Serum erythropoietin (EPO) levels correlate with survival and independently predict response to EPO treatment in patients with myelodysplastic syndromes.

Treatment with recombinant erythropoietin (EPO) can alleviate anaemia in patients with myelodysplastic syndromes (MDS). The present study, based on a long-term follow-up of 68 MDS patients (26RA, 16 RAS, 26 RAEB) treated with EPO alone, pinpoints pre-treatment variables associated with response induction, response duration and overall survival. Response, defined as an increase in haemoglobin >15gL1 or eliminated erythrocyte transfusion requirements, was observed in 22 of 66 (33%) evaluable patients. The median response duration was 15 (range 3-64+) months. Using univariate logistic regression models, responders displayed significantly lower baseline serum EPO levels (S-EPO), more often normal bone marrow blast cell content (RA/RAS vs. RAEB), normal cytogenetics and no need for erythrocyte transfusion. In a multiple logistic regression model, S-EPO (P=0.009), marrow blast content (P=0.031) and erythrocyte transfusion need (P=0.024) remained associated with response induction. The probability of response for a patient with S-EPO >50UL1, RA/RAS and no transfusion need was 0.79 (0.53-0.93, 95% CI). The median overall survival time from start of EPO treatment was 26 months, significantly longer for responders than for non-responders (49 vs. 18 months, P=0.018). Survival was also predicted by baseline S-EPO; patients with S-EPO >50UL1 (n=50) had a median survival of 17 months, as compared to 65 months for those with S-EPO >50UL1 (n=14, P=0.024). The international prognostic scoring system (IPSS) for MDS predicted survival (P=0.003) and progression to acute leukemia (P<0.001) but not response to EPO treatment. Furthermore, in a logistic regression model with S-EPO and IPSS, S-EPO (but not IPSS) was again a significant predictor for response (P=0.007). Our data facilitate the optimal selection of MDS patients suitable for EPO treatment and pinpoint S-EPO as a powerful predictor of response and overall survival in MDS.