Comparison of Clinical Characteristics and Prognosis of a Series of Patients from the Spanish Registry of MDS Diagnosed with Myelodysplastic/Myeloproliferative Neoplasms According to the 2016 Reviewed Classification of the World Health Organization
Authors: Xicoy Blanca , Jimenez María-José , García Olga , Calabuig Marisa , Coll Rosa , Orna Elisa , Cedena María Teresa , Vicente Ana , Rivero Eugenia , Oiartzabal Ormategui Itziar , Zamora Lurdes , Hernandez Jose-Angel , Estrada Natalia , Callejas Marta , González González Bernardo Javier , de Paz Raquel , Cortes Montserrat , Palomo Laura , Bargay Joan , Villalobos María-Lavinia , Bailen Alicia , Montañés María-Ángeles , Bernal Del Castillo Teresa , López Cadenas Félix , Grau Javier , Brunet Salut , Jiménez Ana , Sanz Guillermo , Marco Josefa , Chen-Liang Tzu Hua 
Published: October 2019

Abstract
Background: The 2016 reviewed classification of the World Health Organisation (WHO) defines a group of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) including the chronic myelomonocytic leukemia (CMML), the myelodyplastic syndrome with ring sideroblasts and thrombocytosis (MDS-RS-T) and the MDS/MPN unclassifiable (MDS/MPN-U). The presence of typical clinical characteristics of MDS and MPN hinders the diagnosis and the prognosis of MDS/MPN-U.
Aim: The objective of this study was to compare the clinical characteristics and the prognosis of a series of patients with MDS/MPN such as CMML, MDS-RS-T and MDS/NPM-U from the Spanish registry of MDS.
Method: We analized 107 patients diagnosed with MDS/MPN (MDS-RS-T, MDS/NPM-U and CMML) according to the 2016 WHO classification. A comparison of the clinical characteristics, overall survival (OS) and cumulative incidence of progression (CIP) was performed.
Results: Median (range) age was 74 (23-93) years and 68/107 (64%) were males. The number of patients in each group was: MDS-RS-T (n=45), MDS/MPN-U (n=29) and CMML (n=33). The main clinical characteristics of the three groups are described in Table 1. There were significant statistical differences in hemoglobin and lactate dehydrogenase levels and leukocyte, monocyte and platelet counts between the three groups. With a median (range) of follow-up of 3.1 (0.3-19.3), 3.7(0.7-10.4) and 4 (1.8-8.5) years for MDS-RS-T, MDS/MPN-U, and CMML, respectively, the OS (95%CI) at 5 years was significantly better in patients with MDS-RS-T (61% [42%; 80%]) compared to MDS/MPN-U and CMML patients (21% [1%; 41%] and 19% [3%; 35%], p=0.002) (Figure 1). The CIP (95%CI) at 5 years between the three groups was significantly different: MDS/MPN-U and CMML (40% [18%; 61%] and 32% (14%-52%, respectively) vs. MDS/RS-T 8% [0.4%; 30%]) (p=0.005) (Figure 2).
Conclusions: 1) In this series of patients with MDS/MPN (MDS-RS-T, MDS/MPN-U and CMML) according to the 2016 WHO classification clinical characteristics were similar except for hemoglobin and lactate dehydrogenase levels and leukocyte, monocyte and platelet counts. 2) Patients with MDS-RS-T had longer OS and less CIP than those with MDS/MPN-U and CMML; 3) The prognosis of MDS/MPN-U and CMML were similar.
Supported by grants from: AGAUR 9015-470120/2015, 2017-SGR288 (GRC), CERCA Program from Generalitat de Catalunya, and "La Caixa" Foundation.

Disclosures
No relevant conflicts of interest to declare.