Efficacy and Feasibility of Allogeneic Hematopoietic Stem-Cell Transplantation in the Treatment of Refractory Acute Myeloid Leukemia

Background: Refractory acute myeloid leukemia (AML) includes AML includes failure of disease to respond to standard induction chemotherapy, relapse within 6 months after first CR, and 2 or more relapses. The outcome of these patients is usually very poor; only a small proportion can be rescued by allogenic hematopoietic stem-cell transplantation (allo-HSCT). The aim of this study was to evaluate the efficacy and feasibility of allo-HSCT in patients with refractory AML. Patients and Methods: We retrospectively analyzed the clinical outcome of 91 patients who were diagnosed with treatment-refractory AML at Hacettepe University Hospital between January 2002 and June 2018. Patients' disease status included refractory AML, defined as failure to respond to standard induction chemotherapy and relapse within 6 months after first complete remission. Results: The median follow-up was 12 months (range, 0.5-184 months) for the entire group. Kaplan-Meier estimates of the 3-year overall survival for patients who underwent allo-HSCT and patients who received only salvage chemotherapy were 67% and 12%, respectively. Additionally, the Kaplan-Meier estimates of 5-year overall survival for patients who underwent allo-HSCT and patients who received only salvage chemotherapy were 44% and 4%, respectively (P < .001). Complete remission was obtained in 25 patients (83.3%) who underwent allo-HSCT; however, the disease of only 3 patients (3.8%) exhibited complete response after salvage chemotherapy. Conclusion: Allo-HSCT is still the best-known treatment option with curative potential in patients with treatment-refractory AML. Therefore, all efforts should be made in an attempt to find a suitable matched donor in order to perform allo-HSCT. The group of patients with refractory acute myeloid leukemia includes those patients who fail standard induction chemotherapy, who relapse within 6 months after first complete remission, and who have relapsed twice or more. The outcome of these patients is usually very poor, with only a small proportion who can be rescued by allogenic hematopoietic stem cell transplantation. The aim of this study is to evaluate the efficacy and feasibility of allogenic hematopoietic stem cell transplantation in patients with refractory acute myeloid leukemia.