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: Childhood cancer survivors (CCSs) are at risk for premature ovarian insufficiency (POI). The aim of this study is to evaluate ovarian function and associated health outcomes in female adolescent and young adult survivors of childhood cancer. Materials and Methods: Sixty-nine female CCSs were enrolled. Medical records of CCSs were retrospectively reviewed. The subjects were categorized into three groups according to follicular stimulating hormone (FSH) levels (cutoff, 12, 40 IU/L). Anti-müllerian hormone (AMH) level less than 1 ng/mL was considered low AMH level. Results: Of 69 subjects, 14 (20.3%) had POI and 14 (20.3%) had FSH levels between 12 and 40 IU/L. Forty-one of 69 (59.4%) had normal FSH levels. Pelvic irradiation and stem cell transplantation (SCT) were more frequently performed in subjects with POI (p=0.001 and p < 0.001). AMH levels were remarkably low when FSH levels were over 12 IU/L (p < 0.001). In multivariate analysis, cyclophosphamide equivalent dose and SCT were significant treatment factors for developing low AMH levels (p=0.005 and p=0.002, respectively). Total, low-density lipoprotein cholesterol and triglyceride were significantly different in three groups according to FSH levels (p=0.047, p=0.030, and p=0.045). Z-score of femur neck bone mineral density was significantly reduced when FSH levels were increased (p=0.011). Conclusion Gonadal dysfunction is common in CCSs. Gonadal function was associated with a few treatment factors known to increase the risk of POI. Regular monitoring of gonadal function is needed for better health outcomes.

Background: As the treatment effects for childhood and adolescent cancer continue to improve, the survivor group is gradually growing and their age is increasing. This study aimed to determine the perceptions toward childhood and adolescent cancer survivors and assess the current situation regarding their return to school, to undertake policy development to help them grow into healthy members of society. Methods: From December 2019, for about 4 months, a structured questionnaire was used to conduct one-on-one interviews with childhood and adolescent cancer survivors and their parents, as well as with parents of healthy children and adolescents. Results: The participants included 79 survivors of childhood and adolescent cancer, 186 parents of cancer survivors, and 661 general parents; their mean age was 21.8, 13.9, and 12.5 years, respectively. After completing their cancer treatment, 77.2% of the cancer survivors returned to school, with the majority returning to regular schools in the same grade as their peers. Reasons for not returning to school (20.3%) included concerns about health management (43.8%), concerns about psychological and emotional adjustment (12.5%), and poor school attendance (12.5%). Among the parents of cancer survivors, 48.9% stated that they were “satisfied” with their children’s school life; a better health status in children was associated with a higher level of satisfaction (P=0.0071). In addition, they stated that national-level support was needed in the following areas for a successful return to school: a continuous health management system (36.1%) and understanding homeroom teachers who enable flexible participation in classes and school events (29.5%). Conclusion For survivors of childhood and adolescent cancer to successfully return to school and society, nationwide awareness-raising activities should be expanded, in addition to services that are tailored to the survivors’ needs and characteristics such as management of physical and mental health and educating homeroom teachers and peers.

Patients with inherited bone marrow failure syndrome (IBMFS) can develop peripheral blood cytopenia, which can ultimately progress to myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Although some cases of IBMFS are diagnosed based on their typical presentation, variable disease penetrance and expressivity may result in diagnostic dilemmas. With recent advances in genomic evaluation including next-generation sequencing, many suspected cases of IBMFS with atypical presentations can be identified. Identification of the genetic causes of IBMFS has led to important advances in understanding DNA repair, telomere biology, ribosome biogenesis, and hematopoietic stem cell regulation. An overview of this syndromes is summarized in this paper.

Optic pathway gliomas (OPGs) are insidious, debilitating low-grade tumors. They can affect the optic nerve, optic chiasm, and optic tracts and can be sporadic or associated with neurofibromatosis type 1 (NF1). The location of OPGs within the optic pathway typically precludes complete resection or optimal radiation dose. Treatment is unnecessary for sporadic and NF1-related OPGs that do not cause visual impairments. Chemotherapy is the mainstay of treatment for patients with progressive disease. However, outcomes following standard treatments have been mixed, and standardized outcome measurements are lacking. In recent years, newer molecularly targeted therapies such as anti-vascular endothelial growth factor (VEGF) monoclonal antibody, mitogen-activated protein kinase (MAPK) inhibitor, and mammalian target of rapamycin (mTOR) inhibitor, represent a promising treatment modality.

Purpose: Due to low incidence, epidemiologic data of Ewing sarcoma in the Asian population are scarce. We aimed to examine the incidence pattern and outcome of patients with Ewing sarcoma in the Republic of Korea. Materials and Methods: Data of patients with Ewing sarcoma diagnosed between 1999 and 2017 were obtained from the Korea Central Cancer Registry (KCCR). Incidence, clinical characteristics, and survival rates were analyzed and compared between different age groups. Results: There were 788 cases (459 males, 329 females), with a median age at diagnosis of 20 years. The age-standardized rate of Ewing sarcoma was 1.01. The number of cases and incidence rates in each age group were as follows: children, 1.6; adolescents and young adults (AYA), 0.93; adults, 0.44; and elderly, 0.53. There were more male cases in children and the AYA group (p < 0.001). Extraskeletal tumors (p < 0.001), primary sites other than extremity (p=0.007), and presence of metastasis at diagnosis (p=0.031) were more frequent in the adults and elderly group. With a median survival time of 78 months, the 5-year overall survival (OS) rate of the entire cohort was 52%. Children fared best (5-year OS, 75%), and the 5-year OS of AYA patients (51%) approximated the OS of the entire cohort. A two-fold difference of 5-year OS was observed between adults and elderly patients (42% vs. 19%). On univariate and multivariate analyses, age ≥ 15 years and presence of metastasis were adverse prognostic factors. Conclusion This was the first epidemiologic study of Ewing sarcoma using the KCCR data. With a similar incidence to other Asian countries, the survival rate was slightly lower than that of Euro-American cases. Collaborative clinical studies are necessary to improve the outcome of Ewing sarcoma in low-incidence populations.

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.

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.

Synovial sarcoma occurring in the pleura and lung is extremely rare. We report a case of pleuropulmonary synovial sarcoma as a second malignant neoplasm. The patient had been diagnosed with acute myelomonocytic leukemia at 5 years of age, and received matched sibling donor allogeneic bone marrow transplantation, with total body irradiation and cyclophosphamide conditioning. At 22 years of age, he complained of worsening chest discomfort and exertional dyspnea. Chest CT revealed a huge mass in the right middle lobe, pleura, and diaphragm. The patient was initially diagnosed as sarcomatoid malignant mesothelioma, without any environmental or occupational asbestos exposure. Five months later, the patient presented with soft tissue metastasis and underwent needle biopsy. Pathological examination including SYT-SSX RT-PCR revealed synovial sarcoma, which led to a review of the original tumor findings and confirmed the diagnosis of pleuropulmonary synovial sarcoma.To the best of our knowledge, our patient is the first case of pleuropulmonary synovial sarcoma developed after allogeneic hematopoietic stem cell transplantation.

Purpose: This study investigated the incidence and relative survival rates (RSRs) for cancers among adolescents and young adults (AYAs) aged 15-39 years between 1993 and 2016 in Korea Materials and Methods: Data from the Korea Central Cancer Registry were used to calculate percent distributions, age-specific incidence rates, age-standardized incidence rates (ASRs) per million, annual percent changes (APCs), average APCs, and RSRs for cancers diagnosed in AYAs. Results: ASR of all cancers among AYAs was 654.5 per million. The largest diagnosed group of cancers was carcinomas (almost 80%). Crude incidence increased with age, from 170.4 per million for those aged 15-19 years to 1,639.8 per million for those aged 35-39 years. ASR increased from 414.8 per million to 820.4 per million, with an APC of 9.0%. The incidence of thyroid carcinoma showed the most rapid increment (APC, 14.0%), followed by non-Hodgkin lymphoma (APC, 13.4%). The 5-year RSR among AYAs significantly improved from 62.1% to 90.8%. Survival improvement in AYAs was higher than that in children but lower than that in older adults (APC, 2.1% vs. 1.9% vs. 3.1%). The most marked survival improvement was found for leukemia and lymphoma. Astrocytoma, rhabdomyosarcoma, and carcinoma of the trachea, bronchus, and lung had a 5-year RSR of < 50%. Conclusion There was an improvement in cancer survivals in AYAs, comparable to that achieved in children. However, survivals in several cancer types do not appear to be improving. Further research focusing on the epidemiology and therapeutic strategies for cancers in AYAs is needed.