Genomic profiling for decision-making in post-polycythemia vera and post-essential thrombocythemia myelofibrosis

Secondary myelofibrosis (SMF) represents a late stage of polycythemia vera and essential thrombocythemia, with overall survival (OS) currently defined by the MYelofibrosis SECondary to PV and ET (MYSEC) Prognostic Model (MYSEC-PM). To identify additional myeloid neoplasm-associated cancer gene variants (CGVs) associated with SMF outcome, we evaluated next-generation sequencing panel testing in 644 patients within the MYSEC cohort. Overall, 429 (66.6%) subjects reported at least one CGV, with ASXL1, TET2 and DNMT3A being the most frequently involved. Specific molecular profiles affected OS (p < .001): U2AF1, TP53 or SRSF2 variants (UTS, 9.3% of cases, median OS 4.1 years) and ASXL1 without UTS (25.3%, median OS 8.4 years). By integrating these genetic signatures within the MYSEC-PM through penalized Cox regressions, we identified the following independent predictors (p from < .0001 to .02) and weighted: hemoglobin <11 g/dl (1 point), circulating blasts ⩾3% (2), platelets <150 × 109/l (2), age (0.21 points/year), ASXL1 without UTS mutations (1) and any UTS mutations (3). Finally, we developed the MYSEC-molecular prognostic model (MYSEC-mPM) allocating 582 SMF patients into four categories with different OS (p < .001): low (median OS 18.0 years, 95%CI: 14.2-not reached; score <14), intermediate-1 (8.8. years, 95%CI: 7.7-9.7; score 14-16), intermediate-2 (4.6 years, 95%CI: 3.1-7.2; score 17-18), and high risk (1.9 years, 95%CI: 1.2-2.5; score ⩾19). Additionally, in 381 SMF with available cytogenetics, the MYSEC-mPM was implemented with complex/monosomal karyotype, generating the karyotype-enhanced MYSEC-kmPM. Our study shows that genomic and cytogenetic profiling improve survival prediction in SMF, outperforming the MYSEC-PM.