Trends in Childhood Thyroid Cancer incidence in Korea and Its Potential Risk Factors

Abstract

BackgroundAlthough the incidence of thyroid cancer had been increasing until a few years ago, a decrease has been observed in the last years, probably due to the reduction of the screening tests in Korea. Childhood thyroid cancer has been increasing in the past with the same trend as in adults, but there have been few reports on recent trends. We analyzed the trends of thyroid cancer in Korean children and related factors.MethodsFrom national statistics and cancer register database, the data of age-specific incidence rate in Korean childhood thyroid cancer from 1999 to 2017 was obtained, and levels of seaweed intake, the number of computed tomography (CT) and neck ultrasonography (US), obesity prevalence rate, and smoking and alcohol consumption rates in children were analyzed.ResultsThe age-specific incidence of thyroid cancer in Korean children has increased in both genders between 1999 and 2017 (2.0 in 1999 vs. 7.2 in 2017, per population of 100,000), especially in the age group of 14-18 years (1.5 in 1999 vs. 5.5 in 2017, per population of 100,000). During the same period, levels of seaweed intake, number of CT scans and neck US, and prevalence of obesity in children increased significantly, while childhood smoking and alcohol consumption rates decreased.ConclusionUnlike the adult thyroid cancer in Korea, childhood thyroid cancer continues to increase, and the cause might be accompanied by actual increases due to the environmental factors such as excessive iodine intake, exposure to medical radiation, and increased obesity prevalence as well as the screening effect.

Recent Changes in the Incidence of Thyroid Cancer in Korea between 2005 and 2018: Analysis of Korean National Data

“…After that, the IR tended to de-crease; however, this decrease was insignificant. In patients in their 30s, the IR increased from 28 1, 2, Fig. 2D).…”

“…Additionally, some recent studies reported the increasing incidence of childhood thyroid cancer in Korea [28,29] and worldwide [30][31][32]. In Korea, thyroid cancer is the most common cancer in both sexes among the adolescent and young adult populations (15 to 34 years), accounting for 50.8% of all cancers [17].…”

“…In Korea, thyroid cancer is the most common cancer in both sexes among the adolescent and young adult populations (15 to 34 years), accounting for 50.8% of all cancers [17]. According to Park et al [28], this might be accompanied by actual increases due to environmental factors, such as excessive iodine intake, exposure to medical radiation, and increased obesity prevalence, as well as the screening effect.…”

Association between Consumption of Iodine-Rich Foods and Thyroid Cancer Prevalence: Findings from a Large Population-Based Study

“…East Asia, including Korea, Japan, and China, is characterized by high iodine intake, primarily from seafood consumption, especially seaweed [16,17]. Recent cohort studies have suggested a potential link between seaweed consumption and a reduced risk of cardiovascular diseases, possibly through blood pressure-and lipid-lowering effects [18,19].…”

Cumulative exposure to metabolic syndrome increases thyroid cancer risk in young adults: a population-based cohort study

“…Previous studies have suggested that obesity is a risk factor for thyroid cancer [ 5 , 6 ]. In a meta-analysis, the risk of thyroid cancer increased in a dose-dependent manner with increasing body mass index [ 7 ].…”