Retrospective Analysis of Prognostic Factors Associated With Response and Overall Survival by Baseline Marrow Blast Percentage in Patients With Myelodysplastic Syndromes Treated With Decitabine

BackgroundAfter the World Health Organization (WHO) changed the definition of acute myeloid leukemia (AML) to ≥ 20% blasts, the International Working Group (IWG) response criteria for myelodysplasia were updated. This retrospective analysis evaluated response to decitabine using updated IWG criteria in patients pooled from 2 decitabine trials.Patients and MethodsOutcomes for patients with myelodysplastic syndrome (MDS) with baseline marrow blasts ≥ 20% and < 30% (RAEB-t group) and < 20% (MDS group) were compared.ResultsPatients with RAEB-t (n = 26) had a significantly shorter time from diagnosis to study treatment (7.3 vs. 18.3 months), a higher International Prognostic Scoring System (IPSS) risk (77% vs. 16% high-risk patients), and lower median baseline platelet count (62.3 vs. 112.7 × 103/μL) vs. patients with MDS (n = 157), yet no significant difference in overall response rate (ORR) (15.4% vs. 28.0%). Patients with MDS had better duration of response (9.9 vs. 5 months; P = .024) and overall survival (OS) (16.6 vs. 9.0 months; P = .021) compared with patients with RAEB-t.ConclusionDecitabine is active in and may benefit patients with > 20% blasts (RAEB-t).