Risk stratification of myelofibrosis (MF) is important to determine prognosis and help understand disease trajectoryHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Passamonti F et al. Leukemia. 2017;31(12):2726-2731.

• Given the heterogeneity in clinical presentation and outcomes of MF and the discovery of new prognostic variables, efforts have been made to develop prognostic models that can guide treatment decisionsHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Passamonti F et al. Leukemia. 2017;31(12):2726-2731.
• The International Prognostic Scoring System (IPSS) was the first contemporary prognostic scoring system developed and is still used to evaluate patients at the time of diagnosisPassamonti F et al. Leukemia. 2017;31(12):2726-2731. Tefferi A. Am J Hematol. 2023;98(5):801-821.
  
  
  • The Dynamic International Prognostic Scoring System (DIPSS)/DIPSS-Plus are also used in MF as they can be applied at any time during the disease courseHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Passamonti F et al. Leukemia. 2017;31(12):2726-2731.
• More recently, new models have been developed, such as the Mutation-Enhanced International Prognostic Scoring System for transplant-age patients (MIPSS70) and MIPSS70-Plus v2.0, which consider molecular and cytogenetic findings, leading to more comprehensive risk evaluationHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
  
  
  • Prognostic variables, their individual scorings, and the resulting risk groups vary across the prognostic models, reflecting evolving approaches to risk stratification for MFHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

See below for an overview.

Contemporary Prognostic Models for MFHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

DIPSS, Dynamic International Prognostic Scoring System; GIPSS, Genetically Inspired Prognostic Scoring System; Hb, hemoglobin; HMR, high molecular risk; IPSS, International Prognostic Scoring System; MF, myelofibrosis; MIPSS70, Mutation-Enhanced International Prognostic Scoring System for transplant-age patients; MYSEC-PM, Myelofibrosis Secondary to Polycythemia Vera and Essential Thrombocythemia Prognostic Model.

International Prognostic Scoring System (IPSS) was developed for use at the time of diagnosis to help guide initial treatment decisionsHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Tefferi A. Am J Hematol. 2023;98(5):801-821.

• IPSS applies 5 independent predictors of inferior survival: age >65 years, hemoglobin <10 g/dL, white blood cell count >25 × 10⁹/L, circulating blasts ≥1%, and constitutional symptomsHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
• Patients are stratified into 1 of 4 risk groups (low, intermediate-1, intermediate-2, and high), based on the sum of the individual scores for each parameterHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

  
  
  • Patients with 0 points are classified as low-risk PMF (median survival, 11.3 years^a) and those with ≥3 points as high-risk PMF (median survival, 2.3 years^a)How J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Cervantes F et al. Blood. 2009;113(13):2895-901.

International Prognostic Scoring System (IPSS)How J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Cervantes F et al. Blood. 2009;113(13):2895-901.

^aThe study evaluated median survival per IPSS in only patients with PMF.Cervantes F et al. Blood. 2009;113(13):2895-901.

Hb, hemoglobin; IPSS, International Prognostic Scoring System; PMF, primary myelofibrosis; WBC, white blood cell.

Dynamic International Prognostic Scoring System (DIPSS) and DIPSS-Plus allow risk evaluation at any point during the course of MFHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

• IPSS variables are measured during diagnosis, limiting its prognostic value to this initial time point; DIPSS was developed to incorporate evolving risk, enabling restaging at any point during the course of MFHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
  
  
  • DIPSS applies the same 5 independent predictors of inferior survival as IPSS but highlights the prognostic importance of anemia by assigning 2 points for hemoglobin <10 g/dLHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
  • DIPSS-Plus further refines risk stratification by incorporating 3 additional independent risk factors: platelet count <100 × 10⁹/L, red blood cell transfusion needs, and unfavorable karyotypeHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

• Both DIPSS models stratify patients into 1 of 4 risk groups (low, intermediate-1, intermediate-2, and high), based on the sum of the individual scores for each parameterHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
  
  
  • In DIPSS, patients with 0 points are classified as low-risk PMF (median survival, not reached^b) and those with 5-6 points as high-risk PMF (median survival, 1.5 years^b)How J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
  • In DIPSS‑Plus, the DIPSS risk category contributes to the total score, with point values increasing by risk levelHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.
    
    
    • Patients with 0 points are classified as low-risk PMF (median survival, 15.4 years^b) and those with ≥4 points as high-risk PMF (median survival, 1.3 years^b)How J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278.

Dynamic International Prognostic Scoring System-Plus (DIPSS-Plus)How J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Gangat N et al. J Clin Oncol. 2011;29(4):392-7.

^bThe study evaluated median survival per DIPSS-Plus in only patients with PMF.Gangat N et al. J Clin Oncol. 2011;29(4):392-7.

DIPSS, Dynamic International Prognostic Scoring System; Hb, hemoglobin; IPSS, International Prognostic Scoring System; PMF, primary myelofibrosis; WBC, white blood cell.

Myelofibrosis Secondary to PV and ET Prognostic Model (MYSEC-PM) is an integrated clinical-molecular model used to predict survival for patients with secondary MFPassamonti F et al. Leukemia. 2017;31(12):2726-2731.

• AAlthough IPSS, DIPSS, and DIPSS-Plus are frequently used to predict survival for patients with secondary MF, they were originally developed for patients with PMF and perform less well in the secondary MF settingPassamonti F et al. Leukemia. 2017;31(12):2726-2731.
• MYSEC-PM was uniquely developed for secondary MF and may better predict survival than the other prognostic modelsPassamonti F et al. Leukemia. 2017;31(12):2726-2731.
• MYSEC-PM applies 6 independent predictors of inferior survival: age (0.15 per year of age), hemoglobin <11 g/dL, circulating blasts ≥3%, constitutional symptoms, platelet count <150 × 109/L and absence of CALR mutationHow J et al. J Natl Compr Canc Netw. 2020;18(9):1271-1278. Passamonti F et al. Leukemia. 2017;31(12):2726-2731.
• MYSEC-PM stratifies patients into 1 of 4 risk groups (low, intermediate-1, intermediate-2, and high), based on the sum of the individual scores for each parameterPassamonti F et al. Leukemia. 2017;31(12):2726-2731.
  
  
  • Patients with <11 points are classified as low-risk secondary MF (median survival, not reached) and those with >16 points as high-risk MF (median survival, 2.0 years)Passamonti F et al. Leukemia. 2017;31(12):2726-2731.

Myelofibrosis Secondary to PV and ET Prognostic Model (MYSEC-PM)Passamonti F et al. Leukemia. 2017;31(12):2726-2731.

DIPSS, Dynamic International Prognostic Scoring System; ET, essential thrombocythemia; IPSS, International Prognostic Scoring System; MF, myelofibrosis; PMF, primary myelofibrosis.