Prognostic and therapeutic implications of early treatment response assessment in acute myeloid leukemia

Early assessment of disease response to induction chemotherapy is important in acute myeloid leukemia (AML) in order to plan future therapy and identify chemorefractory disease. Such assessment is customarily performed by examining the bone marrow at around day 14 after initiation of chemotherapy. However, criteria for assessment of residual leukemia in day 14 bone marrow specimens as well as the significance of partial response on long term outcomes remain unclear. Clinical practices vary regarding the therapeutic intervention for residual disease and include readministration of the original induction therapy or use of a different reinduction regimen. In this article, we critically examine the prognostic significance of residual disease detected on interim bone marrow examination as well as data on reinduction therapy with the original induction regimen versus an alternate regimen. We emphasize the need for standardizing reporting of interim bone marrow assessment as well as evaluating new technologies and biomarkers for early assessment of disease response and chemosensitivity in AML.