ABSTRACT
The myelodysplastic syndromes (MDS) are a heterogeneous group of disorders with a variable prognosis. Refractory anemia (RA) and RA with ringed sideroblasts (RARS) are characterized by a low risk of transformation to acute myeloid leukemia (AML) and a median survival usually in excess of 30 months (1). In contrast, the median survival of patients with refractory anemia with excess blasts (RAEB) or RAEB in transformation (RAEB-t) is less than 12 months (2,3). The prognosis for patients with therapy-related MDS, or secondary acute myeloblastic leukemia (secondary leukemia), is also poor, with median survivals of less than 12 months (3,4). In addition to the MDS subtype, the patient’s karyotype is a valuable prognosticator of survival (5,6); see Chapter 5 for a detailed discussion.
