title: Leukemic transformation of polycythemia vera: a single center study of 23 patients.
abstract: BACKGROUND
  Acute leukemia (AL) may occur as rare and late event of polycythemia vera (PV).
  
  
  METHODS
  The current study included 23 patients who developed acute leukemia in a cohort of 414 consecutive PV patients with long-term observation (3208 person years of follow-up). Kaplan-Meier Product-Limit method was used to estimate the cumulative probability of survival; Gehan-Wilcoxon test was applied to compare survival in different groups of patients.
  
  
  RESULTS
  Median age was 68 years, and 18 patients (78%) were > 60 years of age. At diagnosis of AL, most patients had a white blood count > 10 x 10(9)/L (n = 17; 74%), Hgb < 10 g/dL (n = 13; 57%), and platelet count > 50 x 10(9)/L (n = 17; 74%). Of 14 patients in whom cytogenetic analysis was available at leukemic transformation, 12 showed high-risk abnormalities including complex karyotype (n = 10), del (7)(q22) sole (n = 1) and del (X)(q26) sole (n = 1), whereas 2 had a normal karyotype. In patients whose karyotype was available at diagnosis of PV, cytogenetic evolution was documented at progression to AL. Treatment consisted of supportive care and/or low-dose chemotherapy (n = 15), or induction chemotherapy (n = 8). This included idarubicin plus cytarabine (n = 3), high-dose cytarabine (n = 4), and fludarabine-based regimen (n = 1). Allogenic stem cell transplantation was offered to a single patient, who is alive at Day + 70. The outcome of patients was poor, with a median survival of 2.9 months (range, 0.6-20.1 mos), with no significant differences between palliation and intensive treatments.
  
  
  CONCLUSIONS
  AL following PV has distinct clinical and biologic features. Outcome of patients is poor irrespective of the treatment employed.
authors.affiliation: Division of Hematology, IRCCS San Matteo Polyclinic, University of Pavia, Pavia, Italy. f.passamonti@smatteo.pv.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Passamonti
authors.forename: Elisa
authors.initials: E
authors.lastname: Rumi
authors.forename: Luca
authors.initials: L
authors.lastname: Arcaini
authors.forename: Carlo
authors.initials: C
authors.lastname: Castagnola
authors.forename: Monia
authors.initials: M
authors.lastname: Lunghi
authors.forename: Paolo
authors.initials: P
authors.lastname: Bernasconi
authors.forename: Matteo
authors.initials: M
authors.lastname: Giovanni Della Porta
authors.forename: Nora
authors.initials: N
authors.lastname: Columbo
authors.forename: Cristiana
authors.initials: C
authors.lastname: Pascutto
authors.forename: Mario
authors.initials: M
authors.lastname: Cazzola
authors.forename: Mario
authors.initials: M
authors.lastname: Lazzarino
mesh_terms: D000208:Acute Disease; D000368:Aged; D002869:Chromosome Aberrations; D006801:Humans; D007621:Karyotyping; D007938:Leukemia / Q000188:drug therapy / Q000209:etiology*; D008875:Middle Aged; D011087:Polycythemia Vera / Q000150:complications* / Q000235:genetics