High numbers of mobilized CD34+ cells collected in AML in first remission are associated with high relapse risk irrespective of treatment with autologous peripheral blood SCT or autologous BMT

Abstract

The faster hematopoietic recovery after autologous peripheral blood SCT (APBSCT) in patients with AML may be offset by an increased relapse risk as compared with autologous BMT (ABMT). The EORTC and GIMEMA Leukemia Groups conducted a trial (AML-10) in which they compared, as second randomization, APBSCT and ABMT in first CR patients without an HLA compatible donor. A total of 292 patients were randomized. The 5-year DFS rate was 41% in the APBSCT arm and 46% in the ABMT arm with a hazard ratio (HR) of 1.17; 95% confidence interval = 0.85-1.59; P = 0.34. The 5-year cumulative relapse incidence was 56% vs 49% (P = 0.26), and the 5-year OS 50% and 55% (P = 0.6) in the APBSCT and ABMT groups, respectively. APBSCT was associated with significantly faster recovery of neutrophils and platelets, shorter duration of hospitalization, reduced need of transfusion packed RBC and less days of intravenous antibiotics. In both treatment groups, higher numbers of mobilized CD34+ cells were associated with a significantly higher relapse risk irrespective of the treatment given after the mobilization. Randomization between APBSCT and ABMT did not result in significantly different outcomes in terms of DFS, OS and relapse incidence.

Iron overload is correlated with impaired autologous stem cell mobilization and survival in acute myeloid leukemia

“…Low levels of circulating peripheral CD34+ cells at collection may be reflecting a poor hematopoietic stem cell reserve, and a decreased mobilization potential after induction chemotherapy in AML patients may hamper the successful stem cell collection. Finally, kinetics of stem cell mobilization and function affect long‐term outcome, with delayed hematologic recovery after ASCT being associated with better PFS and OS, whereas high levels of mobilized CD34+ cells are associated with a higher relapse risk in AML . A likely explanation for these observations is that a decreased mobilization potential after induction chemotherapy may mirror enhanced effectiveness of the preceding chemotherapy against leukemic stem cells thereby translating into a more favorable outcome …”

“…To consolidate first remission (CR1) after induction treatment in patients with AML, different options can be offered depending on the risk and comorbidity profile of the individual patient and the availability of a donor. Among them, ASCT can be recommended to patients with favorable or intermediate‐risk profile . ASCT has recently been reported to be safe and effective also in AML patients older than 65 years and, thus, is an option for consolidation in CR1 in some elderly patients as well …”

Update on Non-M3 Acute Myeloid Leukemia — Etiology, Classification, Risk Stratification, Emergencies, Complications, Disease in Special Circumstances and Current and Future Therapeutics

“…However, autologous HSCT has few disadvantages including: lack of GVL effect, insufficient number of peripheral stem cells at mobilization, and higher incidence of relapse [169]. Faster recovery of blood counts following autologous HSCT has the following advantages: shorter duration of hospitalization, decreased need for blood product transfusion, and reduction in the days of IV antimicrobials [172].…”

“…BM is the traditional source of stem cells for HSCT [172]. Since 1994, the use of peripheral blood stem cells has resulted in more rapid engraftment kinetics and lower rates of NRM [170].…”

“…Since 1994, the use of peripheral blood stem cells has resulted in more rapid engraftment kinetics and lower rates of NRM [170]. The use of G-CSF-mobilized peripheral blood stem cells use has been associated with more rapid engraftment presumably due to the higher number of infused CD34+ cells and with reduced morbidity and TRM compared to autologous BM transplantation [172,173]. Therefore, autologous peripheral blood HSCT has recently replaced autologous BM transplantation based on reduction in morbidity, resource utilization and duration of hospitalization [174].…”