Allogeneic hematopoietic cell transplantation in patients with acute myeloid leukemia that is not in remission

The most significant prognostic factor in allogeneic hematopoietic cell transplantation (HCT) for acute myeloid leukemia (AML) is the remission status at HCT. Although HCT is recommended to be performed after complete remission, there are cases in which HCT is performed in non-remission status. Although the outcomes of HCT for non-remission AML have been very poor, the subjects in these studies had heterogeneous backgrounds in terms of relapsed, refractory, and untreated AML. In this review article, non-remission AML is classified into the following two categories: refractory/relapsed AML and untreated AML. Recent advances in HCT for non-remission AML, such as prognostic factors and pre and postHCT interventions, have been summarized. In the preHCT setting, preHCT tumor burden was confirmed to be the primary prognostic factor. Preconditioning intervention that successfully eliminated blasts in the peripheral blood was associated with better outcomes after HCT. PostHCT maintenance therapy may be one of the treatment options after HCT. Even in untreated AML, lower tumor burden at HCT was associated with superior outcomes after HCT. With the primary significance of tumor control before and after HCT, it is crucial to establish a comprehensive strategy for HCT in the non-remission stage, including preHCT and postHCT interventions.