Eun Sang Yi

Hematopoietic stem cell transplantation in children with acute leukemia: similar outcomes in recipients of umbilical cord blood versus marrow or peripheral blood stem cells from related or unrelated donors

Purpose This study compared outcomes in children with acute leukemia who underwent transplantations with umbilical cord blood (UCB), bone marrow, or peripheral blood stem cells from a human leukocyte antigen (HLA)-matched related donor (MRD) or an unrelated donor (URD). Methods This retrospective study included consecutive acute leukemia patients who underwent their first allogeneic hematopoietic stem cell transplantation (HSCT) at Samsung Medical Center between 2005 and 2010. Patients received stem cells from MRD (n=33), URD (n=46), or UCB (n=41). Results Neutrophil and platelet recovery were significantly longer after HSCT with UCB than with MRD or URD (P<0.01 for both). In multivariate analysis using the MRD group as a reference, the URD group had a significantly higher risk of grade III to IV acute graft-versus-host disease (GVHD; relative risk [RR], 15.2; 95% confidence interval [CI], 1.2 to 186.2; P=0.03) and extensive chronic GVHD (RR, 6.9; 95% CI, 1.9 to 25.2; P<0.01). For all 3 donor types, 5-year event-free survival (EFS) and overall survival were similar. Extensive chronic GVHD was associated with fewer relapses (RR, 0.1; 95% CI, 0.04 to 0.6; P<0.01). Multivariate analysis showed that lower EFS was associated with advanced disease at transplantation (RR, 3.2; 95% CI, 1.3 to 7.8; P<0.01) and total body irradiation (RR, 2.1; 95% CI, 1.0 to 4.3; P=0.04). Conclusion Survival after UCB transplantation was similar to survival after MRD and URD transplantation. For patients lacking an HLA matched donor, the use of UCB is a suitable alternative.

Cytomegalovirus infection according to cell source after hematopoietic cell transplantation in pediatric patients.

Purpose This study was performed in order to evaluate the incidence and characteristics of cytomegalovirus (CMV) infection in children with acute leukemia according to donor source and graft type. Materials and Methods We retrospectively identified children with acute leukemia who had received allogeneic hematopoietic cell transplantation at Samsung Medical Center in Korea from October 1998 to December 2009. Results In total, 134 recipients were identified. The patients were classified into the following three groups: unrelated cord blood (CB, n=36), related bone marrow or peripheral blood stem cells (RD, n=41), and unrelated bone marrow or peripheral blood stem cells (UD, n=57). The 365-day cumulative incidence of CMV antigenemia was not significantly different among the three groups (CB 67% vs. RD 49% vs. UD 65%, p=0.17). However, CB recipients had the highest median value of peak antigenemia (CB 160/2×105 leukocytes vs. RD 7/2×105 leukocytes vs. UD 19/2×105 leukocytes, p<0.01) and the longest duration of CMV antigenemia than the other stem cell source recipients (CB 87 days vs. RD 17 days vs. UD 28 days, p<0.01). In addition, the 730-day cumulative incidence of CMV disease was the highest in the CB recipients (CB 36% vs. RD 2% vs. UD 5%, p<0.01). Thirteen CB recipients developed CMV disease, in which five of them had more than one organ involvement. Two patients, who were CB recipients, died of CMV pneumonia. Conclusion This study suggests that CB recipients had both longer and higher cumulative incidences of CMV infection. Therefore, a more aggressive and effective strategy of CMV management should be considered in CB recipients.

Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for Atypical Teratoid/Rhabdoid Tumor

Purpose We prospectively evaluated the effectiveness of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) in improving the survival of patients with atypical teratoid/rhabdoid tumors while reducing the risks of late adverse effects from radiotherapy (RT). Materials and Methods For young children (< 3 years old), tandem HDCT/auto-SCT was administered after six cycles of induction chemotherapy. RT was deferred until after 3 years of age unless the tumor showed relapse or progression. For older patients (> 3 years old), RT including reduced-dose craniospinal RT (23.4 or 30.6 Gy) was administered either after two cycles of induction chemotherapy or after surgery, and tandem HDCT/auto-SCT was administered after six cycles of induction chemotherapy. Results A total of 13 patients (five young and eight older) were enrolled from November 2004 to June 2012. Eight patients, including all five young patients, had metastatic disease at diagnosis. Six patients (four young and two older) experienced progression before initiation of RT, and seven were able to proceed to HDCT/auto-SCT without progression during induction treatment. Three of six patients who experienced progression during induction treatment underwent HDCT/auto-SCT as salvage treatment. All five young patients died from disease progression. However, four of the eight older patients remain progression-freewith a median follow-up period of 64 months (range, 39 to 108 months). Treatment-related late toxicities were acceptable. Conclusion The required dose of craniospinal RT might be reduced in older patients if the intensity of chemotherapy is increased. However, early administration of RT should be considered to prevent early progression in young patients.

Immunosuppressive therapy versus alternative donor hematopoietic stem cell transplantation for children with severe aplastic anemia who lack an HLA-matched familial donor.

We compared the outcomes of immunosuppressive treatment (IST) with those of alternative donor hematopoietic stem cell transplantation (HSCT) in children and adolescents with severe aplastic anemia (SAA). The medical records of 42 patients with SAA who received frontline IST (N=19) or frontline HSCT with an alternative donor (N=23) between 1998 and 2012 were analyzed retrospectively. Six patients responded in the frontline IST group, whereas 11 underwent salvage HSCT after IST failure. Twenty-one of 23 patients who underwent frontline HSCT survived without treatment failure. The estimated failure-free survival rate of the frontline HSCT group was higher than that of the frontline IST group (91.3% vs 30.7% respectively, P<0.001). Six of 11 patients who underwent salvage HSCT experienced event-free survival (EFS). The estimated EFS of the frontline HSCT group was higher than that of the salvage HSCT group (91.3% vs 50.9% respectively, P=0.015). The outcome of alternative donor HSCT was better than commonly reported rates, especially in patients who underwent frontline HSCT. These results suggest that frontline alternative donor HSCT may be a better treatment option than IST for children and adolescents with SAA who lack a human leukocyte Ag-matched familial donor.

Incorporation of high-dose (131) I-metaiodobenzylguanidine treatment into killer immunoglobulin-like receptor/HLA-ligand mismatched haploidentical stem cell transplantation for children with neuroblastoma who failed tandem autologous stem cell transplantation.

We performed a pilot study (NCT 00793351) to evaluate the effectiveness and feasibility of a strategy incorporating high‐dose 131I‐metaiodobenzylguanidine (HD‐MIBG) treatment into killer immunoglobulin‐like receptor (KIR)/HLA‐ligand mismatched haploidentical stem cell transplantation (haplo‐SCT) in improving the survival of children with neuroblastoma who failed previous tandem autologous SCT.

Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for High-Grade Gliomas in Children and Adolescents

With the aim to investigate the outcome of tandem high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT) for high-grade gliomas (HGGs), we retrospectively reviewed the medical records of 30 patients with HGGs (16 glioblastomas, 7 anaplastic astrocytomas, and 7 other HGGs) between 2006 and 2015. Gross or near total resection was possible in 11 patients. Front-line treatment after surgery was radiotherapy (RT) in 14 patients and chemotherapy in the remaining 16 patients including 3 patients less than 3 years of age. Eight of 12 patients who remained progression free and 5 of the remaining 18 patients who experienced progression during induction treatment underwent the first HDCT/auto-SCT with carboplatin + thiotepa + etoposide (CTE) regimen and 11 of them proceeded to the second HDCT/auto-SCT with cyclophosphamide + melphalan (CyM) regimen. One patient died from hepatic veno-occlusive disease (VOD) during the second HDCT/auto-SCT; otherwise, toxicities were manageable. Four patients in complete response (CR) and 3 of 7 patients in partial response (PR) or second PR at the first HDCT/auto-SCT remained event free: however, 2 patients with progressive tumor experienced progression again. The probabilities of 3-year overall survival (OS) after the first HDCT/auto-SCT in 11 patients in CR, PR, or second PR was 58.2% ± 16.9%. Tumor status at the first HDCT/auto-SCT was the only significant factor for outcome after HDCT/auto-SCT. There was no difference in survival between glioblastoma and other HGGs. This study suggests that the outcome of HGGs in children and adolescents after HDCT/auto-SCT is encouraging if the patient could achieve CR or PR before HDCT/auto-SCT.

Clinical Significance of Tyrosine Hydroxylase mRNA Transcripts in Peripheral Blood at Diagnosis in Patients with Neuroblastoma

Purpose The purpose of this study is to investigate the clinical significance of tyrosine hydroxylase (TH) expression in peripheral blood (PB) at diagnosis in patients with neuroblastoma. Materials and Methods TH mRNA expression in PB was measured by reverse transcription quantitative real-time polymerase chain reaction in 210 patients who were newly diagnosed with neuroblastoma from July 2005 to June 2015 and the clinical significance of TH expression in PB at diagnosis was evaluated. Results TH expression was positive in 60 patients (28.6%). Fifty of 60 TH-positive patients had metastatic tumors and the remaining 10 had localized tumors. TH expression was associated with high-risk features (i.e., advanced stage, older age, unfavorable pathology, and MYCN amplification) at diagnosis. Among TH-positive patients, higher TH expression level was observed in high-risk patients than in low- or intermediate-risk patients (p=0.035). The probability of 5-year progression-free survival (PFS) was lower in TH-positive patients than in TH-negative patients (63.8±6.9% vs. 94.7±2.1%, p < 0.001). In analysis confined to high-risk patients, the 5-year probability of PFS remained lower in TH-positive patients (55.7±8.2% vs. 89.6±5.8%, p < 0.001). Among TH-positive patients, a higher expression level of TH was associated with a worse outcome. In multivariate analyses, positive TH expression in PB at diagnosis was an independent poor prognostic factor for PFS. Conclusion The treatment intensity should be tailored according to TH expression in PB at diagnosis.

NUDT15 Variants Cause Hematopoietic Toxicity with Low 6-TGN Levels in Children with Acute Lymphoblastic Leukemia

Purpose We aimed to identify the impact of NUDT15 variants on thiopurine intolerance and 6-thioguanine nucleotide (6-TGN) levels in Korean children with acute lymphoblastic leukemia (ALL). Materials and Methods Genotyping of NUDT15 was tested in 258 patients with ALL registered at Samsung Medical Center. Patients were classified into normal-activity (wild-type), intermediate-activity (heterozygous variant), and low-activity groups (homozygous or compound heterozygous variant). Clinical and laboratory features during the first year of maintenance therapy were investigated. Results A total of 182 patients were included in the final analysis. There were five (2.7%), 46 (25.3%), and 131 (72.0%) patients in low-, intermediate-, and normal-activity groups, respectively. The lowest 6-mercaptopurine (6-MP) dose (mg/m2/day) was administered to the low-activity group (low-activity group 7.5 vs. intermediate-activity group 24.4 vs. normalactivity group 31.1, p < 0.01) from three months to a year after beginning maintenance therapy. The low-activity group experienced the longest duration of therapy interruption during the first year (low-activity group 169 days vs. intermediate-activity group 30 days vs. normal-activity group 16 days, p < 0.01). They also showed the lowest blood cell counts and had a longer duration of leukopenia (low-activity group 131 days vs. intermediate-activity group 92 days vs. normal-activity group 59 days, p < 0.01). 6-TGN level and its ratio to 6-MP dose were lowest in the low-activity group. Conclusion NUDT15 variants cause hematopoietic toxicity with low 6-TGN levels. NUDT15 genotyping should be conducted before administering thiopurine, and dose adjustments require caution regardless of 6-TGN levels.

Monosomal karyotype is not a predictor of dismal outcome in childhood de novo acute myeloid leukemia

Monosomal karyotype (MK) is known as a far end of the unfavorable cytogenetics in adult acute myeloid leukemia (AML), while available data in childhood AML is scarce. In this study, we investigated the prevalence and prognostic value of MK with retrospectively analyzed 119 patients newly diagnosed with childhood de novo AML. Ten patients (8.4%) revealed to have MK. All MK-positive (MK(+)) AML were associated with complex cytogenetic abnormalities and belonged to the cytogenetic adverse-risk group. Nine of MK(+) patients (90%) achieved complete remission. The event-free survival (EFS) and overall survival (OS) of MK(+) adverse group were comparable to the ESF and OS of MK-negative non-adverse group (EFS 60.0±15.5% vs 59.0±5.1%, P=0.925; OS 70.0±14.5% vs 58.1±5.3%, P=0.696). In multivariate analysis, MK was not an independent adverse prognostic factor for EFS (hazard ratio 0.45, 95% C.I. 0.13-1.50, P=0.194). In addition, 7 of 9 MK(+) patients who received allogeneic hematopoietic stem cell transplantation (HSCT) survived event-free, with a median follow-up of 64 months. In conclusion, MK did not act as an adverse prognostic factor in childhood de novo AML. Allogeneic HSCT might have contributed to the excellent outcome of MK(+) childhood de novo AML.

Therapy-related myeloid neoplasms in children and adolescents

Background This retrospective study aimed to characterize and analyze the outcome of therapy-related myeloid neoplasms (t-MNs) in children and adolescents. Methods The medical records of 16 patients under 21 years of age at the time of t-MN diagnosis were reviewed. Results The median patient age was 11.5 years (range, 1.6–20.4 yr). Twelve patients had therapy-related acute myeloid leukemia, 3 patients had myelodysplastic syndrome, and 1 patient had chronic myelomonocytic leukemia. The median latency period was 29 months (range, 11–68 mo). Fourteen patients had cytogenetic aberrations, 8 of whom had an 11q23 abnormality. Of the 13 patients treated with curative intent, 12 patients received myeloid-type induction therapy that led to complete remission (CR) in 8 patients. Nine patients underwent allogeneic transplantation; 4 patients did not undergo transplantation due to chemotherapy-related toxic death (N=3) or parental refusal (N=1). The 5-year overall survival and event-free survival of the 13 patients treated with a curative intent were 46.2% and 30.8%, respectively. For the 9 patients who underwent allogeneic transplantation, the 5-year event-free survival was 66.7%. Conclusion A significant proportion of young patients with t-MNs can experience long-term survival, and allogeneic transplantation plays a key role for attaining cure in these patients.