Intensive chemotherapy and bone marrow transplantation for myelodysplastic syndromes.

In myelodysplastic syndromes (MDS), complete remission rates of acute myelogenous leukemia (AML)-type chemotherapeutic regimens vary widely, ranging from 15% in patients with myelodysplasia after previous cytotoxic therapy to 61% in patients with refractory anemia with an excess of blasts in transformation without previous exposure to leukemogenic chemicals. The duration of remission is usually short, and those that exceed 24 months are unusual. Results of treatment are identical in the different types of MDS. No sufficient data on aggressive therapy are available for refractory anemia and refractory anemia with ringed sideroblasts. Prognostically favorable subgroups of patients are defined by age (below 45 or 50 years), no prior history of cytotoxic drug exposure, and absence of cytogenetic aberrations, especially of chromosomes 5 and/or 7. In contrast to AML-type chemotherapy, allogeneic bone marrow transplantation following high-dose (radio) chemotherapy offers a significantly greater chance of cure with a long-term relapse-free survival rate of 30% to 60%.