Retrospective evaluation of thromboembolic episodes, leukemic and myelofibrotic transformation in patients with polycythemia vera and essential thrombocythemia

Polycythemia vera (PV) and Essential thrombocythemia (ET) are myeloproliferative neoplasms that can lead to life-threatening complications such as thrombosis, bleeding, leukemia / myelofibrosis transformation. In our study, it is aimed to evaluate retrospectively these complications, which constitute important causes of morbidity and mortality in the PV and ET patient groups. In this study, 96 patients who were followed up between 2000-2020 were included ; 61 patients as PV group and 35 patients as ET group respectively. The average age in the PV group is 63.84 (± 15.22), 48.4% of whom are male; In the ET group, 63.84 (± 15.22) and 40% are male. In the entire patient group ,bleeding episodes were seen in 11 patients (11.5%); 2 patients (2.1%) at the time of diagnosis and 9 patients (9.4%) during follow-up respectively.Thrombotic episodes were detected in 27 patients (28.1%); 21 patients (21.9%) at the time of diagnosis and 6 patients (6.3%) during follow-up respectively. Transformation to secondary MDS / acute leukemia was found in 2 patients (2.08%) and to secondary myelofibrosis in 12 patients (12.5%). The mortality rate was 11.5% in the entire patient group. The mean follow-up duration was 98.43 (61.24- 144.87) months. The one-year average survival was 98.9% and the 5-year average survival was 95.8%. When both groups were compared, there was no statistically significant difference in terms of bleeding and thrombotic episodes, transformation to leukemia and myelofibrosis and mortality rates. Only female gender in PV group (p: 0.045) and Hb level in ET group (p: 0.052) were associated with development of thrombosis. In the entire patient group, the factor associated with secondary myelofibrosis could not be demonstrated in the multivariate analysis. Secondary MDS / leukemia development (p: 0.029) and spleen size (p: 0.025) were associated with mortality in the entire patient group.