Outcomes of allogenic hematopoietic cell transplantation for childhood chronic myeloid leukemia: Single‐center experience

Abstract

Background/objectives: Despite the apparent efficacy and favorable toxicity profile of TKIs, allogeneic SCT remains the only curative treatment for CML especially in younger patients, but TRM should be considered. We evaluated the clinical outcomes of pediatric CML patients who had SCT in our center. Methods: This retrospective study included children with CML, who received an allogeneic SCT at Children Cancer Hospital Egypt, 57357, from 2007 to 2017. All patients received myeloablative conditioning chemotherapy containing busulfan/cyclophosphamide followed by stem cell infusion from MRD. Results: From 121 patients diagnosed with CML, 43 had available MRD and subjected to HSCT while 78 patients continued TKI therapy. The median time to transplant from diagnosis was 13 months. At initial diagnosis, there were 39 patients in CP and 4 had blastic crises. Bone marrow harvest was the stem cell source in 32 patients, while 11 cases received mobilized peripheral blood stem cells with average stem cell dose of 4.45 × 10 6 /kg. The probabilities of overall survival and event-free survivalat 5 years were 97.4% and 79.8%, respectively. TRM at 100 days and TRM at 1-year post-transplant were 0%. The incidence of chronic GVHD was significantly higher in peripheral blood than bone marrow stem cell source (P = .004). Conclusion:Considering the excellent survival rates and very low TRM, HSCT is still a valid option for pediatric patients with newly diagnosed CML with best using marrow stem cell source to avoid a significant risk of cGVHD and its related complications. K E Y W O R D Schronic myeloid leukemia, hematopoietic stem cell transplantation, transplant-related mortality, tyrosine kinase inhibitors

The Contemporary Role of Hematopoietic Stem Cell Transplantation in the Management of Chronic Myeloid Leukemia: Is It the Same in All Settings?

“…Comparative HSCT-imatinib analysis in pediatric CML indicated similar 84% (HSCT) and 87% (imatinib) two-year OS and relapse rates [47]. Allogeneic HSCT in pediatric CML showed 97.4% 5-year OS and 79.8% EFS, without mortality at 100 days/1-year post-HSCT [48]. Allogeneic HSCT's chronic-phase CML effectiveness, for TKI failure, reported 84% (adults) and 91% (pediatrics) pooled OS in quantitative synthesis [49].…”

Management of children and adolescents with chronic myeloid leukemia in blast phase: International pediatric CML expert panel recommendations

“…Significant benefits in engraftment were observed in MSD bone marrow transplantation [57]. Most studies in CML-CP showed a survival benefit for MSD; the limitation is that those are either retrospective studies and/or were conducted before there were significant improvements in HLA typing, donor search, and treatment of acute graft-versus-host disease (GvHD) [58][59][60]. In addition, these studies have mostly demonstrated a survival advantage for bone marrow as a stem cell source [59,61].…”