Trends in Thyroid Cancer Incidence in Korean Children (1999-2012) Based on Palpation and Nonpalpation Detection Methods

Abstract

Background: The incidence of childhood thyroid cancer is increasing in several populations; however, contributing factors have not been adequately discussed. Objectives: Our aim was to identify trends of childhood thyroid cancer based on the Korea Central Cancer Registry (KCCR) database and to elucidate changes in detection methods of cancers using a single-center database. Methods: Data from the KCCR and Statistics Korea between 1999 and 2012 were used to calculate the crude incidence of thyroid cancer in children. To analyze detection methods for cancers, pediatric patients (aged 0-19 years, n = 126) who underwent thyroid surgery for thyroid cancers at our institution were identified. Subjects were divided into two groups by detection method: (1) palpation group and (2) screening group. Results: The crude incidence of childhood thyroid cancer increased from 0.5 per 100,000 in 1999 to 1.7 in 2012. The proportion of thyroid cancer among total cancers also increased from 4.4% in 1999 to 10.6% in 2012. Among 126 children from our institution, 91 cases (72%) were identified as palpable neck masses, and the remainder were discovered during imaging studies. The numbers in both groups gradually increased during the study period. Conclusions: The incidence of childhood thyroid cancer has steadily increased in Korea. Regarding the detection methods of cancers, most tumors are detected by palpation rather than screening, although the rate of masses identified during screening has increased.

Differentiated thyroid cancer in children: Heterogeneity of predictive risk factors

“…A similar rate is also reported by Cho et al. who also emphasize that, although the proportion of DTC identified during screening procedures is increasing over time, most cases in young subjects are still initially detected by palpation . In our series, DTC was diagnosed by screening in 36 cases (29.0%), mostly during evaluation for other endocrine diseases such as Hashimoto's thyroiditis, Graves’ disease or obesity, while only a few patients were screened because of familiarity (i.e., a relative affected by DTC) or because they were survivors of other cancers.…”

“…Overdiagnosis due to frequent access to sensitive diagnostic procedures that identify small malignant nodules that will never become clinically relevant has been indicated as a main factor for the increased incidence of DTC in adults. However, overdiagnosis in the paediatric population is rather unlikely because children are less subjected to thyroid screening . Indeed, the increased incidence of clinical thyroid tumours in children suggests that overdiagnosis is unlikely to be a factor in this population .…”

“…However, overdiagnosis in the paediatric population is rather unlikely because children are less subjected to thyroid screening. 5 Indeed, the increased incidence of clinical thyroid tumours in children suggests that overdiagnosis is unlikely to be a factor in this population. 4 Environmental factors have been hypothesized to play a role in the increased incidence of DTC in paediatric patients, with exposure to ionizing radiations being the most recognizable risk factor as demonstrated by the significant increase in paediatric papillary thyroid cancer (PTC) both after environmental contamination (e.g.…”

A case-control study of exposure to organophosphate flame retardants and risk of thyroid cancer in women

“…Changes in diagnostic procedures and increased medical attention to thyroid nodules explain part of the rise during the past two decades [ 12 – 14 ]. However, reported incidence rates have increased across all tumor sizes [ 15 , 16 ], in younger age groups that are less likely to receive imaging exams [ 17 , 18 ], and for follicular thyroid cancer, which is less easily detected by newer diagnostic technologies [ 19 ]. Taken together, this supports the role of other factors in addition to increased detection [ 20 ].…”

Thyroid Cancer in the Pediatric Age in Sicily: Influence of the Volcanic Environment

“…The reason for the higher incidence of microcarcinomas in Sicily and specifically in the volcanic area is unclear. In pediatric patients, at variance with adults, a palpable mass in the neck is the main route for the detection of a thyroid nodule and thyroid cancer (35). Therefore, the proportion of incidentally discovered thyroid cancer is small because thyroidectomies for benign thyroid diseases are infrequent and occult PTCs are very rare in those younger than 18 years (36).…”