Detection of minimal residual disease in acute myelogenous leukemia.

Techniques to assay minimal residual disease are available for most patients with acute lymphoblastic leukemia, non-Hodgkin's lymphoma, breast cancer, Ewing's sarcoma, and others. Today, a few such tests exist for acute myelogenous leukemia (AML). This review evaluates the tests available for assessing minimal residual disease in AML: morphology, growth in vitro, cytogenetics, magnetic resonance imaging, polymerase chain reaction (PCR)-based assays for translocation products, and multiparameter flow cytometry. Of these, multiparameter flow cytometry appears most promising. Studies using multiparameter flow cytometry to identify leukemic cells by aberrant antigen expression have reported a high positive predictive value with regard to the incidence of relapse. In addition, the test is specific, rapid, inexpensive, and applicable to a sufficiently broad group of patients, allowing its use outside of the research laboratory setting. Judicious use of some of the available assays singly or in combination should identify patients harboring residual leukemic cells.