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.

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.

Purpose: Effectiveness and safety of clofarabine (one of the treatment mainstays in pediatric patients with relapsed/refractory acute lymphoblastic leukemia [ALL]) was assessed in Korean pediatric patients with ALL to facilitate conditional coverage with evidence development. Materials and Methods: In this multicenter, prospective, observational study, patients receiving clofarabine as mono/combination therapy were followed up every 4-6 weeks for 6 months or until hematopoietic stem cell transplantation (HSCT). Response rates, survival outcomes, and adverse events were assessed. Results: Sixty patients (2-26 years old; 65% B-cell ALL, received prior ≥ 2 regimen, 68.3% refractory to previous regimen) were enrolled and treated with at least one dose of clofarabine; of whom 26 (43.3%) completed 6 months of follow-up after the last dose of clofarabine. Fifty-eight patients (96.7%) received clofarabine combination therapy. Overall remission rate (complete remission [CR] or CR without platelet recovery [CRp]) was 45.0% (27/60; 95% confidence interval [CI], 32.4 to 57.6) and the overall response rate (CR, CRp, or partial remission [PR]) was 46.7% (28/60; 95% CI, 34.0 to 59.3), with 11 (18.3%), 16 (26.7%), and one (1.7%) patients achieving CR, CRp, and PR, respectively. The median time to remission was 5.1 weeks (95% CI, 4.7 to 6.1). Median duration of remission was 16.6 weeks (range, 2.0 to 167.6 weeks). Sixteen patients (26.7%) proceeded to HSCT. There were 24 deaths; 14 due to treatment-emergent adverse events. Conclusion Remission with clofarabine was observed in approximately half of the study patients who had overall expected safety profile; however, there was no favorable long-term survival outcome in this study.

Background: Hodgkin's lymphoma (HL) constitutes 10%–20% of all malignant lymphomas and has a high cure rate (5-year survival, around 90%). Recently, interest has increased concerning preventing secondary complications (secondary cancer, endocrine disorders) in long-term survivors. We aimed to study the epidemiologic features and therapeutic outcomes of HL in children, adolescents, and young adults in Korea. Methods: We performed a multicenter, retrospective study of 224 patients aged < 25 years diagnosed with HL at 22 participating institutes in Korea from January 2007 to August 2016. Results: A higher percentage of males was diagnosed at a younger age. Nodular sclerosis histopathological HL subtype was most common, followed by mixed cellularity subtype.Eighty-one (36.2%), 101 (45.1%), and 42 (18.8%) patients were classified into low, intermediate, and high-risk groups, respectively. Doxorubicin, bleomycin, vinblastine, dacarbazine was the most common protocol (n = 102, 45.5%). Event-free survival rate was 86.0% ± 2.4%, while five-year overall survival (OS) rate was 96.1% ± 1.4%: 98.7% ± 1.3%, 97.7% ± 1.6%, and 86.5% ± 5.6% in the low, intermediate, and high-risk groups, respectively (P = 0.021). Five-year OS was worse in patients with B-symptoms, stage IV disease, highrisk, splenic involvement, extra-nodal lymphoma, and elevated lactate dehydrogenase level.In multivariate analysis, B-symptoms and extra-nodal involvement were prognostic factors for poor OS. Late complications of endocrine disorders and secondary malignancy were observed in 17 and 6 patients, respectively. Conclusion This is the first study on the epidemiology and treatment outcomes of HL in children, adolescents, and young adults in Korea. Future prospective studies are indicated to develop therapies that minimize treatment toxicity while maximizing cure rates in children, adolescents, and young adults with HL.

Background: Multiple hereditary exostosis is a common autosomal dominant inherited musculoskeletal disorder that manifests with multiple osteochondromas. The clinical manifestations and pathological characteristics of osteochondromas found in the long bone and genetic alterations related to multiple hereditary exostosis have been widely reported. In this study, we investigated the characteristics of brachymetacarpia and brachymetatarsia associated with multiple hereditary exostosis. Methods: Of the 133 patients with a diagnosis of multiple hereditary exostosis who were recruited from 2005 to 2018, 101 patients who underwent plain radiography after 10 years of age were included. There were 55 male (54.5%) and 46 female (45.5%) patients. Brachymetacarpia or brachymetatarsia was diagnosed when disruption of the Lièvre parabola connecting the metacarpal or metatarsal heads was observed on plain radiographs. Three orthopedic surgeons individually reviewed hand and foot plain radiographs. Results: Of the 101 patients, 41 patients (40.6%) had more than 1 brachymetacarpia (88 cases) or brachymetatarsia (81 cases). Among 41 cases, 22 (53.7%) were male and 19 (46.3%) were female. The mean age at the time of radiographic evaluation of the hands and feet was 14.6 years (range, 10–63 years). Shortening was most commonly found in the 3rd and 4th metacarpal or metatarsal bones. Conclusions We found a relatively high incidence of brachymetacarpia and brachymetatarsia in our patients. Physicians should suspect the presence of brachymetacarpia and brachymetatarsia when treating patients with multiple hereditary exostosis.

PURPOSE: Pes planovalgus is one of the most common foot deformities among pediatric orthopedic diseases and is divided into idiopathic and neuromuscular planovalgus according to its etiology. This study evaluated the radiologic and pedobarographic outcomes of the treatment for pes planovalgus in children treated with lateral column lengthening, compared the outcomes according to the etiology, and investigated the correlation between the radiologic and pedobarographic findings. MATERIALS AND METHODS: Sixty-three patients (97 feet), who underwent lateral column lengthening, were divided into groups of 30 patients (47 feet) with neuromuscular disease and 33 patients (50 feet) with idiopathic etiology. The preoperative, immediately postoperative, 1 year, and 3 year follow-up radiographic measurements on the plain radiograph antero-posterior (AP) and lateral view were compared. In pedobarography, the foot pressures were subdivided into 4 areas to measure the contact time, contact area, peak pressure, and maximum force. The pre- and postoperative pedobarographic measurements were compared and the correlations between the radiographic and pedobarographic measurements were evaluated. RESULTS: The radiographic index at the 1st postoperative year and 3rd postoperative follow-up did not show significant differences according to the etiology. In pedobarography, idiopathic planovalgus showed a significant increase in the maximum force in the hindfoot and forefoot. The correlation between the radiologic findings and pedobarographic findings was statistically significant between the tibiocalcaneal angle in the lateral view and the maximum force, and the contact area of hindfoot on pedobarography, between tibiocalcaneal angle in the lateral view and the contact area of the toes in idiopathic planovalgus. In neuromuscular planovalgus, the peak pressure in the hindfoot had a strong negative correlation with talonavicular coverage angle in the AP view and talo-1st metatarsal angle, and the talohorizontal angle in the lateral view. CONCLUSION: Lateral column lengthening is an effective surgical procedure for flatfoot patients. On the other hand, the radiographic examination has limitations for accurate assessments of the postoperative results and prognosis. Qualitative and quantitative evaluations are available by pedobarography and it is a useful instrument for an evaluation of planovalgus when used in conjunction with radiography.
Child ; Evaluation Studies as Topic ; Flatfoot ; Follow-Up Studies ; Foot ; Foot Deformities ; Hand ; Humans ; Metatarsal Bones ; Neuromuscular Diseases ; Orthopedics ; Prognosis ; Radiography ; Toes

PURPOSE: To investigate the degree, distribution, and change in refractive error in the pediatric population 5 to 20 years of age. METHODS: We collected data from 7,695 subjects aged 5 to 20 years who participated in the Korean National Health and Nutrition Examination Survey from 2008 to 2012. Non-cycloplegic refractive error was measured using an autorefractor. Mean spherical equivalent calculated from the measured refractive error data in both eyes was used. The subjects were categorized into mild, moderate, or high refractive abnormality or emmetropia according to the degree of refractive error. The degree and distribution of refractive error in all subjects and age-matched subjects were analyzed. The change in refractive error was analyzed according to age. RESULTS: Mean refractive error of the study subjects was -1.82 diopters. As subject age increased, myopia increased from +0.04 diopters at 5 years of age to -2.88 diopters at 20 years of age. Myopia was observed in 66.2% of subjects and accounted for only 18.5% of the 5-year-old subjects, but increased to 84.3% in the 20-year-old subjects. The rate among all study subjects was -0.19 diopters per year. The greatest myopic progression rate (-0.46 diopters per year) among all age groups was in subjects 7 to 9 years of age. Myopic progression continued until 16 years of age. CONCLUSIONS: The ratio of pediatric myopia subjects between 5 and 20 years of age was high in Korea. The rate of myopic progression was the fastest in subjects 7 to 9 years of age. After 16 years of age, myopic change paused.
Child, Preschool ; Emmetropia ; Humans ; Korea* ; Myopia ; Nutrition Surveys* ; Refractive Errors ; Young Adult

PURPOSE: We compared the treatment results and toxicity in nasopharyngeal carcinoma (NPC) patients treated with concurrent chemotherapy (CCRT) alone (the CRT arm) or neoadjuvant chemotherapy followed by CCRT (the NCT arm). MATERIALS AND METHODS: A multi-institutional retrospective study was conducted to review NPC patterns of care and treatment outcome. Data of 568 NPC patients treated by CCRT alone or by neoadjuvant chemotherapy followed by CCRT were collected from 15 institutions. Patients in both treatment arms were matched using the propensity score matching method, and the clinical outcomes were analyzed. RESULTS: After matching, 300 patients (150 patients in each group) were selected for analysis. Higher 5-year locoregional failure-free survival was observed in the CRT arm (85% vs. 72%, p=0.014). No significant differences in distant failure-free survival (DFFS), disease-free survival (DFS), and overall survival were observed between groups. In subgroup analysis, the NCT arm showed superior DFFS and DFS in stage IV patients younger than 60 years. No significant difference in compliance and toxicity was observed between groups, except the radiation therapy duration was slightly shorter in the CRT arm (50.0 days vs. 53.9 days, p=0.018). CONCLUSION: This study did not show the superiority of NCT followed by CCRT over CCRT alone. Because NCT could increase the risk of locoregional recurrences, it can only be considered in selected young patients with advanced stage IV disease. The role of NCT remains to be defined and should not be viewed as the standard of care.
Arm ; Chemoradiotherapy ; Compliance ; Disease-Free Survival ; Drug Therapy* ; Humans ; Induction Chemotherapy ; Methods ; Nasopharyngeal Neoplasms ; Propensity Score* ; Radiotherapy ; Recurrence ; Republic of Korea ; Retrospective Studies* ; Standard of Care ; Treatment Outcome

In this article, an protocol number error was found in the last paragraph of the introduction part, page 872.