ESSENTIAL THROMBOCYTHEMIA IN COLOMBIA: A REAL-WORLD SINGLE-CENTER STUDY

Article type: Original Research Article

Myeloproliferative neoplasms are clonal hematologic disorders driven by recurrent somatic mutations; essential thrombocythemia (ET) is a classical entity within this group, although relatively uncommon. Molecular profiling refines both diagnosis and risk stratification.

This study describes an adult ET cohort treated at a comprehensive cancer center in Cali, Colombia. Patients diagnosed between July 2015 and July 2023 were retrospectively identified. Demographic, clinical, laboratory, molecular, therapeutic, and follow-up data were extracted from medical records. Risk was assigned according to established classification systems.

A total of 169 patients met diagnostic criteria. Median age at diagnosis was 68.3 years (range, 34–84), with female predominance. JAK2 V617F was detected in 59/169 patients (34.9%; 52.2% of those tested), and CALR mutations in 13/169 (7.7%; 54.2% of those tested); no MPL mutations were identified among the 13 patients tested. Mean platelet count at presentation was 886 × 10⁹/L, and 58% of patients were classified as high thrombotic risk, primarily due to age >60 years and/or prior thrombosis.

Twenty-eight percent of cases were diagnosed incidentally; vasomotor and constitutional symptoms predominated among symptomatic patients. Initial management consisted of low-dose acetylsalicylic acid in low-risk patients and cytoreductive therapy (predominantly hydroxyurea), in high-risk individuals. During follow-up, thrombotic events occurred in 18.6% and hemorrhagic complications in 6.8%. Progression to myelofibrosis was documented in two patients; no leukemic transformation was observed.

This regional experience demonstrates overall concordance with international data while highlighting the high proportion of high-risk disease at diagnosis and limited molecular testing availability. These findings support timely molecular evaluation, risk-adapted therapy, and expanded access to diagnostic resources in Latin America.