MRD in AML: it is time to change the definition of remission.

ABSTRACT

The possibility of defining residual disease far below the morphological level of 5% blast cells is changing the landscape of risk classification in acute myeloid leukemia (AML). The so-called minimal residual disease (MRD) approach at this time can establish the presence of leukemia cells down to levels of 11000-110(6) white blood cells, compared to 120 for morphology. Availability of the newer and more sensitive technology to quantify the level of leukemic burden raises the issue of whether MRD should emerge as a new definition of complete response. This paper explores some of the issues surrounding such a change in definition.