[Role of aggressive treatment strategies for myelodysplastic syndromes]

Myelodysplastic syndromes (MDS) constitute a heterogenous group of acquired bone marrow disorders characterized by ineffective hematopoiesis, cellular dysfunction and an increased risk of transformation into acute myeloid leukemia (AML). The percentage of medullary blast cells and the karyotype at diagnosis are the most important predictors of survival. Patients with more than 10% blast cells or an unfavourable karyotype (chromosome 7 abnormalities or complex aberrations) usually survive less than 12 months. This review article focuses on the roles of intensive AML-type chemotherapy, autologous stem cell transplantation and allogeneic bone marrow transplantation in the management of patients with advanced MDS. Recent studies suggest that, with appropriate selection of patients, intensive chemotherapy produces high rates of complete remission. Chances of entering remission are particularly high in patients with a good Karnofsky score, bone marrow blast count < 30% and normal karyotype. When compared with acute myeloid leukemia, results of autologous bone marrow transplantation in MDS are disappointing. A major disadvantage of this approach is the delayed recovery of hematopoiesis. Autologous peripheral blood progenitor cell transplantation overcomes this difficulty and is currently explored as consolidation therapy after successful remission induction with polychemotherapy in an intergroup study of the EORTC and EBMT. Allogeneic bone marrow transplantation remains the treatment of choice for younger MDS patients, offering a good chance of cure if the transplantation is performed at an early stage of disease or if the patient receives the transplant in complete remission after conventional chemotherapy.