Background: Aggressive mature B-cell non-Hodgkin lymphoma (B-NHL) is the most common non-Hodgkin lymphoma in children. The outcome of chemotherapy for B-NHL has improved over decades. Methods: We reviewed 82 children and adolescents with B-NHL diagnosed at Asan Medical Center between 1993 and 2020. The D-COMP/COMP (daunomycin–cyclophosphamide, doxorubicin, vincristine, and prednisolone), Pediatric Oncology Group (POG)-9219/9315/ 9317, R-CHOP/CHOP (rituximab–cyclophosphamide, doxorubicin, vincristine, and prednisolone), and Lymphomes Malins B 89 (LMB89)/LMB96 regimens were administered. In 2018, rituximab was added to the LMB protocol (R-LMB) for advanced-staged Burkitt lymphoma (BL). The patients’ clinical features and treatment outcomes were retrospectively analyzed. Results: The most common subtype was BL (61%), followed by diffuse large B-cell lymphoma (DLBCL) (35%). The median age was 7.8 (range, 1.3‒16.4) years, and the most frequently used regimen was French‒American‒British (FAB)/LMB96 (58 patients, 70.7%). The 5-year overall survival (OS) and event-free survival (EFS) rates were 92.5% and 85.7%, respectively. The EFS rates of patients with BL and DLBCL were 90.0% and 79.3%, respectively. Among the FAB/LMB risk groups, group C (85.7%) had a significantly lower 5-year OS (P =0.037). Eleven events occurred (6 relapses, 3 deaths, and 2 secondary malignancies) during the median follow-up of 7.1 (range, 3.7‒118.5) months. Two patients treated with R-LMB had good outcomes without complications. Conclusion Various treatment regimens have favorable outcomes in pediatric patients with B-NHL.However, further studies are needed to improve survival in high-risk patients. In addition, careful monitoring for acute toxicity or secondary malignancy due to intensive multidrug chemotherapy is required.

Background: Lymphoblastic lymphoma (LBL) is the second most common subtype of pediatric non-Hodgkin lymphoma. Modified treatments derived from the LSA2-L2 regimen resulted in encouraging survival, but toxicities and long-term sequelae have been problematic. At present, the acute lymphoblastic leukemia (ALL)-type protocol has demonstrated efficacy in LBL. We analyzed the outcomes of children and adolescents with LBL treated with various regimens. Methods: From 1991‒2018, this study enrolled 63 patients diagnosed with LBL at Asan Medical Center. Medical records were retrospectively analyzed. Results: Among 63 patients, most patients (38.1%) presented with stage IV at diagnosis, and two had central nervous system (CNS) involvement. At a median follow-up of 160 months, the 5-year event free survival (EFS), overall survival (OS), and relapse free survival (RFS) were 68.8%, 79.3%, and 71.3%, respectively. Among 61 patients who received chemotherapy, 27 patients (44.3%) received the NY protocol, and 14 (23.0%) received the ALL-type protocol. There was no significant difference in 5-yr OS (85.2%/78.6%), EFS (73.5%/78.6%), and RFS (73.5%/78.6%) between the NY and ALL protocol groups, regardless of immunophenotype. Thirteen patients (21.3%) received prophylactic cranial radiotherapy with no difference in the incidence of CNS relapse based on irradiation. Conclusion This study showed no difference in outcome between the NY and ALL-type protocols, regardless of stage or immunophenotype. In addition to improving the effectiveness of treatment, it is necessary to continuously appraise the appropriate chemotherapy regimen, considering toxicities and long-term prognosis, for pediatric LBL.

Hepatoblastoma is the most common malignant hepatic tumor in infants and young children and accounts for approximately 1% of all pediatric malignancies. A treatment strategy incorporating chemotherapy and surgical resection has evolved based on the results of the multicenter clinical trials performed by the major liver study groups during the last two decades and led to significantly improved survival outcomes. The alpha-fetoprotein level, PRE-Treatment EXTent tumor stage, and histological category are well-known prognostic factors that are used for risk stratification. Platinum-based chemotherapy regimens are effective in terms of increasing the likelihood of surgical resectability. Refinement of surgical techniques and the advent of liver transplantation have improved the outcomes in patients with advanced tumors. However, the optimal treatment strategy for advanced hepatoblastoma remains unclear. Unanswered questions include the optimal timing and indications for pulmonary metastasectomy and when the surgical strategy should be complex liver resection or liver transplantation. The major liver study groups have now formed a global coalition known as the Children’s Hepatic tumors International Collaboration and developed an international staging system. The aim of this article is to review current treatment strategies of hepatoblastoma focusing on high risk patients.

Purpose: We aimed to determine the current application and survival trends of hematopoietic stem cell transplantation (HSCT) among Korean children and adolescents with cancer. Materials and Methods: Data of patients aged < 20 years with KCD-10 (Korean Classifications of Diseases, 10th revision) C codes and specific designation codes were collected from the National Health Insurance Service database. Thirty claim codes for HSCT were included, and data from 2009 to 2019 were analyzed. Results: The operational definition of pediatric cancer yielded an annual average of 2,000, with annual cases decreasing. In 2019, 221 HSCTs were performed, a decrease from the ten-year average of 276. Allografts outnumbered autografts with a ratio of 1.5:1. The source of allograft was bone marrow in 15% of patients in 2009; however, it substantially decreased to 3.3% in 2019. Furthermore, 70.5% of allogeneic HSCT used peripheral blood stem cell (PBSC) grafts, which increased to 89.3% by 2015. Cord blood utilization markedly decreased to 2.7% in 2018. The 5-year overall survival (OS) rate of all patients was 85.1%. Overall mortality decreased among patients who underwent recent HSCT, and they exhibited a higher 5-year OS rate. Conclusion In Korea, the number of pediatric patients with cancer is declining; however, the ratio of transplants to all patients remains constant. Patients who recently underwent transplantation showed better survival rates, possibly due to HSCT optimization. Korea showed a substantially greater PBSC utilization in pediatric HSCT. An in-depth examination encompassing donor relations and cause of death with a prospective registry is required in future studies.