Purpose: To determine the treatment outcome of standard acute myeloid leukemia (AML)-type chemotherapy in a subset of patients with newly diagnosed myelodysplastic syndromes (MDS) compared with that of patients with de novo AML as defined using French-American-British (FAB) criteria. In addition, to determine the pretreatment variables having prognostic significance for treatment outcome in patients with MDS.
Patients and methods: Nine hundred seven newly diagnosed patients with no history of cytopenias having a local institutional de novo AML successfully karyotyped and treated on Cancer and Leukemia Group B (CALGB) protocols for AML from 1984 to 1992. Thirty-three of the 907 patients were reclassified as having MDS on central pathology review using FAB criteria and form the basis of this analysis.
Results: The treatment outcomes for patients with MDS and AML were similar; the complete remission (CR) rate was 79% and 68%, respectively (P = .37); median CR duration was 11 and 15 months, respectively (P = .28); and median survival was 13 and 16 months, respectively (P = .72). For the MDS patients, there were no prognostic variables for CR rate identified. For CR duration, only the Sanz classification had prognostic value. The prognostic factors for survival in a univariate analysis included age, WBC count, Sanz classification, and percent blood blasts. In a proportional hazards analysis of survival, age greater than 60 years and WBC less than 2.6 x 10(9)/L were adverse prognostic factors.
Conclusion: In patients with no known history of cytopenias who are treated intensively at diagnosis, the FAB distinctions between MDS (refractory anemia with excess blasts and refractory anemia with excess blasts in transformation) and AML appear to have little therapeutic relevance.