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

Abstract

Background: In this study, we evaluated the recent changes in the standardized, age-specific, stage-specific incidence rates (IRs) of thyroid cancer in Korea and compared them with the incidence data reported by the Surveillance, Epidemiology, and End Results Program. Methods: The analysis was conducted using the incidence data (2005 to 2018) from the Statistics Korea and Korea Central Cancer Registry. Results:The age-standardized IR (SIR) of thyroid cancer increased from 24.09 per 100,000 in 2005 to 74.83 in 2012 (annual percent change [APC], 14.5). From 2012 to 2015, the SIR decreased to 42.52 (APC, -17.9) and then remained stable until 2018 (APC, 2.1). This trend was similar in both men and women. Regarding age-specific IRs, the IRs for ages of 30 years and older showed a trend similar to that of the SIR; however, for ages below 30 years, no significant reduction was observed from the vertex of IR in 2015. Regarding stage-specific IRs, the increase was more prominent in those with regional disease (APC, 17.4) than in those with localized disease until 2012; then, the IR decreased until 2015 (APC, -16.1). The average APC from 2005 to 2018 increased in men, those under the age of 30 years, and those with regional disease. Conclusion:The SIR in Korea peaked in 2012 and decreased until 2015 and then remained stable until 2018. However, in young individuals under the age of 30 years, the IR did not significantly decrease but tended to increase again. In terms of stage-specific IRs, the sharpest increase was seen among those with regional disease.

Survival Comparison of Incidentally Found versus Clinically Detected Thyroid Cancers: An Analysis of a Nationwide Cohort Study

“…A profound increase in the incidence of thyroid cancer in Korea has taken place. The age-standardized incidence rate of thyroid cancer in Korea peaked in 2012 (74.83 per 100,000), declined until 2015 (42.52 per 100,000), and only fluctuated slightly until 2018 (48.62 per 100,000) according to joinpoint regression analysis [6]. Interestingly, this recent increase in the incidence of thyroid cancer was not correlated with the number of thyroid fine-needle aspiration procedures [7].…”

Trends in incidence and overdiagnosis of thyroid cancer in China, Japan, and South Korea

“…In 2014, some clinicians published an open letter recommending that ultrasound not be used for thyroid cancer screening and proposing revisions to thyroid cancer diagnosis and treatment guidelines 40 . From 2012 to 2015, South Korea's ASR decreased from 74.8/10 5 to 42.5/10 5 , with an APC of −17.9, and then remained stable until 2018 41 . These data demonstrate that the increased incidence resulting from overdiagnosis can be reversed.…”

Cancer and Mortality Risks of Graves’ Disease in South Korea Based on National Data from 2010 to 2019

“… 11 In an analysis of Korean national data, the incidence of thyroid diseases, such as thyroid nodules, hypothyroidism, hyperthyroidism, and thyroid cancer, increased and peaked in 2012, decreased until 2015, and remained stable thereafter. 5 , 29 Thyroid cancer mortality in Korea increased from the 1980s to 2004 and then decreased continuously until 2015. 30 In Korea, the prevalence of thyroid cancer in patients with GD was 3.3% based on a prospective single-center study, 31 and 1.7% for those who underwent thyroidectomy according a recent multicenter retrospective study.…”