title: Timely withdrawal of G-CSF reduces the occurrence of thrombocytopenia during dose-dense chemotherapy.
abstract: BACKGROUND
  Post chemotherapy Granulocyte colony stimulating factor (G-CSF) reduces leucopenia, while G-CSF priming shortly before chemotherapy increases myelotoxicity. We performed a trial with a two-schedule crossover design to determine the optimal G-CSF schedule for densified 2-weekly chemotherapy.
  
  
  METHODS
  During 2-weekly chemotherapy days 1 and 2, G-CSF was given on days 3-10, with a G-CSF-free interval before the next chemotherapy cycle of 5 days, or on days 3-13, with a G-CSF-free interval of 2 days. In schedule A, cycle II was preceded by a 5 days, cycle III and IV by a 2 days and cycle V by a 5 days G-CSF free interval. In schedule B, this was 2, 5, 5, and 2 days, respectively.
  
  
  RESULTS
  Intra-patient comparison for cycles II versus III and cycles IV versus V showed that platelet (PLT) nadir count was significantly lower for cycles preceded by a 2-days compared to a 5-days G-CSF free interval: mean difference 45.7 x 10(9)/l (95% CI 33.2-58.2, p = 0.0001). Neutrophil count did not differ significantly (p = 0.85).
  
  
  CONCLUSIONS
  Timely withdrawal of G-CSF in dose-dense chemotherapy reduces chemotherapy-related thrombocytopenia. Leucopenia was not aggravated, reflecting a protective effect of post-chemotherapy G-CSF.
authors.affiliation: Department of Medical Oncology (550), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. J.Timmer@onco.umcn.nl
authors.forename: J N H
authors.initials: JN
authors.lastname: Timmer-Bonte
authors.forename: P H M
authors.initials: PH
authors.lastname: de Mulder
authors.forename: P G M
authors.initials: PG
authors.lastname: Peer
authors.forename: L V A M
authors.initials: LV
authors.lastname: Beex
authors.forename: V C G
authors.initials: VC
authors.lastname: Tjan-Heijnen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy*; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D007958:Leukocyte Count; D008875:Middle Aged; D010976:Platelet Count; D011379:Prognosis; D013921:Thrombocytopenia / Q000517:prevention & control*; D016896:Treatment Outcome
chemical_list: D016179:Granulocyte Colony-Stimulating Factor