Delayed introduction of G-CSF after chemotherapy does not affect peripheral blood stem cell yield and engraftment kinetics in children with high-risk malignancies: retrospective study of 45 cases

Mobilization strategies for the collection of peripheral blood progenitor cells: Results from a pilot study of delayed addition G-CSF following chemotherapy and review of the literature

OBJECTIVE

Given the potential to limit cost, we conducted a pilot study evaluating delayed, low-dose granulocyte colony-stimulating factor (G-CSF) following chemotherapy for the procurement of peripheral blood progenitor cells (PBPCs) for autologous transplantation and reviewed the relevant literature.

PATIENTS AND METHODS

Twenty-eight patients with various malignancies received cyclophosphamide 4 gm/m(2) and paclitaxel 170 mg/m2 followed by G-CSF 300 microg/d or 480 microg/d starting day +5 until two to four daily large volume leukapheresis yielded > or =5.0 x 10(6) CD34+ cells. We searched MEDLINE, Pubmed, and EMBASE databases from 1990 to the present to identify papers on PBPC procurement using delayed G-CSF (starting day +4 or later) following chemotherapy.

RESULTS

G-CSF was administered for a median of 9 days at an average cost of 1260 USD per 70-kg patient. Collection was initiated at a median of 12 days after chemotherapy. A median 2.5 (range 2-4) apheresis were performed yielding an average daily CD34+ collection of 6.9 x 10(6)/kg (range 0.35-56.7). After one apheresis, 82% and 57% of patients collected > or =2.5 x 10(6)/kg and > or =5.0 x 10(6)/kg, respectively. Ultimately, 89% collected > or =5.0 x 10(6)/kg. Febrile neutropenia and catheter-related infection developed in five and two patients, respectively. All patients proceeded to transplantation and engrafted successfully with a median of 14.9 x 10(6)/kg (range 1.05-113) cells infused. Eleven published reports were identified involving 590 patients of whom 498 received G-CSF at a dose range of 250 microg/d to 10 microg/kg/d starting day +4 to 15 for a period of 4 to 9 days for PBPC procurement. Among these reports, 62 to 100% and 33 to 96% of patients collected > or =2 to 2.5 x 10(6) and > or =5.0 x 10(6) CD34+ cells, respectively.

CONCLUSION

The use of delayed, low-dose G-CSF plus chemotherapy for stem cell mobilization was feasible and provides further evidence supporting this potentially cost-effective strategy. A review of the literature supports our findings and emphasizes the need for larger studies to address this issue.

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.

Prophylactic colony-stimulating factors in children receiving myelosuppressive chemotherapy: A meta-analysis of randomized controlled trials

BACKGROUND

The colony-stimulating factors (CSFs) are widely utilized to prevent neutropenic complications in both adults and children, but randomized controlled trials in the pediatric setting have reported varied results. A systematic review of the literature and meta-analysis were conducted to definitively assess the impact of prophylactic CSFs on the risk of febrile neutropenia (FN) in pediatric oncology patients.

METHODS

MEDLINE was searched and references hand-searched through July 2004 for randomized controlled trials of prophylactic G-CSF or GM-CSF in pediatric oncology patients. Objectives, outcomes, and quality of the 16 included studies were extracted by two reviewers. Weighted summary estimates of relative risks (RR) were calculated for FN and documented infection (DI). Mean differences in hospitalization, antibiotic use, and duration of neutropenia were calculated.

RESULTS

FN occurred in 68% of 400 controls and 59% of 404 CSF patients. The estimated RR was 0.88 [0.81-0.97; (P=0.01)] favoring the CSFs for leukemia and high grade lymphoma studies and 0.71 [0.51-0.97; (P=0.03)] for solid tumor studies. DI occurred in 25% of controls and 20% of CSF patients for an estimated RR of 0.80 [0.61-1.06; (P=0.12)]. The mean decrease in duration of neutropenia was 3.5 days [2.2-4.7; (P<0.0001)]. Mean decreases favoring CSF use were also observed for hospital stay of 1.7 days [0.9-2.5 (P<0.01)] and antibiotic use of 2.0 days [0.4-3.6; P=0.02].

CONCLUSIONS

Prophylactic CSFs significantly decrease the incidence of FN and the durations of severe neutropenia, hospitalization, and antibiotic use in pediatric cancer patients, but they do not significantly decrease documented infections.