Clinical Outcome of Autologous Hematopoietic Cell Transplantation in Adult Patients with Acute Myeloid Leukemia: Who May Benefit from Autologous Hematopoietic Cell Transplantation?

Abstract

The role of autologous hematopoietic cell transplantation (auto-HCT) for postremission therapy of acute myeloid leukemia is yet to be elucidated. We retrospectively analyzed 240 patients treated with auto-HCT in first remission. All patients were treated with standard induction chemotherapy, and CD34⁺ stem cells were collected at each cycle of consolidation. Stem cells were infused after total body irradiation (1200 cGy), cytarabine (9 g/m²), and melphalan (100 mg/m²). Estimated 5-year overall survival, disease-free survival (DFS), cumulative incidence of relapse (CIR), and nonrelapse mortality were 58.4%, 55.3%, 38.8%, and 5.9%, respectively. We identified that poor-risk karyotype showed very poor outcome after auto-HCT, and then analyzed 85 patients with good to intermediate-risk molecular cytogenetics with available molecular study results and markers for minimal residual disease (MRD) such as WT1 and core-binding factor (CBF) associated MRD (ie, AML1/ETO and CBFβ/MYH11). Our data identified that old age, pre-HCT markers for MRD, and high post-HCT WT1, high dose of CD34⁺ stem cell (≥4.5 × 10⁶/kg) infusion, and c-kit or FLT3-ITD mutations were associated with higher relapse rate and poor DFS. Using pre-HCT parameters, except for post-HCT WT1, multivariate analysis revealed that patients with young age (<40 years old), no adverse mutations, and limited dose of CD34⁺ stem cells might be good candidate for auto-HCT (3-year DFS and CIR were 83.4% and 16.6%, respectively). Young patients with good- to intermediate-risk molecular cytogenetics may benefit from auto-HCT if stem cell dose is limited.

Keywords: Acute myeloid leukemia; Autologous hematopoietic cell transplantation; Core-binding factor positive; FLT3 mutation; c-kit mutation.