Key Points• Risk assessment is crucial in patients with CMML because survival may range from a few months to several years.• Integrating clinical features, morphology, and genetic lesions significantly improves risk stratification in CMML.Chronic myelomonocytic leukemia (CMML) is a myelodysplastic/myeloproliferative neoplasm with variable clinical course. To predict the clinical outcome, we previously developed a CMML-specific prognostic scoring system (CPSS) based on clinical parameters and cytogenetics.In this work, we tested the hypothesis that accounting for gene mutations would further improve risk stratification of CMML patients. We therefore sequenced 38 genes to explore the role of somatic mutations in disease phenotype and clinical outcome. Overall, 199 of 214 (93%) CMML patients carried at least 1 somatic mutation.Stepwise linear regression models showed that these mutations accounted for 15% to 24% of variability of clinical phenotype. Based on multivariable Cox regression analyses, cytogenetic abnormalities and mutations in RUNX1, NRAS, SETBP1, and ASXL1 were independently associated with overall survival (OS). Using these parameters, we defined a genetic score that identified 4 categories with significantly different OS and cumulative incidence of leukemic evolution. In multivariable analyses, genetic score, red blood cell transfusion dependency, white blood cell count, and marrow blasts retained independent prognostic value. These parameters were included into a clinical/molecular CPSS (CPSS-Mol) model that identified 4 risk groups with markedly different median OS (from >144 to 18 months, hazard ratio [HR] 5 2.69) and cumulative incidence of leukemic evolution (from 0% to 48% at 4 years, HR 5 3.84) (P < .001). The CPSS-Mol fully retained its ability to risk stratify in an independent validation cohort of 260 CMML patients. In conclusion, integrating conventional parameters and gene mutations significantly improves risk stratification of CMML patients, providing a robust basis for clinical decision-making and a reliable tool for clinical trials.

In the current World Health Organization (WHO)-classification, therapy-related myelodysplastic syndromes (t-MDS) are categorized together with therapy-related acute myeloid leukemia (AML) and t-myelodysplastic/myeloproliferative neoplasms into one subgroup independent of morphologic or prognostic features. Analyzing data of 2087 t-MDS patients from different international MDS groups to evaluate classification and prognostication tools we found that applying the WHO classification for p-MDS successfully predicts time to transformation and survival (both p < 0.001). The results regarding carefully reviewed cytogenetic data, classifications, and prognostic scores confirmed that t-MDS are similarly heterogeneous as p-MDS and therefore deserve the same careful differentiation regarding risk. As reference, these results were compared with 4593 primary MDS (p-MDS) patients represented in the International Working Group for Prognosis in MDS database (IWG-PM). Although a less favorable clinical outcome occurred in each t-MDS subset compared with p-MDS subgroups, FAB and WHO-classification, IPSS-R, and WPSS-R separated t-MDS patients into differing risk groups effectively, indicating that all established risk factors for p-MDS maintained relevance in t-MDS, with cytogenetic features having enhanced predictive power. These data strongly argue to classify t-MDS as a separate entity distinct from other WHO-classified t-myeloid neoplasms, which would enhance treatment decisions and facilitate the inclusion of t-MDS patients into clinical studies.

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Secondary acute myeloid leukemia (sAML) comprises a heterogeneous group of patients, and is associated with poor overall survival (OS). We analyze the characteristics, treatment patterns and outcomes of sAML adult patients of the Programa Español de Tratamientos en Hematología (PETHEMA) registry. Overall, 6211 (72.9%) were de novo and 2310 (27.1%) sAML, divided into myelodysplastic syndrome (MDS-AML, 44%), MDS/myeloproliferative (MDS/MPN-AML, 10%), MPN-AML (11%), therapy-related (t-AML, 25%), and antecedent neoplasia without prior chemotherapy/radiotherapy (neo-AML, 9%). Compared to de novo, sAML were older (median age 69 years old), had more ECOG ≥2 (35%) or high-risk cytogenetics (40%), less FLT3-ITD (11%) and NPM1 mutations (21%), and received less intensive chemotherapy regimens (38%) (all P&lt;0.001). Median OS was higher in de novo than in sAML (10.9 vs 5.6 months, P&lt;0.001); and shorter in sAML after hematologic disorder (MDS, MDS/MPN or MPN) as compared to t-AML and neo-AML (5.3 vs 6.1 vs 5.7 months, respectively, P=0.04). After intensive chemotherapy, median OS was better among de novo and neo-AML patients (17.2 and 14.6 months). No OS differences were observed after hypomethylating agents according to type of AML. sAML was as an independent adverse prognostic factor for OS. We confirm high prevalence and adverse features of sAML and we establish its independent adverse prognostic value. This study was registered at www.clinicaltrials.gov as #NCT02607059.

Preliminary Acute Promyelocytic Leukemia (APL) whole exome sequencing (WES) studies have identified a huge number of somatic mutations affecting more than a hundred different genes mainly in a non-recurrent manner, suggesting that APL is a heterogeneous disease with secondary relevant changes not yet defined. To extend our knowledge of subtle genetic alterations involved in APL that might cooperate with PML/RARA in the leukemogenic process, we performed a comprehensive analysis of somatic mutations in APL combining WES with sequencing of a custom panel of targeted genes by next-generation sequencing. To select a reduced subset of high confidence candidate driver genes, further in silico analysis were carried out. After prioritization and network analysis we found recurrent deleterious mutations in 8 individual genes (STAG2, U2AF1, SMC1A, USP9X, IKZF1, LYN, MYCBP2 and PTPN11) with a strong potential of being involved in APL pathogenesis. Our network analysis of multiple mutations provides a reliable approach to prioritize genes for additional analysis, improving our knowledge of the leukemogenesis interactome. Additionally, we have defined a functional module in the interactome of APL. The hypothesis is that the number, or the specific combinations, of mutations harbored in each patient might not be as important as the disturbance caused in biological key functions, triggered by several not necessarily recurrent mutations.