Evaluation of the need for cytoreduction and its potential carcinogenicity in children and young adults with myeloproliferative neoplasms

Essential Thrombocythemia in Adolescents and Young Adults: Clinical Aspects, Treatment Options and Unmet Medical Needs

OPINION STATEMENT

Current treatment of essential thrombocythemia (ET) should primarily prevent thrombo-hemorrhagic events, without increasing the rate of fibrotic progression or leukemic evolution, and secondarily control microvascular symptoms. Unlike other classic BCR::ABL1-negative myeloproliferative neoplasms, ET is frequently diagnosed in adolescents and young adults (AYA), defined as individuals aged 15 to 39 years, in up to 20% of patients. However, since the current risk stratification of this disease is based on models, including that of ELN, IPSET-Thrombosis and its revised version, mainly applied to an older patients' population, international guidelines are needed that specifically consider how to evaluate the prognosis of AYAs with ET. Furthermore, although ET is the most frequent MPN among AYA subjects, there is a lack of specific recommendations on how to treat it in this subgroup of patients, as management decisions are typically extrapolated from those for the elderly. Accordingly, since AYAs with ET represent a unique disease subset defined by attenuated genetic risk, more indolent phenotype, and longer survival than their older counterparts, treatment selection requires special attention to specific issues such as the risk of fibrotic/leukemic transformation, carcinogenicity, and fertility. This review article will provide a comprehensive overview of the diagnosis, prognostic stratification, and possible therapeutic approaches for AYA patients with ET, including antiplatelets/anticoagulants and cytoreductive agents, with a focus on pregnancy management in real-life clinical practice.

A Case Report of Ropeginterferon Alfa-2b for Polycythemia Vera during Pregnancy

Myeloproliferative neoplasms (MPN) such as essential thrombocythemia (ET) and polycythemia vera (PV) are rare during pregnancy. However, they are harmful because they are associated with an increased risk of thromboembolic, hemorrhagic, or microcirculatory disturbances or placental dysfunction leading to fetal growth restriction or loss. Low-dose aspirin and low-molecular-weight heparin (LMWH) are recommended to reduce pregnancy complications, and interferon (IFN) is the only treatment option for cytoreductive therapy based on the likelihood of live birth in pregnant women with MPN. Since ropeginterferon alfa-2b is the only available IFN in South Korea, we present a case report of ropeginterferon alfa-2b use during pregnancy in an MPN patient. A 40-year-old woman who had been diagnosed with low-risk PV in 2017 and had been maintained on phlebotomy, hydroxyurea (HU), and anagrelide (ANA) for 4 years was confirmed as 5 weeks pregnant on 9 December 2021. After stopping treatment with HU and ANA, the patient showed a rapid increase in platelet count (1113 × 109/L to 2074 × 109/L, normal range, 150–450 × 109/L) and white blood cell count (21.93 × 109/L to 35.55 × 109/L, normal range, 4.0–10.0 × 109/L). Considering the high risk of complications, aggressive cytoreductive treatment was required, for which we chose ropeginterferon alfa-2b, as it is the only available IFN agent in South Korea. The patient underwent 8 cycles of ropeginterferon alfa-2b over 6 months during pregnancy and delivered without any neonatal or maternal complications. This case report highlights the importance of considering treatment options for MPN patients who are pregnant or planning a pregnancy, as well as the need for further investigation into the safety and efficacy of ropeginterferon alfa-2b in this population.

Essential Thrombocythemia and Post-Essential Thrombocythemia Myelofibrosis: Updates on Diagnosis, Clinical Aspects, and Management

Although several decades have passed since the description of myeloproliferative neoplasms (MPN), many aspects of their pathophysiology have not been elucidated. In this review, we discuss the mutational landscape of patients with essential thrombocythemia (ET), prognostic scores and salient pathology, and clinical points. We discuss also the diagnostic challenges of differentiating ET from prefibrotic MF. We then focus on post-essential thrombocythemia myelofibrosis (post-ET MF), a rare subset of MPN that is usually studied in conjunction with post-polycythemia vera MF. The transition of ET to post-ET MF is not well studied on a molecular level, and we present available data. Patients with secondary MF could benefit from allogenic hematopoietic stem cell transplantation, and we present available data focusing on post-ET MF.