Real-world study of children and young adults with myeloproliferative neoplasms: identifying risks and unmet needs

Marta Sobas, Jean Jacques Kiladjian, Yan Beauverd, Natalia Curto-Garcia, Parvis Sadjadian, Lee Yung Shih, Timothy Devos, Dorota Krochmalczyk, Serena Galli, Maria Bieniaszewska, Ilona Seferynska, Mary Frances McMullin, Anna Armatys, Adrianna Spalek, Joanna Waclaw, Mihnea Zdrenghea, Laurence Legros, François Girodon, Krzysztof Lewandowski, Anna Angona FiguerasJan Samuelsson, Aitor Abuin Blanco, Pascale Cony-Makhoul, Angela Collins, Chloé James, Rajko Kusec, Marie Lauermannova, Maria Sol Noya, Malgorzata Skowronek, Lukasz Szukalski, Anna Szmigielska-Kaplon, Marielle Wondergem, Iryna Dudchenko, Joanna Gora Tybor, Kamel Laribi, Anna Kulikowska de Nalecz, Jean Loup Demory, Katell Le Du, Sonja Zweegman, Carlos Besses Raebel, Radek Skoda, Stéphane Giraudier, Martin Griesshammer, Claire N. Harrison, Jean Christophe Ianotto*

*Corresponding author for this work

Research output: Contribution to journalJournal Article peer-review

12 Scopus citations


Myeloproliferative neoplasms (MPNs) are uncommon in children/young adults. Here, we present data on unselected patients diagnosed before 25 years of age included from 38 centers in 15 countries. Sequential patients were included. We identified 444 patients, with median follow-up 9.7 years (0-47.8). Forty-nine (11.1%) had a history of thrombosis at diagnosis, 49 new thrombotic events were recorded (1.16% patient per year [pt/y]), perihepatic vein thromboses were most frequent (47.6% venous events), and logistic regression identified JAK2V617F mutation (P 5 .016) and hyperviscosity symptoms (visual disturbances, dizziness, vertigo, headache) as risk factors (P 5 .040). New hemorrhagic events occurred in 44 patients (9.9%, 1.04% pt/y). Disease transformation occurred in 48 patients (10.9%, 1.13% pt/y), usually to myelofibrosis (7.5%) with splenomegaly as a novel risk factor for transformation in essential thrombocythemia (ET) (P5 .000) in logistical regression. Eight deaths (1.8%) were recorded, 3 after allogeneic stem cell transplantation. Concerning conventional risk scores: International Prognostic Score for Essential Thrombocythemia-Thrombosis and new International Prognostic Score for Essential Thrombocythemia-Thrombosis differentiated ET patients in terms of thrombotic risk. Both scores identified high-risk patients with the same median thrombosis-free survival of 28.5 years. No contemporary scores were able to predict survival for young ET or polycythemia vera patients. Our data represents the largest real-world study of MPN patients age, 25 years at diagnosis. Rates of thrombotic events and transformation were higher than expected compared with the previous literature. Our study provides new and reliable information as a basis for prospective studies, trials, and development of harmonized international guidelines for the specific management of young patients with MPN.

Original languageEnglish
Pages (from-to)5171-5183
Number of pages13
JournalBlood Advances
Issue number17
StatePublished - 13 09 2022
Externally publishedYes

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© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.


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