title: 20+ yr without leukemic or fibrotic transformation in essential thrombocythemia or polycythemia vera: predictors at diagnosis.
abstract: OBJECTIVE
  The current study identified patients with either essential thrombocythemia (ET) or polycythemia vera (PV) who have survived for at least 20 yr without the development of either acute myeloid leukemia/myelodysplastic syndrome (AML/MDS) or myelofibrosis (MF) and compared their presenting features with those in whom these complications occurred in the first 10 yr of disease.
  
  
  METHODS
  The study patients were selected from an institutional database of 1061 patients with either ET (n = 603) or PV (n = 458). In both instances, three distinct groups were delineated and their presenting features compared; group A included patients who have remained AML/MDS/MF free after a minimum follow-up of 20 yr; groups B and C included patients who developed either AML/MDS or MF, respectively, in the first decade of their disease.
  
  
  RESULTS
  The respective number of patients who fulfilled the above-mentioned criteria for inclusion in groups A, B and C were 40, 12 and 8 for ET and 23, 18 and 12 for PV. In ET, compared with both groups B and C, group A displayed significantly fewer patients with less than normal hemoglobin level (P < 0.0001 and =0.02) or male sex (P = 0.005 and 0.05), respectively. On multivariable analysis, only anemia sustained its significance. A similar analysis in PV revealed an association between group B and leukocytosis using a leukocyte count threshold of either 10 or 15 x 10(9)/L (P = 0.02).
  
  
  CONCLUSIONS
  The current study identifies PV patients with leukocytosis and ET patients with anemia as the most likely to undergo leukemic or fibrotic transformation.
authors.affiliation: Division of Hematology, Mayo Clinic, Rochester, MN 55905, USA. tefferi.ayalew@mayo.edu
authors.forename: Ayalew
authors.initials: A
authors.lastname: Tefferi
authors.forename: Naseema
authors.initials: N
authors.lastname: Gangat
authors.forename: Alexandra P
authors.initials: AP
authors.lastname: Wolanskyj
authors.forename: Susan
authors.initials: S
authors.lastname: Schwager
authors.forename: Animesh
authors.initials: A
authors.lastname: Pardanani
authors.forename: Terra L
authors.initials: TL
authors.lastname: Lasho
authors.forename: Ruben
authors.initials: R
authors.lastname: Mesa
authors.forename: Rebecca F
authors.initials: RF
authors.lastname: McClure
authors.forename: Chin-Yang
authors.initials: CY
authors.lastname: Li
authors.forename: Curtis A
authors.initials: CA
authors.lastname: Hanson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005355:Fibrosis / Q000473:pathology; D006801:Humans; D007938:Leukemia / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011087:Polycythemia Vera / Q000175:diagnosis* / Q000453:epidemiology; D013920:Thrombocythemia, Essential / Q000175:diagnosis* / Q000453:epidemiology; D013997:Time Factors