title: Prognostic impact of bone marrow fibrosis in polycythemia vera: validation of the IWG-MRT study and additional observations.
abstract: In 2012, the International Working Group for Myeloproliferative Neoplasms (MPN) Research and Treatment (IWG-MRT) reported an associations between mild bone marrow (BM) fibrosis (⩾grade 1) in polycythemia vera (PV) and a lower incidence of thrombosis during the clinical course and a higher risk of fibrotic progression. The objective in the current study of 262 patients with PV was to validate these observations and also identify other risk factors for myelofibrosis-free survival (MFFS). About 127 (48%) patients displayed ⩾grade 1 reticulin fibrosis at the time of diagnosis; presenting clinical and laboratory features were not significantly different between patients with or without BM fibrosis. In univariate analysis, BM fibrosis had no significant impact on overall, leukemia-free or thrombosis-free survival, whereas a significant association was noted for MFFS (P=0.009, hazard ratio 2.9; 95% confidence interval 1.32-6.78); other risk factors for MFFS included leukocytosis ⩾15 × 109/l, presence of palpable splenomegaly and abnormal karyotype. During multivariable analysis, leukocytosis ⩾15 × 109/l, palpable splenomegaly and ⩾grade 1 BM reticulin fibrosis remained significant. The current study validates the previously observed association between ⩾grade 1 BM reticulin fibrosis in PV and subsequent fibrotic progression, and identifies leukocytosis and palpable splenomegaly as additional risk factors for fibrotic progression; additional studies are required to clarify the impact of BM fibrosis on thrombosis and that of abnormal karyotype on MFFS.
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: D
authors.initials: D
authors.lastname: Barraco
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cerquozzi
authors.affiliation: Department of Laboratory and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Hanson
authors.affiliation: Department of Laboratory and Pathology, Mayo Clinic, Rochester, MN, USA.
authors.forename: R P
authors.initials: RP
authors.lastname: Ketterling
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Pardanani
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: N
authors.initials: N
authors.lastname: Gangat
authors.affiliation: Division of Hematology, Department of Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: A
authors.initials: A
authors.lastname: Tefferi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D001706:Biopsy; D001853:Bone Marrow / Q000378:metabolism / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D006801:Humans; D053614:Janus Kinase 2 / Q000235:genetics; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011087:Polycythemia Vera / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality*; D055728:Primary Myelofibrosis / Q000175:diagnosis / Q000401:mortality; D011379:Prognosis; D012155:Reticulin / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D012155:Reticulin; D053614:Janus Kinase 2