title: Suboptimal duration of granulocyte colony-stimulating factor use and chemotherapy-induced neutropenia in women diagnosed with breast cancer.
abstract: OBJECTIVE
  Prophylactic use of granulocyte colony-stimulating factor (G-CSF) is recommended for cancer patients who are at high risk of neutropenic events. However, whether the clinical effectiveness of G-CSF from randomized controlled trials translates into "real-world" clinical practice is questionable. The goal of this retrospective cohort study was to examine the impact of G-CSF prophylaxis and other potential risk factors of severe neutropenia in women with breast cancer.
  
  
  METHODS
  Our study subjects were women who were diagnosed with breast cancer and who received a new course of chemotherapy between January 1, 2010, and December 31, 2010, at a cancer center in Taiwan. Generalized estimating equations were applied to examine the association between G-CSF prophylaxis and neutropenic events.
  
  
  RESULTS
  We identified 353 women with breast cancer who received a total of 2776 cycles of chemotherapy. G-CSF was used as primary prophylaxis in 7% (n = 202) of cycles and as secondary prophylaxis in 11% (n = 319) of cycles. The mean duration of G-CSF for primary and secondary prophylaxis was 4.9 and 3.7 days, respectively. A chemotherapy regimen with high risk of febrile neutropenia was found to be a risk factor for severe neutropenic events (odds ratio, 3.22 [95% CI, 1.97-5.27]). Prophylactic use of G-CSF was not statistically significantly associated with febrile neutropenia.
  
  
  CONCLUSIONS
  The major determinants of neutropenic events among patients with breast cancer were the content and intensity of chemotherapy regimens. Suboptimal use of G-CSF may not be effective in preventing neutropenic events among women with breast cancer.
authors.affiliation: (1)Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Wan-Ting
authors.initials: WT
authors.lastname: Lin
authors.affiliation: (2)Clinical Informatics and Medical Statistics Research Center, Chang Gung University, Tao-Yuan, Taiwan.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Wen
authors.affiliation: Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chun-Ru
authors.initials: CR
authors.lastname: Chien
authors.affiliation: (5)Center for Drug Evaluation, Taipei, Taiwan.
authors.forename: Churn-Shiouh
authors.initials: CS
authors.lastname: Gau
authors.affiliation: (6)Koo Foundation Sun Yat-Sen Cancer Center, Taipei, Taiwan.
authors.forename: Shao C
authors.initials: SC
authors.lastname: Chiang
authors.affiliation: (1)Graduate Institute of Clinical Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan; (7)School of Pharmacy, College of Medicine, National Taiwan University, Taipei, Taiwan; (8)Department of Pharmacy, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: fyshsiao@ntu.edu.tw.
authors.forename: Fei-Yuan
authors.initials: FY
authors.lastname: Hsiao
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000188:drug therapy*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000008:administration & dosage*; D006801:Humans; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan
chemical_list: D016179:Granulocyte Colony-Stimulating Factor
keywords: FN, neutropenia; G-CSF; breast cancer; febrile neutropenia; granulocyte colony–stimulating factor