The epidemiology of osteosarcoma in adolescents and young adults (AYA) remains unclear. We aimed to assess and compare the clinical features of osteosarcoma between AYA and other age groups. We retrieved osteosarcoma cases diagnosed between 1999 and 2017 from the Korea Central Cancer Registry. We compared survival trends and clinical characteristics between AYA and other age groups. AYA comprised 43.3% (1309/3022) of the osteosarcoma cases. Compared to other age groups, the male-to-female ratio was highest in AYA (1.61:1). The proportion of tumors located in an extremity was 80.3% in AYA, which was lower than in young children (92.5%) or pubertal children (93.8%) but higher than in adults (55.7%) or the elderly (47.5%). As for treatments, 71.2% of AYA received local treatment and systemic chemotherapy, and 28.8% received only local treatment (surgery: 261, radiotherapy: 9, surgery and radiotherapy: 5). The 5-year overall survival (OS) was lower in AYA (68%) than in young children (78%) or pubertal children (73%) but higher than in adults (47%) or the elderly (25%). When AYA were divided into five subgroups by age, patients aged 15–19 years constituted the largest proportion (45.4%, n = 594). Additionally, the proportion of patients with a non-extremity tumor increased in an age-dependent manner, from 10.3% in AYA aged 15–19 years to 35.3% in AYA aged 35–39 years. OS did not significantly differ among the different age subgroups of AYA. The clinical characteristics and OS of the AYA were more similar to those of children than to those of adults. There is a need for cooperation between pediatric and adult oncologists for effective osteosarcoma treatment in AYA.

Park EH, et al. Blood Res. 2015 Dec;50(4):204-217. http://dx.doi.org/10.5045/br.2015.50.4.204

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.

Background: We investigated the epidemiologic characteristics of childhood brain tumors (CBT) in Korea, and compared our findings with those from the United States. Methods: We searched the Korea National Cancer Incidence Database of the Korea Central Cancer Registry (KCCR) from 2005 to 2014, which included all Korean patients with CBT aged 0 to 19 years at diagnosis. The age-standardized incidence rates (ASR) and the 5-year relative survival rate (RSR) were determined. The Central Brain Tumor Registry of the United States (CBTRUS) classification and definitions were applied to allow direct comparison with U.S. data. Results: A total of 6,027 CBTs were identified. The ASR of all CBTs was 5.08 per 100,000 population, which was significantly lower than that in the United States (5.57). However, the ASR of nonmalignant CBTs in Korea (2.48) was significantly higher than that in the United States (2.15). Embryonal tumors (ASR: 0.99 and 0.72 in the 0–4 and 5–9 year age groups, respectively) were the most common CBTs in these respective age groups. Germ cell tumors (0.78) and pituitary tumors (1.63) were the most common CBTs in the 10–14 and 15–19 year age groups, respectively. The 5-year RSR of CBTs was 84% and varied according to histology. Conclusions: High incidences of nonmalignant and germ cell tumors are distinct CBT features in Korean children and adolescents. Impact: To our knowledge, this is the first and largest population-based epidemiologic study of CBTs in Asia. Our findings support the notion that East Asian populations have a higher incidence of central nervous system germ cell tumors than other races.

PurposeThis 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 KoreaMaterials and MethodsData 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%.ConclusionThere 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.