Long-term outcome of anemic lower-risk myelodysplastic syndromes without 5q deletion refractory to or relapsing after erythropoiesis-stimulating agents.

A large proportion of lower-risk myelodysplastic syndromes (MDS) respond to erythropoiesis-stimulating agents (ESA), but most responses are transient. We updated a previously reported cohort of lower-risk MDS patients treated with ESA and analyzed outcomes after ESA failure. In 120 patients with primary resistance and 66 patients with relapse after an initial response to ESA, the 5-year cumulative incidence of acute myeloid leukemia (AML) after failure was 18.9% and 11.6%, respectively (P=0.20). Median overall survival (OS) after failure was 40.1 and 44.9 months (P=0.35), respectively. We further categorized patients as 'early failures' (including resistance and relapse after <6 months of response), or 'later failures' (that is, relapse after ≥6 months). The 5-year cumulative incidence of AML and median OS after failure in early and later failure were 21.6% and 9% (P=0.02) and 36.7 and 54.3 months (P=0.02), respectively. Early failure to ESA and a baseline diagnosis of refractory anemia with excess blasts (RAEB)-1 were independent prognostic factors for AML progression and, along with trisomy 8, for shorter OS. Median OS from treatment onset was 40, 90.7 and 65.8 months in early failure, later failure and no relapse, respectively (P=0.001). Lower-risk MDS with early failure to ESA have a relatively unfavorable outcome, and should be offered alternative treatments.