Walsh & Hoyt: Prognosis

Survival of patients with this disorder is poorer than for polycythemia vera and essential thrombocythemia; 45 years is the median. Poor prognostic features include age greater than 60 years, hepatomegaly, low hemoglobin, low or very high leukocyte count, and weight loss, among others. Transformation to an acute nonlymphocytic leukemia occurs in 515% of patients and is responsible for death in about 25% of patients. Other causes of death are related to underlying cardiovascular disease that is affected adversely by anemia, thromboembolic events, and hemorrhage, including intracranial hemorrhage. There is no cure. Treatment is directed toward symptoms. Androgens, danazol, prednisone, and hydroxyurea are used for complications, including anemia, qualitative platelet defects, thrombocytopenia, thrombocytosis, leukocytosis, and organomegaly.