Ayalew Tefferi, MD

Since the topic of risk-stratified management of patients with myelodysplastic syndromes (MDS) was last reviewed in ONCOLOGY in 2007,[1] a few additional clinically relevant studies have emerged that can help inform decision-making in the consultation room.

The development of imatinib mesylate (Gleevec), a tyrosine kinase inhibitor targeted against the causative Bcr-Abl protein in chronic myeloid leukemia (CML), has resulted in hematologic and cytogenetic remissions in all phases of CML. Following imatinib treatment, more than 90% of patients obtain complete hematologic response, and 70% to 80% achieve a complete cytogenetic response. With 5 years of follow-up, the data are very encouraging, exhibiting a major change in the natural history of the disease. The understanding of at least some of the mechanisms of resistance to imatinib has led to a rapid development of new agents that may overcome this resistance. Combination strategies are currently being investigated in preliminary clinical studies and may prove to be useful. Overall, there are an increasing number of treatment options now available for patients with CML.

Most adult patients with hematopoietic failure due to myelodysplastic syndrome (MDS) are treated with supportive care measures, including hematopoietic growth factors (epoetin alfa, darbepoetin alfa, filgrastim, pegfilgrastim, sargramostim), red blood cell or platelet transfusions, and antimicrobial agents. Allogeneic stem cell transplantation can be curative, but only a small subset of patients are eligible for transplantation, and until recently there were few options other than supportive care for transplant-ineligible patients. Since 2004, the US Food and Drug Administration (FDA) has approved three new therapies specifically for the indication of MDS: two DNA methyltransferase inhibitors (azacitidine and decitabine) and an immunomodulatory agent (lenalidomide). Several other drugs are used by clinicians for treatment of patients with MDS, but are not specifically FDA-approved for this indication. With several therapeutic options available, yet none of them effective in the majority of cases, it can be challenging for clinicians to choose the most appropriate treatment for an individual patient. Here we discuss a risk-based management approach to MDS that incorporates recent data regarding these new therapies. While many questions remain about the optimal use of newer agents, the long-standing perception of MDS as a syndrome where therapeutic nihilism is the only realistic approach is slowly beginning to change.

Myeloproliferative disorders originate in the clonal expansion of a transformed pluripotential hematopoietic progenitor cell. This results in a group of syndromes that include polycythemia vera, essential thrombocythemia,