Clinical data on treatment regimen and use of medication among patients with hemophilia B in Korea.

BACKGROUND: To investigate the clinical treatment status, such as treatment regimen, bleeding events, and drug dose, in patients with hemophilia B in South Korea. METHODS: In this retrospective chart review, data of patients with hemophilia B from eight university hospitals were collected. Demographic and clinical data, treatment data, such as regimen and number of injections, dose of factor IX concentrate, and bleeding data were reviewed. Descriptive analyses were performed with annual data for 2019, 2020, and 2021, as well as the three years consecutively. RESULTS: The medical records of 150 patients with hemophilia B between January 1, 2019, and December 31, 2021, were collected. Among these, 72 (48.0%) were severe, 47 (31.3%) were moderate, and 28 (18.7%) were mild. The results showed approximately two times more patients receiving prophylaxis as those receiving on-demand therapy, with 66.1% of patients receiving prophylaxis in 2019, 64.9% in 2020, and 72.1% in 2021. Annualized bleeding rates were 2.2% (± 3.1) in 2019, 1.8% (± 3.0) in 2020, and 1.8% (± 2.9) in 2021 among patients receiving prophylaxis. For the doses of factor IX concentrate, patients receiving prophylaxis received an average of 41.6 (± 11.9) IU/Kg/Injection in 2019, 45.7 (± 12.9) IU/Kg/Injection in 2020, and 60.1 (± 24.0) IU/Kg/Injection in 2021. CONCLUSIONS: Clinically, prophylaxis is more prevalent than reported. Based on insights gained from current clinical evidence, it is expected that the unmet medical needs of patients can be identified, and physicians can evaluate the status of patients and actively manage hemophilia B using more effective treatment strategies.

Clinical and economic burden of immune tolerance induction in entire patients with hemophilia A: Insights from a real-world Korean setting.

INTRODUCTION: The most notable challenge facing hemophilia A treatment is the development of inhibitors against factor VIII, resulting in increased clinical and socioeconomic burdens due to the need for expensive bypassing agents (BPAs). Although immune tolerance induction (ITI) is currently the primary approach for inhibiting and reducing the inhibitors, the lengthy duration of ITI necessitates the continued use of BPA to manage bleeding episodes. In this study, we aimed to obtain real-world evidence on the clinical and economic aspects and associated burdens experienced by patients with hemophilia A with inhibitors undergoing ITI in Korea. METHODS: Claims data from January 1, 2007, to December 31, 2020, were used in this study. The study cohort comprised patients with hemophilia A undergoing ITI, who were categorized into three groups: successful, failed, or continuation of ITI. We evaluated clinical and economic burdens, including monthly healthcare visits, medication costs, and total medical expenses. RESULTS: The study involved 33 cases of ITI across 32 patients. Excluding seven continuation cases where success could not be determined at the observation point, the estimated success rate of ITI was 80.8 %. The median duration of ITI for all patients was 25.7 months. While no significant disparities were noted in the ITI duration between successful and unsuccessful cases (24.51 vs. 25.66 months), substantial discrepancies were observed in the duration of BPA usage (11.10 vs. 25.66 months) and the number of prescribed BPAs (1.79 vs. 2.97). CONCLUSION: Successful ITI reduced both clinical and economic burdens, resulting in decreased monthly medication expenses and overall medical costs.

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.

Kaposiform hemangioendothelioma of skull base with dura invasion in a pediatric patient: a case report.

Kaposiform hemangioendothelioma is an extremely rare vascular tumor which shows aggressive local growth. We present a case of rapid growing vascular skull tumor with dura invasion in a pediatric patient with neurofibromatosis type 1. A 14-year-old male complained of headache and dizziness for 1 month after minor head trauma. Brain magnetic resonance imaging (MRI) revealed a 5-cm-sized tumor in the left frontotemporal bone with internal hemorrhage and cystic changes. The gross total resection of tumor was done. At the 7-month follow-up, brain MRI revealed a recurrent skull tumor with intracranial dura mass. He underwent second surgery, and the pathologic diagnosis was suggestive of Kaposiform hemangioendothelioma. For this vascular proliferative tumor, mTOR inhibitor was treated for 6 months, and there was the recurred nodular-enhancing mass along the sphenoid ridge. After additional 2 months of medication, the following MRI revealed a decreased nodular-enhancing mass.

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.

Self-reported physical activity behaviors of childhood cancer survivors: comparison to a general adolescent population in Korea.

PURPOSE: Adequate physical activity (PA) can significantly contribute to the prevention of undesirable health outcomes in childhood cancer survivors (CCS). This study aimed to identify the patterns of PA and related factors in Korean CCS. METHODS: Study subjects were 184 adolescents selected from an ongoing cohort study of Korean CCS and 1,840 sex- and school grade-matched controls randomly selected from the participants of the 2019 Korea Youth Risk Behavior Web-based Survey. Information on PA and sedentary behaviors was collected by self-administered questionnaire. We estimated body mass index (BMI)-adjusted odds ratio (OR) and 95% confidence interval (CI) for the advisable healthy behaviors of CCS compared with healthy controls using conditional logistic regression analysis. In addition, the associations of advisable healthy behaviors of CCS with sociodemographic and clinical factors were estimated using multiple logistic regression analysis. RESULTS: CCS were less likely to be physically active than controls, but this finding was evident only in males. The ORs (95% CIs) for regular exercise, moderate intensity PA, vigorous intensity PA, and walking were 0.42 (0.27-0.65), 0.39 (0.24-0.63), 0.53 (0.33-0.84), and 0.64 (0.42-0.98), respectively, in male CCS compared with same-sex controls. Compared with same-sex controls, male CCS were 4.60 times and female survivors were 15.19 times more likely to sleep longer than 8 h a day. Among CCS, males were 2.92 times and 3.07 times more likely to perform moderate intensity PA and muscle-strengthening exercise, respectively, than female. Higher BMI (OR: 1.16), highest family income (OR: 3.98), and a caregiver who performed regular exercise (OR: 2.08) were positively associated with vigorous intensity PA of CCS. With increasing time after treatment completion, the probability of engaging in sedentary activity for less than 6 h per day decreased (OR = 0.89, 95% CI 0.79-1.00). CONCLUSION: Korean adolescent CCS were physically inactive compared with control adolescents. Several sociodemographic factors such as sex, family income, caregiver PA, and obesity level were associated with PA behaviors of CCS. IMPLICATIONS: Strategic effort would be needed to increase physical activity of childhood cancer survivors in adolescent period with consideration of various sociodemographic factors found in this study.

Epidemiologic and Clinical Outcomes of Pediatric Renal Tumors in Korea: A Retrospective Analysis of The Korean Pediatric Hematology and Oncology Group (KPHOG) Data.

PURPOSE: Renal tumors account for approximately 7% of all childhood cancers. These include Wilms tumor (WT), clear cell sarcoma of the kidney (CCSK), malignant rhabdoid tumor of the kidney (MRTK), renal cell carcinoma (RCC), congenital mesoblastic nephroma (CMN) and other rare tumors. We investigated the epidemiology of pediatric renal tumors in Korea. MATERIALS AND METHODS: From January 2001 to December 2015, data of pediatric patients (0-18 years) newly-diagnosed with renal tumors at 26 hospitals were retrospectively analyzed. RESULTS: Among 439 patients (male, 240), the most common tumor was WT (n=342, 77.9%), followed by RCC (n=36, 8.2%), CCSK (n=24, 5.5%), MRTK (n=16, 3.6%), CMN (n=12, 2.7%), and others (n=9, 2.1%). Median age at diagnosis was 27.1 months (range 0-225.5) and median follow-up duration was 88.5 months (range 0-211.6). Overall, 32 patients died, of whom 17, 11, 1, and 3 died of relapse, progressive disease, second malignant neoplasm, and treatment-related mortality. Five-year overall survival and event free survival were 97.2% and 84.8% in WT, 90.6% and 82.1% in RCC, 81.1% and 63.6% in CCSK, 60.3% and 56.2% in MRTK, and 100% and 91.7% in CMN, respectively (p < 0.001). CONCLUSION: The pediatric renal tumor types in Korea are similar to those previously reported in other countries. WT accounted for a large proportion and survival was excellent. Non-Wilms renal tumors included a variety of tumors and showed inferior outcome, especially MRTK. Further efforts are necessary to optimize the treatment and analyze the genetic characteristics of pediatric renal tumors in Korea.

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.

Parent caregivers' preferences and satisfaction with currently provided childhood cancer survivorship care.

PURPOSE: The aim of this study was to investigate the level of satisfaction of parent caregivers of childhood cancer survivors (CCSs) with currently provided survivorship care and their preferences for survivorship care provider. METHODS: Study subjects were parent caregivers recruited at three hospitals in Korea. Study data were collected from self-administered questionnaires and medical records. We assessed parent caregivers' levels of satisfaction with specific survivorship care contents and preferred types of survivorship care provider among oncologists, primary care physicians (PCPs), and institutional general physicians (IGPs). Factors associated with parent caregivers' preferences for survivorship care provider were evaluated by multiple logistic regression analysis. RESULTS: 680 parent caregivers (mother 62.1% and father 37.9%) of 487 CCSs (mean age at diagnosis: 6.9 ± 5.1 years; mean time since treatment completion 5.4 ± 4.4 years) were included. Parent caregivers' dissatisfaction was the highest with screening for second primary cancer, followed by psychosocial problem management. Higher educational level of parent caregiver, parent caregiver's higher level of dissatisfaction with currently provided care, higher age of CCSs at cancer diagnosis, history of receiving hematopoietic stem cell transplant, and longer time lapse after cancer treatment were significantly associated with parent caregivers' higher preference for PCPs or IGPs than oncologists. Parent caregiver's multiple comorbidities and higher fear of cancer recurrence were associated with parent caregivers' higher preference for oncologists than PCPs or IGPs. Around 80% of parent caregivers recognized that a shared care system was helpful for promoting the health of CCSs. CONCLUSION: Parent caregivers were substantially dissatisfied with currently provided care, especially regarding the health issues not directly associated with the primary cancer. Parent caregivers' preferences for survivorship care provider is influenced by multiple factors, including age and survival time of CCSs, characteristics of parent caregivers, satisfaction level with care, and specific survivorship care contents. IMPLICATIONS FOR CANCER SURVIVORS: The findings of our study suggest that shared survivorship care for CCSs with consideration of specific care contents can complement the current oncologist-led survivorship care system.

Multiple craniospinal tumors in a pediatric patient with neurofibromatosis type 2: a case report.

INTRODUCTION: Neurofibromatosis type 2 (NF-2) is an inherited disease, linked with abnormalities in the NF-2 gene, which is located on chromosome 22 and involved in merlin production. Many craniospinal tumors are common in individuals with NF-2. We present a case of NF-2 with the rapid symptomatic progression of multiple craniospinal tumors. CASE REPORT: A 12-year-old male complained of headache and hearing impairment in the right ear for 7 months. Brain magnetic resonance imaging (MRI) revealed a right frontal meningioma, bilateral vestibular and trigeminal schwannomas, and a brainstem tumor. He was diagnosed with NF-2 and underwent brain surgery and radiotherapy for chordoid meningioma. He complained of right leg motor weakness 5 months post-surgery. The spine MRI showed multiple heterogeneously enhanced masses spreading over the entire spinal cord. The symptomatic intradural extramedullary mass at the cervicothoracic area was removed and the histological finding was schwannoma. His leg motor weakness was relieved after surgery. At the 6-month follow-up, brain MRI revealed the progression of the vestibular schwannoma, trigeminal schwannoma, and brainstem tumor. The patient was treated with bevacizumab (5 mg/kg) every 2 weeks for 6 months. For 2 years, all of the craniospinal tumors were stable without neurological deterioration after the completion of chemotherapy. CONCLUSION: Meningiomas and schwannomas grow slowly in most patients with NF-2, but these multiple craniospinal tumors can show sudden rapid growth and manifest as neurological symptoms in a pediatric patient. These tumors could be controlled with local symptomatic and systemic bevacizumab treatments.

Successful Management of Massive Congenital Hepatic Hemangioma and Systemic Hypertension With Sirolimus.

Congenital hepatic hemangioma (CHH) is a common benign vascular tumor of the liver, seen in infancy. The clinical manifestations vary from incidental findings to life-threatening complications. The authors present here a case of an infant with massive CHH who developed systemic hypertension because of compression of the right renal artery by the CHH and did not respond to other lines of treatment. After sirolimus therapy, the CHH size decreased and antihypertensive drugs were no longer necessary. In a critical situation, if the embolization and/or steroids do not seem to control the situation, then adding sirolimus may be considered as secondary therapy with good additive effects.

Staged operations for a hypervascular mixed germ cell tumor with growing teratoma syndrome: a case report.

INTRODUCTION: A mixed germ cell tumor with a teratoma component can become enlarged following chemotherapy, and such an event is diagnosed as growing teratoma syndrome. Removing large, hypervascular tumors including a tumor encased by developed vasculatures from the pineal region is challenging during a single operation. CASE REPORT: A 15-year-old male underwent chemotherapy for mixed germ cell tumors according to the KSPNO G082 protocol. This case of a mixed germ cell tumor with growing teratoma syndrome was recognized very early during chemotherapy. The tumor was completely removed during the staged operations. First, the anteriorly located tumor on the third ventricle was removed via the transcallosal interforniceal approach, and 1 month later, the occipital transtentorial approach was used for the pineal tumor with decreased vascularity. CONCLUSION: Performing staged operations could be recommended for large hypervascular pineal tumors, which can be safely removed during the second operation once vascularity has decreased.

Factors associated with the comprehensive needs of caregivers of childhood cancer survivors in Korea.

PURPOSE: Caregivers of childhood cancer survivors (CCS) have diverse needs, which should be addressed to provide comprehensive cancer care. We aimed to evaluate the unmet needs of caregivers of CCS. METHODS: The subjects were 700 caregivers recruited at three major hospitals in South Korea. We collected study data using self-administered questionnaires and a thorough review of medical records. We assessed the unmet needs of caregivers using the comprehensive needs assessment tool for cancer caregivers and evaluated factors associated with the highest tertile range of unmet needs by multiple logistic regression analysis. RESULTS: The greatest unmet needs of caregivers had to do with healthcare staff, followed by information. Compared with father-caregivers, mother-caregivers had greater unmet needs related to health and psychological problems, family/social support, and religious/spiritual support, with odds ratios (95% confidence interval) of 3.79 (2.52-5.69), 3.17 (2.09-4.81), and 1.69 (1.14-2.50), respectively. Compared with caregivers of the youngest CCS (< 6 years), caregivers of CCS aged 12-18 years and caregivers of the oldest CCS (≥ 19 years) respectively showed 2.62 (1.24-5.52) and 3.18 (1.34-7.55) times greater unmet needs for information. Caregivers of CCS who received haematopoietic stem-cell transplantation had a 2.01-fold (1.14-3.57) greater need for practical support. CONCLUSION: Caregivers of CCS had substantial unmet needs required for comprehensive care for CCS. Several individual characteristics of caregivers and their children were significantly associated with greater unmet needs of the caregivers. IMPLICATIONS FOR CANCER SURVIVORS: Personalized support based on the characteristics of both CCS and their caregivers is required to provide comprehensive care for CCS.

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.

Open-Label, Multicenter Phase II Study of Combination Therapy of Imatinib Mesylate and Mycophenolate Mofetil in Pediatric Patients with Steroid-Refractory Sclerotic/Fibrotic Type Chronic Graft-versus-Host Disease.

Steroid-refractory chronic graft-versus-host disease (cGVHD) is associated with high morbidity. To date, there is no standard therapy for patients who fail to respond to steroids. In this nonrandomized, open-label, single-arm, multicenter prospective phase II study, we evaluated the efficacy and safety of imatinib mesylate and mycophenolate mofetil (MMF) to treat sclerotic/fibrotic type cGVHD. The primary endpoint was the overall response rate (ORR) to imatinib mesylate plus MMF in 1 year, and the secondary endpoints included safety, quality of life, discontinuation of steroids, and overall survival (OS) rate. A total of 13 patients were enrolled, with a median age of 10.4 years (range, 5.0 to 20.1 years). All patients received a myeloablative conditioning regimen. Specifically, 6 of these patients had previously experienced acute GVHD. The most frequently affected organs were the eyes, lungs, skin, and liver. There were 2 premature deaths. One patient died of pulmonary infection and progression of cGVHD, and the other patient died from neuroblastoma progression and septic shock. The ORR was 76.9% (10 of 13 patients), and the median steroid dose was decreased from 1.0 mg/kg/day to 0.21 mg/kg/day. One-year OS was 84.6% (n = 13), and common adverse events included elevated liver enzyme and serum creatinine levels and fever. Although our sample size was limited, treatment of cGVHD with imatinib mesylate plus MMF shows promising results with acceptable toxicity.

Patients' and parents' satisfaction with, and preference for, haemophilia A treatments: a cross-sectional, multicentre, observational study.

INTRODUCTION: Reports on patients' satisfaction and preferred characteristics for treatments would be worthwhile when choosing an optimal treatment reflecting patients' perspectives. AIM: To identify the characteristics and treatment patterns of patients with haemophilia A, or their caregivers, in Korea and explore patient preferences and satisfaction with their treatment. METHODS: This cross-sectional, multicentre, observational study was conducted from April 2018 to September 2019 at six nationwide hospitals and three Korea Hemophilia Foundation clinics. Patients aged ≥16 years, or legal caregivers of paediatric patients, who had used factor VIII (FVIII) concentrates for ≥1 month were enrolled. Satisfaction with treatment was measured using the Treatment Satisfaction Questionnaire for Medication (TSQM); preference was evaluated using discrete choice experiment (DCE), with 10 series of two hypothetical treatment options created from D-efficient block design, which varied across five attributes. RESULTS: Overall, 505 patients (mean age 31 years) were enrolled in the study. Patients had received FVIII concentrate for an average of 102.9 months (prophylaxis: 53.5%; on-demand: 22.2%). Mean TSQM scores were 64.6 (effectiveness domain), 97.9 (side effects), 57.1 (convenience) and 66.8 (global satisfaction). The number of vials per injection, and the frequency of drug administration, was significantly associated with treatment satisfaction. According to DCE, simpler treatment options were preferred by patients/caregivers. CONCLUSION: The lowest satisfaction levels were shown in the treatment convenience domain. Patients/parents preferred simpler and easier treatment characteristics. In an attempt to enhance the overall satisfaction of patients and caregivers with treatment, consideration of more convenient characteristics is required in future decisions regarding treatment selection.

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.

Atypical Teratoid/Rhabdoid Tumor of the Central Nervous System in Children under the Age of 3 Years.

PURPOSE: Atypical teratoid/rhabdoid tumor (ATRT) is a highly aggressive malignancy with peak incidence in children aged less than 3 years. Standard treatment for central nervous system ATRT in children under the age of 3 years have not been established yet. The objective of this study was to analyze characteristics and clinical outcomes of ATRT in children aged less than 3 years. MATERIALS AND METHODS: A search of medical records from seven centers was performed between January 2005 and December 2016. RESULTS: Forty-three patients were enrolled. With a median follow-up of 90 months, 27 patients (64.3%) showed at least one episode of disease progression (PD). The first date of PD was at 160 days after diagnosis. The 1- and 3-year progression-free survivals (PFS) were 51.2% and 28.5%, respectively. The 1- and 3-year overall survivals were 61.9% and 38.1%, respectively. The 3-year PFS was improved from 0% in pre-2011 to 47.4% in post-2011. Excluding one patient who did not receive any further therapy after surgery, 27 patients died due to PD (n=21), treatment-related toxicity (n=5), or unknown cause (n=1). In univariate analysis, factors associated with higher 3-year PFS were no metastases, diagnosis after 2011, early adjuvant radiotherapy, and high-dose chemotherapy (HDCT). In multivariate analysis, the use of HDCT and adjuvant radiotherapy remained significant prognostic factors for PFS (both p < 0.01). CONCLUSION: Aggressive therapy including early adjuvant radiotherapy and HDCT could be considered to improve outcomes of ATRT in children under the age of 3 years.

MEF2D-BCL9 B-Lymphoblastic Leukemia Blast Morphology Does Not Always Mimic Mature B-Cell Leukemia.

MEF2D (myocyte enhancer factor 2D)-rearranged acute lymphoblastic leukemia (ALL) has recently been documented by transcriptome sequencing in B-cell precursor ALL. It is associated with older age of onset (median: 14 y), and characterized by very early relapse and poorer outcomes than other B-cell precursor ALL groups. According to report by Suzuki and colleagues, all 4 cases of MEF2D-BCL9-fusion ALL among 59 children with relapsed or primary refractory ALL had leukemic blasts morphologically mimicking mature B-cell leukemia cells. However, we display morphologically different blast populations in 2 patients with MEF2D-BCL9-rearranged ALL. Mature B-cell leukemia-like morphology would aid the detection of MEF2D-BCL9 fusion, but not all cases might have typical morphology.