IS5-5 - Immediate Allogeneic Hematopoietic Cell Transplantation (HCT) in Acute Myeloid Leukemia (AML) Arising from Myleodysplastic Syndrome (MDS)

Abstract

ABSTRACT Background In treating secondary AML arising from MDS, the complete remission (CR) rate after standard induction chemotherapy is low and relapse is common without allogeneic HCT. We therefore analyzed the benefit of immediate allogeneic HCT versus induction chemotherapy in AML arising from MDS. Methods Between 1991 and 2010, 95 patients were diagnosed with AML arising from MDS. After the diagnosis of AML, 10 patients received supportive care only. This retrospective study involved analysis of data from remaining 85 patients; 11 proceeded to immediate allogeneic HCT without induction chemotherapy (HCT group) and 74 were treated with induction chemotherapy (IC group). Results Patient characteristics at AML diagnosis were similar between the HCT and IC groups except total leukocyte counts, which were higher in the IC group than the HCT group (P = 0.009). Patients in the IC group were initially treated with induction chemotherapy consisted mostly of cytarabine plus daunorubicin or idarubicin, while those in the HCT group received allogeneic HCT from HLA matched sibling donors (n = 7) or unrelated volunteers (n = 4). CR was achieved in thirty-one patients (41.9%) in the IC group and 9 (81.8%) in the HCT group (P = 0.013). Of 74 patients in IC group, 28 underwent allogeneic HCT in the first CR (n = 13), primary refractory disease (n = 10), or the first or second relapse (n = 5). The median overall survival (OS) and event-free survival (EFS) were 8.3 and 6.4 months, respectively. Relapse probability at 5 years was 49.2%. The HCT group showed a significantly longer EFS than the IC group (median 29.2 versus 5.2 months, P = 0.042). OS of the HCT group was higher than that of the IC group, but the difference was not statistically significant (median 34.6 versus 7.6 months, P = 0.149). Relapse probability was not significantly different between the two groups (P = 0.278). After adjustment for other variables, the HCT group showed significantly better outcomes than did the IC group in terms of CR rate (HR, 11.195; 95% CI, 1.940–64.619; P = 0.007) and EFS (HR, 0.384; 95% CI, 0.163–0.905; P = 0.029). Conclusions Immediate allogeneic HCT is a viable option in AML arising from MDS if an appropriate donor is available.