Minimal Residual Disease in AML: Why Has It Lagged Behind Pediatric ALL?

Although the concept of minimal residual disease (MRD) as an indicator for the quality of treatment response is the same in acute myeloid leukemia (AML) and acute lymphoid leukemia (ALL), the practice of measuring MRD levels for monitoring response and guiding therapy after induction has been implemented much more rapidly in ALL, particularly pediatric ALL, than in AML. In this perspective we examine the facts and discuss why ALL appears to be more amenable to MRD-shaped risk allocation and a revised definition of complete remission.