title: Granulocyte-macrophage colony-stimulating factor treatment before doxorubicin and cyclophosphamide chemotherapy priming in women with early-stage breast cancer.
abstract: OBJECTIVE
  To determine if inhibition of stem-cell activity induced by granulocyte-macrophage colony-stimulating factor ([GM-CSF]; Sargramostim; Immunex Corporation, Seattle, WA) withdrawal or priming protects hematopoietic stem cells from the cytotoxic effects of adjuvant chemotherapy for early-stage breast cancer.
  
  
  METHODS
  Serial blood counts were performed in 20 women with early-stage breast cancer receiving four courses of cyclophosphamide and doxorubicin chemotherapy. By a double-blind, placebo-controlled, balanced randomization, subjects received GM-CSF priming on days 5 to 1 for courses 1 and 3 or courses 2 and 4.
  
  
  RESULTS
  Compared with before priming, after priming the times to neutrophil nadir (12.8 +/- 2.5 days v 14.8 +/- 1.5 days, respectively; P =.0001) and platelet nadir (mean +/- SD, 10.1 +/- 1.9 days v 11.1 +/- 2.2 days, P <.05) were shorter, indicating a shift of cytotoxicity to later progenitors. The neutrophil nadir was similar with and without priming (mean +/- SD, 490 +/- 310/microL v 550 +/- 350/microL, respectively; P =.2); however, on day 16 the mean neutrophil count was higher (mean +/- SD, 1030 +/- 580/microL v 690 +/- 370/microL, P =.004), and the proportion of patients with a neutrophil count less than 500/microL was lower after priming than before (six of 35 or 17. 1% v 12 of 34 or 35.3%, respectively; P =.04). The platelet nadir was higher (mean +/- SD, 166,000 +/- 51,000/microL after priming v 151,000 +/- 45,000/microL before priming, P =.007), and the duration of thrombocytopenia, ie, a platelet count less than 150,000/microL, was shorter (1.5 +/- 2.1 days v 2.8 +/- 2.9 days, P =.0025) after priming. Episodes of fever and neutropenia were not observed.
  
  
  CONCLUSIONS
  GM-CSF priming from days 5 to 1 before doxorubicin and cyclophosphamide chemotherapy was associated with an earlier neutrophil and platelet nadir. On day 16, a higher mean neutrophil count and a lower proportion of patients with severe (< 500/microL) neutropenia were observed. Beneficial effects on the severity and duration of thrombocytopenia were also noted. These observations support the hypothesis that GM-CSF priming protects hematopoietic progenitors from the cytotoxic effects of chemotherapy.
authors.affiliation: MeritCare Roger Maris Cancer Center, Fargo, ND 58122, USA.
authors.forename: N L
authors.initials: NL
authors.lastname: Kobrinsky
authors.forename: D E
authors.initials: DE
authors.lastname: Sjolander
authors.forename: M S
authors.initials: MS
authors.lastname: Cheang
authors.forename: R
authors.initials: R
authors.lastname: Levitt
authors.forename: P D
authors.initials: PD
authors.lastname: Steen
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy*; D003520:Cyclophosphamide / Q000008:administration & dosage; D004311:Double-Blind Method; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged
chemical_list: D004317:Doxorubicin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D003520:Cyclophosphamide