Leukemic transformation of polycythemia vera: a single center study of 23 patients.
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.
Passamonti
Francesco
F
Division of Hematology, IRCCS San Matteo Polyclinic, University of Pavia, Pavia, Italy. f.passamonti@smatteo.pv.it
Rumi
Elisa
E
Arcaini
Luca
L
Castagnola
Carlo
C
Lunghi
Monia
M
Bernasconi
Paolo
P
Giovanni Della Porta
Matteo
M
Columbo
Nora
N
Pascutto
Cristiana
C
Cazzola
Mario
M
Lazzarino
Mario
M
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