Background: The prophylactic use of hematopoietic growth factors has been shown to reduce the duration of neutropenia and related complications encountered after anticancer chemotherapy. However, the optimal timing for initiation of granulocyte colony-stimulating factor (G-CSF) has not been established.
Procedure: We evaluated the clinical parameters of the early versus delayed start (+1 day vs. +5 days postchemotherapy) of filgrastim (G-CSF; 5 micrograms/kg) after 36 courses of anticancer chemotherapy in 18 children with cancer in randomized fashion. Each child received two identical anticancer chemotherapeutic courses followed by one early (group 1) and one delayed (group 2) administration of G-CSF. Filgrastim was administered until absolute neutrophil count (ANC) exceeded 1.0 x 10(9)/l.
Results: The mean duration of G-CSF therapy was 8.6 (range, 5-14) days in group 1 and 5.4 (range, 3-10) days in group 2 (P = 0.001). The mean duration of neutropenia (ANC < 1.0 x 10(9)/l) did not differ between the study groups (7.8 vs. 8.2 days). Seven infection episodes occurred in group 1 and eight in group 2, respectively. The mean number of hospital days on broad-spectrum antibiotics was 2.3 (range, 0-8) in group 1 and 3.3 (range, 0-11) in group 2 (ns).
Conclusions: We conclude that the delayed start of filgrastim reduced the costs of this treatment, but was not followed by more prolonged neutropenia or febrile neutropenias.