Endpoints for screening thyroid cancer in the Republic of Korea: thyroid specialists' perspectives

Decreasing trends in thyroid cancer incidence in South Korea: What happened in South Korea?

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.

Time trend analysis of thyroid cancer surgery in China: single institutional database analysis of 15,000 patients

PURPOSE

The institutional database of the Thyroid Surgery Division in China-Japan Union Hospital of Jilin University was queried to audit time trend patterns in thyroid cancer (TC) management between 2008 and 2017.

METHODS

Retrospective longitudinal analysis. Clinicopathological features and treatment strategies were analyzed. Frequencies and multivariate tests were used to detect correlations.

RESULTS

Clinical data were obtained from 15,000 TC patients (i.e., 71.3% of 21,044 operations). Papillary was the most common histological subtype (n = 14,916, 99%), and 76% were microcarcinomas. Stage I (95%) and low-risk patients (58%) were prevalent throughout the 10-year period. The trend for total thyroidectomy increased from 29.1% (2008-2012) to 67.9% (2013-2015), and then dropped to 48.6% (2016-2017). A total of 8827 (52%) patients received central lymph node dissection (CLND). The tendency for CLND increased from 15.7 to 86.4% during the 10-year period. While the trend of lateral lymph node dissection decreased from 71.3 to 13.3%. Radioactive iodine therapy was offered to 10% of patients (2008-2012), except for a low value (5.4%) in 2009, and then increased from 12.3% (2012) to 41.3% (2015), while decreased to 32.4% (2017).

CONCLUSION

The surgical management of TC patients has undergone continuous changes over the past 10 years. The evolution from aggressive treatment to a more conservative approach has been constant. Our results suggest that the current surgical management approach for TC is adequate and in support of the published guidelines. Our findings warrant further investigation to determine the clinical implications of decision making for TC.

Puzzle over active surveillance for micropapillary thyroid carcinoma

It is worth distinguishing between the two strategies of management for low risk micropapillary thyroid cancer (MPTC). Immediate therapy, whereas active surveillance (AS) entails delivering curative treatment on signs of disease progression. AS appears to reduce overtreatment in patients with low-risk MPTC without compromising cancer-specific survival at 10 years. Therefore, AS is an option for select patients who want to avoid the side-effects inherent to the different types of immediate treatment. However, inclusion criteria for AS and the most appropriate method of monitoring patients on AS have not yet been standardized.

Ultrasound Risk Categories for Thyroid Nodules and Cytology Results: A Single Institution's Experience after the Adoption of the 2016 Update of Medical Guidelines by the American Association of Clinical Endocrinologists and Associazione Medici Endocrinologi

Objectives

In 2016, the American Association of Clinical Endocrinologists (AACE) and Associazione Medici Endocrinologi (AME) released updated guidelines for the diagnosis and management of thyroid nodules. The aim of this study was to evaluate the AACE/AME recommendations for FNA in clinical practice, by comparing the (US) stratification risk and indications for FNA with cytologic results.

Methods

From May to December 2016, we collected the cytologic results from FNAs of nodules that were classified using a three-tier US category system (low, intermediate, and high risk).

Results

We obtained 859 FNAs from 598 patients: 341 (39.7%) from low, 489 (56.9%) from intermediate, and 29 (3.4%) from high risk nodules. Of these, 88.5% and 74.9% of low and intermediate risk nodules, respectively, were cytologically benign, whereas 84.6% of high risk nodules had a moderate-to-elevated risk of malignancy or were malignant. If FNAs had been limited to intermediate risk nodules >20 mm, we would have missed 13/17 (76.5%) nodules that had moderate-to-elevated risk of malignancy or were malignant (11/13 were malignant based on histology).

Conclusions

A nonnegligible number of cytologically malignant nodules or nodules that were suspected to be malignant would be missed if intermediate US risk nodules <20 mm were not biopsied.