Impact of colony-stimulating factors to reduce febrile neutropenic events in breast cancer patients receiving docetaxel plus cyclophosphamide chemotherapy.
BACKGROUND
Data from US Oncology Adjuvant Trial 9735 has shown that four cycles of docetaxel plus cyclophosphamide (TC) improved disease-free and overall survival when compared against doxorubicin and cyclophosphamide (AC) in early-stage breast cancer. The febrile neutropenia (FN) rate was 4% in this study without primary granulocyte colony-stimulating factors (G-CSF) prophylaxis. However, the incidence of docetaxel-induced myelosuppression is recognized to be higher among Asian population. Hence, this study was designed to evaluate the impact of G-CSF to reduce FN-related events in Asian cancer patients treated with TC.


METHODS
This retrospective cohort study was conducted on Asian breast cancer patients who have received intravenous docetaxel 75 mg/m(2) and cyclophosphamide 600 mg/m(2) between 2006 to 2008. Patients did not receive oral antibiotic prophylaxis, and prophylactic G-CSF after chemotherapy was prescribed under the discretion of the primary oncologist.


RESULTS
During cycle 1 of chemotherapy, 6.3% patients received G-CSF manifested FN, while 25% patients who did not receive G-CSF manifested FN (RR = 0.252, 95% CI 0.102 to 0.622). Introduction of G-CSF as primary prophylaxis provided an absolute risk reduction of FN events by 18.7%. Chemotherapy doses were maintained throughout all cycles. Patients with pretreatment white blood cell counts (WBC) below 6.0 × 10(3)/mm(3) and absolute neutrophil counts (ANC) below 3.1 × 10(3)/mm(3) were associated with higher rates of FN during Cycle 1 (p = 0.009, p = 0.007).


CONCLUSIONS
Our findings indicate that TC was associated with higher rates of FN than reported in the clinical trial. The 25% incidence fulfills the requirement of primary prophylaxis with G-CSF. Routine administration of G-CSF is highly recommended to reduce the rates of FN in breast cancer patients receiving TC.
Department of Pharmacy, Faculty of Science, National University of Singapore, Singapore, Singapore. phaac@nus.edu.sg
Alexandre
A
Chan
Wing Hang
WH
Fu
Vivianne
V
Shih
Jurja Chua
JC
Coyuco
Sze Huey
SH
Tan
Raymond
R
Ng
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects* / Q000627:therapeutic use; D044466:Asian People; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D015331:Cohort Studies; D003520:Cyclophosphamide / Q000008:administration & dosage; D000077143:Docetaxel; D005260:Female; D005334:Fever / Q000139:chemically induced / Q000517:prevention & control; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced / Q000517:prevention & control*; D012189:Retrospective Studies; D012307:Risk Factors; D043823:Taxoids / Q000008:administration & dosage; D016896:Treatment Outcome
D043823:Taxoids; D016179:Granulocyte Colony-Stimulating Factor; D000077143:Docetaxel; D003520:Cyclophosphamide