Abstract Topic: 16. Myeloproliferative neoplasms - Clinical
Background: The Myelofibrosis Secondary to PV and ET – Prognostic Model (MYSEC-PM) was validated in 2018 in order to predict overall survival (OS) and define the therapeutic approach in patients with Myelofibrosis secondary to Polycythemia Vera and Essential Thrombocythemia (ET).
Aims: This study aims to evaluate the applicability of the MYSEC-PM in a clinical practice setting and compare its efficacy with the Dynamic International Prognostic Scoring System (DIPSS).
Methods: Single-center and retrospective study, with patients diagnosed with Secondary Myelofibrosis (SMF) between 2012 and 2022. The cohort was characterized and prognostic scores were applied at the time of the initial diagnosis. The OS of each of the MYSEC-PM risk groups was analyzed and compared to the DIPSS risk groups by the Kaplan-Meier method, log-rank test.
Results: There was a total of 39 patients included, median age 66 (47-82) years, 71.8% (n=28) were males. The majority (56.4%; n=22) had an initial diagnosis of ET. Median time to SMF progression was 66.9 (21.9-289.7) months. The most common drive mutation was JAK2V617F (87.2%; n=34).
After the diagnosis of SMF, median OS was 53.0 (18.2-87.8) months and leukemia-free survival at 4 years was 85.3%. According to the MYSEC-PM risk groups, the median OS in months was not reached for the low-risk group, 53.0 [HR 1.5 (0.2-15.2)], 33.8 [HR 2.2 (0.2-19.7)] and 12.1 [HR 7.5 (0.9 -64.2)] for the intermediate (int)-1, int-2 and high-risk groups, respectively (p=0.04). In the low-risk group, OS was 85.7% at 3 years. As for DIPSS, at 3 years, there was an OS of 100%, 49.5%, 66.7% and 0% for the low, int-1, int-2 and high-risk groups, respectively (p<0.001). The predictive prognostic power, assessed by the death event, was sufficient both by the MYSEC-PM and DIPSS, with an area under the curve of 0.726 versus 0.744. After reclassification of risk groups according to the MYSEC-PM, 15 (38.5%) patients were reclassified (12 upstaged and 3 under staged).
Summary/Conclusion: The MYSEC-PM model demonstrated prognostic stratification capacity in the context of a real-life cohort, however without significant differences in the ability to predict OS, compared to DIPSS. There was also a significant percentage of patients understaged by DIPSS, which may imply more aggressive therapeutic strategies in young patients with good performance status. The validity of different prognostic models in the context of treatment is essential for their subsequent use in therapeutic decisions.
Keywords: Prognosis, Myeloproliferative disorder, Myelofibrosis