Clinical Outcomes of Repeated Radioactive Iodine Therapy for Graves' Disease.

BACKGRUOUND: Radioactive iodine (RAI) therapy is a successful therapeutic modality for Graves' disease. However, RAI therapy can fail, and RAI therapy after antithyroid drugs (ATDs) has a lower remission rate. Therefore, many patients require repeated RAI therapy. This study investigated the clinical outcomes of repeated RAI therapy for Graves' disease. METHODS: Patients who underwent RAI therapy as second-line therapy after failure of ATD treatment between 2001 and 2015 were reviewed. Remission was defined as hypothyroid or euthyroid status without ATD, and with or without levothyroxine at 12 months after RAI therapy. RESULTS: The 1-year remission rate after 2nd RAI therapy (66%, 152/230) is significantly higher than that after 1st RAI therapy (48%, 393/815) or long-term ATD treatment after 1st RAI therapy failure (42%). The clinical response to 2nd RAI therapy was more rapid. The median time intervals from the 2nd RAI therapy to ATD discontinuation (1.3 months) and to the start of levothyroxine replacement (2.5 months) were significantly shorter than those for the 1st RAI therapy. A smaller goiter size, a longer time interval between the 1st and 2nd RAI therapies, and a longer ATD discontinuation period predicted remission after the 2nd RAI therapy. Finally, in 78 patients who failed the 2nd RAI therapy, the mean ATD dosage significantly reduced 5.1 mg over 12 months. CONCLUSION: Repeated RAI therapy can be a good therapeutic option, especially in patients with smaller goiters and those who are more responsive to the 1st RAI therapy.

Secular Trends in Ablation Therapy for Graves' Disease: An Analysis of a 15-Year Experience at a Tertiary Hospital in South Korea.

Ablation therapy, such as radioactive iodine (RAI) therapy or thyroidectomy, is generally used as the second-line treatment for Graves' disease (GD) in Asia. This study investigated changes in the clinical characteristics and outcomes of ablation therapies for GD over 15 years. Patients who underwent ablation therapy between 2001 and 2015 at a single tertiary hospital were included. Among the 10,991 GD patients treated over this 15-year period, 1357 (12.3%) underwent ablation therapy, and the most common reason was intractable GD. The proportion of patients who underwent any type of ablation therapy significantly decreased from 9.0% (2001-2005) to 7.7% (2011-2015). However, the proportion of patients who underwent surgery significantly increased from 1.1% (2001-2005) to 2.4% (2011-2015), and the proportion of patients who received ablation therapy due to suspected thyroid cancer increased from 5% to 13% over time. With a median follow-up duration of 6.2 years, remission was achieved in 86% and 98% of patients in the RAI and surgery groups, respectively, and these rates remained stable over time. In conclusion, although the proportion of patients who underwent ablation therapy for GD decreased during 15 years, the proportion of those who underwent surgery increased in association with the increased rate of suspected thyroid cancers.

Malignancy rate of Bethesda category III thyroid nodules according to ultrasound risk stratification system and cytological subtype.

The risk of malignancy is considered to be 10% to 30% for cases of thyroid nodules with atypia or follicular lesion of undetermined significance (AUS/FLUS). However, only a minority of patients with AUS/FLUS undergo surgery; therefore, the risk of malignancy might be overestimated due to selection bias. To overcome this problem, we categorized cases of thyroid nodules with AUS/FLUS using the ultrasound risk stratification system (US-RSS) to calculate the malignancy rate and identify the patients most suitable for surgical treatment.In this retrospective observational study, we subcategorized 382 pathologically confirmed thyroid nodules with AUS/FLUS using current US-RSSs (American Thyroid Association, Korean-Thyroid Imaging Report and Data System, American College of Radiology-Thyroid Imaging, Reporting and Data System, European Thyroid Imaging Report and Data System) and calculated the malignancy rate. Additionally, cases of nodules with AUS/FLUS were categorized according to their cytological subtypes, and the malignancy rate was calculated.Current US-RSSs showed good or moderate agreement among them. The overall malignancy rate for thyroid nodules with AUS/FLUS was 38.7%. On categorization of the nodules with AUS/FLUS, the malignancy rates were found to be 60% to 67.5% for the high suspicion category, 32.2-36.6% for the intermediate suspicion category, and 12.4% to 16.3% for the low suspicion category. The malignancy rate for nodules with cytologic atypia was significantly higher than that for nodules with architectural atypia, especially in the intermediate suspicion category.Categorization of thyroid nodules with AUS/FLUS using current US-RSSs helps to determine the optimal course of management of patients, especially when combined with cytological subtype characterization.

Effects of Pioglitazone on Nonalcoholic Fatty Liver Disease in the Absence of Constitutive Androstane Receptor Expression.

Nonalcoholic fatty liver disease or steatohepatitis (NAFLD/NASH) is a fatty liver disease that is closely related to obesity, diabetes, and dyslipidemia. Pioglitazone, which was developed as an antidiabetic drug, is known to improve NALFD. Pioglitazone is metabolized by multiple cytochrome P450 (CYP) enzymes, which are regulated by the xenobiotic receptor constitutive androstane receptor (CAR). In this study, we investigated the effects of pioglitazone on NAFLD by absence of CAR activity under high-fat (HF)-fed conditions. CAR-/- mice showed significant improvement in NALFD after 12 weeks of pioglitazone treatment compared to wild-type mice. This improvement in NAFLD persisted in CAR-/- mice regardless of blood pioglitazone concentration. The expression of lipogenesis genes in the liver, sterol-regulatory element binding protein-1c (SREBP-1c), and stearoyl-CoA desaturase (SCD)-1 was decreased after pioglitazone treatment in HF-fed CAR-/- mice. In addition, the expression of peroxisome proliferator-activated receptor gamma 2 (PPARγ2) was decreased by pioglitazone in HF-fed CAR-/- mice. Changes in SREBP-1c and PPAR γ2 remained constant over short-term (6 h) pioglitazone and lipid injection. Our results showed that NAFLD was improved significantly by pioglitazone in a CAR deletion state. These results might be valuable because they suggest that interaction with CAR and pioglitazone/PPARγ2 may be important in regulating gene expression associated with NAFLD.

Thyrocyte-specific deletion of insulin and IGF-1 receptors induces papillary thyroid carcinoma-like lesions through EGFR pathway activation.

Insulin and insulin-like growth factor (IGF)-1 signaling in the thyroid are thought to be permissive for the coordinated regulation by thyroid-stimulating hormone (TSH) of thyrocyte proliferation and hormone production. However, the integrated role of insulin receptor (IR) and IGF-1 receptor (IGF-1R) in thyroid development and function has not been explored. Here, we generated thyrocyte-specific IR and IGF-1R double knockout (DTIRKO) mice to precisely evaluate the coordinated functions of these receptors in the thyroid of neonates and adults. Neonatal DTIRKO mice displayed smaller thyroids, paralleling defective folliculogenesis associated with repression of the thyroid-specific transcription factor Foxe1. By contrast, at postnatal day 14, absence of IR and IGF-1R paradoxically induced thyrocyte proliferation, which was mediated by mTOR-dependent signaling pathways. Furthermore, we found elevated production of TSH during the development of follicular hyperplasia at 8 weeks of age. By 50 weeks, all DTIRKO mice developed papillary thyroid carcinoma (PTC)-like lesions that correlated with induction of the ErbB pathway. Taken together, these data define a critical role for IR and IGF-1R in neonatal thyroid folliculogenesis. They also reveal an important reciprocal relationship between IR/IGF-1R and TSH/ErbB signaling in the pathogenesis of thyroid follicular hyperplasia and, possibly, of papillary carcinoma.

Genotypic characteristics and their association with phenotypic characteristics of hereditary medullary thyroid carcinoma in Korea.

BACKGROUND: Hereditary medullary thyroid carcinoma can present as a part of multiple endocrine neoplasia syndrome by rearranged during transfection gene mutation. We evaluated the prevalence of rearranged during transfection gene mutation in patients who have medullary thyroid carcinoma and the correlations of genotype with medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism according to the revised American Thyroid Association risk level. METHODS: A total of 331 patients were diagnosed with medullary thyroid carcinoma, 172 of whom were tested for the rearranged during transfection germline mutation by sequencing of exon 8, 10, 11, and 13-16. These patients were diagnosed during the years 1982-2012 at 2 Korean tertiary hospitals. Patients were analyzed according to the route of diagnosis (screened versus index cases) or the mutational site of rearranged during transfection gene (the American Thyroid Association risk group). RESULTS: Rearranged during transfection mutation was found in 23.8% of patients tested, showing a decreasing trend with time. The most commonly mutated codon was codon 634 (37.1%), followed by codon 918 (14.3%). rearranged during transfection-positive patients were younger than rearranged during transfection-negative patients, although no other clinicopathologic characteristics differed. Screened cases were younger and had smaller tumors than index cases. Among rearranged during transfection-positive patients, pheochromocytoma manifested in 35.1% and hyperparathyroidism in 7.0%. Notably, pheochromocytoma and hyperparathyroidism emerged at any time after the diagnosis of medullary thyroid carcinoma. The American Thyroid Association risk-group analysis demonstrated that medullary thyroid carcinoma patients in the highest risk group were younger, had larger tumors, and higher disease-specific mortality. Similar results for pheochromocytoma were found, according to the American Thyroid Association risk group, although the results were not significant. CONCLUSIONS: Korean patients who have medullary thyroid carcinoma showed a similar distribution of rearranged during transfection gene mutation with those in Western countries. The American Thyroid Association risk classification was shown to be useful for pheochromocytoma, as well as for medullary thyroid carcinoma. Familial screening for rearranged during transfection mutation and lifelong monitoring for associated pheochromocytoma should be emphasized in hereditary medullary thyroid carcinoma.

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.

Validation of Three Scoring Risk-Stratification Models for Thyroid Nodules.

BACKGROUND: To minimize potential harm from overuse of fine-needle aspiration, Thyroid Imaging Reporting and Data Systems (TIRADSs) were developed for thyroid nodule risk stratification. The purpose of this study was to perform validation of three scoring risk-stratification models for thyroid nodules using ultrasonography features, a web-based malignancy risk-stratification system, and a model developed by the Korean Society of Thyroid Radiology and the American College of Radiology. METHODS: Using ultrasonography images, radiologists assessed thyroid nodules according to the following criteria: internal content, echogenicity of the solid portion, shape, margin, and calcifications. A total of 954 patients (Mage = 50.8 years; range 13-86 years) with 1112 nodules were evaluated at the authors' institute from January 2013 to December 2014. The discrimination ability of the three models was assessed by estimating the area under the receiver operating characteristic curve. Additionally, Hosmer-Lemeshow goodness-of-fit statistics (calibration ability) were used to evaluate the agreement between the observed and expected number of nodules that were benign or malignant. RESULTS: Thyroid malignancy was present in 37.2% (414/1112) of nodules. According to the 14-point web-based scoring risk-stratification system, malignancy risk ranged from 4.5% to 100.0% and was positively associated with an increase in risk scores. The areas under the receiver operating characteristic curve of the validation set were 0.884 in the web-based model, 0.891 in the Korean Society of Thyroid Radiology model, and 0.875 in the American College of Radiology model. The Hosmer-Lemeshow goodness-of-fit test indicated that the web-based scoring system showed the best-calibrated result, with a p-value of 0.078. CONCLUSION: The three scoring risk-stratification models using the ultrasonography features of thyroid nodules to stratify malignancy risk showed acceptable predictive accuracy and similar areas under the curve. The web-based scoring system demonstrated the strongest agreement in calibration ability analysis. The easily accessible automated web-based scoring risk-stratification system may overcome the complexity of the various Thyroid Imaging Reporting and Data System guidelines and provide simplified guidance on personalized and optimal management in real practice.

Association between thyroid function and lipid profiles, apolipoproteins, and high-density lipoprotein function.

BACKGROUND: Thyroid hormone regulates lipid metabolism. In particular, it has been reported to regulate plasma high-density lipoprotein cholesterol (HDL-C) levels and the activity of molecules involved in HDL metabolism. OBJECTIVE: We investigated changes in the concentrations of lipids and apolipoproteins and in the function of HDL according to acute dynamic changes in thyroid function. METHODS: Concentrations of plasma lipids and apolipoproteins, paraoxonase-1 activity, and cholesterol efflux were measured in 27 patients with differentiated thyroid carcinoma who underwent total thyroidectomy and radioactive iodine (RAI) treatment, at 3 distinct times: After surgery (baseline subclinical hyperthyroid state), on the day of undergoing RAI treatment (overt hypothyroid state), and 3 months post-RAI treatment (subclinical hyperthyroid state). RESULTS: The mean free T4 and thyroid-stimulating hormone concentrations were 0.24 ± 0.06 ng/dL and 91.2 (77.8-118.2) µIU/mL, respectively, on the day of RAI treatment. Total cholesterol, triglyceride, low-density lipoprotein cholesterol, and apoB levels, and the apoA-I/II ratio were significantly increased in the overt hypothyroid state and recovered to baseline values with levothyroxine replacement. HDL-C and apoE levels were persistently elevated despite levothyroxine replacement. Paraoxonase-1 activity, corrected for apoA-I, decreased in the overt hypothyroid state but recovered with levothyroxine replacement (P = .009). Cholesterol efflux also decreased significantly in the overt hypothyroid state (21.5 ± 5.1% vs 18.9 ± 2.9%, P = .005), but remained low despite recovery of thyroid function. CONCLUSION: Changes in thyroid function are associated not only with changes in the concentrations of various plasma lipid components but also with changes in HDL function.

Changes in the clinicopathological characteristics and genetic alterations of follicular thyroid cancer.

OBJECTIVE: Changes in the clinicopathological characteristics and genetic alterations of follicular thyroid cancer (FTC) over time have not been reported. Moreover, the prognostic effects of RAS and TERT promoter mutations in FTC have not been clearly elucidated. We investigated changes in the clinicopathological characteristics of patients with FTC over four decades, as well as the clinical significance of genetic mutations of FTC. DESIGN AND METHODS: This retrospective study included 690 patients with FTC who underwent thyroidectomy between 1973 and 2015 at the Seoul National University Hospital. In 134 samples, genetic tests for N/H/KRAS and TERT promoter mutations and PAX8/PPARγ rearrangement were performed. RESULTS: The age at diagnosis has increased (P < 0.001) in recent decades and extrathyroidal extension of the tumor has become less common (P = 0.033). Other clinicopathological characteristics and prognosis of FTC have not significantly changed. The prevalence of RAS mutations decreased (P = 0.042) over time, whereas that of TERT promoter mutations remained stable. RAS mutations were associated with distant metastasis and persistent disease, and TERT promoter mutations were associated with distant metastasis, advanced TNM stage, recurrence and disease-specific mortality. FTC patients with coexistent RAS and TERT promoter mutations showed a higher recurrence risk than those with only one mutation. CONCLUSIONS: The age at diagnosis of FTC and the frequency of extrathyroidal extension have changed over four decades. Moreover, the prevalence of RAS mutations decreased. RAS and TERT promoter mutations may be associated with poor clinical outcomes in FTC, especially when the two mutations coexist.

Serum 25-hydroxyvitamin D might be an independent prognostic factor for Graves disease recurrence.

Graves disease is the most common cause of thyrotoxicosis. Although medical intervention with antithyroid drugs (ATDs) is commonly the first choice of treatment in Korea, the remission rate associated with this approach is not satisfactory. During ATD therapy, low or undetectable serum levels of thyroid-stimulating hormone (TSH) receptor antibodies (TRAbs) have been reported to affect the incidence of Graves disease remission. This study evaluated the correlation between serum 25-hydroxyvitamin D levels and TRAb levels, as well as the effect of 25-hydroxyvitamin D on the recurrence of Graves disease.A total of 143 patients, who were diagnosed with Graves disease and treated with ATDs, were retrospectively included in our observational study. These patients were followed for more than 1 year after ATD discontinuation. The levels of serum 25-hydroxyvitamin D and TRAb (ie, thyroid-stimulating antibody [TSAb], as detected by bioassay, and TSH-binding inhibitory immunoglobulins [TBIIs]) were measured, and a thyroid function test was performed upon ATD discontinuation. Recurrence was evaluated every 3 months, and was defined as an occurrence of overt thyrotoxicosis during the follow-up period.A total of 95 patients (66.4%) experienced recurrence with a median latency period of 182 days (ranging 28-1219 days). The serum 25-hydroxyvitamin D levels at the time of ATD discontinuation were not correlated with either TBII or TSAb. In the Cox proportional hazard regression analysis, higher free T4 levels (>1.4 ng/dL; hazard ratio [HR], 3.252; 95% confidence interval [CI], 1.022-10.347) and low levels of 25-hydroxyvitamin D (≤14.23 ng/mL) were associated with a higher probability of Graves disease recurrence (HR, 3.016; 95% CI, 1.163-7.819).Lower serum 25-hydroxyvitamin D levels were associated with a higher incidence of Graves disease recurrence. Therefore, serum 25-hydroxyvitamin D might be an independent risk factor for predicting Graves disease recurrence after ATD discontinuation.

Radiofrequency ablation of low-risk small papillary thyroidcarcinoma: preliminary results for patients ineligible for surgery.

PURPOSE: The purpose of this study is to retrospectively evaluate the outcomes of radiofrequency ablation (RFA) of low-risk small papillary thyroid carcinomas (PTCs) in patients who were ineligible for surgery. MATERIALS AND METHODS: Between 2005 and 2009, six PTCs (mean diameter, 0.92 cm; range, 0.6-1.3 cm) in six patients were treated with RFA by three radiologists in two hospitals. The inclusion criteria for this study were (1) pathologically confirmed PTC without cytological aggressiveness, (2) single PTC without extrathyroidal extension, (3) no metastatic tumours and (4) ineligibility for surgery. RFA was performed using a radiofrequency generator and an 18-gauge internally cooled electrode. The medical records were reviewed and analysed, focussing on the procedural profiles of RFA, symptoms and complications during and after RFA, and changes in tumours on follow-up ultrasonography. RESULTS: Before and after RFA, the results of thyroid function tests were normal in all patients. During 48.5 ± 12.3 months (range, 36-65 months) of follow-up, along with a significant reduction in the mean volume (98.5 ± 3.3%), four ablation zones (4/6, 66.7%) completely disappeared. Two ablation zones exhibited only small calcified residues with nearly complete disappearance of the corresponding non-calcified solid portions, and in one of them, malignant cells were absent as assessed by fine-needle aspiration and core-needle biopsy. Transient hypertension with mild headache (n = 1) and mild neck pain (n = 1) developed during the procedure and subsided without any treatment. CONCLUSION: Besides surgery and active surveillance, which are conflicting currently used management plans, RFA might represent an effective and a safe alternative for managing low-risk small PTCs, especially in patients ineligible for surgery.

The Second Antithyroid Drug Treatment Is Effective in Relapsed Graves' Disease Patients: A Median 11-Year Follow-Up Study.

BACKGROUND: Antithyroid drug (ATD) is a widely used treatment for Graves' disease (GD). However, its long-term efficiency remains unclear. This study investigated the long-term disease prognosis and predictive factors for relapse in ATD-treated GD patients. METHODS: Newly diagnosed, ATD-treated GD patients with at least four years of follow-up were recruited (n = 187). Remission was defined as maintaining a euthyroid status for more than one year after ATD withdrawal. RESULTS: During 11.1 years (range 4.0-23.7 years) of median follow-up, overall, 51.9% of the newly diagnosed ATD-treated GD patients achieved remission, 32.1% continued ATD treatment, and 13.4% underwent other ablation treatments. The 10-year remission rates were higher in the first (34.2%) and second (25.5%) ATD courses than in any of the other subsequent ATD courses, and decreased as ATD treatments were repeated. The 10-year relapse rate was the highest after the third ATD treatment (71.4%) compared with that after the first (60.5%) and second (58.3%) courses. Longer duration of ATD treatment (odds ratio [OR] = 1.4 [confidence interval (CI) 1.2-1.7], p < 0.001), higher number of relapses (OR = 4.7 [CI 2.3-9.8], p < 0.001), and moderate to severe Graves' ophthalmopathy (OR = 4.1 [CI 1.1-15.2], p = 0.032) were associated with persistent disease status. CONCLUSIONS: A second course of ATD can be considered for GD patients after the first relapse because the chance of remission and the relapse rate are similar to the one after the first ATD treatment course. For GD patients with more than two relapses, or with an ATD treatment duration of more than four to five years, low-dose maintenance of ATD or ablative treatment needs to be considered.

Clinical factors affecting intraocular pressure change after orbital decompression surgery in thyroid-associated ophthalmopathy.

OBJECTIVE: To report the physiological monitoring of intraocular pressure (IOP) during the postoperative periods after orbital decompression surgery and ascertain the correlation between the clinical factors and IOP changes. METHODS: The medical records of 113 orbits from 60 patients who underwent orbital decompression surgery were reviewed retrospectively. IOP measurement during the postoperative periods was classified based on the postoperative day: week 1 (1-7 days), month 1 (8-41 days), month 2 (42-70 days), month 3 (71-97 days), month 4 (98-126 days), and final (after 127 days). The mean postoperative follow-up was 286.5 days for orbits with at least 6 months of follow-up. Univariate and multivariate linear regression analyses were performed to assess the correlation between the IOP reduction percentage and clinical factors. RESULTS: The mean IOP increased from 16.9 to 18.6 mmHg (10.1%) at postoperative week 1 and decreased to 14.4 mmHg (14.5%) after 2 months. Minimal little changes were observed postoperatively in the IOP after 2 months. Preoperative IOP had a significant positive effect on the reduction percentage both at postoperative week 1 (ß=2.51, P=0.001) and after 2 months (ß=1.07, P=0.029), and the spherical equivalent showed a positive correlation with the reduction level at postoperative week 1 (ß=1.71, P=0.021). CONCLUSION: Surgical decompression caused a significant reduction in the IOP in thyroid-associated orbitopathy, and the amount of reduction was closely related to preoperative IOP; however, it may also cause a transient elevation in the IOP during the early postoperative phase in highly myopic eyes.

Serum 25-Hydroxyvitamin D Level Does Not Affect the Aggressiveness and Prognosis of Papillary Thyroid Cancer.

BACKGROUND: Vitamin D deficiency has been known to be associated with the aggressiveness and prognosis of several cancers. This study evaluated the effect of preoperative serum vitamin D levels on the aggressiveness and prognosis of papillary thyroid cancer (PTC). METHODS: In total, 820 patients with PTC were enrolled. 25-hydroxyvitamin D levels were measured in blood samples before surgery. Clinical, pathologic, and recurrence data were accessed to examine the prognostic effects of vitamin D. Patients were categorized into four quartiles by preoperative serum vitamin D levels. RESULTS: Of the enrolled patients, 795 (97%) had insufficient vitamin D levels (<30 ng/mL). Vitamin D levels showed positive correlations with age and body mass index (BMI), and negative correlations with serum thyrotropin levels and antithyroid peroxidase antibody titers. The association between vitamin D quartile and the risks of extrathyroidal invasion, lymph node metastasis, advanced cancer stages (III or IV), and risk of recurrence were not significant after adjusting for age, sex, BMI, preoperative ionized calcium, and parathyroid hormone. Additionally, serum vitamin D was not associated with recurrent or persistent PTC. CONCLUSION: Serum vitamin D levels are not associated with either disease aggressiveness or poor outcomes among patients with PTC and vitamin D insufficiency.

Postoperative biochemical remission of serum calcitonin is the best predictive factor for recurrence-free survival of medullary thyroid cancer: a large-scale retrospective analysis over 30 years.

CONTEXT: The increase in thyroid screening in the general population may lead to earlier detection of medullary thyroid carcinoma (MTC). OBJECTIVE: We aimed to evaluate secular trends in clinicopathological characteristics and long-term prognosis of MTC and its prognostic factors. DESIGN: This was a retrospective analysis from 1982 to 2012. PATIENTS: Three hundred and thirty-one patients with MTC were included and grouped based on the year of diagnosis (1982-2000, 2001-2005, 2006-2010 and 2011-2012). MEASUREMENTS: These included recurrence and mortality as well as biochemical remission (BCR) of serum calcitonin. RESULTS: Mean tumour size (from 2·5 cm to 1·7 cm, P < 0·001) and percentage of extrathyroidal extension (from 52·0% to 26·0%, P = 0·026) decreased. The percentage of patients achieving BCR within six postoperative months (po-BCR) increased with time (from 39·6% to 76·1%, P < 0·001). The 5-year overall recurrence rate significantly decreased in 2006-2012 compared to 1982-2005 (10% vs 18%, respectively, P = 0·031), although the 5-year survival rate did not improve (92% vs 92%, P = 0·929). Failure to achieve po-BCR was the strongest predictive factor associated with recurrence (hazard ratio [HR] = 58·04, 95% CI 7·14-472·11; P < 0·001). Male gender (HR = 3·18, 95% CI 1·18-8·56; P = 0·022), tumour size >2 cm (HR = 18·33, 95% CI 2·35-143·06; P = 0·006) and distant metastasis (HR = 4·00, 95% CI 1·31-12·21; P = 0·015) were significant prognostic factors for mortality. CONCLUSIONS: Clinicopathological characteristics and recurrence of MTC improved with time. Po-BCR was the best predictive factor for recurrence-free survival.

The Presence of Thyroid-Stimulation Blocking Antibody Prevents High Bone Turnover in Untreated Premenopausal Patients with Graves' Disease.

Osteoporosis-related fractures are one of the complications of Graves' disease. This study hypothesized that the different actions of thyroid-stimulating hormone receptor (TSHR) antibodies, both stimulating and blocking activities in Graves' disease patients might oppositely impact bone turnover. Newly diagnosed premenopausal Graves' disease patients were enrolled (n = 93) and divided into two groups: patients with TSHR antibodies with thyroid-stimulating activity (stimulating activity group, n = 83) and patients with TSHR antibodies with thyroid-stimulating activity combined with blocking activity (blocking activity group, n = 10). From the stimulating activity group, patients who had matched values for free T4 and TSH binding inhibitor immunoglobulin (TBII) to the blocking activity group were further classified as stimulating activity-matched control (n = 11). Bone turnover markers BS-ALP, Osteocalcin, and C-telopeptide were significantly lower in the blocking activity group than in the stimulating activity or stimulating activity-matched control groups. The TBII level showed positive correlations with BS-ALP and osteocalcin levels in the stimulating activity group, while it had a negative correlation with the osteocalcin level in the blocking activity group. In conclusion, the activation of TSHR antibody-activated TSH signaling contributes to high bone turnover, independent of the actions of thyroid hormone, and thyroid-stimulation blocking antibody has protective effects against bone metabolism in Graves' disease.

A Possible Association Between Thyroid Cancer and Breast Cancer.

BACKGROUND: Several lines of evidence suggest that breast cancer (BC) and thyroid cancer (TC) occur together in the same female patients more frequently than would be expected by chance. This study investigated the prevalence and clinicopathological characteristics of second primary BC in TC patients and second primary TC in BC patients. METHODS: A retrospective case-controlled study was performed in 4243 patients with differentiated TC and 6833 patients with BC. Age-matched control groups without second malignancies were selected. RESULTS: Of the 4243 patients with TC, 55 patients developed subsequent BC during a five-year follow-up (range 2-40 years); the standardized incidence ratio (SIR) was 2.45 [confidence interval (CI) 1.83-2.96]. Among the 6833 patients with BC, 81 patients developed subsequent TC during a 6.2-year follow-up (range 2-40 years); the SIR was 2.18 [CI 1.43-2.82]. Subsequent second BC or TC diagnosed within five years of the initial primary malignancy showed more clinical characteristics consistent with early-stage cancer than did control BC or TC patients. Notably, the expression of both the estrogen and progesterone receptors was significantly higher in the tissues of BC patients with coexisting TC compared with those with BC alone. CONCLUSIONS: The overall risk of second primary TC or BC is increased in patients with prior BC or TC, respectively. The early detection of second cancer might have contributed to these findings. However, BC that coexisted with TC had a higher expression of hormone receptors, suggesting an association between the molecular pathogenesis of TC and BC.

Radioactive Iodine Therapy Did Not Significantly Increase the Incidence and Recurrence of Subsequent Breast Cancer.

CONTEXT: Previous studies on the extent to which radioactive iodine (RAI) therapy for thyroid cancer increases the risk of subsequently developing breast cancer have given conflicting results. OBJECTIVE: This study aimed to evaluate the effect of RAI treatment on breast cancer development and recurrence among female patients with primary thyroid cancer. DESIGN: This was a retrospective cohort study. The risk of subsequent breast cancer associated with RAI and its dose in hazard ratios (HRs) with 95% confidential intervals (CIs) were calculated using time-dependent Cox proportional hazard models. PATIENTS: A total of 6150 patients with thyroid cancer enrolled between 1973 and 2009 were followed until December 2012. Of these, 3631 (59.0%) received RAI therapy. During the follow-up period, 99 primary breast cancers were diagnosed. MAIN OUTCOME MEASURE: Risk of breast cancer development according to RAI therapy and RAI dose during treatment for primary thyroid cancer. RESULTS: RAI therapy did not significantly increase the incidence of subsequent breast cancer among female patients (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.22-1.06) when a 2-year latency period was accounted for. High-dose RAI (≥120 mCi) was associated with a reduced incidence of subsequent breast cancer (HR, 0.17; 95% CI, 0.05-0.62) in the cohort with a 2-year latency period. CONCLUSIONS: The long-term follow-up results of this study suggest that RAI treatment for patients with thyroid cancer may not increase the risk or recurrence of breast cancer.

Efficacy and Safety of Radiofrequency Ablation for Treatment of Locally Recurrent Thyroid Cancers Smaller than 2 cm.

PURPOSE: To evaluate the efficacy and safety of radiofrequency ablation (RFA) for localized small recurrent thyroid cancers less than 2 cm by comparing them with those at repeat surgery. MATERIALS AND METHODS: This retrospective study was institutional review board-approved, and informed consent was waived. From December 2008 to December 2011, this study evaluated 73 patients (17 men and 56 women; age, 50.3 years ± 13.6) with recurrent thyroid cancer who had been treated with RFA (n = 27) or repeat surgery (n = 46) who met the following criteria: (a) three or fewer recurrences or lesions with high probability of recurrence at ultrasonography; (b) no tumor other than the target tumors; and (c) at least 1 year of follow-up. RFA was recommended and performed in cases of surgical ineligibility, such as patient refusal and poor medical condition. Recurrence-free survival rates and posttreatment complication rates (eg, hoarseness and hypocalcemia) were compared between RFA and reoperation groups after adjustment with weighted analysis by using inverse probability of treatment weights. RESULTS: After this adjustment, the 1- and 3-year recurrence-free survival rates were comparable (P = .681) for RFA (96.0% and 92.6%, respectively) and reoperation (92.2% and 92.2%, respectively) groups. The posttreatment hoarseness rate did not differ between the RFA (7.3% [1.8 of 24]) and reoperation (9.0% [3.6 of 39.5]) groups (P = .812), and posttreatment hypocalcemia occurred exclusively in the reoperation group (11.6% [4.6 of 39.5]) but not in the RFA group (0% [0 of 24]) (P = .083). CONCLUSION: RFA may be an effective and safe alternative to repeat surgery in patients with locally recurrent small thyroid cancers.