Chemotherapy or Allogeneic Stem Cell Transplantation as Salvage Therapy for Patients with Refractory Acute Myeloid Leukemia: A Multicenter Analysis

Introduction: The overall outcome of patients with refractory AML (rAML) remains poor. Though allogeneic hematopoietic stem cell transplantation (allo-HSCT) is considered as the only curative therapy, it is routinely recommended only for patients after remission with salvage chemotherapy.

Objective: In this study, we evaluated the impact of salvage chemotherapy or allo-HSCT on the overall outcome in rAML.

Methods: We collected the clinical data of 220 patients from 4 medical centers and performed retrospective analysis of prognosis factors, including salvage chemotherapy, intensity of chemotherapy, and allo-HSCT.

Results: A total of 29 patients received allo-HSCT directly without salvage chemotherapy, 26 patients achieved complete remission (CR) or complete remission with incomplete hematological recovery (CRi) after transplantation and 4-year leukemia-free survival (LFS) and overall survival (OS) were 45.0 ± 10.7 and 51.0 ± 10.6%, respectively. Another 191 patients received salvage chemotherapy and 81 (42.2%) achieved CR or CRi. Thirty-four patients among them underwent subsequent allo-HSCT with 4-year LFS and OS of 46.0 ± 8.8 and 46.2 ± 9.0%. The 4-year LFS and OS in 26 patients who failed to obtain CR or CRi but received allo-HSCT with active disease were 32.9 ± 10.0 and 36.9 ± 10.8%, respectively. For patients who received salvage chemotherapy but not allo-HSCT, few of them became long-term survivors. In multivariate analysis, salvage chemotherapy and the intensity of chemotherapy failed to have significant impact on both OS and LFS. Allo-HSCT was the only prognostic factor for improved OS and LFS in multivariate analysis.

Conclusions: These results indicate the benefit of allo-HSCT in patients with rAML and direct allo-HSCT without salvage chemotherapy could be treatment option.