Prognostic parameters in myeloid metaplasia: agnogenic versus postpolycythemic.

Thirty-nine patients with myelofibrosis and myeloid metaplasia were diagnosed and followed during the period 1955-74. Twenty-eight suffered from agnogenic myeloid metaplasia and 11 from myeloid metaplasia following polycythemia vera. In an attempt to compare the two groups and to define prognostic guidelines, an analysis of survival with respect to various clinical parameters was made. The median survival time of patients with agnogenic myeloid metaplasia was seven years as opposed to only 28 months for the poltpolycythemic group. Older age at diagnosis, a large spleen, or its rapid enlargement, anemia and leukocytosis, but not thrombocytopenia, had a marked negative effect on survival. The clinical condition of most patients was remarkably stable during the entire course of their disease. If a significant drop in hemoglobin occurred, it was sudden, and caused by gastrointestinal hemorrhage or the development of acute leukemia. No demonstrable effect of therapy on survival was found.