Timely Withdrawal of G-CSF Reduces the Occurrence of Thrombocytopenia During Dose-dense Chemotherapy

Efficacy of delayed administration of post-chemotherapy granulocyte colony-stimulating factor: evidence from murine studies of bone marrow cell kinetics

The optimal schedule of post-chemotherapy granulocyte colony-stimulating factor (G-CSF) administration has not been determined. G-CSF is customarily started 24 hours after chemotherapy; however, clinical data demonstrated that delaying G-CSF until 5 days after completion of chemotherapy has not resulted in a longer duration of neutropenia. Here, we examined the optimal timing of post-chemotherapy G-CSF administration in a mouse model, to show that delayed administration does not postpone the appearance of mature granulocytes in the peripheral blood. We also investigated the mechanism of decreased efficacy of the early G-CSF application after chemotherapy by characterizing the changes in bone marrow cellular composition. To our knowledge, we demonstrate for the first time, that early after chemotherapy, the bone marrow is predominantly composed of mature residual granulocytes and very few progenitors and precursors, on which G-CSF would act to generate granulocytes. The point when immature progenitors reappear does not occur in murine bone marrow until 48 hours after a single dose of cyclophosphamide. Our results indicate that the bone marrow cellular composition early after discontinuation of chemotherapy is not optimal for G-CSF action on acceleration of myeloid recovery. Given the high cost of G-CSF prophylaxis, its delayed administration may potentially result in substantial economic benefits.

Prevention of chemotherapy-induced febrile neutropenia by prophylactic antibiotics plus or minus granulocyte colony-stimulating factor in small-cell lung cancer: a Dutch Randomized Phase III Study

PURPOSE

Febrile neutropenia (FN) is a major complication of chemotherapy. Antibiotics as well as granulocyte colony-stimulating factor (G-CSF) are effective in preventing FN. This multicenter randomized phase III trial determines whether the addition of G-CSF to antibiotic prophylaxis can further reduce the incidence of FN in patients with small-cell lung cancer (SCLC) at the risk of FN.

PATIENTS AND METHODS

Patients (N = 175) were stratified for stage of disease, performance status, age, and prior chemotherapy treatment, and were randomly assigned for treatment with cyclophosphamide, doxorubicin, and etoposide (CDE), followed by prophylactic antibiotics alone (ciprofloxacin and roxithromycin) or by antibiotics in combination with G-CSF on days 4 to 13.

RESULTS

In cycle 1, 20 patients (24%) in the antibiotics group developed FN compared with nine patients (10%) in the antibiotics plus G-CSF group (P = .01). In cycles 2 to 5, the incidences of FN were practically the same in both groups (17% v 11%). Only the treatment parameters (odds ratio, 0.33; 95% CI, 0.14 to 0.78) and age (1.067 per year; 95% CI, 1.013 to 1.0124) were related to the probability of FN in cycle 1.

CONCLUSION

Primary G-CSF prophylaxis added to primary antibiotic prophylaxis is effective in reducing FN and infections in SCLC patients at the risk of FN with the first cycle of CDE chemotherapy. For patients with similar risk of FN, the combined use of prophylactic antibiotics plus G-CSF can be considered, specifically in the first cycle of chemotherapy.