probabilities of relapse-free survival at 2 years for patients transplanted in REL1 and REM2 were 45% +/- 22% and 32% +/- 18%, respectively (P = .33). The corresponding probabilities of relapse were 30% +/- 26% and 44% +/- 23%, respectively (P = .45). No conclusions could be drawn about the benefits of adding TBI to BU plus CY. There were no significant differences in neutrophil or platelet recovery or in posttransplant probabilities of relapse and nonrelapse mortality between patients who received marrow treated or not treated with 4-HC.
Conclusion: These results suggest that ABMT may produce long-term leukemia-free survival in approximately one third of patients with AML in REL1 or in REM2. There is no apparent clinical advantage in attempting to obtain second remissions in relapsed patients before ABMT if marrow has been cryopreserved during REM1. Although a strategy of transplantation in REL1 has advantages for the patient, such an approach involves the storage of marrow, which may not be used, and is impractical without the coordinated support of the treating physician, the patient, and the marrow transplant center.