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.

BACKGROUND: Thyroid cancer affects relatively young adults, and its overall survival is excellent. With long life expectancy, the development of subsequent cancers is an important concern for survivors of thyroid cancer. The objective of this study was to investigate the incidence and types of second primary malignancies in Korean patients with thyroid cancer.METHODS: The study cohort included 178,844 registrants with thyroid cancer from the Korea Central Cancer Registry (KCCR) database between 1993 and 2010. Standardized incidence ratios (SIRs) were calculated using a statistical software program (SEER*Stat 8.0.4).RESULTS: Among 178,844 patients with thyroid cancer, 2895 (1.6%) were diagnosed with subsequent second primary malignancies. The overall risks of a second primary cancer were elevated by 6% in patients who had thyroid cancer compared with the general population during the same period. The elevated risks for developing second cancers were observed in all sites except the stomach and cervix. The elevated risk of second primary cancers was observed within the first 10 years of follow‐up. Leukemia and cancers of the salivary gland, kidney, prostate, lung, and breast had the most significantly elevated risks as secondary cancers and presented as early as during the first 5 years after the initial diagnosis of thyroid cancer.CONCLUSIONS: This is the largest, standardized, population‐based study to date using nationwide data from the entire Korean population. The risks of several cancers were elevated significantly during follow‐up, thus alerting physicians to pay special attention in their care of patients with thyroid cancer and long‐term survivors. Cancer 2015;121:259–68. © 2014 American Cancer Society.

Kim SI, et al. J Gynecol Oncol. 2015 Dec;27(1):e5. https://doi.org/10.3802/jgo.2016.27.e5

Background: South Korea has the highest incidence of thyroid cancer in the world. Our study examined the trends in thyroid cancer incidence by the histologic type, cancer stage, and age group and explored possible factors that affected thyroid cancer trends.Methods: We conducted a descriptive epidemiological study using the national cancer registry data and cause of death data from 1999 to 2016 in South Korea. Age‐standardized rates were calculated using Segi's world standard population. Joinpoint regression analysis was applied to determine the changing point of thyroid cancer trends according to histologic type; Surveillance, Epidemiology, and End Results (SEER) summary stage; and age groups by sex.Results: The age‐standardized incidence of thyroid cancer in both men and women increased from 6.3 per 100,000 people in 1999 to 63.4 per 100,000 in 2012 but declined from 2012 to 2016, before the debates for over diagnosis of thyroid cancer began in 2014. The age‐standardized mortality rate of thyroid cancer, incidence of distant thyroid cancer, and incidence of regional and localized thyroid cancer started to decline since early 2000, 2010, and 2012, respectively. In addition, thyroid cancer prevalence in thyroid nodules showed decreasing trends from 1999–2000 to 2013–2014.Conclusions: The incidence of thyroid cancer began declining from 2012, before the debates for over diagnosis of thyroid cancer began in 2014. Changes in guidelines for thyroid nodule examinations may have affected this inflection point. Moreover, the debates for over diagnosis of thyroid cancer may have accelerated the decline in thyroid cancer.

As patients with prostate cancer have a long life expectancy, there is increasing interest in predicting the risk of development of a second primary cancer (SPC), and we therefore designed this study to estimate the overall risk of developing SPCs among Korean prostate cancer patients. We used a population-based cohort from the Korean Central Cancer Registry composed of 55,378 men diagnosed with a first primary prostate cancer between 1993 and 2011. Standardized incidence ratios (SIRs) of SPCs were analyzed by age at diagnosis, latency period, period of diagnosis, and type of initial treatment. Survival analysis was stratified by development of SPC. Men with primary prostate cancer had an overall lower risk of developing an SPC [SIR = 0.75; 95% CI, 0.72−0.78], which was significant for SPCs of the esophagus, stomach, rectum, liver, gallbladder, bile duct, pancreas, larynx, lung, and bronchus. In contrast, there were significant increases in the risk of bladder and thyroid cancers, which tended to decrease after longer follow-up. Patients who received initial radiation therapy had an increased risk of subsequent rectal cancer, although this was still lower than that of the general male population. Other urinary tract cancers including those of the kidney, renal pelvis, and ureter tended to be associated with a higher risk of developing an SPC, but this difference did not reach statistical significance. The patients with prostate cancer and SPC had lower overall survival rates than those with one primary prostate cancer. Our findings suggest that men with prostate cancer have a 25% lower risk of developing an SPC in Korea, but a higher risk of developing subsequent bladder and thyroid cancers, which suggests the need for continued cancer surveillance among prostate cancer survivors.

Purpose This descriptive study assessed the current trends in the incidence of urological cancers and patient survival in Korea. Materials and Methods In this nationwide retrospective observational study based on the data from the Korea National Cancer Incidence Database (KNCIDB), this study analyzed the age-standardized incidence rates (ASRs) and annual percentage changes (APCs) of kidney, bladder, prostate, testicular, and penile cancers as well as cancer of the renal pelvis and ureter between 1999 and 2012. The relative survival rates (RSRs) were calculated for urological cancer patients diagnosed between 1993 and 2012 from the KNCIDB data. Results Prostate cancer was diagnosed in 66,812 individuals followed by bladder (41,549) and kidney (36,836) cancers. The overall ASR (18.26 per 100,000) increased with age because of the higher ASRs of bladder and prostate cancers in the elderly. The ASR for kidney cancer was highest in the 40-59-year-old group, whereas testicular cancer occurred most frequently before the age of 40. The incidence of most urological cancers increased (overall APC, 6.39%; p < 0.001), except for penile (APC, -2.01%; p=0.05) and bladder (APC, -0.40%; p=0.25) cancers. The overall survival increased steadily (5-year RSR, 66.4% in 1993-1995 vs. 84.2% in 2008-2012; p < 0.001), particularly for prostate (by 34.10%) and kidney (by 16.30%) cancers, but not for renal pelvis and ureter cancers (-7.20%). Conclusion The most common urological cancer in Korea was prostate cancer followed by bladder and kidney cancers. The incidence of most urological cancers, except for penile and bladder cancers, increased. Survival also increased, particularly for prostate and kidney cancers.