The term myelodysplastic syndrome (MDS) refers to a very heterogeneous group of myeloid disorders. In a majority of patients, MDS results from defects in a primitive hematopoietic stem cell compartment.
Individuals with evidence of clonal hematopoiesis are at increased risk of developing MDS.
Prognosis is calculated using a number of variables, including degree of cytopenia, percentage of blasts, cytogenetic alterations, and more recently genomic annotation.
Using either the International Prognostic Scoring System or the Revised International Prognostic Scoring System, patients are divided into those with lower and higher risk disease.
For patients with lower-risk disease, treatment approaches include growth factors, iron chelation, luspatercept, lenalidomide (for del5q- MDS), hypomethylating agents (HMAs; azacitidine or decitabine) or antithymocyte globulin–-based therapy (for patients with hypoplastic MDS). Allogeneic stem cell transplantation (allo-SCT) is reserved for younger patients with poor risk features.
For patients with higher risk disease, the main treatment options include the HMAs and less frequently acute myeloid leukemia–like therapy. Allo-SCT should be considered in candidate patients early in the course of the disease in responding patients. Clinical trials should be considered for a majority of patients with MDS.
Myelodysplastic syndromes (MDSs) refer to a group of hematopoietic disorders characterized by ineffective hematopoiesis and increased risk of transformation to acute myeloid leukemia (AML). The median age of patients with MDS is 70 to 75 years. It is likely that environmental factors play an important role in the pathogenesis of this disease. MDSs are classified according to the World Health Organization (WHO) criteria, and a number of prognostic scores can be used to calculate survival and risk of transformation. Cytogenetic, genomic, and epigenetic alterations are common in MDS and help in the prediction of prognosis and potentially in the selection of therapy. Over the past decade, we have witnessed significant improvements in supportive care and therapeutic modalities for patients with MDS. These include growth factors, luspatercept, immune modulatory agents (lenalidomide), and hypomethylating agents (HMAs; 5-azacitidine and decitabine), with new oral formulations. We also better understand patient subgroups, such as those with hypomethylating failure disease. In this chapter, we summarize our knowledge of MDS and the treatment approach we use at MD Anderson Cancer Center (MDACC).
THE MD ANDERSON APPROACH TO PATIENTS WITH MYELODYSPLASTIC SYNDROMES
Approximately 350 to 400 patients are referred to MDACC annually with a diagnosis of MDS, and nearly 20% of these patients receive a different diagnosis. In most instances, the final diagnosis is AML or a form of higher risk MDS. Other benign and malignant conditions are also diagnosed. In a study of 915 patients referred to MDACC between 2005 and 2009,12% of patients were reclassified after evaluation at MDACC using very strict criteria.1 This justifies our practice to repeat a confirmatory bone marrow aspiration and biopsy at the time of initial MDS evaluation at MDACC.
After the diagnosis is confirmed, the next important step is ...