Objective: To assess the incidence of thrombotic events among patients with BCR::ABL1-negative myeloproliferative neoplasm (MPN) within a single center in Thailand.

Materials and Methods: Conducted as a retrospective cohort study between 2008 and 2019, the present research focused on patients diagnosed with BCR::ABL1-negative MPN. Diagnoses were reviewed and reclassified based on the WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues (2017). Data collected encompassed demographic details, comorbidities, investigation results, treatments, and outcomes. The primary focus was on thrombosis rates in arterial and venous sites. Secondary outcomes included the incidence of major bleeding, thrombosisfree survival (TFS), and overall survival (OS).

Results: One hundred seventy-five patients participated in the present study and comprised of 46 patients (26.3%) with polycythemia vera (PV), 123 (70.3%) patients with essential thrombocythemia (ET), and six patients (3.4%) with primary myelofibrosis (PMF). Most patients were over 60 years old. The rate of overall thrombosis rate was 28.0%, with 43.5% in PV and 23.6% in ET. Common sites of thrombotic events included the cerebral artery at 16.6%, coronary artery at 6.3%, peripheral artery at 4.0% and venous thromboembolism at 3.4%. The overall bleeding event rate was 13.7%, with 70.8% classified as major bleeding. The all-cause mortality rate within the present cohort was 30.9%. TFS and OS stood 72.0% and 69.1%, respectively.

Conclusion: Thrombosis emerged as a significant complication in patients with BCR::ABL1-negative MPN, affecting 28.0% of individuals in the present cohort. Arterial thromboses, particularly ischemic stroke and cardiovascular events, were the predominant occurrences.

Keywords: Myeloproliferative neoplasm; Polycythemia vera; Essential thrombocythemia; Thrombosis; Bleeding

DOI: 10.35755/jmedassocthai.2024.2.13945

Received 25 October 2023 | Revised 18 January 2024 | Accepted 21 January 2024