Development and validation of a multiple factor-based prognostic score system of thrombosis in polycythemia vera (MFPS-PV)

Thrombosis is an important cause of death in patients with polycythemia vera (PV). This study aimed to develop and validate a multiple factor-based prediction model of thrombosis and to propose risk-adapted treatment strategies for the 2016 World Health Organization-defined PV. The study involved 301 patients in the training cohort and another 194 patients in the external validation cohort. Multivariate analysis indicated that age ≥ 57 years (hazard ratio [HR] 2.586, p = 0.006), cardiovascular risk factors (HR 4.599, p = 0.005), previous thrombosis (HR 4.780, p < 0.001), and at least one high-risk mutation for thrombosis (mutations in DNMT3A, ASXL1, and BCOR/BCORL1) (HR 3.732, p < 0.001) were independent risk factors for thrombosis. After assigning HR-weighted scores to each risk factor, a multiple factor-based prognostic score system of thrombosis (MFPS-PV) was developed, classifying patients into low-risk (0–1 points), intermediate-risk (2–3 points), and high-risk (≥ 4 points) groups. Patients in the three groups had significantly different thrombosis-free survival rates (p < 0.001). The MFPS-PV outperformed the conventional two-tiered stratification (C-index 0.746 vs 0.643) and remained consistent during external validation. Finally, a risk-adapted therapeutic strategy was established based on the MFPS-PV. In conclusion, the MFPS-PV, integrating genetic and clinical characteristics for the first time, can significantly predict thrombosis and has great therapeutic implications.