Post-remission therapy in acute myeloid leukemia: what should I do now?

T oday, we are unable to select an indisputable winner as the single best post-remission therapy for an individual patient with acute myeloid leukemia (AML) who achieves first remission (CR1) after induction chemotherapy. Choices for subsequent treatment are made based on the probability of future relapse: low risk patients traditionally receive only cyto-toxic chemotherapy; conversely, high risk patients undergo allogeneic transplantation in CR1, if possible. However, many low risk patients still eventually die of disease relapse, and some high risk patients have durable remissions without receiving a transplant. Based on available risk stratification tools such as clinical status, cytogenetics, and molecular markers of disease as well as considering practical matters including an available source of allogeneic stem cells, current recommendations for post-remission therapy depend on whether the relapse risk is high enough to merit the potential toxicities of allogeneic transplantation, or sufficiently low to forgot the procedure. Fortunately, advances in risk stratification and improved understanding of the molecular basis of AML are together steadily improving our ability to select the optimal post-remission therapy for each patient. In this issue of the journal, two articles describe challenges in the selection of the best post-remission therapy for patients with AML. Messerer et al. highlight problems of decreased quality of life faced by AML survivors who received allogeneic transplantation in CR1, compared to survivors who received other post-remission treatments. 1 Foulliard et al. remind us of the complexities involved in donor selection and timing of allogeneic transplantation in their retrospective study of syngeneic transplantation in acute leukemia. 2 This review summarizes current evidence guiding the selection of post-remission therapy for AML in CR1. How do we assess risk? Clinical factors, cytogenetics, and molecular techniques Clinical factors including performance status, age, presenting white blood cell count, presence of an antecedent hematologic disorder, and response to the first cycle of induction chemotherapy remain critically important in assessment of risk and the appropriate selection of post-remission therapy. Beyond medical assessment of eligibility for various modalities of therapy, cytogenetics performed from bone marrow collected at the time of diagnosis are currently the most important prognostic factor in predicting outcome of AML in CR1. Though differences in the classification of karyotypes exist between various cooperative groups, AML patients are generally classified into good, intermediate, or poor risk groups based on cytogenetics. At least in younger AML patients (age < 55-60 years), cytogenetics are a powerful tool, with 5-year …