CALR and ASXL1 mutations-based molecular prognostication in primary myelofibrosis: an international study of 570 patients.
Current prognostication in primary myelofibrosis (PMF) is based on the dynamic international prognostic scoring system (DIPSS)-plus, which employs clinical and cytogenetic variables. We recently reported DIPSS-plus independent prognostic significance for calreticulin (CALR) (favorable) and ASXL1 (unfavorable) mutations. In the current study, 570 PMF patients were recruited for derivation (n=277) and validation (n=293) of a molecular prognostic model based on these two mutations. Survival was the longest in CALR(+)ASXL1(-) (median 10.4 years) and shortest in CALR(-)ASXL1(+) patients (median, 2.3 years; hazard ratio (HR), 5.9; 95% confidence interval (CI), 3.5-10.0). CALR(+)ASXL1(+) and CALR(-)ASXL1(-) patients had similar survival and were grouped together in an intermediate-risk category (median survival, 5.8 years; HR, 2.5; 95% CI, 1.5-4.0). The CALR/ASXL1 mutations-based prognostic model was DIPSS-plus independent (P<0.0001) and effective in identifying low-/intermediate-1-risk patients with shorter (median, 4 years) or longer (median 20 years) survival and high-/intermediate-2-risk patients with shorter (median, 2.3 years) survival. Multivariable analysis distinguished CALR(-)ASXL1(+) mutational status as the most significant risk factor for survival: HR 3.7 vs 2.8 for age >65 years vs 2.7 for unfavorable karyotype. These observations signify immediate clinical relevance and warrant i) CALR and ASXL1 mutation determination in all patients with PMF and ii) molecular revision of DIPSS-plus.
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Tefferi
Laboratorio Congiunto MMPC, Department of experimental and clinical medicine, University of Florence, Florence, Italy.
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Guglielmelli
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Lasho
Laboratorio Congiunto MMPC, Department of experimental and clinical medicine, University of Florence, Florence, Italy.
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Rotunno
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Finke
Laboratorio Congiunto MMPC, Department of experimental and clinical medicine, University of Florence, Florence, Italy.
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Mannarelli
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Belachew
Laboratorio Congiunto MMPC, Department of experimental and clinical medicine, University of Florence, Florence, Italy.
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Pancrazzi
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Wassie
Division of Cytogenetics, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Ketterling
Division of Hematopathology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Hanson
Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
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Pardanani
Laboratorio Congiunto MMPC, Department of experimental and clinical medicine, University of Florence, Florence, Italy.
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Vannucchi
D000368:Aged; D000369:Aged, 80 and over; D037282:Calreticulin / Q000235:genetics*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D055728:Primary Myelofibrosis / Q000235:genetics* / Q000401:mortality*; D011379:Prognosis; D012097:Repressor Proteins / Q000235:genetics*
C473949:ASXL1 protein, human; D037282:Calreticulin; D012097:Repressor Proteins