Clinical and prognostic characterization of myelodysplastic syndromes

The myelodysplastic syndromes (MDS) provide a clinical model for evaluating the evolution of a relatively indolent malignancy into one which is frankly aggressive. The morbidity and mortality in this myeloid clonal hemopathy relate to either marrow dysfunction associated with ineffective hematopoiesis and its peripheral blood cytopenias or to disease evolution into a variant of acute myeloid leukemia (AML-MDS). MDS may arise de novo or is therapy-related (secondary, t-MDS) following treatment with chemotherapy or chemoradiotherapy for other illnesses. The disease is generally relatively indolent, with a rate of progression related to a number of defined clinical features.1