The detection of flow cytometric G-CSF receptor expression and it's effect on therapy in acute myeloid leukemia

The Impact of Prophylactic Post-Chemotherapy G-CSF on the Relapse Rates in Patients with Acute Myeloid Leukemia: A Meta-Analysis

This meta-analysis evaluated the impact of prophylactic post-chemotherapy granulocyte colony-stimulating factor (G-CSF) in patients with acute myeloid leukemia (AML). Overall, the relapse rate, overall survival, event-free survival, and mortality rate were similar in G-CSF (+) compared to G-CSF (-) patients. However, the relative risk (RR) of relapse was higher in children and in secondary AML patients who were treated with G-CSF compared to the G-CSF (-) group [RR, 95% confidence interval: 1.26, 1.04-1.52, and 1.12 (1.02-1.24)]. Treatment with post-chemotherapy G-CSF should be prescribed with caution in pediatric patients with AML and secondary AML as possibly increasing the relapse risk.

Effects of priming with recombinant human granulocyte colony-stimulating factor on conditioning regimen for high-risk acute myeloid leukemia patients undergoing human leukocyte antigen-haploidentical hematopoietic stem cell transplantation: a multicenter randomized controlled study in southwest China

HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) is an effective and immediate treatment for high-risk acute myeloid leukemia (HR-AML) patients lacking matched donors. Relapse remains the leading cause of death for HR-AML patients after haplo-HSCT. Accordingly, the prevention of relapse remains a challenge in the treatment of HR-AML. In a multicenter randomized controlled trial in southwestern China, 178 HR-AML patients received haplo-HSCT with conditioning regimens involving recombinant human granulocyte colony-stimulating factor (rhG-CSF) or non-rhG-CSF. The cumulative incidences of relapse and graft-versus-host disease (GVHD), 2-year leukemia-free survival (LFS), and overall survival (OS) were evaluated. HR-AML patients who underwent the priming conditioning regimen with rhG-CSF had a lower relapse rate than those who were treated with non-rhG-CSF (38.2%; 95% confidence interval [CI], 28.1% to 48.3% versus 60.7%, 95% CI, 50.5% to 70.8%; P < .01). The cumulative incidences of acute GVHD, chronic GVHD, transplantation-related toxicity, and infectious complications appeared to be equivalent. In total, 53 patients in the rhG-CSF-priming group and 31 patients in the non-rhG-CSF-priming group were still alive at the median follow-up time of 42 months (range, 24 to 80 months). The 2-year probabilities of LFS and OS in the rhG-CSF-priming and non-rhG-CSF-priming groups were 55.1% (95% CI, 44.7% to 65.4%) versus 32.6% (95% CI, 22.8% to 42.3%) (P < .01) and 59.6% (95% CI, 49.4% to 69.7%) versus 34.8% (95% CI, 24.9% to 44.7%) (P < .01), respectively. Multivariate analyses indicated that the 2-year probability of LFS of patients who achieved complete remission (CR) before transplantation was better than that of patients who did not achieve CR. The 2-year probability of LFS of patients with no M4/M5/M6 subtype was better than that of patients with the M4/M5/M6 subtype in the G-CSF-priming group (67.4%; 95% CI, 53.8% to 80.9% versus 41.9%; 95% CI, 27.1% to 56.6%; P < .05). This study suggests that the rhG-CSF-priming conditioning regimen is an acceptable choice for HR-AML patients, especially for the patients with no M4/M5/M6 subtype who achieved CR before transplantation.

Use of G-CSF to hasten neutrophil recovery after auto-SCT for AML is not associated with increased relapse incidence: a report from the Acute Leukemia Working Party of the EBMT

Application of G-CSF in AML is controversial as leukemic blasts may express receptors interacting with the cytokine, which may stimulate leukemia growth. We retrospectively analyzed the impact of G-CSF use to accelerate neutrophil recovery after auto-SCT on outcome. Adults with AML in first CR autografted between 1994 and 2010 were included. Nine hundred and seventy two patients were treated with G-CSF after auto-SCT whereas 1121 were not. BM and PB were used as a source of stem cells in 454 (22%) and 1639 (78%) cases, respectively. The incidence of relapse at 5 years in the BM-auto-SCT group was 38% for patients receiving post-transplant G-CSF and 43% for those not treated with G-CSF, P=0.46. In the PB-auto-SCT cohort, respective probabilities were 48% and 49%, P=0.49. No impact of the use of G-CSF could be demonstrated with respect to the probability of leukemia-free survival: in the BM-auto-SCT group, 51% for G-CSF(+) and 48% for G-CSF(-), P=0.73; in PB-auto-SCT group, 42% for G-CSF(+) and 43% for G-CSF(-), P=0.83. Although G-CSF administration significantly shortened the neutropenic phase, no beneficial effect was observed with regard to non-relapse mortality. In patients with AML, the use of G-CSF after auto-SCT is not associated with increased risk of relapse irrespective of the source of stem cells used.

Cytarabine, aclarubicin and granulocyte colony-stimulating factor regimen represents an effective and safe salvage regimen for patients with acute myeloid leukemia refractory to first course of induction chemotherapy

There is no consensus regarding the optimal second induction course regimen for patients with acute myeloid leukemia (AML) refractory to an initial course of front-line induction. The CAG regimen (cytarabine, aclarubicin and granulocyte colony-stimulating factor) has shown promise for relapsed/refractory AML. We retrospectively compared the efficacy and toxicity of the CAG regimen (n = 44) with a non-CAG regimen (n = 31) in 75 patients with AML refractory to an initial induction chemotherapy. The complete remission (CR) rate was higher for the CAG than the non-CAG regimen (63.5% vs. 38.7%, p = 0.038), and this was more pronounced in the subgroup of patients with a lower white blood cell (WBC) count before first/second induction, better- and intermediate-risk patients, and non-AML-M4/5 (p = 0.019). Although the CAG group demonstrated a higher disease-free survival than the non-CAG group among the intermediate- and poor-risk patients (p = 0.019), no differences in overall survival were observed. The CAG regimen produced hematological and non-hematological side effects similar to those of the non-CAG regimen. The most frequent CAG regimen side effects were infection (45.5%), fever (50%) and elevated transaminase levels (31.8%). No patients died within 4 weeks after initiating the second induction course in the CAG regimen. Thus, CAG represents a highly effective and safe salvage regimen for patients with AML who are refractory to the first induction chemotherapy. This regimen may be of specific benefit for CR in patients with low WBC count, better- and intermediate-risk, and non-M4/5 disease.

Therapeutic use of granulocyte-colony stimulating factor could conceal residual malignant cells in patients with AML1/ETO+ acute myelogenous leukemia

We have experienced a number of cases of AML1/ETO+ acute myelogenous leukemia that showed remission based on bone marrow (BM) morphological criteria, but that revealed clonal abnormalities in most cells by fluorescence in situ hybridization (FISH). Interestingly, most of these cases had AML with AML1/ETO rearrangement. The malignant cells were differentiated and considered mature cells after granulocyte-colony stimulating factor (G-CSF) treatment. To clarify the possible mechanisms underlying this phenomenon, we investigated the expression levels of G-CSFR in AML cells with AML1/ETO rearrangement by flow cytometry and real-time polymerase chain reaction (PCR). The number of AML1/ETO+ cells expressing G-CSFR at baseline was significantly higher than that of AML1/ETO- AML cells (2673 vs 522). In addition, the G-CSFR gene was more highly expressed in AML1/ETO+ cells than in AML1/ETO- cells by real-time PCR. This study reveals that cases showing remission after treatment with G-CSF mostly had leukemia with AML1/ETO rearrangement. This finding might be explained by the higher expression of G-CSF receptor in AML1/ETO+ cells than in AML1/ETO- cells. We recommend that remission should be confirmed by FISH, because malignant clones can be differentiated and masked in morphological examination or chromosome test, especially for AML with AML1/ETO rearrangement.