Overdiagnosis and screening for thyroid cancer in Korea

Global burden of disease study analysis of thyroid cancer burden across 204 countries and territories from 1990 to 2019

Background

The purpose of this study is to assess the burden of thyroid cancer over the course of 30 years in 204 countries and territories.

Methods

Data from the Global Burden of Disease (GBD) 2019 database was analyzed to extract information on prevalence, deaths, DALYs(disability-adjusted life-years), YLL(years of life los), YLD(years lived with disability), and their corresponding age-standardized rates at global, regional, and national levels. The primary focus of the study was to examine trends in thyroid cancer from 1990 to 2019, specifically looking at the Estimated Annual Percentage Change (EAPC) for ASPR, ASDR, and ASDR. Additionally, the study investigated the relationship between cancer burden and the Socio-Demographic Index (SDI).

Results

Globally, there will be approximately 18.3 million thyroid cancer (TC) cases in 2019; China and the USA are projected to be the most significant with 310,327 and 220,711 cases (16.17 and 14.82 cases per 100,000 people, respectively).Over the period from 1990 to 2019, age-standardized prevalence rates exhibited a global rise, whereas deaths and DALYs saw a decrease(EAPC:1.63, -0.15- -0.14, respectively). Significantly, the age-standardized prevalence rate increased in 21 GBD regions, affecting 195 out of 204 countries or territories. Over the studied period, thyroid cancer cases, deaths, and DALYs were consistently higher among females than males. Furthermore, a higher Socio-demographic Index was associated with increased age-standardized prevalence rates.

Contents analysis of thyroid cancer-related information uploaded to YouTube by physicians in Korea: endorsing thyroid cancer screening, potentially leading to overdiagnosis

BACKGROUND

Thyroid cancer overdiagnosis is a major public health issue in South Korea, which has the highest incidence rate. The accessibility of information through the Internet, particularly on YouTube, could potentially impact excessive screening. This study aimed to analyze the content of thyroid cancer-related YouTube videos, particularly those from 2016 onwards, to evaluate the potential spread of misinformation.

METHODS

A total of 326 videos for analysis were collected using a video search protocol with the keyword "thyroid cancer" on YouTube. This study classified the selected YouTube videos as either provided by medical professionals or not and used topic clustering with LDA (latent dirichlet allocation), sentiment analysis with KoBERT (Korean bidirectional encoder representations from transformers), and reliability evaluation to analyze the content. The proportion of mentions of poor prognosis for thyroid cancer and the categorization of advertising content was also analyzed.

RESULTS

Videos by medical professionals were categorized into 7 topics, with "Thyroid cancer is not a 'Good cancer'" being the most common. The number of videos opposing excessive thyroid cancer screening decreased gradually yearly. Videos advocating screening received more favorable comments from viewers than videos opposing excessive thyroid cancer screening. Patient experience videos were categorized into 6 topics, with the "Treatment process and after-treatment" being the most common.

CONCLUSION

This study found that a significant proportion of videos uploaded by medical professionals on thyroid cancer endorse the practice, potentially leading to excessive treatments. The study highlights the need for medical professionals to provide high-quality and unbiased information on social media platforms to prevent the spread of medical misinformation and the need for criteria to judge the content and quality of online health information.

Epidemiological and histopathological characteristics of thyroid carcinoma in a Tunisian health care center

Background

Thyroid carcinoma (TC) accounts for almost 0.5%-1% of total malignancies. Its incidence is increasing rapidly worldwide. Several studies have drawn up the epidemiological profile of TC and its clinical and pathological features. However, to date, no similar studies have been conducted in Tunisia.

Aims

To establish an epidemiological profile of TC in a Tunisian health care institute and to analyze its clinical and histopathological characteristics in our institute.

Materials and Methods

We present a retrospective study reviewing the cases of TC diagnosed in our institution in a 4-year period.

Results

We collected a sample of 192 cases of TC. It consisted of 31 males and 161 females (83.8%) with a sex-ratio M/F of 0.19. The mean age was 46.4 years. Papillary thyroid carcinoma was the most frequent histological subtype. The multifocality rate was 33.8%. The mean size of TC was 2.2 ± 1.9 cm. 60.9% of TC were staged pT1 and 20.3% had nodal involvement. Papillary thyroid microcarcinomas were noted in 37.5% of cases.

Conclusion

Our results were consistent with those of the literature. A high proportion of pT1 and pN0 tumors were noted in our series, suggesting that TC's diagnosis and management was performed at an early stage of the disease in our institution. In addition, our study enabled us to notice the impact of the Coronavirus disease 19 crisis on the management of TC in our institution. Further studies are needed to establish the epidemiological profile of TC in Tunisia and to assess its clinical and pathological features.

Thyroid ultrasound and its ancillary techniques

Ultrasound (US) of the thyroid has been used as a diagnostic tool since the late 1960s. US is the most important imaging tool for diagnosing thyroid disease. In the majority of cases a correct diagnosis can already be made in synopsis of the sonographic together with clinical findings and basal thyroid hormone parameters. However, the characterization of thyroid nodules by US remains challenging. The introduction of Thyroid Imaging Reporting and Data Systems (TIRADSs) has improved diagnostic accuracy of thyroid cancer significantly. Newer techniques such as elastography, superb microvascular imaging (SMI), contrast enhanced ultrasound (CEUS) and multiparametric ultrasound (MPUS) expand diagnostic options and tools further. In addition, the use of artificial intelligence (AI) is a promising tool to improve and simplify diagnostics of thyroid nodules and there is evidence that AI can exceed the performance of humans. Combining different US techniques with the introduction of new software, the use of AI, FNB as well as molecular markers might pave the way for a completely new area of diagnostic accuracy in thyroid disease. Finally, interventional ultrasound using US-guided thermal ablation (TA) procedures are increasingly proposed as therapy options for benign as well as malignant thyroid diseases.

Gastroesophageal reflux disease and risk of cancer: Findings from the Korean National Health Screening Cohort

AIM

Little is known about the association of cancers other than esophageal adenocarcinoma with gastroesophageal reflux disease (GERD). This study aimed to examine the association between GERD and the risk of different types of cancer.

METHODS

A cohort study was conducted using data from the National Health Screening Cohort. We included 10,261 GERD patients and 30,783 non-GERD individuals who were matched in a 1:3 ratio by age and sex. All participants were followed-up until cancer diagnosis, death, or end of the study (December 31, 2015). Hazard ratios were calculated using the Cox proportional hazards model, adjusting for smoking and alcohol consumption, physical activity, body mass index, income, area, and Charlson Comorbidity Index.

RESULTS

The median follow-up time was 9.9 years. GERD was associated with an increased risk of esophageal (adjusted hazard ratios [aHR] = 3.20 [1.89-5.41]), laryngeal (aHR = 5.42 [2.68-10.96]), and thyroid cancers (aHR = 1.91 [1.55-2.34]) after controlling for all covariates. The results were consistent when examining GERD with esophagitis (K210) and without esophagitis (K219) separately. For thyroid cancer, the results were insignificant after controlling for having ever-received thyroid biopsy procedures. A dose-response relationship was found between GERD and esophageal cancer as well as laryngeal cancer, with patients with a longer duration of GERD treatment showing a stronger effect. In contrast, GERD was associated with a reduced risk of colorectal (aHR = 0.73 [0.59-0.90]), liver (aHR = 0.67 [0.51-0.89]), and pancreatic cancers (aHR = 0.43 [0.24-0.76]), which might have resulted from differences in healthcare utilization between GERD and non-GERD groups.

CONCLUSION

GERD was associated with an increased risk of esophageal and laryngeal cancers. Additionally, early detection and treatment of precancerous lesions among the GERD group could lead to a lower risk of colorectal, liver, and pancreatic cancers.

Incidentalomas in the head & neck

Incidental findings (IFs) in the head & neck are a frequent challenge to the reporting radiologist. A combination of complex anatomy, widely varied imaging techniques and the high prevalence of benign pathology, makes safe and appropriate management of head & neck IFs problematic. The non-head & neck radiologist is unlikely to have prior personal experience of the relevant specialties or current involvement with the pertinent multidisciplinary teams, creating unfamiliarity with both the clinical aspects of head & neck disease and the value of examination techniques. This triumvirate of complex anatomy, pathology and imaging creates the perfect environment for excessive investigation and overdiagnosis. In this article, the most frequently encountered and clinically relevant head & neck IFs are summarised. To reflect daily clinical practice, we will firstly consider anatomic abnormalities identified on cross-sectional imaging and ultrasound, followed by a review of PET-CT incidental findings.

Active surveillance for PTMC warranted for the UK population?

BACKGROUND

The incidence of thyroid cancer is increasing globally due to the increase in detection of subclinical, low volume papillary thyroid microcarcinomas (PTMC) (<1 cm). Several international groups have recommended an active surveillance approach for this low-risk disease. In contrast to many other countries, the United Kingdom's (UK's) approach to thyroid nodules is to avoid detection of incidental lesions where appropriate.

OBJECTIVE

This study aims to establish the proportion of patients with thyroid cancer in the UK that would benefit from active surveillance.

DESIGN, PARTICIPANTS, AND OUTCOME MEASURES

Individuals with PTMC in NHS Lothian from 2009-2020 were reviewed from a local thyroid cancer database. The mode of detection of PTMC and proportion of patients who might benefit from active surveillance were established.

RESULTS

From 651 individuals with differentiated thyroid cancer managed over 12-year period, 185 individuals with PTMC were identified (28.4%). The majority of PTMC 151/185 (81.6%) were either diagnosed post-operatively following thyroidectomy for benign disease or with nodal disease. Only 24 individuals with PTMC were identified following palpable thyroid nodule, incidental finding on imaging, and surveillance screening. Therefore, when the indication for surgery was considered, only 24/651 (3.7%) patients were identified pre-operatively and would, therefore, be realistic candidates for active surveillance.

CONCLUSION

Less than 4% of patients with thyroid cancer in the UK would be appropriate for active surveillance. Rather than developing programmes to deal with this minority of patients, focus should be maintained on minimising detection of these low-risk cases.

Projection of Cancer Incidence and Mortality From 2020 to 2035 in the Korean Population Aged 20 Years and Older

OBJECTIVES

This study aimed to identify the current patterns of cancer incidence and estimate the projected cancer incidence and mortality between 2020 and 2035 in Korea.

METHODS

Data on cancer incidence cases were extracted from the Korean Statistical Information Service from 2000 to 2017, and data on cancer-related deaths were extracted from the National Cancer Center from 2000 to 2018. Cancer cases and deaths were classified according to the International Classification of Diseases, 10th edition. For the current patterns of cancer incidence, age-standardized incidence rates (ASIRs) and age-standardized mortality rates were investigated using the 2000 mid-year estimated population aged over 20 years and older. A joinpoint regression model was used to determine the 2020 to 2035 trends in cancer.

RESULTS

Overall, cancer cases were predicted to increase from 265 299 in 2020 to 474 085 in 2035 (growth rate: 1.8%). The greatest increase in the ASIR was projected for prostate cancer among male (7.84 vs. 189.53 per 100 000 people) and breast cancer among female (34.17 vs. 238.45 per 100 000 people) from 2000 to 2035. Overall cancer deaths were projected to increase from 81 717 in 2020 to 95 845 in 2035 (average annual growth rate: 1.2%). Although most cancer mortality rates were projected to decrease, those of breast, pancreatic, and ovarian cancer among female were projected to increase until 2035.

CONCLUSIONS

These up-to-date projections of cancer incidence and mortality in the Korean population may be a significant resource for implementing cancer-related regulations or developing cancer treatments.

Autoimmune Thyroid Disorders Are More Prevalent in Patients with Celiac Disease: A Retrospective Case-Control Study

Background. Among patients with celiac disease (CD), there is an increased incidence of autoimmune thyroid disorders (AITDs), with hypothyroidism being more frequent than hyperthyroidism. This retrospective case-control study aimed to explore the prevalence of TDs in a population of adult celiac patients from Northern Sardinia, a geographic area with a high prevalence of autoimmune disorders. Methods. Data were collected from consecutive patients with CD (cases) and without CD (controls) who were undergoing upper endoscopy and referred to a tertiary gastroenterology section of a teaching hospital (University of Sassari, Italy). Thyroid disorders were stratified as (i) autoimmune: including Hashimoto’s disease in euthyroidism or with hypofunction, and Graves’ disease; or (ii) non-autoimmune: thyroid nodules/goiter, iatrogenic thyroid hypo/hyperfunction, and thyroidectomy for any reason, including cancer. Results. Among a total of 8489 participants (females 5839, 64.7%) enrolled, there were 623 (7.3%) celiac patients and 7866 controls (92.7%). The overall frequency of TDs was 1177 (13.9%) and was higher (26.0%) in celiac patients than in controls (12.9%) (p < 0.001). The difference between AITDs (15.4% vs. 7.5%) and no-AITDs (2.7% vs. 1.1%) was statistically significant in CD patients compared with controls, respectively, and prevailed in the fifth and sixth decades. Hashimoto’s thyroiditis was more commonly associated with gland hypofunction. Odds ratios with their 95% confidence intervals (CIs) for the presence of AITDs were calculated, adjusting for sex, age, body mass index, smoking habits, occupation, and residence, and they were 2.387 (95% CI 1.857−3.068, p < 0.001) in CD patients, 5.855 (95% CI 4.434−7.731, p < 0.001) for female sex, and 1.012 (95% CI, 1.007−1.017, p < 0.001) for age. Conclusion. These results suggest the need for surveillance for TDs in patients with CD at onset and during follow-up.

Differentiation of Thyroid Nodules (C-TIRADS 4) by Combining Contrast-Enhanced Ultrasound Diagnosis Model With Chinese Thyroid Imaging Reporting and Data System

Objectives

To establish a contrast-enhanced ultrasound (CEUS) diagnostic schedule by CEUS analysis of thyroid nodules of C-TIRADS 4. To establish a CEUS-TIRADS diagnostic model to differentiate thyroid nodules (C-TIRADS 4) by combining CEUS with Chinese thyroid imaging reporting and data system (C-TIRADS).

Methods

A total of 228 thyroid nodules (C-TIRADS 4) were estimated by CEUS. The arrival time, enhancement degree, enhancement homogeneity, enhancement pattern, enhancement ring, and wash-out time were analyzed in CEUS for all of the nodules. Multivariate factors logistic analysis was performed and a CEUS diagnostic schedule was established. If the nodule had a regular hyper-enhancement ring or got a score of less than 2 in CEUS analysis, CEUS-TIRADS subtracted 1 category. If the nodule got a score of 2 in the CEUS schedule, the CEUS-TIRADS category remained the same as before. If the nodule got a score of more than 2 in the CEUS schedule, CEUS-TIRADS added 1 category. When it reflected an absent enhancement in CEUS, the nodule was judged as CEUS-TIRADS 3. All of the C-TIRADS 4 nodules were re-graded by CEUS-TIRADS. We then compare the diagnosis performance of C-TIRADS, CEUS, and CEUS-TIRADS by sensitivity, specificity, and accuracy.

Results

Among the 228 C-TIRADS 4 nodules, 69 were determined as C-TIRADS 4a, 114 were C-TIRADS 4b, and 45 were C-TIRADS 4c. The sensitivity, specificity, and accuracy of C-TIRADS were 93.1%, 55.3%, and 74.6% respectively. The area under the curve was 0.753. Later arrival time, hypo-enhancement, heterogeneous enhancement, centripetal enhancement, and rapid washout were risk factors of malignancy in multivariate analysis. The sensitivity, specificity, and accuracy of CEUS were 78.7%, 87.5%, and 83.3% respectively. The area under the curve was 0.803. By CEUS-TIRADS diagnostic model combining CEUS with C-TIRADS, a total of 127 cases were determined as malignancy (111 were malignant and 16 were benign) and 101 were diagnosed as benign ones (5 were malignant and 96 were benign). The sensitivity, specificity, and accuracy of CEUS-TIRADS were 95.7%, 85.7%, and 92.1% respectively. The area under the curve was 0.916. The diagnostic performance of CEUS-TIRADS was significantly better than CEUS and C-TIRADS. The difference was statistically significant (P<0.05).

Conclusions

The diagnostic schedule of CEUS could get better diagnostic performance than US in the differentiation of thyroid nodules. The CEUS-TIRADS combining CEUS analysis with C-TIRADS could make up for the deficient sensibility of C-TIRADS, showing a better diagnostic performance than US and CEUS.

Psychological Distress and Sleep Disturbance Throughout Thyroid Nodule Screening, Diagnosis, and Treatment

CONTEXT

Many controversies exist regarding screening and treatment of thyroid cancer (TC), especially papillary thyroid microcarcinoma (PTMC).

OBJECTIVE

The aim of this study was to evaluate patients' psychological distress and sleep disturbance throughout thyroid nodule (TN) screening, diagnosis, and treatment.

METHODS

A total of 2834 participants (1153 participants with TNs) were enrolled during the screening phase, and 1105 individuals with TNs (87 individuals with TC) were enrolled during the diagnosis phase. Of the 87 TC patients, 66 underwent immediate operation (OP), and 21 patients with PTMC opted for active surveillance (AS). Four validated scales were applied to quantify the outcome indicators at prescreening, postscreening, postdiagnosis, and posttreatment.

RESULTS

Higher psychological distress and sleep disturbance were found postscreening than prescreening in subjects with TNs, but no differences in those without nodules. Compared with postscreening, higher scores of psychological distress and sleep disturbance were identified in patients with suspicious TC treated with fine needle aspiration (FNA) or with AS. Lower psychological distress and sleep disturbance were noted for patients with benign nodules than for TC patients. OP for TC, especially PTMC, did not alleviate psychological distress or sleep disturbance compared with the same parameters in patients who underwent AS.

CONCLUSION

Based on the findings of impaired psychological health and sleep quality, screening for TNs in adults who show no symptoms should be performed with caution. Psychological distress and sleep disturbance should also be taken into consideration when FNA is performed for suspected TC or OP for papillary thyroid cancer, especially PTMC.

Incidence and outcomes of malignant ovarian germ cell tumors in Korea, 1999-2017

OBJECTIVE

Malignant ovarian germ cell tumor (MOGCT) is a rare ovarian malignancy accounting for less than 5% of all ovarian cancers. We aimed to evaluate the incidence, survival, and subsequent malignancies after the diagnosis of MOGCT.

METHODS

Data from the Korea Central Cancer Registry were used to identify MOGCTs between 1999 and 2017. The age-standardized rates (ASRs), 5-year relative survival rates (RSR) and standardized incidence ratio (SIR) for subsequent cancer after diagnosis of MOGCT were estimated.

RESULTS

Of 2125 cases of newly diagnosed MOGCTs, 596 (28.0%) were diagnosed with dysgerminoma and 1529 (72.0%) with non-dysgerminoma. The ASR per 100,000 women-years was 0.539; ASR slightly increased over the study period (annual percent change [APC] = 1.01%; p = 0.02). There was an increase and decrease in the incidence of MOGCTs in the age groups 0-19 years (APC = 1.96%; p < 0.01) and ≥ 50 years (APC = -6.51%; p < 0.01), respectively. Patients with dysgerminoma showed significantly higher RSR than patients with non-dysgerminoma (98.0% vs. 94.9%, p < 0.01). Patients aged ≥50 years showed worst 5-year RSR (68.7%) than patients aged 0-19 years (97.8%) and 20-34 years (96.4%) (p < 0.01). The overall SIR for a subsequent cancer occurrence was 2.07, with the most frequent site of subsequent primary cancer being the thyroid (SIR = 2.78).

CONCLUSIONS

Our data demonstrated an excellent prognosis of MOGCTs among Korean women. There was a slight increase in MOGCT prevalence, which was more pronounced among those aged <19 years. After MOGCT diagnosis, the risk of developing a subsequent malignancy was doubled compared with the general population.

Global burden of thyroid cancer and its attributable risk factors in 204 countries and territories from 1990 to 2019

Background

To investigate the burden of thyroid cancer and its attributable risk factors in 204 countries and territories during 30 years.

Methods

We extracted data from the Global Burden of Disease (GBD) 2019 database, including incidence, mortality, disability‐adjusted life‐years (DALYs), and the attributable risk factors of thyroid cancer from 1990 to 2019. Estimated annual percentage changes (EAPC) were calculated to assess the changes in age‐standardized incidence rate (ASIR), age‐standardized mortality rate (ASMR), and age‐standardized DALYs rate (ASDR). We also examined the associations between cancer burden and the sociodemographic index (SDI).

Results

The global new cases, death, and DALYs of thyroid cancer in 2019 were 233 847 (95% UI: 211 637–252 807), 45 576 (95% UI: 41 290‐48 775), and 1 231 841 (95% UI: 1 113 585–1 327 064), respectively. From 1990 to 2019, the ASIR of thyroid cancer showed an upward trend (EAPC = 1.25), but ASMR (EAPC = −0.15) and ASDR (EAPC = −0.14) decreased. The burden of thyroid cancer varied at regional and national levels, but the association between ASIR and SDI was positive. We found that the burden of thyroid cancer was mainly concentrated in females and that the age of onset tended to be younger. The proportion of DALYs from thyroid cancer attributable to high body‐mass index was higher in high SDI regions, especially in males.

Conclusions

The global incidence of thyroid cancer has continued to increase in the past three decades. The high body‐mass index as an important risk factor for thyroid cancer deserves greater attention, especially in high SDI regions.

A double mutation of BRAF L597Q and V600E in situ and solitary brain metastasis of occult papillary thyroid carcinoma: A case report

RATIONALE

The rare BRAF L597Q (c.T1790A) point mutation has been previously reported in childhood acute lymphoblastic leukemia. We present the first rare case of occult papillary thyroid carcinoma with BRAF L597Q mutation in a Tibetan patient.

PATIENT CONCERNS

A 57-year-old male patient presented with a protruding mass on the left forehead for 2 years and numbness in the right limb for 3 weeks.

DIAGNOSES

The patient had a double mutation of BRAF L597Q and V600E in 2 separate lesions at thyroid and brain, the immunohistochemical staining showed that the cytokeratin (CK), thyroglobulin (Tg) and thyroid transforming factor-1 (TTF-1) were immunoreactive. All the findings supported the diagnosis of solitary brain metastasis of occult papillary thyroid carcinoma.

INTERVENTIONS

The patient underwent left frontal lobe metastasis (thyroid cancer) resection that involved craniectomy and artificial skull repair.

OUTCOMES

During the 24-month follow-up, no postoperative complications or recurrence and metastasis were found.

LESSONS

This is the first case of solitary brain metastasis of occult papillary thyroid carcinoma with double mutation of BRAF L597Q and V600E in 2 separate lesions reported in the literature. Our study extends the disease spectrum of occult papillary thyroid carcinoma and suggests that the BRAF L597Q mutation might play a specific role in inducing the solitary brain metastasis of occult papillary thyroid carcinoma in a Chinese Tibetan patient, but the detailed molecular mechanism remains to be confirmed by a large number of functional experiments and clinical research.

Income differences in screening, incidence, postoperative complications, and mortality of thyroid cancer in South Korea: a national population-based time trend study

Background

The incidence of thyroid cancer (TC) has increased rapidly over the past few decades in Korea. This study investigated whether the TC epidemic has been driven by overdiagnosis.

Methods

We calculated the TC screening rate from mid-2008 through mid-2014, and the incidence, postoperative complication, and mortality rates of TC between 2006 and 2015, using data from the Korea Community Health Survey, the National Health Insurance Database, and the cause-of-death data of Statistics Korea. Trends in age-standardized rates of all indicators were examined, along with income gaps therein. Analyses were conducted for lung cancer and stroke as negative control outcomes.

Results

The incidence rate of TC increased from 46.6 per 100,000 to 115.0 per 100,000 between 2006 and 2012, and then decreased to 63.5 per 100,000 in 2015. Despite these remarkable changes in incidence, mortality did not fluctuate during the same period. High income was associated with high rates of screening, incidence, and postoperative complications, while low income showed an association with a high mortality rate. Analyses using negative control outcomes showed that high income was associated with low rates of both incidence and mortality, which contrasted with the patterns of TC. The recent decreases in TC incidence and postoperative complications, which reflect societal concerns about the overdiagnosis of TC, were more pronounced in high-income individuals than in low-income individuals.

Conclusions

The time trends in income gaps in screening, incidence, postoperative complications, and mortality of TC, as well as negative control outcomes, provided corroborating evidence of TC overdiagnosis in Korea.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07597-4.

Cancer Incidence and Survival among Adolescents and Young Adults in Korea: An Update for 2016

PURPOSE

This study investigated the incidence and relative survival rates (RSRs) for cancers among adolescents and young adults (AYAs) aged 15-39 years between 1993 and 2016 in Korea.

Materials and Methods

Data from the Korea Central Cancer Registry were used to calculate percent distributions, age-specific incidence rates, age-standardized incidence rates (ASRs) per million, annual percent changes (APCs), average APCs, and RSRs for cancers diagnosed in AYAs.

RESULTS

ASR of all cancers among AYAs was 654.5 per million. The largest diagnosed group of cancers was carcinomas (almost 80%). Crude incidence increased with age, from 170.4 per million for those aged 15-19 years to 1,639.8 per million for those aged 35-39 years. ASR increased from 414.8 per million to 820.4 per million, with an APC of 9.0%. The incidence of thyroid carcinoma showed the most rapid increment (APC, 14.0%), followed by non-Hodgkin lymphoma (APC, 13.4%). The 5-year RSR among AYAs significantly improved from 62.1% to 90.8%. Survival improvement in AYAs was higher than that in children but lower than that in older adults (APC, 2.1% vs. 1.9% vs. 3.1%). The most marked survival improvement was found for leukemia and lymphoma. Astrocytoma, rhabdomyosarcoma, and carcinoma of the trachea, bronchus, and lung had a 5-year RSR of < 50%.

CONCLUSION

There was an improvement in cancer survivals in AYAs, comparable to that achieved in children. However, survivals in several cancer types do not appear to be improving. Further research focusing on the epidemiology and therapeutic strategies for cancers in AYAs is needed.

Global Burden of Thyroid Cancer From 1990 to 2017

IMPORTANCE

Thyroid cancer is the most pervasive endocrine cancer worldwide. Studies examining the association between thyroid cancer and country, sex, age, sociodemographic index (SDI), and other factors are lacking.

OBJECTIVE

To examine the thyroid cancer burden and variation trends at the global, regional, and national levels using data on sex, age, and SDI.

DESIGN, SETTING, AND PARTICIPANTS

In this cross-sectional study, epidemiologic data were gathered using the Global Health Data Exchange query tool, covering persons of all ages with thyroid cancer in 195 countries and 21 regions from January 1, 1990, to December 31, 2017; data analysis was completed on October 1, 2019. All participants met the Global Burden of Disease Study inclusion criteria.

MAIN OUTCOMES AND MEASURES

Outcomes included incidence, deaths, and disability-adjusted life-years (DALYs) of thyroid cancer. Measures were stratified by sex, region, country, age, and SDI. The estimated annual percentage changes (EAPCs) and age-standardized rates were calculated to evaluate the temporal trends.

RESULTS

Increases of thyroid cancer were noted in incident cases (169%), deaths (87%), and DALYs (75%). Age-standardized incidence rate (ASIR) showed an upward trend over time, with an EAPC of 1.59 (95% CI, 1.51-1.67); decreases were noted in EAPCs of age-standardized death rate (-0.15; 95% CI, -0.19 to -0.12) and age-standardized DALY rate (-0.11; 95% CI, -0.15 to -0.08). Almost half (41.73% for incidence, 50.92% for deaths, and 54.39% for DALYs) of the thyroid cancer burden was noted in Southern and Eastern Asia. In addition, females accounted for most of the thyroid cancer burden (70.22% for incidence, 58.39% for deaths, and 58.68% for DALYs) and increased by years in this population, although the ASIR of males with thyroid cancer (EAPC, 2.18; 95% CI, 2.07-2.28) increased faster than that of females (EAPC, 1.38; 95% CI, 1.30-1.46). A third (34%) of patients with thyroid cancer resided in countries with a high SDI, and most patients were aged 50 to 69 years, which was older than the age in other quintiles (high SDI quintile compared with all other quintiles, P<.05). The most common age at onset of thyroid cancer worldwide was 15 to 49 years in female individuals compared with 50 to 69 years in male individuals (P<.05). Death from thyroid cancer was concentrated in participants aged 70 years or older and increased by years (average annual percentage change, 0.10; 95% CI, 0.01-0.21; P<.05). Furthermore, people in lower SDI quintiles developed thyroid cancer and died from it earlier than those in other quintiles (high and high-middle SDI vs low and low-middle SDI, P<.05).

CONCLUSIONS AND RELEVANCE

Data from this study suggest considerable heterogeneity in the epidemiologic patterns of thyroid cancer across sex, age, SDI, region, and country, providing information for governments that may help improve national and local cancer control policies.

BRAFV600E Transduction of an SV40-Immortalized Normal Human Thyroid Cell Line Induces Dedifferentiated Thyroid Carcinogenesis in a Mouse Xenograft Model

Background: Despite active studies of the clinical importance of BRAF^V600E, suitable research models to investigate the role of this mutation in the etiopathogenesis of human thyroid cancers are limited. Thus, we generated cell lines by transducing the simian virus (SV)-40 immortalized human thyroid cell line Nthy-ori 3-1 (Nthy) with lentiviral vectors expressing either BRAF^WT (Nthy/WT) or BRAF^V600E. Nthy/WT and Nthy/V600E cells were then xenografted into mice to evaluate the carcinogenic role of BRAF^V600E. Methods: Each cell line was subcutaneously injected into NOD.Cg-Prkdc^scid Il2rg^tm1Wjl/SzJ mice, and a pathological analysis was performed. The effects of the mutation were further verified by using a BRAF^V600E-selective inhibitor (PLX-4032, vemurafenib). The transcriptome was analyzed by RNA sequencing and compared with data from The Cancer Cell Line Encyclopedia and Gene Expression Omnibus. Results: While Nthy/WT was not tumorigenic in vivo, Nthy/V600E formed tumors reaching 2784.343 mm³ in 4 weeks, on average. A pathological analysis indicated that Nthy/V600E tumors were dedifferentiated thyroid cancer. We found metastases in the lung, liver, and relevant lymph nodes. A transcriptomic analysis revealed 5512 differentially expressed genes (DEGs) between the mutant and wild-type cell lines, and more DEGs were shared with anaplastic thyroid cancer than with papillary thyroid cancer. BRAF^V600E activated the cell cycle mainly by regulating G1/S phases. PLX-4032 treatment significantly inhibited tumor growth and metastasis. Conclusions: Our data show that BRAF^V600E plays a pivotal role in the carcinogenic transformation of an SV40-transfected immortalized normal human thyroid cell line. This xenograft model is expected to contribute to studies of the etiopathogenesis and treatment of highly malignant thyroid cancers.

Early Diagnosis of Low-Risk Papillary Thyroid Cancer Results Rather in Overtreatment Than a Better Survival

We are witnessing a rapid worldwide increase in the incidence of papillary thyroid carcinoma (PTC) in the last thirty years. Extensive implementation of cancer screening and wide availability of neck ultrasound or other imaging studies is the main reason responsible for this phenomenon. It resulted in a detection of a growing number of clinically asymptomatic PTCs, mainly low-risk tumors, without any beneficial impact on survival. An indolent nature of low-risk PTC, particularly papillary thyroid microcarcinoma (PTMC), and the excellent outcomes raise an ongoing discussion regarding the adequacy of treatment applied. The question of whether PTMC is overtreated or not is currently completed by another, whether PTMC requires any treatment. Current ATA guidelines propose less extensive preoperative diagnostics and, if differentiated thyroid cancer is diagnosed, less aggressive surgical approach and limit indications for postoperative radioiodine therapy. However, in intrathyroidal PTMCs in the absence of lymph node or distant metastases, active surveillance may constitute alternative management with a low progression rate of 1%-5% and without any increase in the risk of poorer outcomes related to delayed surgery in patients, in whom it was necessary. This review summarizes the current knowledge and future perspectives of active surveillance in low-risk PTC.

Proteomic analysis of the papillary thyroid microcarcinoma

OBJECTIVE

The present study applied iTRAQ and LC-MS/MS techniques for proteome analysis and compared data between specimens of papillary thyroid microcarcinoma (PTMC) vs appropriate controls, in order to investigate the mechanisms underlying the invasion and metastasis process in PTMC development.

MATERIALS AND METHODS

Fresh-tissue specimens were collected from 40 patients with thyroid disease who underwent surgical treatment. Specimens were divided into four groups: normal histology (NH; n=8), benign thyroid tumor (BTT; n=10), classic PTMC with lymph node metastasis (PTC-LNM⁽⁺⁾; n=11), and classic PTMC without lymph node metastasis (PTC-LNM^(-); n=11). Proteomic studies were conducted on PTMC tissue samples without capsule invasion and with tumor diameter ranging from 0.5cm to 1cm, so as to focus the study on PTMC development excluding metastasis.

RESULTS

A total of 8036 proteins were identified in the four groups. Based on protein function analysis, proteins that might be associated with PTMC invasion and metastasis were screened: alpha-actinin-1, alpha-1-antitrypsin, hepatoma-derived growth factor (HDGF), high-mobility group protein HMGI-C, and carbonic anhydrase 4. In addition, proteins involved in the focal adhesion pathway were examined. Immunohistochemistry confirmed the reliability of the iTRAQ results and the universality of differentially expressed proteins. The data showed that HDGF and high-mobility group protein HMGI-C are up-regulated in PTMC and that the focal adhesion pathway that promotes PTMC LNM is activated.

CONCLUSIONS

These findings provide insight into the mechanisms underlying PTMC invasion and metastasis.

Automatic thyroid nodule recognition and diagnosis in ultrasound imaging with the YOLOv2 neural network

BACKGROUND

In this study, images of 2450 benign thyroid nodules and 2557 malignant thyroid nodules were collected and labeled, and an automatic image recognition and diagnosis system was established by deep learning using the YOLOv2 neural network. The performance of the system in the diagnosis of thyroid nodules was evaluated, and the application value of artificial intelligence in clinical practice was investigated.

METHODS

The ultrasound images of 276 patients were retrospectively selected. The diagnoses of the radiologists were determined according to the Thyroid Imaging Reporting and Data System; the images were automatically recognized and diagnosed by the established artificial intelligence system. Pathological diagnosis was the gold standard for the final diagnosis. The performances of the established system and the radiologists in diagnosing the benign and malignant thyroid nodules were compared.

RESULTS

The artificial intelligence diagnosis system correctly identified the lesion area, with an area under the receiver operating characteristic (ROC) curve of 0.902, which is higher than that of the radiologists (0.859). This finding indicates a higher diagnostic accuracy (p = 0.0434). The sensitivity, positive predictive value, negative predictive value, and accuracy of the artificial intelligence diagnosis system for the diagnosis of malignant thyroid nodules were 90.5%, 95.22%, 80.99%, and 90.31%, respectively, and the performance did not significantly differ from that of the radiologists (p > 0.05). The artificial intelligence diagnosis system had a higher specificity (89.91% vs 77.98%, p = 0.026).

CONCLUSIONS

Compared with the performance of experienced radiologists, the artificial intelligence system has comparable sensitivity and accuracy for the diagnosis of malignant thyroid nodules and better diagnostic ability for benign thyroid nodules. As an auxiliary tool, this artificial intelligence diagnosis system can provide radiologists with sufficient assistance in the diagnosis of benign and malignant thyroid nodules.

Genetic variations in TAS2R3 and TAS2R4 bitterness receptors modify papillary carcinoma risk and thyroid function in Korean females

Type 2 taste receptors (T2Rs, TAS2Rs) mediate bitterness perception and are involved in diverse defence mechanisms in extraoral tissues. The thyrocyte-expressed T2Rs control thyroid hormone production, and this regulatory role may be associated with susceptibility to thyroid diseases. This study examined whether the variations in TAS2Rs modify the risk of papillary thyroid carcinoma (PTC) and whether such T2R-related PTC risk is associated with genetically modified thyroid function. We conducted a case-control study with 763 Korean females, including 250 PTC cases. Seventy-three single-nucleotide polymorphisms in 13 TAS2R genes and the pre-diagnosis levels of 4 thyroid-related functional markers [total triiodothyronine (TT3), free thyroxine, thyroid-stimulating hormone and thyroglobulin] were analysed. Individuals with TAS2R3/4 CC haplotype (rs2270009 and rs2234001) were at a lower risk for PTC than those with the remaining haplotypes (odds ratio = 0.59, 95% confidence interval: 0.36-0.97). Furthermore, TT3 levels were significantly reduced for TAS2R3/4 CC haplotype carriers compared with other haplotype carriers (p = 0.005). No other genetic variants exhibited critical associations with the PTC phenotype and biomarkers. In summary, genetic variations in T2R3/4 bitterness receptors may modify the PTC risk, and the genetically modified thyroid hormone level by those variations may be linked with the PTC-T2Rs association.

Thyroid cancer among female workers in Korea, 2007-2015

Background

Prevalence of thyroid cancer has been increasing rapidly worldwide, especially among women. There has been a debate as to whether such an increase represents consequences of over-diagnosis or a true increase. To find the occupational risk of Korean female workers in different industry sectors, we analyzed the data of Korean female workers.

Methods

National Female Worker Cohort data that contain information on total female workers were used for our analysis of prevalence of thyroid cancer (C73 according to KCD-5, 6 code) derived from National Health Insurance data. By combining industrial codes from National Health Insurance Service and those from Korea Workers' Compensation and Welfare Service, the classification of industrial codes became to consist of the total of thirty three representing both non-office (NO) and office (O) categories. Both an internal comparison among female workers within the cohort and an external comparison to compare female workers with Korean general female population were carried out.

Results

Among 149,258 female workers, 2,641 cases of thyroid cancers were identified. Differences in prevalence of thyroid cancer between female workers (40.5%) and general Korean female population (32.6%) were observed; however, the differences in prevalence of thyroid cancer between NO workers and O workers were not apparent. An analysis involving workers in Financial and insurance activities sector revealed that, standardized prevalence rate (SPR) of both NO (2.96, 95% CI = 2.01-4.20) and O workers (3.68, 95% CI = 3.10-4.33) increased significantly and that an AOR (adjusted odds ratio) increased marginally (1.38, 95% CI = 0.97-1.96). Further, when stratified in respect to the duration of employment, an AOR of female workers having been employed for more than 8 years showed a significant increase (1.63, 95% CI = 1.07-2.49).

Conclusions

Female workers had a higher risk of thyroid cancer than general female population but the difference between NO workers and O workers was not found to be significant in most industrial sectors. Further studies using data with information regarding specific occupational exposures are needed.

Long-term survival of patients with thyroid cancer according to the methods of tumor detection: A nationwide cohort study in Korea

In this retrospective cohort study, we compared the survival of patients detected by screening with those detected based on symptoms, according to their tumor stages. After propensity score matching, 2,130 patients with papillary or follicular thyroid cancer, identified by screening detection (SD) and clinical detection (CD), were included. We compared the survival rates of patients identified by SD and CD in the early and advanced stages of thyroid cancer. Cox proportional hazard models were used to compare the hazard ratios (HRs) for mortality between the two groups. Of the 1,065 patients in each group, 12 (1.1%) died in the SD group, compared to 44 (4.1%) in the CD group, during an average 9.4 years (p<0.001). For early stage, there was no significant difference in all-cause and thyroid cancer-specific mortality between the two groups (p = 0.08, p = 0.0502). However, for advanced stage, the survival rates in the SD group were significantly higher than in the CD group (p<0.001, p = 0.004). Moreover, after adjusting for covariates, the HRs of all-cause mortality of the SD group was significantly lower than that of the CD group for the advanced stage patients (HRs: 0.37 [95% CIs: 0.17–0.80]), while no significant difference was observed in the early stage. While screening for thyroid cancer was not beneficial for early stage patients, our findings suggest that detection via screening is associated with better survival for patients with advanced stage cancer. However, the effects of selection bias and lead time bias could not be entirely excluded.

Rising incidence of thyroid cancer in Singapore not solely due to micropapillary subtype

Introduction The annual incidence of thyroid cancer is known to vary with geographic area, age and gender. The increasing incidence of thyroid cancer has been attributed to increase in detection of micropapillary subtype, among other factors. The aim of the study was to investigate time trends in the incidence of thyroid cancer in Singapore, an iodine-sufficient area. Materials and methods Data retrieved from the Singapore National Cancer Registry on all thyroid cancers that were diagnosed from 1974 to 2013 were reviewed. We studied the time trends of thyroid cancer based on gender, race, pathology and treatment modalities where available. Results The age-standardised incidence rate of thyroid cancer increased to 5.6/100,000 in 2013 from 2.5/100,000 in 1974. Thyroid cancer appeared to be more common in women, with a higher incidence in Chinese and Malays compared with Indians. Papillary carcinoma is the most common subtype. The percentage of papillary microcarcinoma has remained relatively stable at around 38% of all papillary cancers between 2007 and 2013. Although the incidence of thyroid cancer has increased since 1974, the mortality rate has remained stable. Conclusion This trend of increase in incidence of thyroid cancer in Singapore compares with other published series; however, the rise seen was not solely due to micropapillary type. Thyroid cancer was also more common in Chinese and Malays compared with Indians for reasons that needs to be studied further.

Long term outcomes of simple clinical risk stratification in management of differentiated thyroid cancer

OBJECTIVE

To establish the long term outcomes of risk stratified management of differentiated thyroid cancer (DTC).

BACKGROUND

Guidelines for management of DTC lack a strong evidence base and expose patients to overtreatment. This prospective study of patients diagnosed with DTC between 1977 and 2012 describes the long term outcomes of a conservative risk stratified (AMES) management policy.

METHODS

Outcomes were analysed around patient and tumour characteristics, primary intervention (surgery ± radioiodine (RAI)), in terms of mortality, recurrence and reintervention.

RESULTS

Median follow-up in 348 patients was 14 years: mean age 48 (range 10-91) years, 257 (73.9%) female, 222 (68.3%) papillary cancer, tumour size 3.4 ± 2.0 cm (mean ± SD). 89 (25.6%) AMES high risk, 116 (33.3%) TNM stage III/IV and 16 (4.6%) had distant metastases. Primary surgery comprised lobectomy in 189 (54.3%): 11 (5.8%) patients had subsequent completion total thyroidectomy with cancer present in five. Primary nodal surgery was performed in 142 (40.8%) patients. 35 (13.5%) low and 43 (48.3%) high risk patients received RAI following initial surgery. Overall disease specific survival (DSS) was 92.1% at 10 years and 90.7% at 20 years. DSS at 20 years was 99.2% in low risk cases. AMES risk scoring predicted both survival and recurrence. Patients receiving RAI and AMES high risk were significantly associated with increased risk of death and recurrence.

CONCLUSIONS

Routine total thyroidectomy and RAI are not justifiable for low risk DTC. Treatment should be tailored to risk and AMES risk stratification remains a simple reliable clinical tool.

Interaction between alcohol consumption and methylenetetrahydrofolate reductase polymorphisms in thyroid cancer risk: National Cancer Center cohort in Korea

The effect of alcohol intake on thyroid cancer is unestablished, and its interaction effects with genetic susceptibility are unclear. In this case-control study, the relationship among alcohol intake, the methylenetetrahydrofolate reductase (MTHFR) gene, and thyroid cancer risk has been evaluated. In total, 642 cases and 642 controls of Korean origin were included, and the genetic variants C677T and A1298C of the MTHFR gene were analysed. The interactions between alcohol-consumption behaviour and genetic variants were analysed with a likelihood ratio test, wherein a multiplicative interaction term was added to a logistic regression model. There was an independent association between the C677T polymorphism and thyroid cancer risk but not for drinking history. For C677T C/C homozygotes, individuals with a history of alcohol consumption showed a protective OR (95% CI) of 0.42 (0.15–1.13) when never drinkers were used as the reference. However, this protective association was not observed among individuals with a T+ allele with an OR (95% CI) of 1.27 (0.89–1.82), showing different directions for the association between genotypes with a significant interaction (P_interaction = 0.009). Based on the genetic characteristics of individuals included, an interaction between alcohol intake and MTHFR C677T may modify the risk of thyroid cancer.

Growing incidence of thyroid carcinoma in recent years: Factors underlying overdiagnosis

There is an increasing incidence of well-differentiated thyroid cancer worldwide. Much of the increase is secondary to increased detection of small, low-risk tumors, with questionable clinical significance. This review addresses the factors that contribute to the increasing incidence and considers environmental, and patient-based and clinician-led influences. Articles addressing the causes of the increased incidence were critically reviewed. A complex interplay of environmental, medical, and social pressures has resulted in increased awareness of the thyroid disease risk, increased screening of thyroid cancers, and increased diagnosis of thyroid cancers. Although there is evidence to suggest that the true disease incidence may be changing slightly, most of the increase is related to factors that promote early diagnosis of low-risk lesions, which is resulting in a significant phenomenon of overdiagnosis. An improved understanding of these pressures at a global level will enable healthcare policymakers to react appropriately to this challenge in the future.

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

Cancer screening is aimed primarily at reducing deaths from the specific cancer. Thyroid-specific cancer mortality may be the most ambitious endpoint for obtaining estimates of screening effect. Numerous observations have accumulated over the years, indicating that thyroid cancer mortality endpoint has been difficult to study and is confounded by population heterogeneity, provision of randomization, and requirement of large cohorts with sufficiently long follow-up due to the excellent prognosis of the cancer. Accordingly, it may be important to reconsider how to best measure thyroid cancer screening efficacy. Recommendations against thyroid cancer screening should be based upon trials designed to evaluate its effectiveness not only in significant reduction in cancer mortality, but also of other distinct endpoints. It is desirable to evaluate derivative endpoints that can reliably predict reductions in mortality. The term "derivative" means a variable that is related to the true endpoint and is likely to be observable before the primary endpoint. Derivative endpoints may include thyroid cancer incidence, the proportion of early-stage tumors detected, more treatable stage, the identification of small tumors (to maintain in observation), decrease in the number of people who develop metastatic disease, the increased chance of lesser extent surgery, and the application of minimally invasive approaches, as well as no need for lifelong thyroid replacement therapy, a consistent follow-up, low-dose or no RAI administration and risk factor assessments where case findings should be continuous. The Korean guidelines for thyroid cancer national-level screening were published by a relevant group of multidisciplinary thyroid experts. It was concluded that the evidence is insufficient to balance the benefits and harms of thyroid cancer screening. However, the paper seems to raise the necessary investments in future research and demand a complete analysis for derivative endpoints, and offer screening participants with complete information necessary to make decisions that will provide them with the most value when a small thyroid cancer is screen-identified.

Total thyroidectomy may be more reasonable as initial surgery in unilateral multifocal papillary thyroid microcarcinoma: a single-center experience

BACKGROUND

The extent of surgery in patients with unilateral multifocal papillary thyroid microcarcinoma (UMPTMC) remains to be controversial. Aimed to improve surgical management of UMPTMC, this study was performed to identify the recurrence of UMPTMC and analyze its predictive factors.

METHODS

This study was approved by the Ethical Committee of The First Hospital of the Jilin University, and written informed consent was given by participants for their clinical records to be used in this study. We retrospectively analyzed a total of 97 consecutive patients who underwent initial surgery for the treatment of UMPTMC at The First Hospital of Jilin University, between October 2005 and October 2006.

RESULTS

Altogether, 97 patients of UMPTMC have been enrolled in our study, in which 57 cases were performed with hemithyroidectomy (HT) while other 40 cases with total thyroidectomy (TT). The sum diameter of all tumors >1 cm was more frequent in HT group than in TT group (40.35 vs 20%; p = 0.046). Positive central lymph nodes were found more frequently in the TT patients than in the HT patients (80 vs 59.65%; p = 0.046). Tumor recurrence was seen more frequently in the HT cases than in the TT cases (26 vs 5%; p = 0.007). The disease-free survival period was significantly shorter for the HT patients than for the TT patients (p = 0.0059 by the log-rank test). The disease-free survival rates at 5 and 10 years were 91.23 and 73.68%, respectively, in the HT group and 100 and 92.5%, respectively, in the TT group. Univariate analysis by Cox's proportional hazards method showed male gender, sum diameter of all tumors >1 cm, and central lymph node metastases (CLNM) to be risk factors for recurrence of HT patients. Male gender and sum diameter >1 cm were factors identified for multivariate analysis by Cox's proportional hazards method which yielded risk ratios of 3.037 [CI 1.026-8.988; p = 0.045] and 5.475 [CI 1.389-21.572; p = 0.015] in the HT group.

CONCLUSIONS

In summary, with an increased risk of recurrence, TT may be more reasonable as initial surgery in UMPTMC, especially with male gender and total tumor diameter greater than 1 cm.

Thyroid fine-needle aspiration biopsy positively correlates with increased diagnosis of thyroid cancer in South Korean patients

BACKGROUND

The incidence of thyroid cancer among South Koreans is more than 10-fold greater than its incidence in other countries, although its associated mortality rate is similar. Amidst concerns regarding the over-diagnosis of thyroid cancer related to gradually expanded medical testing in South Korea, we hypothesized that the number of thyroid fine-needle aspiration biopsies has led to increased diagnosis of thyroid cancer.

METHODS

We used data from the National Health Insurance Service National Sample Cohort 2003-2013, which included all medical claims filed for the 1,122,456 people in a nationally representative sample. We performed a Poisson regression analysis using generalized estimating equation to investigate the relationship between the number of thyroid fine-needle aspiration biopsies and the newly diagnosed cases of thyroid cancer.

RESULTS

The study included 60 annual patients per 100,000 individuals out of 11,024,548 person-years. The number of biopsies per 100,000 patients positively correlated with increased incidence of thyroid cancer diagnosis (per 100 biopsy cases: RR = 1.108; 95% CI: 1.090-1.126; P < 0.0001). Such relationships were greater in males, patients with a higher socioeconomic status, and patients from regions with relatively less accessibility to biopsies.

CONCLUSION

Our findings suggest that a higher number of thyroid fine-needle aspiration biopsies per 100,000 individuals in a specific Si-Gun-Gu is positively associated with excessively increased diagnosis of thyroid cancer. Regarding the continually increasing thyroid cancer incidence in South Korea, healthcare professionals and policy makers should consider proper guidelines for recognizing the role of thyroid fine-needle aspiration biopsies in the potential over-diagnosis of thyroid cancer.

Comparison of the costs of active surveillance and immediate surgery in the management of low-risk papillary microcarcinoma of the thyroid

The incidence of thyroid cancer is increasing rapidly in many countries, resulting in rising societal costs of the care of thyroid cancer. We reported that the active surveillance of low-risk papillary microcarcinoma had less unfavorable events than immediate surgery, while the oncological outcomes of these managements were similarly excellent. Here we calculated the medical costs of these two managements. We created a model of the flow of these managements, based on our previous study. The flow and costs include the step of diagnosis, surgery, prescription of medicine, recurrence, salvage surgery for recurrence, and care for 10 years after the diagnosis. The costs were calculated according to the typical clinical practices at Kuma Hospital performed under the Japanese Health Care Insurance System. If conversion surgeries were not considered, the 'simple cost' of active surveillance for 10 years was 167,780 yen/patient. If there were no recurrences, the 'simple cost' of immediate surgery was calculated as 794,770 yen/patient to 1,086,070 yen/patient, depending on the type of surgery and postoperative medication. The 'simple cost' of surgery was 4.7 to 6.5 times the 'simple cost' of surveillance. When conversion surgeries and recurrence were considered, the 'total cost' of active surveillance for 10 years became 225,695 yen/patient. When recurrence were considered, the 'total cost' of immediate surgery was 928,094 yen/patient, which was 4.1 times the 'total cost' of the active surveillance. At Kuma Hospital in Japan, the 10-year total cost of immediate surgery was 4.1 times expensive than active surveillance.

Cancer incidence and mortality projections in the UK until 2035

Background:

Cancer incidence and mortality projections are important for understanding the evolving landscape for cancer risk factors as well as anticipating future burden on the health service.

Methods:

We used an age–period–cohort model with natural cubic splines to estimate cancer cases and deaths from 2015 to 2035 based on 1979–2014 UK data. This was converted to rates using ONS population projections. Modified data sets were generated for breast and prostate cancers.

Results:

Cancer incidence rates are projected to decrease by 0.03% in males and increase by 0.11% in females yearly between 2015 and 2035; thyroid, liver, oral and kidney cancer are among the fastest accelerating cancers. 243 690 female and 270 261 male cancer cases are projected for 2035. Breast and prostate cancers are projected to be the most common cancers among females and males, respectively in 2035. Most cancers' mortality rate is decreasing; there are notable increases for liver, oral and anal cancer. For 2035, there are 95 961 female deaths projected and 116 585 male deaths projected.

Conclusions:

These findings stress the need to continue efforts to address cancer risk factors. Furthermore, the increased burden of the number of cancer cases and deaths as a result of the growing and ageing population should be taken into consideration by healthcare planners.

Differences in the Recurrence and Survival of Patients with Symptomatic and Asymptomatic Papillary Thyroid Carcinoma: An Observational Study of 11,265 Person-Years of Follow-Up

BACKGROUND

Papillary thyroid carcinoma (PTC) generally has an indolent course and favorable prognosis. However, an optimal treatment strategy for asymptomatic PTC is not clear. We compared the recurrence and survival outcomes of patients with asymptomatic and symptomatic PTC and identified the associated risk factors.

MATERIALS AND METHODS

Patients with previously untreated PTC of size ≤2 cm and who underwent curative surgery were included in this analysis. Asymptomatic PTC was defined as a tumor detected only by ultrasonography, computed tomography (CT), magnetic resonance imaging, and/or ¹⁸F-fluorodeoxyglucose positron emission tomography/CT. Clinical factors, operative and pathologic findings, and posttreatment outcomes were compared between the aforementioned two groups. Univariate and multivariate analyses were performed to identify the factors associated with recurrence-free survival (RFS) and overall survival (OS).

RESULTS

Out of 1419 patients, 1259 patients (88.7%) were asymptomatic. Patients with symptomatic PTC had significantly larger tumor size, palpability, extrathyroidal extension, high tumor and node stages, and were more likely to undergo treatment with radioactive iodine therapy compared with patients with asymptomatic PTC (p < 0.05 each). Recurrence was significantly higher in the symptomatic PTC group than in the asymptomatic group (p < 0.001). Asymptomatic PTC was an independent predictor of RFS and OS and had higher five-year rates than those associated with symptomatic tumors: 97.3% and 90.6% for RFS (p < 0.001) and 99.4% and 96.9% for OS (p < 0.001), respectively.

CONCLUSION

Symptomatic PTC is associated with higher recurrence and lower overall survival rates than asymptomatic PTC. Symptomatic PTC may require total thyroidectomy and close posttreatment surveillance.

Responses to Overdiagnosis in Thyroid Cancer Screening among Korean Women

Purpose

Communicating the harms and benefits of thyroid screening is necessary to help individuals decide on whether or not to undergo thyroid cancer screening. This study was conducted to assess changes in thyroid cancer screening intention in response to receiving information about overdiagnosis and to determine factors with the greatest influence thereon.

Materials and Methods

Data were acquired from subjects included in the 2013 Korean National Cancer Screening Survey (KNCSS), a nationwide, population-based, cross-sectional survey. Of the 4,100 respondents in the 2013 KNCSS, women were randomly subsampled and an additional face-to-face interview was conducted. Finally, a total of 586 female subjects were included in this study. Intention to undergo thyroid cancer screening was assessed before and after receiving information on overdiagnosis.

Results

Prior awareness of overdiagnosis in thyroid cancer screening was 27.8%. The majority of subjects intended to undergo thyroid cancer screening before and after receiving information on overdiagnosis (87% and 74%, respectively). Only a small number of subjects changed their intention to undergo thyroid cancer screening from positive to negative after receiving information on overdiagnosis. Women of higher education level and Medical Aid Program recipients reported being significantly more likely to change their intention to undergo thyroid cancer screening afterreceiving information on overdiagnosis,whilewomen with stronger beliefs on the efficacy of cancer screening were less likely to change their intention.

Conclusion

Women in Korea appeared to be less concerned about overdiagnosis when deciding whether or not to undergo thyroid cancer screening.

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

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.

A qualitative study of women's views on overdiagnosis and screening for thyroid cancer in Korea

Background

The incidence of thyroid cancer in Korea has increased by about 25 % every year for the past 10 years. This increase is largely due to a rising incidence in papillary thyroid cancer, which is associated with an overdiagnosis of small tumors that may never become clinically significant. This study was conducted to explore Korean women’s understanding of overdiagnosis and to investigate changes in screening intention in response to overdiagnosis information.

Methods

Focus group interviews were conducted among women of ages 30–69 years, who are commonly targeted in Korea for cancer screening. Women were divided into four groups according to thyroid cancer screening history and history of thyroid disease. Of 51 women who were contacted, 29 (57 %) participated in the interviews.

Results

Prior awareness of thyroid cancer overdiagnosis was minimal. When informed about the risks of overdiagnosis, the participants were often surprised. Overcoming initial malcontent, many women remained skeptic about overdiagnosis and trusted in the advice of their physicians. Meanwhile, some of the study participants found explanations of overdiagnosis difficult to understand. Further, hearing about the risks of overdiagnosis had limited impact on the participants’ attitudes and intentions to undergo thyroid cancer screening, as many women expressed willingness to undergoing continued screening in the future.

Conclusion

A large majority of Korean women eligible for and had undergone thyroid cancer screening were unaware of the potential for overdiagnosis. Nevertheless, overdiagnosis information generally had little impact on their beliefs about thyroid cancer screening and their intentions to undergo future screening. Further research is needed to determine whether these findings could be generalized to the wider Korean population.

TERT Promoter Mutations in Papillary Thyroid Microcarcinomas

BACKGROUND

Small papillary thyroid carcinomas have contributed to the worldwide increased incidence of differentiated thyroid cancer observed over the past decades. However, the mortality rate has not changed over the same period of time, raising questions about the possibility that thyroid cancer patients, especially those with small tumors, are overdiagnosed and overtreated. Molecular prognostic marker able to discriminate aggressive thyroid cancers from those with an indolent course would be of great relevance to tailor the therapeutic approach and reduce overtreatment. Mutations in the TERT promoter were recently reported to correlate strongly with aggressiveness in advanced forms of thyroid cancer, holding promise for a possible clinical application. The occurrence and potential clinical relevance of TERT mutations in papillary thyroid microcarcinomas (mPTCs) is currently unknown. This study aimed to analyze the occurrence of two TERT promoter mutations (-124C>T and -146C>T) and their potential association with unfavorable clinical features in a large cohort of mPTCs.

METHODS

A total of 431 mPTCs cases were collected from six Italian institutions, and TERT promoter mutational status was assessed by a next-generation sequencing approach.

RESULTS

TERT promoter mutations were found in 4.7% of the analyzed mPTCs, showing that even microcarcinomas carry mutations in this gene. Correlation analysis showed that TERT promoter mutations are not associated with aggressive features or clinical outcome in the cohort analyzed.

CONCLUSIONS

TERT mutations are present but uncommon in mPTCs. Apparently, in mPTCs, the occurrence of TERT mutations is not correlated with unfavorable clinical features.

Association of Dietary Vitamin D and Calcium With Genetic Polymorphisms in Colorectal Neoplasia

The incidence trends of colorectal cancer have varied over time, and there is wide geographical variation across the world. Regarding colorectal cancer, diverse modifiable environmental or intrinsic risk factors have been investigated. This review summarizes the effects of both dietary intake of vitamin D and calcium in particular and diet-associated genetic factors on colorectal cancer risk. We searched the electronic database PubMed for articles published between January 2000 and March 2015. We reviewed case-control studies that included dietary factors, genetic polymorphisms, and gene-diet interactions in association with colorectal cancer risk. Overall, 21 studies were selected as eligible studies. These studies demonstrated that dietary consumption of vitamin D and calcium may decrease the risk of colorectal cancer or adenoma. Colorectal carcinogenesis was discussed in conjunction with dietary factors and mediating genetic factors. The epidemiological findings suggested that the gene-diet interactions may possibly alter the associations between dietary intake, genetic polymorphisms, and the risk of colorectal cancer. However, the reported effects of the same potential factors on colorectal cancer risk were inconsistent, depending on the study population and geographical location. This finding may imply the necessity of considering the environmental differences and genetic variations existing between individuals or specified populations. Therefore, further studies are required to investigate modifiable risk factors in diverse locations to derive useful implications for colorectal neoplasia.

Overdiagnosis: epidemiologic concepts and estimation

Overdiagnosis of thyroid cancer was propounded regarding the rapidly increasing incidence in South Korea. Overdiagnosis is defined as 'the detection of cancers that would never have been found were it not for the screening test', and may be an extreme form of lead bias due to indolent cancers, as is inevitable when conducting a cancer screening programme. Because it is solely an epidemiological concept, it can be estimated indirectly by phenomena such as a lack of compensatory drop in post-screening periods, or discrepancies between incidence and mortality. The erstwhile trials for quantifying the overdiagnosis in screening mammography were reviewed in order to secure the data needed to establish its prevalence in South Korea.