Chronic myelomonocytic leukemia treated with 5-azacytidine - results from the Hellenic 5-Azacytidine Registry: proposal of a new risk stratification system.

Hypomethylating agents are widely used in chronic myelomonocytic leukemia (CMML). We analyzed the characteristics of 88 patients with CMML homogeneously treated with 5-azacytidine (Hellenic 5-Azacytidine Registry). The overall response rate was 48.9% and the median overall survival (OS) 29.7 months. Out of the seven most widely used prognostic scoring systems for CMML, the Dusseldorf score (DUSS) showed the best prognostic capability (HR, 2.27; p < .001). Forty-one (48.8%) patients progressed to acute myeloid leukemia (AML) after a median time of 15.2 months following treatment initiation. High serum ferritin levels at diagnosis were independently correlated with low OS (HR, 2.84; p = .022), as were circulating blasts (HR, 3.47; p = .014), while a platelet count <100 × 109/L was marginally predictive of lower OS (HR, 1.45; p = .06). We selected these three factors to create a new risk stratification system for CMML with three risk groups. Finally, we highlighted for the first time the prognostic significance of serum ferritin levels in CMML.