IPSET-Thrombosis Better Identifies Thrombosis-Free Survival: A Turkish Cohort

Abstract

Essential thrombocythemia (ET) is the most common of the myeloproliferative neoplasms. For better predicting the occurrence of thrombotic events, an International Prognostic Score of Thrombosis for ET (IPSET-Thrombosis) was recently developed. We aimed to investigate the validity of IPSET-Thrombosis in a Turkish patient cohort and to compare the efficacy of IPSET-Thrombosis and conventional risk scoring systems in predicting thrombosis-free survival. We retrospectively evaluated the clinical characteristics and risk factors for thrombosis in 112 Turkish patients. Median thrombosis-free survival and Harrell C concordance indexes were calculated for both conventional and IPSET-Thrombosis. Median age of 112 patients included in the study was 61 (range, 27-90) years at the time of diagnosis. When patients were stratified according to the conventional risk stratification system, 43.8% of patients were in the low-risk group and 56.2% in the high-risk group. A total of 22.4% of low-risk and 42.9% of high-risk patients had at least one thromboembolic event. When patients were stratified according to the IPSET-Thrombosis, 33% were in the low-risk group, 26.8% in the intermediate-risk group, and 40.2% in the high-risk group. Considering IPSET-Thrombosis risk groups, 5.4% of low-risk, 26.7% of intermediate-risk, and 66.2% of high-risk patients had at least one thromboembolic event. Regarding IPSET-Thrombosis risk groups, 10-year thrombosis-free survival was 86.8% for low-risk, 39.4% for intermediate-risk, and 32.9% for high-risk groups (P< .001). Harrell C concordance indexes of conventional and IPSET-Thrombosis were 0.60 and 0.77, respectively. By validating the reproducibility of IPSET-Thrombosis in Turkish ET patients, we found that IPSET-Thrombosis identifies thrombosis-free survival better than the conventional risk stratification system.