Combination of disease burden before allogeneic transplantation and early post-transplant minimal residual disease predicts survival in patients with acute myeloid leukemia

The burden disease before allogeneic transplantation (HSCT) or the early post-transplant minimal residual disease (MRD) are both predictive parameters for relapse and post-HSCT survival in acute myeloid leukemia (AML). Nonetheless, the combination of both can provide more accurate information to identify high risk patients. To analyze the impact of pre-HSCT disease burden (MRD- vs. MRD + vs. active disease (AD), the early post-transplant MRD (posMRD + vs. posMRD-), and the combination of both pre- and post-HSCT disease status of the post-HSCT outcomes in AML patients. We retrospectively analyzed 173 patients with AML who underwent HSCT in a single institution, patients were classified according to pre-HSCT disease status, and post-HSCT MRD. MRD was measured by multiparameter flow cytometry using a cut-off of 0.1% for MRD+. The post-HSCT outcomes were analyzed based on the pre-transplant status, post-transplant status, and by combining both parameters. Patients with AD and MRD + before HSCT had worse 3y-event free (EFS) and overall survival (OS) than MRD- patients, due to a higher cumulative incidence of relapse (CIR). Also, patients with posMRD + had worse outcomes than posMRD- group. In the combined analysis, patient with MRD-/posMRD- had the best EFS and OS (3y-EFS 66.5%, 3y-OS 70.0%). Patients with MRD+/posMRD- have worse prognosis (3y-EFS 39.0%, 3y-OS 54.0%) and specially the group with AD/MRD- (3y-EFS 13.5%, 3y-OS 22.0%) and posMRD + regardless pre-HSCT disease status(3y-EFS 26.5%, 3y-OS 28.0%) had dismal OS and EFS. The combination of pre-HSCT disease burden and post-HSCT MRD measurements help us for identifying high-risk subgroups. Any level of pre-transplant disease (MRD+, and especially patients with active AD) is a risk factor, even when MRD- was achieved post-transplant. Patients with post-transplant MRD + also had an adverse prognosis. These should be target groups for implementing tailored pre- and post-transplant strategies to improve outcomes.