El sistema de predicción de riesgo para la leucemia mielomonocítica crónica (cpss) en el contexto de la nueva clasificación de la WHO 2016

Chronic Myelomonocytic Leukemia (CMML) is a clonal disorder sharing features of myelodysplastic syndromes (MD) and myeloproliferative (MP) disorders. The CMML-Prognostic-Scoring-System (CPSS) was designed specifically for these patients. Recently, the WHO committee proposed classifying them into: CMML-0, -1 and 2. Since both proposals have not been widely reproduced, our aim was to validate them and to evaluate different prognostic factors in a series of 277 patients with CMML from South America (197-Argentina and 80-Brazil). CMML patients showed a median age of 72.6 years and a gender ratio M/F: 2.1. With a median overall survival of 32.6 months, 61(22.0%) evolved to AML and 157(56.7%) died. All evaluated variables, including the WHO-2016 proposal and all prognostic scoring systems, were useful to predict the outcome in our population (Kaplan-Meier and log-rank test, p<0.05). The CPSS-Hb (hemoglobin threshold of 10g/dL) sustained its independence for survival (p<0.001, HR1.856) and evolution to AML (p<0.001, HR 2.275) in a multivariate model including the other CPSS variants (Cox-Regression, Backward-Stepwise method). Afterward, variables not originally considered into the CPSS were included in multivariate analyses. The WHO proposal sustained its independency as an adverse prognostic factor to predict survival and evolution to AML (p=0.005 and p=0.001, HR1.420 and 1.964) when compared with the CPSS-Hb variant (p<0.001, HR1.741 and 1.890). Also, IPSS-R platelet cut-points were relevant to predict leukemic evolution (p=0.003, HR 2.929). Our results showed that the new WHO-2016 proposal adds prognostic information to the CPSS, and that platelet count is also important to predict leukemic evolution in CMML patients.