Myelodysplasia: new approaches.

The myelodysplastic syndromes (MDS) are a group of clonal hematopoietic disorders characterized by bone marrow failure and a risk of progression to acute myelogenous leukemia (AML). A precise diagnosis is critical, because there is overlap between the clinical and laboratory findings of MDS and other malignant and nonmalignant hematologic disorders. Several prognostic scoring systems (IPSS, WPSS, LR-PSS, and IPSS-R) assess a patient's risk of progression to AML and overall survival. Many patients are elderly, so age and comorbidities are an important consideration. Patients with lower-risk disease are treated with growth factors (erythropoietin stimulating agents and/or G-CSF) and immunomodulatory agents (antithymocyte globulin and/or lenalidomide). Patients with higher-risk disease have a higher risk of progression to AML and are treated with hypomethylating agents (azacitidine or decitabine) and allogeneic stem cell transplantation if appropriate. Recent laboratory studies have increased our understanding of the pathophysiology of this disease. Mutations in genes effecting ribosomes, splicing of RNA and epigenetics have been discovered. It is likely that these breakthroughs will lead to newer classes of targeted therapies against this disease.