Characteristics of Long-Term Survival in Patients With Myelodysplastic Syndrome Treated With 5-Azacyditine: Results From the Hellenic 5-Azacytidine Registry

Abstract

Background: Hypomethylating agents have altered the prognosis of myelodysplastic syndrome (MDS) so that long-term survival is now a feasible treatment goal. Patients and Methods: We analyzed data from patients with MDS treated with 5-azacytidine recorded in the Hellenic 5-azacytidine registry. We divided patients, on the basis of their survival after 5-azacytidine initiation (OST), in groups of long-term survivors (Q3 and P90 group with OST above the third quartile and the 90th percentile of the whole group, respectively) and short-term survivors comprising the remaining patients, and compared the characteristics between the groups. The study included 626 patients, 157 in the Q3 group and 63 in the P90 group. Results: Categorization per the International Prognostic Scoring System (IPSS), revised IPSS (IPSS-R), and World Health Organization–based prognostic scoring system (WPSS) was found to predict long-term survival, while multivariate analysis revealed that response to 5-azacytidine was the strongest predictor of long-term survival. Nevertheless, patients with hematologic improvement (HI) and stable disease (SD) were equally distributed in the groups of short- and long-term survival. Conclusion: SD should not be considered a poor treatment response and should not be grouped with failure, while HI offers similar prognosis to SD and thus should not be grouped with complete and partial remission. Patients with SD should continue treatment with 5-azacytidine. The prognosis of myelodysplastic syndrome (MDS) has changed since the introduction of hypomethylating agents that offer the potential for long-term survival. We studied the characteristics of long-term survival in a cohort of 626 patients with MDS treated with 5-azacytidine; response was found to be the single most important predictive factor of long-term survival, while stable disease (SD) and hematologic improvement were equally distributed in the groups with long- and short-term survival. Achieving SD has prognostic significance, and SD should not be grouped with treatment failure. © 2019 Elsevier Inc.