Lower Thyroid Cancer Mortality in Patients Detected by Screening: A Meta-Analysis

Background@#Thyroid cancer screening has contributed to the skyrocketing prevalence of thyroid cancer. However, the true benefit of thyroid cancer screening is not fully understood. This study aimed to evaluate the impact of screening on the clinical outcomes of thyroid cancer by comparing incidental thyroid cancer (ITC) with non-incidental thyroid cancer (NITC) through a meta-analysis. @*Methods@#PubMed and Embase were searched from inception to September 2022. We estimated and compared the prevalence of high-risk features (aggressive histology of thyroid cancer, extrathyroidal extension, metastasis to regional lymph nodes or distant organs, and advanced tumor-node-metastasis [TNM] stage), thyroid cancer-specific death, and recurrence in the ITC and NITC groups. We also calculated pooled risks and 95% confidence intervals (CIs) of the outcomes derived from these two groups. @*Results@#From 1,078 studies screened, 14 were included. In comparison to NITC, the ITC group had a lower incidence of aggressive histology (odds ratio [OR], 0.46; 95% CI, 0.31 to 0.7), smaller tumors (mean difference, −7.9 mm; 95% CI, −10.2 to −5.6), lymph node metastasis (OR, 0.64; 95% CI, 0.48 to 0.86), and distant metastasis (OR, 0.42; 95% CI, 0.23 to 0.77). The risks of recurrence and thyroid cancer-specific mortality were also lower in the ITC group (OR, 0.42; 95% CI, 0.25 to 0.71 and OR, 0.46; 95% CI, 0.28 to 0.74) than in the NITC group. @*Conclusion@#Our findings provide important evidence of a survival benefit from the early detection of thyroid cancer compared to symptomatic thyroid cancer.

Different Molecular Phenotypes of Progression in BRAF- and RAS-Like Papillary Thyroid Carcinoma

Background@#Papillary thyroid carcinoma (PTC) can be classified into two distinct molecular subtypes, BRAF-like (BL) and RASlike (RL). However, the molecular characteristics of each subtype according to clinicopathological factors have not yet been determined. We aimed to investigate the gene signatures and tumor microenvironment according to clinicopathological factors, and to identify the mechanism of progression in BL-PTCs and RL-PTCs. @*Methods@#We analyzed RNA sequencing data and corresponding clinicopathological information of 503 patients with PTC from The Cancer Genome Atlas database. We performed differentially expressed gene (DEG), Gene Ontology, and molecular pathway enrichment analyses according to clinicopathological factors in each molecular subtype. EcoTyper and CIBERSORTx were used to deconvolve the tumor cell types and their surrounding microenvironment. @*Results@#Even for the same clinicopathological factors, overlapping DEGs between the two molecular subtypes were uncommon, indicating that BL-PTCs and RL-PTCs have different progression mechanisms. Genes related to the extracellular matrix were commonly upregulated in BL-PTCs with aggressive clinicopathological factors, such as old age (≥55 years), presence of extrathyroidal extension, lymph node metastasis, advanced tumor-node-metastasis (TNM) stage, and high metastasis-age-completeness of resection- invasion-size (MACIS) scores (≥6). Furthermore, in the deconvolution analysis of tumor microenvironment, cancer-associated fibroblasts were significantly enriched. In contrast, in RL-PTCs, downregulation of immune response and immunoglobulin-related genes was significantly associated with aggressive characteristics, even after adjusting for thyroiditis status. @*Conclusion@#The molecular phenotypes of cancer progression differed between BL-PTC and RL-PTC. In particular, extracellular matrix and cancer-associated fibroblasts, which constitute the tumor microenvironment, would play an important role in the progression of BL-PTC that accounts for the majority of advanced PTCs.

Postprandial Free Fatty Acids at Mid-Pregnancy Increase the Risk of Large-for-Gestational-Age Newborns in Women with Gestational Diabetes Mellitus

Background@#To investigate the association between free fatty acid (FFA) level at mid-pregnancy and large-for-gestational-age (LGA) newborns in women with gestational diabetes mellitus (GDM). @*Methods@#We enrolled 710 pregnant women diagnosed with GDM from February 2009 to October 2016. GDM was diagnosed by a ‘two-step’ approach with Carpenter and Coustan criteria. We measured plasma lipid profiles including fasting and 2-hour postprandial FFA (2h-FFA) levels at mid-pregnancy. LGA was defined if birthweights of newborns were above the 90th percentile for their gestational age. @*Results@#Mean age of pregnant women in this study was 33.1 years. Mean pre-pregnancy body mass index (BMI) was 22.4 kg/m2. The prevalence of LGA was 8.3% (n=59). Levels of 2h-FFA were higher in women who delivered LGA newborns than in those who delivered non-LGA newborns (416.7 μEq/L vs. 352.5 μEq/L, P=0.006). However, fasting FFA was not significantly different between the two groups. The prevalence of delivering LGA newborns was increased with increasing tertile of 2h-FFA (T1, 4.3%; T2, 9.8%; T3, 10.7%; P for trend <0.05). After adjustment for maternal age, pre-pregnancy BMI, and fasting plasma glucose, the highest tertile of 2h-FFA was 2.38 times (95% confidence interval, 1.11 to 5.13) more likely to have LGA newborns than the lowest tertile. However, there was no significant difference between groups according to fasting FFA tertiles. @*Conclusion@#In women with GDM, a high 2h-FFA level (but not fasting FFA) at mid-pregnancy is associated with an increasing risk of delivering LGA newborns.

DEHP Down-Regulates Tshr Gene Expression in Rat Thyroid Tissues and FRTL-5 Rat Thyrocytes: A Potential Mechanism of Thyroid Disruption

Background@#Di-2-ethylhexyl phthalate (DEHP) is known to disrupt thyroid hormonal status. However, the underlying molecular mechanism of this disruption is unclear. Therefore, we investigated the direct effects of DEHP on the thyroid gland. @*Methods@#DEHP (vehicle, 50 mg/kg, and 500 mg/kg) was administered to Sprague-Dawley rats for 2 weeks. The expression of the thyroid hormone synthesis pathway in rat thyroid tissues was analyzed through RNA sequencing analysis, quantitative reverse transcription-polymerase chain reaction (RT-PCR), and immunohistochemical (IHC) staining. DEHP was treated to FRTL-5 rat thyroid cells, and an RT-PCR analysis was performed. A reporter gene assay containing the promoter of thyroid stimulating hormone receptor (TSHR) in Nthy-ori 3-1 human thyroid cells was constructed, and luciferase activity was determined. @*Results@#After DEHP treatment, the free thyroxine (T4) and total T4 levels in rats significantly decreased. RNA sequencing analysis of rat thyroid tissues showed little difference between vehicle and DEHP groups. In the RT-PCR analysis, Tshr expression was significantly lower in both DEHP groups (50 and 500 mg/kg) compared to that in the vehicle group, and IHC staining showed that TSHR expression in the 50 mg/kg DEHP group significantly decreased. DEHP treatment to FRTL-5 cells significantly down-regulated Tshr expression. DEHP treatment also reduced luciferase activity in a reporter gene assay for TSHR. @*Conclusion@#Although overall genetic changes in the thyroid hormone synthesis pathway are not clear, DEHP exposure could significantly down-regulate Tshr expression in thyroid glands. Down-regulation of Tshr gene appears to be one of potential mechanisms of thyroid disruption by DEHP exposure.

DEHP Down-Regulates Tshr Gene Expression in Rat Thyroid Tissues and FRTL-5 Rat Thyrocytes: A Potential Mechanism of Thyroid Disruption

Background@#Di-2-ethylhexyl phthalate (DEHP) is known to disrupt thyroid hormonal status. However, the underlying molecular mechanism of this disruption is unclear. Therefore, we investigated the direct effects of DEHP on the thyroid gland. @*Methods@#DEHP (vehicle, 50 mg/kg, and 500 mg/kg) was administered to Sprague-Dawley rats for 2 weeks. The expression of the thyroid hormone synthesis pathway in rat thyroid tissues was analyzed through RNA sequencing analysis, quantitative reverse transcription-polymerase chain reaction (RT-PCR), and immunohistochemical (IHC) staining. DEHP was treated to FRTL-5 rat thyroid cells, and an RT-PCR analysis was performed. A reporter gene assay containing the promoter of thyroid stimulating hormone receptor (TSHR) in Nthy-ori 3-1 human thyroid cells was constructed, and luciferase activity was determined. @*Results@#After DEHP treatment, the free thyroxine (T4) and total T4 levels in rats significantly decreased. RNA sequencing analysis of rat thyroid tissues showed little difference between vehicle and DEHP groups. In the RT-PCR analysis, Tshr expression was significantly lower in both DEHP groups (50 and 500 mg/kg) compared to that in the vehicle group, and IHC staining showed that TSHR expression in the 50 mg/kg DEHP group significantly decreased. DEHP treatment to FRTL-5 cells significantly down-regulated Tshr expression. DEHP treatment also reduced luciferase activity in a reporter gene assay for TSHR. @*Conclusion@#Although overall genetic changes in the thyroid hormone synthesis pathway are not clear, DEHP exposure could significantly down-regulate Tshr expression in thyroid glands. Down-regulation of Tshr gene appears to be one of potential mechanisms of thyroid disruption by DEHP exposure.

Mechanisms of TERT Reactivation and Its Interaction with BRAFV600E

The telomerase reverse transcriptase (TERT) gene, which is repressed in most differentiated human cells, can be reactivated by somatic TERT alterations and epigenetic modulations. Moreover, the recruitment, accessibility, and binding of transcription factors also affect the regulation of TERT expression. Reactivated TERT contributes to the development and progression of cancer through telomere lengthening-dependent and independent ways. In particular, because of recent advances in high-throughput sequencing technologies, studies on genomic alterations in various cancers that cause increased TERT transcriptional activity have been actively conducted. TERT reactivation has been reported to be associated with poor prognosis in several cancers, and TERT promoter mutations are among the most potent prognostic markers in thyroid cancer. In particular, when a TERT promoter mutation coexists with the BRAFV600E mutation, these mutations exert synergistic effects on a poor prognosis. Efforts have been made to uncover the mechanisms of these synergistic interactions. In this review, we discuss the role of TERT reactivation in tumorigenesis, the mechanisms of TERT reactivation across all human cancers and in thyroid cancer, and the mechanisms of interactions between BRAFV600E and TERT promoter mutations.

Recent Improvements in Genomic and Transcriptomic Understanding of Anaplastic and Poorly Differentiated Thyroid Cancers

Anaplastic thyroid cancer (ATC) is a lethal human cancer with a 5-year survival rate of less than 10%. Recently, its genomic and transcriptomic characteristics have been extensively elucidated over 5 years owing to advance in high throughput sequencing. These efforts have extended molecular understandings into the progression mechanisms and therapeutic vulnerabilities of aggressive thyroid cancers. In this review, we provide an overview of genomic and transcriptomic alterations in ATC and poorly-differentiated thyroid cancer, which are distinguished from differentiated thyroid cancers. Clinically relevant genomic alterations and deregulated signaling pathways will be able to shed light on more effective prevention and stratified therapeutic interventions for affected patients.

Star-Shaped Intense Uptake of ¹³¹I on Whole Body Scans Can Reflect Good Therapeutic Effects of Low-Dose Radioactive Iodine Treatment of 1.1 GBq

BACKGROUND: After initial radioactive iodine (RAI) treatment in differentiated thyroid cancer patients, we sometimes observe a star-shaped region of intense uptake of 131I on whole body scans (WBSs), called a ‘star artifact.’ We evaluated the clinical implications of star artifacts on the success rate of remnant ablation and long-term prognosis. METHODS: Total 636 patients who received 131I dose of 1.1 GBq for the initial RAI therapy and who did not show distant metastasis at the time of diagnosis were retrospectively evaluated. A negative second WBS was used for evaluating the ablation efficacy of the RAI therapy. Among them, 235 patients (36.9%) showed a star artifact on their first WBS. RESULTS: In patients with first stimulated thyroglobulin (sTg) levels ≤2 ng/mL, patients with star artifacts had a higher rate of negative second WBS compared with those without star artifacts (77.8% vs. 63.9%, P=0.044), and showed significantly higher recurrence-free survival (P=0.043) during the median 8.0 years (range, 1.0 to 10.0) of follow-up. The 5- and 10-year recurrence rates (5YRR, 10YRR) were also significantly lower in patients with star artifacts compared with those without (0% vs. 4.9%, respectively, P=0.006 for 5YRR; 0% vs. 6.4%, respectively, P=0.005 for 10YRR). However, ablation success rate or recurrence-free survival was not different among patients whose first sTg levels >2 ng/mL regardless of star artifacts. CONCLUSION: Therefore, star artifacts at initial RAI therapy imply a good ablation efficacy or a favorable long-term prognosis in patients with sTg levels ≤2 ng/mL.

Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

BACKGROUND: The ongoing Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) aims to observe the natural course of papillary thyroid microcarcinoma (PTMC), develop a protocol for active surveillance (AS), and compare the long-term prognosis, quality of life, and medical costs between the AS and immediate surgery groups. METHODS: This multicenter prospective cohort study of PTMC started in June 2016. The inclusion criteria were suspicious of malignancy or malignancy based on fine needle aspiration or core needle biopsy, age of ≥18 years, and a maximum diameter of ≤1 cm. If there was no major organ involvement, no lymph node/distant metastasis, and no variants with poor prognosis, the patients were explained of the pros and cons of immediate surgery and AS before selecting AS or immediate surgery. Follow-up visits (physical examination, ultrasonography, thyroid function, and questionnaires) are scheduled every 6 months during the first 2 years, and then every 1 year thereafter. Progression was defined as a maximum diameter increase of ≥3, ≥2 mm in two dimensions, suspected organ involvement, or lymph node/distant metastasis. RESULTS: Among 439 enrolled patients, 290 patients (66.1%) chose AS and 149 patients (33.9%) chose immediate surgery. The median follow-up was 6.7 months (range, 0.2 to 11.9). The immediate surgery group had a larger maximum tumor diameter, compared to the AS group (7.1±1.9 mm vs. 6.6±2.0 mm, respectively; P=0.014). CONCLUSION: The results will be useful for developing an appropriate PTMC treatment policy based on its natural course and risk factors for progression.

Improvement of Glycosylated Hemoglobin in Patients with Type 2 Diabetes Mellitus under Insulin Treatment by Reimbursement for Self-Monitoring of Blood Glucose

BACKGROUND: In Korea, the costs associated with self-monitoring of blood glucose (SMBG) for patients with type 2 diabetes mellitus (T2DM) under insulin treatment have been reimbursed since November 2015. We investigated whether this new reimbursement program for SMBG has improved the glycemic control in the beneficiaries of this policy. METHODS: Among all adult T2DM patients with ≥3 months of reimbursement (n=854), subjects without any changes in anti-hyperglycemic agents during the study period were selected. The improvement of glycosylated hemoglobin (HbA1c) was defined as an absolute reduction in HbA1c ≥0.6% or an HbA1c level at follow-up < 7%. RESULTS: HbA1c levels significantly decreased from 8.5%±1.3% to 8.2%±1.2% during the follow-up (P < 0.001) in all the study subjects (n=409). Among them, 35.5% (n=145) showed a significant improvement in HbA1c. Subjects covered under the Medical Aid system showed a higher prevalence of improvement in HbA1c than those with medical insurance (52.2% vs. 33.3%, respectively, P=0.012). In the improvement group, the baseline HbA1c (P < 0.001), fasting C-peptide (P=0.016), and daily dose of insulin/body weight (P=0.024) showed significant negative correlations with the degree of HbA1c change. Multivariate analysis showed that subjects in the Medical Aid system were about 2.5-fold more likely to improve in HbA1c compared to those with medical insurance (odds ratio, 2.459; 95% confidence interval, 1.138 to 5.314; P=0.022). CONCLUSION: The reimbursement for SMBG resulted in a significant improvement in HbA1c in T2DM subjects using insulin, which was more prominent in subjects with poor glucose control at baseline or covered under the Medical Aid system.

Effects of Maternal Iodine Status during Pregnancy and Lactation on Maternal Thyroid Function and Offspring Growth and Development: A Prospective Study Protocol for the Ideal Breast Milk Cohort

BACKGROUND: Iodine is an intrinsic element of thyroid hormone, which is essential for childhood growth and development. The Ideal Breast Milk (IBM) cohort study aims to evaluate the effects of maternal iodine status during pregnancy and lactation on maternal thyroid function, offspring growth and development, and offspring thyroid function. METHODS: The IBM cohort study recruited pregnant women from Seoul National University Hospital between June 2016 and August 2017, followed by enrollment of their offspring after delivery. For the maternal participants, iodine status is evaluated by urinary iodine concentration (UIC) and dietary records in the third trimester and at 3 to 4 weeks and 12 to 15 months postpartum. For the child participants, cord blood sampling and UIC measurements are performed at birth. At 3 to 4 weeks of age, UIC and breastmilk iodine concentrations are measured. At 12 to 15 months of age, growth and development are assessed and measurements of UIC, a thyroid function test, and ultrasonography are performed. RESULTS: A total of 198 pregnant women in their third trimester were recruited. Their mean age was 35.1±3.5 years, and 78 (39.4%) of them were pregnant with twins. Thirty-three (16.7%) of them had a previous history of thyroid disease. CONCLUSION: Korea is an iodine-replete area. In particular, lactating women in Korea are commonly exposed to excess iodine due to the traditional practice of consuming brown seaweed soup postpartum. The study of the IBM cohort is expected to contribute to developing guidelines for optimal iodine nutrition in pregnant or lactating women.

Corrigendum: Study Protocol of Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro)

No abstract available.

Expression of Sodium-Iodide Symporter Depending on Mutational Status and Lymphocytic Thyroiditis in Papillary Thyroid Carcinoma

BACKGROUND AND OBJECTIVES: Sodium-iodine symporter (NIS) is a marker for the degree of differentiation in thyroid cancer. The genetic factors or microenvironment surrounding tumors can affect transcription of NIS. In this study, we investigated the NIS mRNA expression according to mutational status and coexistent lymphocytic thyroiditis in papillary thyroid cancer (PTC). MATERIALS AND METHODS: The RNA expression levels of NIS in the samples from database of The Caner Genome Atlas (TCGA; n=494) and our institute (n=125) were analyzed. RESULTS: The PTCs with the BRAFV600E mutation and the coexistence of BRAFV600E and TERT promoter mutations showed significantly lower expression of NIS (p < 0.001, respectively), and those with BRAF-like molecular subtype also had reduced expression of NIS (p < 0.001). NIS expression showed a positive correlation with thyroid differentiation score (r=0.593, p < 0.001) and negative correlations with expressions of genes involved in ERK signaling (r=−0.164, p < 0.001) and GLUT-1 gene (r=−0.204, p < 0.001). The PTCs with lymphocytic thyroiditis showed significantly higher NIS expression (p=0.013), regardless of mutational status. CONCLUSION: The NIS expression was reduced by the BRAFV600E mutation and MAPK/ERK pathway activation, but restored by the presence of lymphocytic thyroiditis.

A Case of Aggravation of Thyroid Goiter after Treatment with PD-1 Inhibitor for Breast Cancer in Patients with Underlying Hashimoto's Thyroiditis

Anti-programmed cell death-1 (PD-1) humanized monoclonal antibody inhibits PD-1 activity by binding to the PD-1 receptor on T-cells and blocking PD-1 ligands and induces immune tolerance of cancer cells. It has been widely used for various kinds of cancer treatment. However, many immune-related adverse events (irAEs) have been reported because it modulates our immune system. In this case study, we reported a case of 42-year-old woman with Hashimoto's thyroiditis who showed rapid aggravation of thyroid goiter and acute hyperventilation syndrome after treatment with PD-1 inhibitor as a neoadjuvant chemotherapy for breast cancer.

Ten Years of the Korean Thyroid Association: Achievement and Future: Correction

Correction of the text.

Ten Years of the Korean Thyroid Association: Achievement and Future

The Korean Thyroid Association (KTA) is a multi-disciplinary organization founded by various Korean societies involved in thyroid disease. The KTA has become a foundation stone of the rapid development of the thyroidology in Korea by utilizing the characteristic of multi-discipline for the past 10 years. On February 16, 2008, the inaugural conference was held with great success. Since then, in a short period of 10 years, the number of lifetime members of the KTA reached 623. On March 29, 2012, the KTA became an approved organization by Korean Medical Association within the record time of 4 years after its establishment. In terms of patient care, mutual cooperation among experts in the various fields of thyroid disease have been promoted based on the KTA. On the academic side, the number of papers were awarded and published at international conferences or international academic journals has increased dramatically, and finally, the research on thyroid disease in Korea has reached the global level. The KTA is a multi-disciplinary society consisting of experts from various fields such as internal medicine, surgery, otolaryngology, nuclear medicine, radiology, and pathology. The reason why the KTA has achieved unparalleled growth is that all the KTA members, including senior professors who served as the president and vice president, and incumbent executives, have been harmonized and developed together. Here, we review the activities of the KTA for 10 years from its establishment, and present the future direction of the KTA.

Application of the 2013 American College of Cardiology/American Heart Association Cholesterol Guideline to the Korean National Health and Nutrition Examination Surveys from 1998 to 2012

BACKGROUND: The 2013 American College of Cardiology/American Heart Association (ACC/AHA) guideline for the treatment of blood cholesterol recommends statin therapy for individuals at high risk of atherosclerotic cardiovascular disease (ASCVD). The aim of this study was to investigate serial trends in the percentages of Korean adults considered eligible for statin therapy according to the new ACC/AHA cholesterol guideline. METHODS: Data from the Korean National Health and Nutrition Examination Survey (KNHANES) I (1998, n=7,698), II (2001, n=5,654), III (2005, n=5,269), IV (2007 to 2009, n=15,727), and V (2010 to 2012, n=16,304), which used a stratified, multistage, probability sampling design, were used as representative of the entire Korean population. RESULTS: The percentage of adults eligible for statin therapy according to the ACC/AHA cholesterol guideline increased with time: 17.0%, 19.0%, 20.8%, 20.2%, and 22.0% in KNHANES I, II, III, IV, and V, respectively (P=0.022). The prevalence of ASCVD was 1.4% in KNHANES I and increased to 3.3% in KNHANES V. The percentage of diabetic patients aged 40 to 75 years with a low density lipoprotein cholesterol levels of 70 to 189 mg/dL increased from 4.8% in KNHANES I to 6.1% in KNHANES V. People with an estimated 10-year ASCVD risk ≥7.5% and aged 40 to 75 years accounted for the largest percentage among the four statin benefit groups: 9.1% in KNHANES I and 11.0% in KNHANES V. CONCLUSION: Application of the 2013 ACC/AHA guideline has found that the percentage of Korean adults in the statin benefit groups has increased over the past 15 years.

Enhancement of Osteogenic Differentiation by Combination Treatment with 5-azacytidine and Thyroid-Stimulating Hormone in Human Osteoblast Cells

BACKGROUND AND OBJECTIVES: The role of thyroid-stimulating hormone (TSH) signaling on osteoblastic differentiation is still undetermined. The aim of this study was to investigate the effects of 5-aza-2′-deoxycytidine (5-azacytidine) on TSH-mediated regulations of osteoblasts. MATERIALS AND METHODS: MG63, a human osteoblastic cell-line, was treated with 5-azacytidine before inducing osteogenic differentiation using osteogenic medium (OM) containing L-ascorbic acid and β-glyceophosphate. Bovine TSH or monoclonal TSH receptor stimulating antibody (TSAb) was treated. Quantitative real-time PCR analyses or measurement of alkaline phosphatase activities were performed for evaluating osteoblastic differentiation. RESULTS: Studies for osteogenic-related genes or alkaline phosphatase activity demonstrated that treatment of TSH or TSAb alone had no effects on osteoblastic differentiation in MG63 cells. However, treatment of 5-azacytidine, per se, significantly increased osteoblastic differentiation and combination treatment of 5-azacytidine and TSH or TSAb in the condition of OM showed further significant increase of osteoblastic differentiation. CONCLUSION: Stimulating TSH signaling has little effects on osteoblastic differentiation in vitro. However, in the condition of epigenetic modification using inhibitor of DNA methylation, TSH signaling positively affects osteoblastic differentiation in human osteoblasts.

Secular Trends for Diagnostic Motives and Environmental Risk Factors in Thyroid Cancer Using Questionnaire Survey

BACKGROUND AND OBJECTIVES: We analyzed the clinicopathologic differences of thyroid cancer by diagnosis periods, diagnostic motives, residence history and clinical risk factors in thyroid cancer patients. MATERIALS AND METHODS: Total 1599 thyroid cancer patients who answered the questionnaires about family history of thyroid cancer, residence history including duration of residence and location were enrolled from two hospitals, Seoul National University Hospital and National Cancer Center in Korea. Demographics and environmental information were collected via questionnaires and clinical data were reviewed via electronic medical records. RESULTS: More thyroid cancer has been diagnosed in 2011 to 2013 by screening test without specific symptom than before 1990. The size of cancer at diagnosis was significantly smaller and multifocal tumor was more frequently found in 2011 to 2013 than before 1990 as well. The tumors of obese or overweight patients tended to harbor extrathyroidal extension and lymph node metastasis than normal weight subjects with statistical significance. However, there were no differences in clinicopathologic characteristics according to residence and smoking history. CONCLUSION: In this study, there were some different clinicopathologic characteristics according to the diagnosis era, diagnostic motives, family history of thyroid cancer and body mass index.

Rare Manifestations of Anaplastic Thyroid Carcinoma: the Role of BRAF Mutation Analysis

Anaplastic thyroid carcinoma (ATC) is difficult to distinguish from other cancers, especially when its pathological features are atypical for ATC or when the tumor is totally undifferentiated and occurs after a considerable lapse of time, in an area remote from the original site of the tumor. Here, we present two patients (68-year-old man and 56-year-old woman) with rare manifestations of ATC, which were initially thought to be other malignancies. Immunohistochemical tests, using various markers, failed to provide information about the origin of these tumors. However, both patients had a history of papillary thyroid carcinoma (PTC) from several years ago and BRAF mutations were observed in the undifferentiated tumors, as well as in the previous PTCs. Therefore, we could make a diagnosis of ATC derived from PTC. As such, BRAF mutation analysis may serve as a useful tool for ATC diagnosis in challenging ATC cases.