Hydroxyurea versus busulfan in the treatment of chronic myelogenous leukemia.

A retrospective analysis of 67 patients with chronic myelogenous leukemia treated with hydroxyurea (41 patients) and busulfan (26 patients) compared the effectiveness of treatment and resulting survival. After 4 days of treatment, the white blood count in the hydroxyurea group fell at a rate of 31% +/- 10% per day compared to 10% +/- 8% for the busulfan group. At 6 months, the hemoglobin was similar, but in the busulfan group, the white blood count was significantly lower (12,500 vs. 29,900) (p = greater than 0.03). The platelet count was lower (311,000 vs. 481,000) in the busulfan group; however, the difference was not significant. When treatment was discontinued because of progression of the disease, the hemoglobin and white blood counts for both groups were similar. The platelet count was higher in the hydroxyurea group (762,000 vs. 269,000) (p greater than 0.02). The duration of therapy for both groups was similar. The median survival was also similar (hydroxyurea = 51 months; busulfan = 45 months). Hydroxyurea was associated with less life-threatening toxicity. Hydroxyurea is as effective as busulfan in treating chronic myelogenous leukemia.