Clinical features of long-term survivors of refractory myelodysplastic anemias. A Japanese cooperative study.

Eighty-one of 473 patients with refractory myelodysplastic anemias registered by the Japanese Cooperative Study Group prior to January 1987 survived more than 5 years. At presentation, most patients had mild cytopenia, a less aggressive form of the disease (48 with refractory anemia, 23 with refractory anemia with ring sideroblasts, 10 with refractory anemia with excess of blasts), less blast cells in the marrow and blood, and onset at younger ages. Their clinical profiles 5 years after presentation showed no significant improvement. The results suggest that the long-term survivors were found in a subpopulation of patients with a favorable prognosis and that it is a part of the natural course rather than the results of treatment.