Prognosis in Acute Myeloid Leukemia: Cytogenetics and Beyond

This chapter discusses the laboratory work-up for acute myeloid leukemia (AML). Conventional chromosome analysis is a critical part of this work-up. Karyotyping is the only clinically available test to detect both balanced and unbalanced rearrangements at any chromosomal location, and it is irreplaceable at diagnosis. The karyotype of the leukemic cells is the strongest predictor of response to induction therapy and for survival in AML, and recently, the characterization of a number of molecular markers has allowed further refinement of risk stratification in AML. Fluorescent in situ hybridization (FISH) is a highly sensitive, targeted test for known chromosome rearrangements, but it does not provide the genome-wide screen obtainable by classical cytogenetics. Also, FISH testing will occasionally give false-negative results in cases of atypical chromosomal rearrangements. No single genetic testing procedure fulfills all the needs of clinical care for patients with AML; however, next-generation sequencing has the capacity to assess several abnormalities simultaneously, and its costs are rapidly decreasing. It is important to use a combination of testing methods that are best suited for each clinical situation.