Bone marrow autotransplantation in acute myeloblastic leukemia in its first complete remission. The clinical results in 41 patients

BACKGROUND: A single-center experience using autologous bone marrow transplantation (ABMT) as postremission therapy for acute myeloid leukemia (AML) in first complete remission (CR1) in 41 patients is analyzed. PATIENTS AND METHODS: From July 1986 to March 1994, 41 patients with AML in CR1 underwent an ABMT. Source of hematopoietic stem cells was bone marrow in all cases. In eleven patients the marrow was purged with mafosfamide (ASTA-Z 7654). Median age was 31 years (17-59) and median time from CR to ABMT was 7 months (3-27). Busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) was employed as conditioning regimen in 36 patients. The rest 5 patients were prepared with cyclophosphamide (120 mg/kg) and fractioned total body irradiation (12 Gy). Eleven patients received G-CSF after AMBT because of an absolute neutrophil count lower than 0.5 x 10(9) on day +30. Survival analysis was performed according to the methods of Kaplan and Meier and comparison between groups used the log-rank test. RESULTS: With a median follow-up of 26 months (12-75) 21 patients remain alive in CR. Disease-free survival (DFS) at five years was 40% (95% CI: 25-55%). Transplant-related mortality, mainly for infection and hemorrhage, occurred in 6/41 patients (16%). Leukemia relapse was the main cause of treatment failure: 14/35 (40%). Probability of DFS and relapse was similar for those patients with purged ABMT on unpurged ABMT 45 +/- 23% vs 38 +/- 16% and 37 +/- 14% vs 54 +/- 22% respectively. A significantly longer engraftment time for neutrophils (> 0.5 x 10(9)) and platelets (> 20 x 10(9)) was observed in those patients who received a bone marrow treated with mafosfamide compared with the unpurged group (54 vs 29 days for neutrophils and 102 vs 58 for platelets respectively) (p < 0.05). CONCLUSIONS: ABMT is a feasible treatment for AML in CR1. Using bone marrow as hematopoietic stem cell support we observed that delayed engraftment was a common finding among AML patients, specially when the marrow was treatment with mafosfamide. Leukemia relapse remains as the main cause of treatment failure for ABMT.