Filgrastim-mediated neutrophil recovery in patients with breast cancer treated with docetaxel and doxorubicin.
OBJECTIVE
To study the impact of filgrastim 5 microg/kg given once/day through absolute neutrophil count (ANC) recovery on the duration of grade 4 neutropenia (ANC < 0.5 x 10(3)/mm3) and time to ANC recovery. Additional objectives were to study the average number of filgrastim injections/cycle required to achieve ANC recovery and differences in outcome by cycle.


METHODS
Combined analysis of two double-blind, randomized, multicenter trials.


METHODS
Two hundred twenty-two patients treated for breast cancer.


RESULTS
All patients but one were evaluable for efficacy end points. Mean +/- SD duration of grade 4 neutropenia was 1.7 +/- 1.3 days in cycle 1; the duration decreased in cycles 2-4 to between 1.0 and 1.2 days. Fifty percent of patients had ANC recovery to 10 x 10(3)/mm3 or greater by day 11 of the cycle, and 90% by day 13, corresponding to 10 and 12 days of filgrastim administration, respectively. Across all cycles, the mean +/- SD number of filgrastim injections/cycle was 10.51 +/- 1.70, with little variation among cycles.


CONCLUSIONS
When filgrastim is administered as recommended, starting 24 hours after chemotherapy and continuing through an ANC of 10 x 10(3)/mm3 or greater, neutrophil recovery is rapid and predictable. Because the first cycle of chemotherapy has the highest rates of neutropenia and febrile neutropenia, it seems prudent to administer growth factor support preemptively.
Meza
Luis A
LA
Southwest Oncology Associates, Lafayette, Louisiana 70503, USA.
Green
Michael D
MD
Hackett
James R
JR
Neumann
Theresa A
TA
Holmes
Frankie A
FA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage / Q000009:adverse effects*; D001943:Breast Neoplasms / Q000097:blood / Q000188:drug therapy*; D000077143:Docetaxel; D004317:Doxorubicin / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D000069585:Filgrastim; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000097:blood / Q000139:chemically induced* / Q000188:drug therapy*; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects; D011994:Recombinant Proteins; D043823:Taxoids / Q000008:administration & dosage / Q000009:adverse effects; D013997:Time Factors
D011994:Recombinant Proteins; D043823:Taxoids; D016179:Granulocyte Colony-Stimulating Factor; D000077143:Docetaxel; D004317:Doxorubicin; D000069585:Filgrastim