OUTLINE: This is a randomized, multicenter study. Patients are stratified according to FAB subtype: 1. Refractory anemia with excess blasts 2. Refractory anemia with excess blasts in transformation 3. Chronic myelomonocytic leukemia 4. Refractory anemia, refractory anemia with ringed sideroblasts, and refractory cytopenia with multilineage dysplasia Patients are randomized to receive oral topotecan either twice daily for 5 days or once daily for 10 days. Courses are repeated every 21 days. Patients are evaluated for hematologic response after the initial 2 courses, and then every 4 courses. If a partial response or hematologic improvement is observed, treatment continues until disease progression to acute myeloid leukemia, relapse, death, or irreversible toxicity. Patients who achieve a complete response receive an additional 2 courses of therapy before discontinuation of protocol treatment. Patients are followed every 3 months for 2 years, then every year for an additional 3 years, and at time of progression.