Monitoring and Prevention of Relapse after Allogeneic Hematopoietic Cell Transplantation for Myeloid Malignancies

Acute myeloid leukemia and myelodysplastic syndromes are the most common indications for allogeneic hematopoietic cell transplantation. Although this treatment can be curative, even in advanced disease, treatment failure is commonly manifested by relapse of disease, for which treatment is successful in only a minority of patients. There is a necessity for new strategies for prevention of posttransplantation relapse through early disease detection and intervention in order to improve patient outcomes. Detection of minimal residual disease in posttransplantation surveillance is felt to be a necessary component of any strategy. In chronic myeloid leukemia, assessment of the BCR-ABL1 load by quantitative real-time PCR provides an optimal guideline for posttransplantation therapeutic decisions, but in patients with acute myeloid leukemia or myelodysplastic syndromes, the situation is more complex because of the genetic heterogeneity of these disorders. Past strategies for relapse prevention have focused on use of donor lymphocyte infusions with variable success. Peritransplantation and maintenance therapies (eg, azacitidine) are under current investigation. This review summarizes the current status of minimal residual disease monitoring and prevention strategies for both pediatric and adult patients with myeloid malignancies in the transplantation setting and discusses perspectives for further improvement.