Treatment of adult myelodysplastic syndromes

Patients with myelodysplastic syndromes (MDS) suffer from pancytopenia and are at substantial risk for progression to acute myeloid leukemia. The prin cipal pathogenetic features of MDS are clonal evolution, ineffective hemato poiesis (apoptosis), and reduced cellular maturation. T-cell-mediated myelo supression may add to disease development in some patients. The disease is progressive and, for the majority of patients, the aim of treatment will be to improve blood values and quality of life. A minority of patients could be cured by allogeneic bone marrow transplantation, which results in an ove rall disease-free survival of about 40%. The value of autologous stem-cell transplantation is currently being investigated in clinical trials; this tr eatment may be found to be beneficial for some MDS patients. High-dose chem otherapy may lead to significant improvement and complete remission in abou t 50% of treated patients, but remission duration is usually short. Low-dos e chemotherapy may also be used to improve peripheral blood values. Several new low-dose treatments are being tested at present. Growth factors can be used to improve both ineffective hematopoiesis and cytopenia. The value of treatment with growth factors alone for granulocytopoiesis is uncertain, w hereas treatment for impaired erythropoiesis using erythropoietin alone or erythropoietin in combination with other growth factors seems more promisin g. Subgroups of MDS in which T-cell-mediated myelosuppression are present m ay respond favorably to cyclosporin A or antithymoglobulin. Antiapoptotic a gents such as amifostine may improve blood values in some patients with MDS , but the value of this treatment is not yet clear. Increasing pathogenetic knowledge and better use of predictive models have resulted in some progre ss in MDS treatment. In the future, more effective treatments may result fr om further insights into the biology of the disease, the discovery of new t herapeutic approaches, and the search for better ways to use existing thera peutic options. (C) 1999 The Japanese Society of Hematology.