title: Effect of Red Blood Cell Transfusion Dependence on the Natural History of Myeloproliferative Neoplasm-Associated Myelofibrosis.
abstract: BACKGROUND
  There are 2 widely used criteria for red blood cell (RBC) transfusion dependence in persons with myeloproliferative neoplasm (MPN)-associated myelofibrosis: (1) the International Working Group-Myelofibrosis Research and Therapy (IWG-MRT) criteria (receipt of 2 U RBC in the preceding month); and (2) the Rand-Delphi definition (2 U RBC per month averaged over 3 months). We studied effect of these criteria on survival and risk of leukemic transformation in 259 subjects with MPN-associated myelofibrosis.
  
  
  METHODS
  On the basis of hemoglobin (Hb) and transfusion history, subjects were assigned to 1 of the 4 cohorts: (1) Hb ≥ 100 g/L (n = 136; 52%) and no RBC transfusions in the preceding 4 months; (2) Hb < 100 g/L, and no RBC transfusions in the preceding 4 months (n = 56; 22%); (3) subjects who met IWG-MRT criteria, but not the Rand-Delphi criteria for RBC transfusion dependence (n = 34; 13%); and (4) subjects who met the Rand-Delphi criteria for RBC transfusion dependence (n = 33; 13%).
  
  
  RESULTS
  Three-year probability of survival among the 4 cohorts was 81% (95% confidence interval [CI], 71-87), 55% (95% CI, 36-71), 52% (95% CI, 31-69), and 47% (95% CI, 24-67), respectively (P = .0005). There was no significant difference in baseline characteristics or survival between cohorts 3 and 4 and they were combined for subsequent analyses. In multivariate analyses, subjects who met either definition of RBC transfusion dependence had significantly worse survival (hazard ratio, 2.61; 95% CI, 1.38-4.96; P = .01).
  
  
  CONCLUSIONS
  RBC transfusion dependence is associated with worse survival irrespective of definition of transfusion dependence. No effect of anemia or RBC transfusion dependence on leukemic transformation was observed.
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Justyna
authors.initials: J
authors.lastname: Bartoszko
authors.affiliation: Department of Biostatistics, Princess Margaret Cancer Center, Toronto, Ontario, Canada.
authors.forename: Tony
authors.initials: T
authors.lastname: Panzarella
authors.affiliation: Department of Biostatistics, Princess Margaret Cancer Center, Toronto, Ontario, Canada.
authors.forename: Anthea
authors.initials: A
authors.lastname: Lau
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Aaron
authors.initials: A
authors.lastname: Schimmer
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Andre
authors.initials: A
authors.lastname: Schuh
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Shanavas
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Karen
authors.initials: K
authors.lastname: Yee
authors.affiliation: Medical Oncology and Hematology, Princess Margaret Cancer Center, University of Toronto, Toronto, Ontario, Canada. Electronic address: vikas.gupta@uhn.ca.
authors.forename: Vikas
authors.initials: V
authors.lastname: Gupta
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016026:Bone Marrow Transplantation; D015331:Cohort Studies; D003131:Combined Modality Therapy; D018450:Disease Progression; D017707:Erythrocyte Transfusion; D005260:Female; D006454:Hemoglobins; D006801:Humans; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D055728:Primary Myelofibrosis / Q000175:diagnosis / Q000401:mortality / Q000473:pathology* / Q000628:therapy*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D006454:Hemoglobins
keywords: Anemia; Criteria; Myelofibrosis; Prognosis; Transfusion dependency