Detection of risk groups in myelodysplastic syndromes. A multicenter study

Myelodysplastic syndromes (MDS) comprise a group of heterogeneous hematologic disorders with risk of leukemic evolution (LE). The French-American-British (FAB) co-operative group classifies them into five morphologic entities and the International Prognostic Scoring System (IPSS) proposes four groups of risk on the basis of clinical and cytogenetic variables. The aim of this study was to evaluate the application of the IPSS in our Argentine population, to test the prognostic value of its variables and to determine whether this score helps to associate prognostic subgroups of risk into FAB subtypes.

Two hundred and thirty-four patients with primary MDS and a median follow-up of 28 months were evaluated using univariate analyses to determine median survival (SV) and the time to LE. The variables analyzed were FAB classification, IPSS, percentage of myeloblasts, cytogenetic groups of risk and number of cytopenias.

Univariate analyses showed that all variables analyzed were predictive for SV and for LE in our MDS population. Application of the IPSS allowed discrimination into the 4 groups of risk and helped to identify prognostic subclasses among the FAB classification, associating 5%, 15% and 19% of cases with worse prognosis within the FAB classification of refractory anemia (RA), RA with ringed sideroblasts and RA with excess of blasts (RAEB), respectively. The IPSS was not informative for RAEB in transformation cases and would not be applied to patients with chronic myelomonocytic leukemia.

This score could be applied to our MDS population, showing no geographic differences. Stratification of FAB patients according to IPSS would be helpful to develop risk-adapted therapeutic strategies.