Tandem High-Dose Chemotherapy Increases the Risk of Secondary Malignant Neoplasm in Pediatric Solid Tumors.

PURPOSE: This study aimed to investigate the incidence and risk factors for secondary malignant neoplasms (SMN) in pediatric solid tumors, focusing on the effects of tandem high-dose chemotherapy (HDCT). MATERIALS AND METHODS: Patients (aged < 19 years) diagnosed with or treated for pediatric solid tumors between 1994 and 2014 were retrospectively analyzed. The cumulative incidence of SMN was estimated using competing risk methods by considering death as a competing risk. RESULTS: A total of 1,435 patients (413 with brain tumors and 1,022 with extracranial solid tumors) were enrolled. Seventy-one patients developed 74 SMNs, with a 10-year and 20-year cumulative incidence of 2.680±0.002% and 10.193±0.024%, respectively. The types of SMN included carcinoma in 28 (37.8%), sarcoma in 24 (32.4%), and hematologic malignancy in 15 (20.3%) cases. Osteosarcoma and thyroid carcinoma were the most frequently diagnosed tumors. Multivariate analysis showed that radiotherapy (RT) > 2, 340 cGy, and tandem HDCT were significant risk factors for SMN development. The SMN types varied according to the primary tumor type; carcinoma was the most frequent SMN in brain tumors and neuroblastoma, whereas hematologic malignancy and sarcomas developed more frequently in patients with sarcoma and retinoblastoma, respectively. CONCLUSION: The cumulative incidence of SMN in pediatric patients with solid tumors was considerably high, especially in patients who underwent tandem HDCT or in those who received RT > 2,340 cGy. Therefore, the treatment intensity should be optimized based on individual risk assessment and the long-term follow-up of pediatric cancer survivors.

Treatment outcome and prognostic factors in relapsed pediatric acute myeloid leukemia.

Background: Despite improved outcomes for pediatric patients with acute myeloid leukemia (AML), the prognosis for relapse remains poor. This study aimed to examine the clinical factors associated with prognosis in relapsed pediatric AML. Methods: We conducted a chart review of pediatric patients with AML who experienced their first relapse and received treatment at our institution between 2008 and 2019. Risk stratification at diagnosis was performed according to the definition suggested by the ongoing AML 2012 study in Korea, and the clinical factors associated with prognosis were analyzed. Results: A total of 27 pediatric patients with relapsed AML were identified. The 5-year overall survival (OS) and event-free survival (EFS) rates were 32.9% and 32.9%, respectively. A duration ≥12 months from diagnosis to relapse had a favorable impact on survival outcomes (5-yr OS, 64.0% vs. 15.7%; P=0.007). Patients who achieved complete remission (CR) after 1 course of chemotherapy following relapse (N=15) had a 5-year OS rate of 59.3%, while none of the other patients survived (P＜0.0001). Additionally, the 5-year OS differed significantly based on the risk group at initial diagnosis (62.3% [favorable and intermediate prognosis groups, N=11] vs. 13.3% [poor prognosis group, N=15]; P=0.014). Conclusion: Patients with a longer duration of CR before relapse, who achieved CR following 1 course of reinduction chemotherapy, and were in the favorable or intermediate prognosis group at diagnosis demonstrated better outcomes. These findings emphasize the importance of tailoring treatment strategies based on the expected prognosis at relapse in pediatric patients with AML.

Current Status and Physicians' Perspectives of Childhood Cancer Survivorship in Korea: A Nationwide Survey of Pediatric Hematologists/Oncologists.

BACKGROUND: Data on the status of long-term follow-up (LTFU) care for childhood cancer survivors (CCSs) in Korea is lacking. This study was conducted to evaluate the current status of LTFU care for CCSs and relevant physicians' perspectives. METHODS: A nationwide online survey of pediatric hematologists/oncologists in the Republic of Korea was undertaken. RESULTS: Overall, 47 of the 74 board-certified Korean pediatric hematologists/oncologists currently providing pediatric hematology/oncology care participated in the survey (response rate = 63.5%). Forty-five of the 47 respondents provided LTFU care for CCSs five years after the completion of primary cancer treatment. However, some of the 45 respondents provided LTFU care only for CCS with late complications or CCSs who requested LTFU care. Twenty of the 45 respondents oversaw LTFU care for adult CCSs, although pediatric hematologists/oncologists experienced more difficulties managing adult CCSs. Many pediatric hematologists/oncologists did not perform the necessary screening test, although CCSs had risk factors for late complications, mostly because of insurance coverage issues and the lack of Korean LTFU guidelines. Regarding a desirable LTFU care system for CCSs in Korea, 27 of the 46 respondents (58.7%) answered that it is desirable to establish a multidisciplinary CCSs care system in which pediatric hematologists/oncologists and adult physicians cooperate. CONCLUSION: The LTFU care system for CCS is underdeveloped in the Republic of Korea. It is urgent to establish an LTFU care system to meet the growing needs of Korean CCSs, which should include Korean CCSs care guidelines, provider education plans, the establishment of multidisciplinary care systems, and a supportive national healthcare policy.

Response to chemotherapy in juvenile myelomonocytic leukemia and its clinical implications for survival: A retrospective registry-based study of the Korean Pediatric Hematology-Oncology Group.

Juvenile myelomonocytic leukemia (JMML) is a life-threatening myeloproliferative neoplasm. The chemotherapeutic effect on survival remains unclear, and feasible standardized response criteria are yet to be established. We aimed to evaluate the chemotherapeutic response and its effect on survival in patients with JMML. A retrospective registry was reviewed for children diagnosed with JMML between 2000 and 2019. Response was assessed according to the criteria proposed by the International JMML Symposium in 2007 (criteria I) and the updated version in 2013 with its modifications (criteria II). A total of 73 patients were included in this study. Complete response (CR) rates were 46.6% and 28.8% using the criteria I and criteria II, respectively. A platelet count ≥ 40 × 109/L at diagnosis was associated with higher CR rates using the criteria II. Patients with criteria I-based CR had a better overall survival (OS) than those without CR (81.1% vs. 49.1% at 5 years). Patients with criteria II-based CR showed better OS (85.7% vs. 55.5% at 5 years) and event-free survival (EFS) (71.1% vs. 44.7% at 5 years) than those without CR. Additionally, a trend toward better EFS was observed in patients with criteria II-based CR than in those with criteria I-based CR but without criteria II-based CR (71.1% vs. 53.8% at 5 years). Chemotherapeutic response is associated with better survival outcomes. Along with splenomegaly, the addition of platelet count recovery, existence of extramedullary leukemic infiltration, and more stringent leukocyte counts to the response criteria allows for a more sensitive prediction of survival outcomes.

High-dose chemotherapy followed by autologous stem cell transplantation in pediatric patients with relapsed osteosarcoma.

BACKGROUND: Patients with relapsed osteosarcoma have poor treatment outcomes. High-dose chemotherapy with autologous stem cell transplantation (HDCT/ASCT) has been used in several high-risk malignant solid tumors; however, few studies have evaluated their role in treating osteosarcoma. We evaluated the effectiveness of HDCT/ASCT in relapsed pediatric osteosarcoma cases. PROCEDURE: We retrospectively reviewed the medical records of 40 patients diagnosed with and treated for relapsed osteosarcoma at Asan Medical Center and Samsung Medical Center from January 1996 to July 2019. RESULTS: The median age of this cohort was 13.4 years (range: 6.1-18.2). The cohort's 5-year overall survival (OS) was 51.0% ± 0.1% during a median follow-up period of 67.5 months. Twenty-five patients (62.5%) achieved complete remission (CR) with salvage treatment, and the 5-year OS was 82.4% ± 0.1%, whereas none of the remaining 15 patients who did not achieve CR survived (p < .0001). Of the 25 CR cases, 15 underwent subsequent HDCT/ASCT. We compared the effect of HDCT/ASCT among patients who achieved CR. There were no significant differences in the 5-year OS outcomes between patients who did and did not receive HDCT/ASCT (83.9% ± 0.1%, 13/15 vs. 80.0% ± 0.1%, 8/10, respectively; p = .923). CONCLUSION: To our knowledge, we report the first comparative cohort study that proved HDCT/ASCT does not significantly improve survival outcomes in relapsed osteosarcoma. Achievement of CR remains the most crucial factor for good survival outcomes.

Minimal dose of hematopoietic stem cell transplantation without myelosuppressive conditioning for T-B+NK- severe combined immunodeficiency.

We reviewed the medical records of five patients with T-B+NK- severe combined immunodeficiency (SCID) who received minimal dose allogeneic hematopoietic cell transplantation (HCT) (total nucleated cell count (TNC) lower than 1.0 × 108/kg). Patients were administered a median of 5.0 mL of bone marrow or peripheral blood without conditioning (in four) or with anti-thymocyte globulin alone (in one). Three patients received HCT from a matched sibling donor, one from unrelated donor, and one from familial mismatched donor. The median TNC and CD34+ cells were 0.54 (0.29-0.84) × 108/kg and 0.61 (0.35-0.84) × 106/kg, respectively. Engraftment was achieved in all. Total T cell, CD4+ cell, and CD8+ cell recovery was obtained within a year in four, and immunoglobulin replacement was discontinued in all. All patients survived, exhibiting stable donor chimerism. We obtained sufficient therapeutic effects with minimal dose transplantation without intensive conditioning in patients with T-B+NK- SCID.

Allogeneic hematopoietic cell transplantation in patients with juvenile myelomonocytic leukemia in Korea: a report of the Korean Pediatric Hematology-Oncology Group.

Juvenile myelomonocytic leukemia (JMML) is a life-threatening myeloproliferative neoplasm. This multicenter study evaluated the characteristics, outcomes, and prognostic factors of allogeneic hematopoietic cell transplantation (HCT) in recipients with JMML who were diagnosed between 2000 and 2019 in Korea. Sixty-eight patients were retrospectively enrolled-28 patients (41.2%) received HCT during 2000-2010 and 40 patients (58.8%) during 2011-2020. The proportion of familial mismatched donors increased from 3.6 to 37.5%. The most common conditioning therapy was changed from Busulfan/Cyclophosphamide-based to Busulfan/Fludarabine-based therapy. The 5-year probabilities of event-free survival (EFS) and overall survival (OS) were 52.6% and 62.3%, respectively. The 5-year incidence of transplant-related mortality was 30.1%. Multivariate analysis revealed that the proportion of hemoglobin F ≥ 40%, abnormal cytogenetics, and matched sibling donors were independent risk factors for a higher relapse rate. Patients whose donor chimerism was below 99% had a significantly higher relapse rate. Better OS and lower treatment-related mortality were observed in patients with chronic graft-versus-host disease (GVHD), whereas grade III or IV acute GVHD was associated with worse EFS. In conclusion, the number of transplant increased along with the increase in alternative donor transplants, nevertheless, similar results were maintained. Alternative donor transplantation should be encouraged.

Clinical significance of germline telomere length and associated genetic factors in patients with neuroblastoma.

Studies investigating the relationship between germline telomere length and the clinical characteristics of tumors are very limited. This study evaluated the relationship between germline telomere length and the clinical characteristics of neuroblastoma. In addition, a genome-wide association study (GWAS) was performed to investigate the genetic factors associated with germline telomere length. The germline telomere length of peripheral blood mononuclear cells from 186 patients with neuroblastoma was measured by quantitative polymerase chain reaction. The association between germline telomere length and clinical characteristics, including long-term survival, was investigated. For the GWAS, genotyping was performed with a high-density bead chip (Illumina, San Diego, CA, USA). After strict quality-control checks of the samples, an association analysis was conducted. The result showed that longer germline telomeres were significantly associated with longer event-free survival (P = 0.032). To identify significantly assocated genetic markers for germline telomere length, genome wide association analysis was performed. As a result, several single nucleotide polymorphisms located in HIVEP3, LRRTM4, ADGRV1, RAB30, and CHRNA4 genes were discovered. During gene-based analysis (VEGAS2 tool), the CNTN4 gene had the most significant association with germline telomere length (P = 1.0E-06). During gene ontology analysis, susceptible genes associated with germline telomere length were mainly distributed in neurite morphogenesis and neuron development. A longer germline telomere length is associated with favorable prognostic factors at diagnosis and eventually better event-free survival in patients with neuroblastoma. In addition, the GWAS demonstrated that genetic markers and genes related to germline telomere length are associated with neurite morphogenesis and neuron development. Further research with larger cohorts of patients and functional investigations are needed.

Postchemotherapy gross residual tumor in non-high-risk neuroblastoma: Clinical significance and the role of adjuvant therapy.

BACKGROUND: Although survival rate among patients with non-high-risk neuroblastoma is excellent, a gross residual tumor (GRT) is often present at the end of treatment. However, reliable data do not exist on the relevance of a GRT for the risk of progression and the role of adjuvant therapy for patients with GRT. METHODS: A retrospective review of 131 patients with non-high-risk neuroblastoma who underwent chemotherapy was performed. GRT was defined as >1 cm3 residual soft tissue density on end-of-chemotherapy scans. Progression-free survival (PFS) and overall survival (OS) rates were compared between patients with GRT and those without GRT. A proportional hazards model was also used to assess the effects of GRT and adjuvant therapies, including radiation and isotretinoin therapy on outcomes. RESULTS: GRT was found in 52 (40%) patients in the study cohort. Correlation was not found between GRT and outcomes (PFS; p = .954, OS; p = .222). In multivariable analysis, GRT remained a nonsignificant predictor of outcome after adjusting for confounders. Local radiation and isotretinoin therapy did not affect outcome for patients with GRT. However, within GRT subgroups, the degree of volume reduction, as well as absolute residual volume in the primary tumor after induction treatment, were significantly associated with outcomes. CONCLUSION: GRT in non-high-risk neuroblastoma may not indicate active disease that requires additional treatment. However, risk of progression is increased in patients with GRT whose response to treatment was less prominent, thus adjuvant therapy should be reserved only for those patients.

The Positive Effects of Cancer Survivor Support Service on Distress in South Korea: A Nationwide Prospective Study.

BACKGROUND AND AIM: Cancer survivors are gradually increasing, however, they suffer from various difficulties. We aimed to investigate the characteristics of cancer survivors and the effects of the services of the Korean Cancer Survivorship Center Pilot Project launched by the South Korean government on distress. METHODS: A prospective observational cohort study was performed on cancer survivors who completed primary treatment. Cancer survivors' distress and symptoms such as fatigue, pain, depressive mood, anxiety, and insomnia were evaluated by well-trained nurses. Regarding their needs, medical and psychosocial support services were provided. RESULTS: This study included 1,921 cancer survivors, with a mean age of 57.3 years (68.7% females). Breast cancer was most common, followed by stomach and colorectal cancer. Psychosocial and medical support decreased the percentage of the high-distress group from 50.9 to 30.5% and decreased the percentage of cancer survivors with high scores in fatigue, pain, anxiety, depressive mood, and insomnia. The independent predictors of a low distress level after the use of the services were older age, the relief of fatigue, pain, and insomnia. CONCLUSION: This study showed that psychosocial and medical support is associated with the lower distress and physical and mental symptoms of cancer survivors. Psychosocial and medical support could contribute to distress relief in cancer survivors. Further management strategies for fatigue, pain and insomnia are required.

Risk Stratification of Childhood Medulloblastoma Using Integrated Diagnosis: Discrepancies with Clinical Risk Stratification.

BACKGROUND: Recent genomic studies identified four discrete molecular subgroups of medulloblastoma (MB), and the risk stratification of childhood MB in the context of subgroups was refined in 2015. In this study, we investigated the effect of molecular subgroups on the risk stratification of childhood MB. METHODS: The nCounter® system and a customized cancer panel were used for molecular subgrouping and risk stratification in archived tissues. RESULTS: A total of 44 patients were included in this study. In clinical risk stratification, based on the presence of residual tumor/metastasis and histological findings, 24 and 20 patients were classified into the average-risk and high-risk groups, respectively. Molecular subgroups were successfully defined in 37 patients using limited gene expression analysis, and DNA panel sequencing additionally classified the molecular subgroups in three patients. Collectively, 40 patients were classified into molecular subgroups as follows: WNT (n = 7), SHH (n = 4), Group 3 (n = 8), and Group 4 (n = 21). Excluding the four patients whose molecular subgroups could not be determined, among the 17 average-risk group patients in clinical risk stratification, one patient in the SHH group with the TP53 variant was reclassified as very-high-risk using the new risk classification system. In addition, 5 out of 23 patients who were initially classified as high-risk group in clinical risk stratification were reclassified into the low- or standard-risk groups in the new risk classification system. CONCLUSION: The new risk stratification incorporating integrated diagnosis showed some discrepancies with clinical risk stratification. Risk stratification based on precise molecular subgrouping is needed for the tailored treatment of MB patients.

Vincristine, Irinotecan, and Temozolomide as a Salvage Regimen for Relapsed or Refractory Sarcoma in Children and Young Adults.

PURPOSE: No standard salvage regimen is available for relapsed or refractory sarcoma. We investigated the efficacy and toxicity of the vincristine, irinotecan, and temozolomide combination (VIT) for relapsed or refractory sarcomas of variable histology in children and young adults. MATERIALS AND METHODS: We retrospectively reviewed data from the relapsed or refractory sarcoma patients who were treated with VIT. The VIT protocol was given every 3 weeks as follows: vincristine, 1.5 mg/m2 intravenously on day 1, irinotecan, 50 mg/m2/day intravenously on days 1-5, and temozolomide, 100 mg/m2/day orally on days 1-5. RESULTS: A total of 26 patients (12 males) with various sarcoma histology were included in the study. Most common diagnosis was rhabdomyosarcoma (n=8) followed by osteosarcoma (n=7). Median age at the start of VIT was 18.5 years (range, 2.0 to 39.9). VIT was delivered as 2nd to 7th line of treatment, with 4th line most common (9/26, 34.6%). Median number of VIT courses given was 3 (range, 1 to 18). Of the 25 evaluable patients, there was two partial response (PR) and 11 stable disease (SD) with an overall control rate (complete remission+PR+SD) of 52%. PR was seen in one (50%) of the two evaluable patients with Ewing sarcoma and one (14.3%) of the seven patients with osteosarcoma. Overall survival and progression-free survival rates were 79.3% and 33.9% at 1 year, and 45.5% and 25.4% at 2 years, respectively. There was no treatment-related mortality. CONCLUSION: The VIT regimen was effective and relatively safe in our cohort of sarcoma patients.

Absolute Neutrophil Count after the First Chemotherapy Cycle as a Surrogate Marker for Treatment Outcomes in Patients with Neuroblastoma.

PURPOSE: We performed this study to determine whether the degree of neutropenia after the first chemotherapy cycle can be used as a surrogate marker of individual susceptibility to chemotherapeutic agents affecting treatment outcome in patients with neuroblastoma. MATERIALS AND METHODS: The study included 313 patients who received the first cycle chemotherapy with a CEDC (cisplatin+etoposide+doxorubicin+cyclophosphamide) regimen and had absolute neutrophil count (ANC) data available. The cumulative incidences of progression and treatment-related mortality (TRM) were estimated. To identify genetic variations associated with the ANC, a genome-wide association study (GWAS) was performed. RESULTS: An ANC of 32.5/µL was determined as the cutoff point to categorize patients into the good and poor prognosis subgroups in terms of progression. Patients with a high nadir ANC had a higher cumulative incidence of progression than those with a low nadir ANC (p < 0.001). In multivariate analysis, high nadir ANC, age, bone marrow involvement, and unfavorable histology were poor prognostic factors. With regard to the TRM, patients with a low nadir ANC (ANC < 51.0/µL) had a higher cumulative incidence of TRM than those with a high nadir ANC (p=0.010). In GWAS, single-nucleotide polymorphisms of LPHN2 and CRHR1 were significantly associated with the nadir ANC. CONCLUSION: In neuroblastoma patients, the degree of neutropenia after the first chemotherapy cycle can be used as a surrogate marker to predict an individual's susceptibility to chemotherapeutic agents. Tailoring of treatment based on the degree of neutropenia needs to be considered.

Safety and Efficacy of Pegteograstim on Chemotherapy-induced Neutropenia in Children and Adolescents With Solid Tumors.

PURPOSE: Pegteograstim (Neulapeg) is a recombinant human granulocyte colony-stimulating factor conjugated with methoxy-maleimide-polyethylene glycol. We conducted a single-arm study investigating its safety and noninferiority to conventional filgrastim in children and adolescents. MATERIALS AND METHODS: Patients younger than 21 years with solid tumors were eligible for the study. Pegteograstim was administered on day 7 of the fourth chemotherapy cycle. Toxicities were monitored, and the change in absolute neutrophil count was compared with that of the historic control (conventional filgrastim). This trial was registered at ClinicalTrials.gov as NCT02787876. RESULTS: Thirty-two patients were enrolled. Adverse events possibly related to pegteograstim were musculoskeletal pain (n=3), skin nodule (n=1), paroxysmal cough (n=1), urticaria (n=2), rash (n=1), and itching (n=1). These adverse events were all grade 1 or 2. Duration of neutropenia (ANC<500/µL) was shorter in the pegteograstim group compared with the historic control (median 6.5 vs. 10 d, P=0.004). The time from day 0 to neutrophil recovery (ANC>500/µL) was shorter in the pegteograstim group (median 15 vs. 18 d, P=0.003). CONCLUSIONS: Pegteograstim is safe and shows comparable efficacy to conventional filgrastim in children and adolescents. Randomized controlled trials are needed to confirm its safety and efficacy.

Clinical Characteristics and Treatment Outcomes of Childhood Acute Promyelocytic Leukemia in Korea: A Nationwide Multicenter Retrospective Study by Korean Pediatric Oncology Study Group.

PURPOSE: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. MATERIALS AND METHODS: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. RESULTS: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). CONCLUSION: This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

Clinical implication of residual MIBG-positive disease in the follow-up of high-risk neuroblastoma treated with tandem high-dose chemotherapy and autologous stem cell transplantation.

BACKGROUND: The implication of residual metaiodobenzylguanidine (MIBG)-positive disease in the era of tandem high-dose chemotherapy (HDCT) with autologous stem cell transplantation (auto-SCT) has not yet been established in neuroblastoma. Moreover, most published studies have not evaluated the long-term prognosis of patients with residual MIBG-positive disease following treatment completion. Therefore, we investigated the prognostic significance of residual MIBG-positive disease at each treatment phase and after treatment completion. METHODS: We assessed MIBG scans labeled with either iodine-123 (123 I) or 131 I from 150 patients with MIBG-avid and high-risk neuroblastoma enrolled in the NB-2004, -2009, and -2014 trials at postinduction, posttandem HDCT/auto-SCT, and completion of treatment. RESULTS: The residual MIBG-positive disease at postinduction and posttandem HDCT/auto-SCT evaluation was highly correlated with the risk of progression. However, at treatment completion, there was no significant difference in survival and risk of progression between patients with residual MIBG-positive disease and MIBG-negative patients. Patients with persistent MIBG-positive disease at the end of treatment were more likely to have indolent tumor characteristics, such as favorable histology at diagnosis, lower incidence of MYCN amplification, and slow response to chemotherapy. CONCLUSION: Residual MIBG-positive disease during treatment predicted unfavorable outcomes for patients with high-risk neuroblastoma, even under tandem HDCT/auto-SCT. However, persistent MIBG uptake at the completion of all treatments may not always indicate an active disease.

Conditioning with 10 Gy Total Body Irradiation, Cyclophosphamide, and Fludarabine without ATG Is Associated with Improved Outcome of Cord Blood Transplantation in Children with Acute Leukemia.

BACKGROUND: The optimal conditioning regimen in cord blood transplantation (CBT) needs to be determined. This study aimed to identify the impact of conditioning regimen on the outcome of CBT in children with acute leukemia. METHODS: Medical records of patients with acute leukemia who received CBT were retrospectively reviewed. RESULTS: A total of 71 patients were allocated into 2 groups; patients who received total body irradiation 10 Gy, cyclophosphamide 120 mg/kg, and fludarabine 75 mg/m² were named as TCF group (n = 18), while the non-TCF group (n = 53) included patients conditioned with regimens other than the TCF regimen. All patients in the TCF group were successfully engrafted, while 22.6% in the non-TCF group (n = 12) failed to achieve donor-origin hematopoiesis (P = 0.028). The incidence of cytomegalovirus diseases was 5.6% in the TCF group and 30.2% in the non-TCF group (P = 0.029). The 5-year overall survival rates of the TCF and non-TCF groups were 77.8% and 44.2%, respectively (P = 0.017). CONCLUSION: Patients conditioned with the TCF regimen achieved better engraftment and survival rates, less suffering from cytomegalovirus disease. Our data suggest that the TCF regimen is a preferred option for CBT in children with acute leukemia.

Methotrexate polyglutamate quantification for clinical application in patients with pediatric acute lymphoblastic leukemia in association with genetic polymorphisms.

We developed and validated a quantification method for methotrexate (MTX) polyglutamates (MTX-PGs, MTX-PG1 to MTX-PG5) by liquid chromatography-tandem mass spectrometry using stable isotope-labeled internal standards and applied to 196 clinical samples collected from pediatric acute lymphoblastic leukemia patients treated with MTX. MTX-PGs levels and their proportions (%) in sum of all MTX-PGs (MTXSum) were evaluated in relation to TPMT, NUDT15, and MTHFR genotypes. For the developed method, linearity ranges 1-500 nmol/L, bias for accuracy 0.3-13.5 %, coefficient of variation for within- and between-run imprecision of 3.2-9.5% and 1.5-12.0%, respectively. Recoveries achieved were 74.2-105.8 %. There was no significant carryover. The median level of the MTXSum for 196 clinical samples was 129.4 nmol/L (interquartile range 28.1-241.2). MTX dose and MTX-PGs were associated (P < 0.05) and among five MTX-PGs, MTX-PG3 was the predominant form (median 41.7 %). The MTX-PG3 level was significantly higher in patients with TPMT *1/*3C than in patients with wild type and MTX-PG3% was significantly higher and MTX-PG5% was significantly lower in NUDT15 intermediate metabolizers than normal or indeterminate phenotypes (P < 0.05). This validated MTX-PGs quantification method can facilitate a better understanding of MTX metabolism and therapeutic drug monitoring for MTX treatment.

Erratum: Correction of Affiliations in the Article "Clinical Characteristics and Treatment Outcomes in Children, Adolescents, and Young-adults with Hodgkin's Lymphoma: a KPHOG Lymphoma Working-party, Multicenter, Retrospective Study".

This corrects the article on p. e393 in vol. 35, PMID: 33258329.