Management of the myelodysplastic syndromes.

It is important to make the correct diagnosis of MDS and to exclude very carefully all other disorders that may induce dysplastic features in the bone marrow. In patients without excess of bone marrow blasts, cytogenetics and in vitro bone marrow cultures may aid in making the correct diagnosis. MDS patients without excess of bone marrow blasts or symptomatic cytopenia or cytogenetic abnormalities associated with poor prognosis should be followed on a regular basis with sequential examinations of blood counts and bone marrow specimens. In the absence of obvious disease progression, ie, increasing cytopenia or increasing percentage of marrow blasts, patients should only receive supportive care. An increase in RBC requirements alone is insufficient reason to start cytotoxic therapy. Once progression of the disease has been well documented, cytotoxic treatment is indicated. There is no reason to delay treatment until these patients have progressed to overt AML. In patients over the age of 50, the best available therapy is low-dose cytarabine with a 30% probability of a good response; this therapy requires careful supervision and the availability of intensive supportive care. In patients under 50 years with progressive disease, or with clear evidence of a poor prognosis, allogeneic BMT is the therapy of choice if a HLA-identical sibling can be identified. In those patients who lack a HLA-identical sibling, intensive combination therapy is the treatment of choice and should preferably include high-dose cytarabine. Intensive consolidation therapy will be necessary for a durable remission. Trials with inducers of differentiation remain experimental. Results to date have been disappointing.