title: Assessment and prognostic value of the European LeukemiaNet criteria for clinicohematologic response, resistance, and intolerance to hydroxyurea in polycythemia vera.
abstract: Criteria of response and definition of resistance and intolerance to hydroxyurea (HU) in polycythemia vera (PV) were proposed by the European LeukemiaNet (ELN). Such criteria were evaluated in 261 PV patients (median follow-up, 7.2 years) treated with HU for a median of 4.4 years. Complete response, partial response, and no response were observed in 24%, 66%, and 10% of patients, respectively. Achieving ELN response (complete or partial) or hematocrit response did not result in better survival or less thrombosis and bleeding. On the contrary, having no response in leukocyte count was associated with higher risk of death (HR, 2.7; 95% confidence interval [CI], 1.3%-5.4%; P = .007), whereas lack of response in platelet count involved a higher risk of thrombosis and bleeding. Resistance and intolerance to HU was registered in 11% and 13% of patients, respectively. Resistance to HU was associated with higher risk of death (HR, 5.6; 95% CI, 2.7%-11.9%; P < .001) and transformation (HR, 6.8; 95% CI, 3.0%-15.4%; P < .001). In summary, fulfilling the ELN definition for response to HU was not associated with a benefit in the clinical outcome in PV, whereas response in platelet and white blood cell counts were predictive of less thrombohemorrhagic complications and better prognosis, respectively. Resistance to HU was an adverse prognostic factor.
authors.affiliation: Department of Hematology, Hospital del Mar, Passeig Marítim 25-29, Barcelona, Spain. 95967@parcdesalutmar.cat
authors.forename: Alberto
authors.initials: A
authors.lastname: Alvarez-Larrán
authors.forename: Arturo
authors.initials: A
authors.lastname: Pereira
authors.forename: Francisco
authors.initials: F
authors.lastname: Cervantes
authors.forename: Eduardo
authors.initials: E
authors.lastname: Arellano-Rodrigo
authors.forename: Juan-Carlos
authors.initials: JC
authors.lastname: Hernández-Boluda
authors.forename: Francisca
authors.initials: F
authors.lastname: Ferrer-Marín
authors.forename: Anna
authors.initials: A
authors.lastname: Angona
authors.forename: Montse
authors.initials: M
authors.lastname: Gómez
authors.forename: Begoña
authors.initials: B
authors.lastname: Muiña
authors.forename: Helga
authors.initials: H
authors.lastname: Guillén
authors.forename: Anabel
authors.initials: A
authors.lastname: Teruel
authors.forename: Beatriz
authors.initials: B
authors.lastname: Bellosillo
authors.forename: Carmen
authors.initials: C
authors.lastname: Burgaleta
authors.forename: Vicente
authors.initials: V
authors.lastname: Vicente
authors.forename: Carles
authors.initials: C
authors.lastname: Besses
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic; D004351:Drug Resistance; D004361:Drug Tolerance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019384:Nucleic Acid Synthesis Inhibitors / Q000627:therapeutic use; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000592:standards*; D010976:Platelet Count; D011087:Polycythemia Vera / Q000188:drug therapy*; D011379:Prognosis; D012074:Remission Induction; D018570:Risk Assessment; D012307:Risk Factors; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D006918:Hydroxyurea