Real-time ultrasound elastography in the diagnosis of newly identified thyroid nodules in adults: the ElaTION RCT.

Background: Strain and shear wave elastography which is commonly used with concurrent real-time imaging known as real-time ultrasound shear/strain wave elastography is a new diagnostic technique that has been reported to be useful in the diagnosis of nodules in several organs. There is conflicting evidence regarding its benefit over ultrasound-guided fine-needle aspiration cytology alone in thyroid nodules. Objectives: To determine if ultrasound strain and shear wave elastography in conjunction with fine-needle aspiration cytology will reduce the number of patients who have a non-diagnostic first fine-needle aspiration cytology results as compared to conventional ultrasound-only guided fine-needle aspiration cytology. Design: A pragmatic, unblinded, multicentre randomised controlled trial. Setting: Eighteen centres with a radiology department across England. Participants: Adults who had not undergone previous fine-needle aspiration cytology with single or multiple nodules undergoing investigation. Interventions: Ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology (intervention arm) - strain or shear wave elastography-guided fine-needle aspiration cytology. Ultrasound-only guided fine-needle aspiration cytology (control arm) - routine ultrasound-only guided fine-needle aspiration cytology (the current standard recommended by the British Thyroid Association guidelines). Main outcome measure: The proportion of patients who have a non-diagnostic cytology (Thy 1) result following the first fine-needle aspiration cytology. Randomisation: Patients were randomised at a 1 : 1 ratio to the interventional or control arms. Results: A total of 982 participants (80% female) were randomised: 493 were randomised to ultrasound shear/strain wave elastography-ultrasound guided fine-needle aspiration cytology and 489 were randomised to ultrasound-only guided fine-needle aspiration cytology. There was no evidence of a difference between ultrasound shear/strain wave elastography and ultrasound in non-diagnostic cytology (Thy 1) rate following the first fine-needle aspiration cytology (19% vs. 16% respectively; risk difference: 0.030; 95% confidence interval -0.007 to 0.066; p = 0.11), the number of fine-needle aspiration cytologies needed (odds ratio: 1.10; 95% confidence interval 0.82 to 1.49; p = 0.53) or in the time to reach a definitive diagnosis (hazard ratio: 0.94; 95% confidence interval 0.81 to 1.10; p = 0.45). There was a small, non-significant reduction in the number of thyroid operations undertaken when ultrasound shear/strain wave elastography was used (37% vs. 40% respectively; risk difference: -0.02; 95% confidence interval -0.06 to 0.009; p = 0.15), but no difference in the number of operations yielding benign histology - 23% versus 24% respectively, p = 0.70 (i.e. no increase in identification of malignant cases) - or in the number of serious adverse events (2% vs. 1%). There was no difference in anxiety and depression, pain or quality of life between the two arms. Limitations: The study was not powered to detect differences in malignancy. Conclusions: Ultrasound shear/strain wave elastography does not appear to have additional benefit over ultrasound-guided fine-needle aspiration cytology in the diagnosis of thyroid nodules. Future work: The findings of the ElaTION trial suggest that further research into the use of shear wave elastography in the diagnostic setting of thyroid nodules is unlikely to be warranted unless there are improvements in the technology. The diagnostic difficulty in distinguishing between benign and malignant lesions still persists. Future studies might examine the role of genomic testing on fine-needle aspiration samples. There is growing use of targeted panels of molecular markers, particularly aimed at improving the diagnostic accuracy of indeterminate (i.e. Thy3) cytology results. The application of these tests is not uniform, and their cost effectiveness has not been assessed in large-scale trials. Study registration: This study is registered as ISRCTN (ISRCTN18261857). Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 12/19/04) and is published in full in Health Technology Assessment; Vol. 28, No. 46. See the NIHR Funding and Awards website for further award information.

About half the population will have lumps in their thyroid if examined by an ultrasound scan but may not know they have one. About one in twenty people will feel a thyroid lump in their neck at some time in their life, with about one in twenty of those being malignant. Currently, the recommended way of getting a diagnosis of thyroid nodules is by using ultrasound to guide a needle to get cells from the lump, called ultrasound-guided fine-needle aspiration cytology. These cells are examined to determine the cause of the lump. If there are enough cells, Doctors can then make a diagnosis of whether the lump is benign or malignant. If not, patients will undergo another ultrasound-guided fine-needle aspiration cytology. One in five ultrasound-guided fine-needle aspiration cytologies are non-diagnostic with an overall false-positive rate of approximately 24%. This means one in five patients, with benign disease, may undergo unnecessary diagnostic operations. Thyroid surgery carries risks of complications, which could be avoided if we had better ways to diagnose which patients actually need an operation. We conducted a randomised trial, ElaTION, to determine if a new technology called strain and shear wave elastography, commonly known as real-time elastography, would be better at helping the radiologist take a sufficient sample of cells and reduce the number of non-diagnostic results, reducing the number of fine-needle aspiration cytologies required to make a definitive diagnosis. Nine hundred eighty-two patients were recruited between 2015 and 2018 and followed up until the end of the trial. Patients were randomised into two groups: 489 patients received the standard ultrasound-guided fine-needle aspiration cytology alone, and 493 patients received ultrasound-guided fine-needle aspiration cytology + shear wave elastography. Ultrasound shear/strain wave elastography did not reduce non-diagnostic cytology at first fine-needle aspiration cytology or improve the likelihood of determining whether the lump is benign or malignant. The results of ElaTION do not support the use of shear wave elastography-fine-needle aspiration cytology in the diagnosis of thyroid nodules.

Risk Factors for Thyroid Dysfunction in Pregnancy: An Individual Participant Data Meta-Analysis.

Background: International guidelines recommend targeted screening to identify gestational thyroid dysfunction. However, currently used risk factors have questionable discriminative ability. We quantified the risk for thyroid function test abnormalities for a subset of risk factors currently used in international guidelines. Methods: We included prospective cohort studies with data on gestational maternal thyroid function and potential risk factors (maternal age, body mass index [BMI], parity, smoking status, pregnancy through in vitro fertilization, twin pregnancy, gestational age, maternal education, and thyroid peroxidase antibody [TPOAb] or thyroglobulin antibody [TgAb] positivity). Exclusion criteria were pre-existing thyroid disease and use of thyroid interfering medication. We analyzed individual participant data using mixed-effects regression models. Primary outcomes were overt and subclinical hypothyroidism and a treatment indication (defined as overt hypothyroidism, subclinical hypothyroidism with thyrotropin >10 mU/L, or subclinical hypothyroidism with TPOAb positivity). Results: The study population comprised 65,559 participants in 25 cohorts. The screening rate in cohorts using risk factors currently recommended (age >30 years, parity ≥2, BMI ≥40) was 58%, with a detection rate for overt and subclinical hypothyroidism of 59%. The absolute risk for overt or subclinical hypothyroidism varied <2% over the full range of age and BMI and for any parity. Receiver operating characteristic curves, fitted using maternal age, BMI, smoking status, parity, and gestational age at blood sampling as explanatory variables, yielded areas under the curve ranging from 0.58 to 0.63 for the primary outcomes. TPOAbs/TgAbs positivity was associated with overt hypothyroidism (approximate risk for antibody negativity 0.1%, isolated TgAb positivity 2.4%, isolated TPOAb positivity 3.8%, combined antibody positivity 7.0%; p < 0.001), subclinical hypothyroidism (risk for antibody negativity 2.2%, isolated TgAb positivity 8.1%, isolated TPOAb positivity 14.2%, combined antibody positivity 20.0%; p < 0.001) and a treatment indication (risk for antibody negativity 0.2%, isolated TgAb positivity 2.2%, isolated TPOAb positivity 3.0%, and combined antibody positivity 5.1%; p < 0.001). Twin pregnancy was associated with a higher risk of overt hyperthyroidism (5.6% vs. 0.7%; p < 0.001). Conclusions: The risk factors assessed in this study had poor predictive ability for detecting thyroid function test abnormalities, questioning their clinical usability for targeted screening. As expected, TPOAb positivity (used as a benchmark) was a relevant risk factor for (subclinical) hypothyroidism. These results provide insights into different risk factors for gestational thyroid dysfunction.

Combined Vorinostat and Chloroquine Inhibit Sodium-Iodide Symporter Endocytosis and Enhance Radionuclide Uptake In Vivo.

PURPOSE: Patients with aggressive thyroid cancer are frequently failed by the central therapy of ablative radioiodide (RAI) uptake, due to reduced plasma membrane (PM) localization of the sodium/iodide symporter (NIS). We aimed to understand how NIS is endocytosed away from the PM of human thyroid cancer cells, and whether this was druggable in vivo. EXPERIMENTAL DESIGN: Informed by analysis of endocytic gene expression in patients with aggressive thyroid cancer, we used mutagenesis, NanoBiT interaction assays, cell surface biotinylation assays, RAI uptake, and NanoBRET to understand the mechanisms of NIS endocytosis in transformed cell lines and patient-derived human primary thyroid cells. Systemic drug responses were monitored via 99mTc pertechnetate gamma counting and gene expression in BALB/c mice. RESULTS: We identified an acidic dipeptide within the NIS C-terminus that mediates binding to the σ2 subunit of the Adaptor Protein 2 (AP2) heterotetramer. We discovered that the FDA-approved drug chloroquine (CQ) modulates NIS accumulation at the PM in a functional manner that is AP2 dependent. In vivo, CQ treatment of BALB/c mice significantly enhanced thyroidal uptake of 99mTc pertechnetate in combination with the histone deacetylase (HDAC) inhibitor vorinostat/SAHA, accompanied by increased thyroidal NIS mRNA. Bioinformatic analyses validated the clinical relevance of AP2 genes with disease-free survival in RAI-treated DTC, enabling construction of an AP2 gene-related risk score classifier for predicting recurrence. CONCLUSIONS: NIS internalization is specifically druggable in vivo. Our data, therefore, provide new translatable potential for improving RAI therapy using FDA-approved drugs in patients with aggressive thyroid cancer. See related commentary by Lechner and Brent, p. 1220.

The optimal healthy ranges of thyroid function defined by the risk of cardiovascular disease and mortality: systematic review and individual participant data meta-analysis.

BACKGROUND: Reference intervals of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) are statistically defined by the 2·5-97·5th percentiles, without accounting for potential risk of clinical outcomes. We aimed to define the optimal healthy ranges of TSH and FT4 based on the risk of cardiovascular disease and mortality. METHODS: This systematic review and individual participant data (IPD) meta-analysis identified eligible prospective cohorts through the Thyroid Studies Collaboration, supplemented with a systematic search via Embase, MEDLINE (Ovid), Web of science, the Cochrane Central Register of Controlled Trials, and Google Scholar from Jan 1, 2011, to Feb 12, 2017 with an updated search to Oct 13, 2022 (cohorts found in the second search were not included in the IPD). We included cohorts that collected TSH or FT4, and cardiovascular outcomes or mortality for adults (aged ≥18 years). We excluded cohorts that included solely pregnant women, individuals with overt thyroid diseases, and individuals with cardiovascular disease. We contacted the study investigators of eligible cohorts to provide IPD on demographics, TSH, FT4, thyroid peroxidase antibodies, history of cardiovascular disease and risk factors, medication use, cardiovascular disease events, cardiovascular disease mortality, and all-cause mortality. The primary outcome was a composite outcome including cardiovascular disease events (coronary heart disease, stroke, and heart failure) and all-cause mortality. Secondary outcomes were the separate assessment of cardiovascular disease events, all-cause mortality, and cardiovascular disease mortality. We performed one-step (cohort-stratified Cox models) and two-step (random-effects models) meta-analyses adjusting for age, sex, smoking, systolic blood pressure, diabetes, and total cholesterol. The study was registered with PROSPERO, CRD42017057576. FINDINGS: We identified 3935 studies, of which 53 cohorts fulfilled the inclusion criteria and 26 cohorts agreed to participate. We included IPD on 134 346 participants with a median age of 59 years (range 18-106) at baseline. There was a J-shaped association of FT4 with the composite outcome and secondary outcomes, with the 20th (median 13·5 pmol/L [IQR 11·2-13·9]) to 40th percentiles (median 14·8 pmol/L [12·3-15·0]) conveying the lowest risk. Compared with the 20-40th percentiles, the age-adjusted and sex-adjusted hazard ratio (HR) for FT4 in the 80-100th percentiles was 1·20 (95% CI 1·11-1·31) for the composite outcome, 1·34 (1·20-1·49) for all-cause mortality, 1·57 (1·31-1·89) for cardiovascular disease mortality, and 1·22 (1·11-1·33) for cardiovascular disease events. In individuals aged 70 years and older, the 10-year absolute risk of composite outcome increased over 5% for women with FT4 greater than the 85th percentile (median 17·6 pmol/L [IQR 15·0-18·3]), and men with FT4 greater than the 75th percentile (16·7 pmol/L [14·0-17·4]). Non-linear associations were identified for TSH, with the 60th (median 1·90 mIU/L [IQR 1·68-2·25]) to 80th percentiles (2·90 mIU/L [2·41-3·32]) associated with the lowest risk of cardiovascular disease and mortality. Compared with the 60-80th percentiles, the age-adjusted and sex-adjusted HR of TSH in the 0-20th percentiles was 1·07 (95% CI 1·02-1·12) for the composite outcome, 1·09 (1·05-1·14) for all-cause mortality, and 1·07 (0·99-1·16) for cardiovascular disease mortality. INTERPRETATION: There was a J-shaped association of FT4 with cardiovascular disease and mortality. Low concentrations of TSH were associated with a higher risk of all-cause mortality and cardiovascular disease mortality. The 20-40th percentiles of FT4 and the 60-80th percentiles of TSH could represent the optimal healthy ranges of thyroid function based on the risk of cardiovascular disease and mortality, with more than 5% increase of 10-year composite risk identified for FT4 greater than the 85th percentile in women and men older than 70 years. We propose a feasible approach to establish the optimal healthy ranges of thyroid function, allowing for better identification of individuals with a higher risk of thyroid-related outcomes. FUNDING: None.

Consensus statement on the management of incidentally discovered FDG avid thyroid nodules in patients being investigated for other cancers.

With the widespread use of 18F-fluorodeoxyglucose positron emission tomography (FDG PET/CT) in the investigation and staging of cancers, incidental discovery of FDG-avid thyroid nodules is becoming increasingly common, with a reported incidence in the range 1%-4% of FDG PET/CT scans. The risk of malignancy in an incidentally discovered FDG avid thyroid nodule is not clear due to selection bias in reported retrospective series but is likely to be less than 15%. Even in cases where the nodule is found to be malignant, the majority will be differentiated thyroid cancers with an excellent prognosis even without treatment. If, due to index cancer diagnosis, age and co-morbidities, it is unlikely that the patient will survive 5 years, further investigation of an incidental FDG avid thyroid nodule is unlikely to be warranted. We provide a consensus statement on the circumstances in which further investigation of FDG avid thyroid nodules with ultrasound and fine needle aspiration might be appropriate.

Postradioiodine Graves' management: The PRAGMA study.

OBJECTIVE: Thyroid status in the months following radioiodine (RI) treatment for Graves' disease can be unstable. Our objective was to quantify frequency of abnormal thyroid function post-RI and compare effectiveness of common management strategies. DESIGN: Retrospective, multicentre and observational study. PATIENTS: Adult patients with Graves' disease treated with RI with 12 months' follow-up. MEASUREMENTS: Euthyroidism was defined as both serum thyrotropin (thyroid-stimulating hormone [TSH]) and free thyroxine (FT4) within their reference ranges or, when only one was available, it was within its reference range; hypothyroidism as TSH ≥ 10 mU/L, or subnormal FT4 regardless of TSH; hyperthyroidism as TSH below and FT4 above their reference ranges; dysthyroidism as the sum of hypo- and hyperthyroidism; subclinical hypothyroidism as normal FT4 and TSH between the upper limit of normal and <10 mU/L; and subclinical hyperthyroidism as low TSH and normal FT4. RESULTS: Of 812 patients studied post-RI, hypothyroidism occurred in 80.7% and hyperthyroidism in 48.6% of patients. Three principal post-RI management strategies were employed: (a) antithyroid drugs alone, (b) levothyroxine alone, and (c) combination of the two. Differences among these were small. Adherence to national guidelines regarding monitoring thyroid function in the first 6 months was low (21.4%-28.7%). No negative outcomes (new-onset/exacerbation of Graves' orbitopathy, weight gain, and cardiovascular events) were associated with dysthyroidism. There were significant differences in demographics, clinical practice, and thyroid status postradioiodine between centres. CONCLUSIONS: Dysthyroidism in the 12 months post-RI was common. Differences between post-RI strategies were small, suggesting these interventions alone are unlikely to address the high frequency of dysthyroidism.

Targeting non-canonical pathways as a strategy to modulate the sodium iodide symporter.

The sodium iodide symporter (NIS) functions to transport iodide and is critical for successful radioiodide ablation of cancer cells. Approaches to bolster NIS function and diminish recurrence post-radioiodide therapy are impeded by oncogenic pathways that suppress NIS, as well as the inherent complexity of NIS regulation. Here, we utilize NIS in high-throughput drug screening and undertake rigorous evaluation of lead compounds to identify and target key processes underpinning NIS function. We find that multiple proteostasis pathways, including proteasomal degradation and autophagy, are central to the cellular processing of NIS. Utilizing inhibitors targeting distinct molecular processes, we pinpoint combinatorial drug strategies giving robust >5-fold increases in radioiodide uptake. We also reveal significant dysregulation of core proteostasis genes in human tumors, identifying a 13-gene risk score classifier as an independent predictor of recurrence in radioiodide-treated patients. We thus propose and discuss a model for targetable steps of intracellular processing of NIS function.

The potential interaction between medical treatment and radioiodine treatment success: A systematic review.

Introduction: Radioactive iodine (RAI) therapy is a critical component in the post-surgical management of thyroid cancer patients, as well as being a central therapeutic option in the treatment of hyperthyroidism. Previous work suggests that antithyroid drugs hinder the efficacy of RAI therapy in patients. However, the effects of other background medications on RAI treatment efficacy have not been evaluated. Therefore, we performed a systematic review and meta-analysis investigating the potential off-target effects of medication on RAI therapy in patients with thyroid cancer and hyperthyroidism. Methods: Systematic review and meta-analysis according to the 2020 PRISMA guidelines. Databases searched: MEDLINE, EMBASE and Cochrane Library for studies published between 2001 and 2021. Results: Sixty-nine unique studies were identified. After screening, 17 studies with 3313 participants were included. One study investigated thyroid cancer, with the rest targeted to hyperthyroidism. The majority of studies evaluated the effects of antithyroid drugs; the other drugs studied included lithium, prednisone and glycididazole sodium. Antithyroid drugs were associated with negative impacts on post-RAI outcomes (n = 5 studies, RR = 0.81, p = 0.02). However, meta-analysis found moderate heterogeneity between studies (I2 = 51%, τ2 = 0.0199, p = 0.08). Interestingly, lithium (n = 3 studies), prednisone (n = 1 study) and glycididazole (n = 1 study) appeared to have positive impacts on post-RAI outcomes upon qualitative analysis. Conclusion: Our systematic review strengthens previous work on antithyroid medication effects on RAI, and highlights that this field remains under researched especially for background medications unrelated to thyroid disease, with very few papers on non-thyroid medications published. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php, identifier CRD42021274026.

Recurrence of Papillary Thyroid Cancer: A Systematic Appraisal of Risk Factors.

CONTEXT: Thyroid cancer recurrence is associated with increased mortality and adverse outcomes. Recurrence risk is currently predicted using clinical tools, often restaging patients after treatment. Detailed understanding of recurrence risk at disease onset could lead to personalized and improved patient care. OBJECTIVE: We aimed to perform a comprehensive bioinformatic and experimental analysis of 3 levels of genetic change (mRNA, microRNA, and somatic mutation) apparent in recurrent tumors and construct a new combinatorial prognostic risk model. METHODS: We analyzed The Cancer Genome Atlas data (TCGA) to identify differentially expressed genes (mRNA/microRNA) in 46 recurrent vs 455 nonrecurrent thyroid tumors. Two exonic mutational pipelines were used to identify somatic mutations. Functional gene analysis was performed in cell-based assays in multiple thyroid cell lines. The prognostic value of genes was evaluated with TCGA datasets. RESULTS: We identified 128 new potential biomarkers associated with recurrence, including 40 mRNAs, 39 miRNAs, and 59 genetic variants. Among differentially expressed genes, modulation of FN1, ITGα3, and MET had a significant impact on thyroid cancer cell migration. Similarly, ablation of miR-486 and miR-1179 significantly increased migration of TPC-1 and SW1736 cells. We further utilized genes with a validated functional role and identified a 5-gene risk score classifier as an independent predictor of thyroid cancer recurrence. CONCLUSION: Our newly proposed risk model based on combinatorial mRNA and microRNA expression has potential clinical utility as a prognostic indicator of recurrence. These findings should facilitate earlier prediction of recurrence with implications for improving patient outcome by tailoring treatment to disease risk and increasing posttreatment surveillance.

ENDOCRINOLOGY IN THE TIME OF COVID-19: Management of hyperthyroidism and hypothyroidism.

This manuscript provides guidance on the management of thyroid dysfunction during the COVID-19 pandemic. Autoimmune thyroid diseases are not linked to increased risks of COVID-19. Uncontrolled thyrotoxicosis may result in more severe complications from SARS-CoV-2 infection, including thyroid storm. The management of patients with a new diagnosis of hyperthyroidism is best undertaken with a block-and-replace regimen due to limited biochemical testing availability. Antithyroid drug (ATD)-induced neutropenia may favour the progression of COVID-19 and symptoms of infection may be confused with SARS-CoV-2 infection. The withdrawal of ATDs and urgent measurement of neutrophils should be considered in case of flu-like manifestations occurring in the initial months of treatment. Urgent surgery or 131-I may be undertaken in selected cases of uncontrolled thyrotoxicosis. Patients with COVID-19 infection may present with conjunctivitis, which could cause diagnostic difficulties in patients with new or existing Graves' ophthalmopathy. Patients who are on replacement treatment with thyroid hormones should ensure they have sufficient supply of medication. The usual advice to increase dosage of levothyroxine during pregnancy should be adhered to. Many newly presenting and previously diagnosed patients with thyroid dysfunction can be managed through virtual telephone or video clinics supported by a dedicated nurse-led service, depending on available facilities.

Targeting Novel Sodium Iodide Symporter Interactors ADP-Ribosylation Factor 4 and Valosin-Containing Protein Enhances Radioiodine Uptake.

The sodium iodide symporter (NIS) is required for iodide uptake, which facilitates thyroid hormone biosynthesis. NIS has been exploited for over 75 years in ablative radioiodine (RAI) treatment of thyroid cancer, where its ability to transport radioisotopes depends on its localization to the plasma membrane. The advent of NIS-based in vivo imaging and theranostic strategies in other malignancies and disease modalities has recently increased the clinical importance of NIS. However, NIS trafficking remains ill-defined. Here, we used tandem mass spectrometry followed by coimmunoprecipitation and proximity ligation assays to identify and validate two key nodes-ADP-ribosylation factor 4 (ARF4) and valosin-containing protein (VCP)-controlling NIS trafficking. Using cell-surface biotinylation assays and highly inclined and laminated optical sheet microscopy, we demonstrated that ARF4 enhanced NIS vesicular trafficking from the Golgi to the plasma membrane, whereas VCP-a principal component of endoplasmic reticulum (ER)-associated degradation-governed NIS proteolysis. Gene expression analysis indicated VCP expression was particularly induced in aggressive thyroid cancers and in patients who had poorer outcomes following RAI treatment. Two repurposed FDA-approved VCP inhibitors abrogated VCP-mediated repression of NIS function, resulting in significantly increased NIS at the cell-surface and markedly increased RAI uptake in mouse and human thyroid models. Collectively, these discoveries delineate NIS trafficking and highlight the new possibility of systemically enhancing RAI therapy in patients using FDA-approved drugs. SIGNIFICANCE: These findings show that ARF4 and VCP are involved in NIS trafficking to the plasma membrane and highlight the possible therapeutic role of VCP inhibitors in enhancing radioiodine effectiveness in radioiodine-refractory thyroid cancer.

Dimerization of the Sodium/Iodide Symporter.

Background: The ability of thyroid follicular epithelial cells to accumulate iodide via the sodium/iodide symporter (NIS) is exploited to successfully treat most thyroid cancers, although a subset of patients lose functional NIS activity and become unresponsive to radioiodide therapy, with poor clinical outcome. Our knowledge of NIS regulation remains limited, however. While numerous membrane proteins are functionally regulated via dimerization, there is little definitive evidence of NIS dimerization, and whether this might impact upon radioiodide uptake and treatment success is entirely unknown. We hypothesized that NIS dimerizes and that dimerization is a prerequisite for iodide uptake. Methods: Coimmunoprecipitation, proximity ligation, and Förster resonance energy transfer (FRET) assays were used to assess NIS:NIS interaction. To identify residues involved in dimerization, a homology model of NIS structure was built based on the crystal structure of the dimeric bacterial protein vSGLT. Results: Abundant cellular NIS dimerization was confirmed in vitro via three discrete methodologies. FRET and proximity ligation assays demonstrated that while NIS can exist as a dimer at the plasma membrane (PM), it is also apparent in other cellular compartments. Homology modeling revealed one key potential site of dimeric interaction, with six residues <3Å apart. In particular, NIS residues Y242, T243, and Q471 were identified as critical to dimerization. Individual mutation of residues Y242 and T243 rendered NIS nonfunctional, while abrogation of Q471 did not impact radioiodide uptake. FRET data show that the putative dimerization interface can tolerate the loss of one, but not two, of these three clustered residues. Conclusions: We show for the first time that NIS dimerizes in vitro, and we identify the key residues via which this happens. We hypothesize that dimerization of NIS is critical to its trafficking to the PM and may therefore represent a new mechanism that would need to be considered in overcoming therapeutic failure in patients with thyroid cancer.

Antigen-Specific Immunotherapy with Thyrotropin Receptor Peptides in Graves' Hyperthyroidism: A Phase I Study.

Background: Graves' disease is one of the most common autoimmune conditions, but treatment remains imperfect. This study explores the first-in-human use of antigen-specific immunotherapy with a combination of two thyrotropin receptor (TSHR) peptides (termed ATX-GD-59) in Graves' hyperthyroidism. Methods: Twelve participants (11 female) with previously untreated mild to moderate Graves' hyperthyroidism were enrolled in a Phase I open label trial to receive 10 doses of ATX-GD-59 administered intradermally over an 18-week period. Adverse events, tolerability, changes in serum free thyroid hormones, and TSHR autoantibodies were measured. Results: Ten subjects received all 10 doses of ATX-GD-59, five (50%) of whom had free triiodothyronine within the reference interval by the 18-week visit. Two further subjects had improved free thyroid hormones by the end of the study (7/10 responders), whereas three subjects showed worsening thyrotoxicosis during the study. Serum TSHR autoantibody concentrations reduced during the study and correlated with changes in free thyroid hormones (r = 0.85, p = 0.002 for TSHR autoantibody vs. free triiodothyronine). Mild injection-site swelling and pain were the most common adverse events. Conclusions: These preliminary data suggest that ATX-GD-59 is a safe and well-tolerated treatment. The improvement in free thyroid hormones in 70% of subjects receiving the medication suggests potential efficacy as a novel treatment for Graves' hyperthyroidism.

Risk of incident circulatory disease in patients treated for differentiated thyroid carcinoma with no history of cardiovascular disease.

CONTEXT: The incidence of differentiated thyroid cancer (DTC) is increasing, yet the prognosis is favourable and long-term survival is expected. Exogenous TSH suppression has been used for many years to prevent DTC recurrence and may be associated with increased risks of circulatory diseases. DESIGN: Risks of circulatory disease in patients treated for DTC were compared to randomly matched patients without DTC (controls) up to a 1:5 ratio using age, sex, body mass index (BMI) and smoking as the matching parameters in a population-based, open cohort study using The Health Improvement Network. PATIENTS: A total of 3009 patients treated for DTC with no pre-existing cardiovascular disease were identified and matched to 11 303 controls, followed up to median of 5 years. RESULTS: A total of 1259 incident circulatory events were recorded during the observation period. No difference in the risk of ischaemic heart disease (IHD) (adjusted hazards ratio [aHR]: 1.04, 95% CI: 0.80-1.36) or heart failure (HF) (aHR: 1.27, 95% CI: 0.89-1.81) was detected. The risk of atrial fibrillation (AF) and stroke was significantly higher in patients with DTC (aHR: 1.71, 95% CI: 1.36-2.15 and aHR: 1.34, 95% CI: 1.05-1.72, respectively). In a sensitivity analysis limited to newly diagnosed patients with DTC, only the risk of AF was consistently elevated (aHR: 1.86, 95% CI: 1.33-2.60). CONCLUSIONS: The increased risk of AF in patients who have undergone treatment for DTC but without pre-existing CVD may warrant periodic screening for this arrhythmia. Whereas no evidence of increased risk of IHD or HF was observed, the increased risk of stroke/TIA warrants further investigation.

Knowledge of Thyroid Eye Disease in Graves' Disease Patients With and Without Orbitopathy.

BACKGROUND: Thyroid eye disease (TED) develops in around 25% of those with Graves' disease (GD). Patients with TED may present late to ophthalmologists, when debilitating orbital inflammatory changes have already occurred. The reasons for this are multifactorial, but poor knowledge of TED in GD patients may be contributory. This study aimed to assess the knowledge of TED in those with established TED, GD without orbitopathy, and control subjects. METHODS: A validated, anonymized questionnaire, with 20 knowledge-based questions, was prospectively completed by 100 GD patients, 100 TED patients, and 100 age- and sex-matched controls (with no history of thyroid disease or TED) in two tertiary referral thyroid and orbital diseases clinics. Demographic data and details of highest educational level, disease duration, and follow-up were gained. Residence postcode was used to determine Index of Multiple Deprivation (2015) quintile. Knowledge score was established for each of the study groups of interest. Statistical analysis was undertaken with Kruskal-Wallis test, chi-square test, and multivariable logistic regression. RESULTS: There was no significant difference in median knowledge scores (out of 20) between GD (13.71, range 9-18) and TED (14.25, range 9-18) patients. However, both groups had significantly higher scores than controls (11.53, range 4-16; p < 0.001). Multivariable analysis determined no particular independent factor associated with lower knowledge score. There were a number of important areas in which patient knowledge of TED was poor. While almost all (99% TED, 89% GD) knew that TED involved orbital tissue inflammation, a large proportion (60% TED, 50% GD) were unaware that TED may develop in the absence of hyperthyroidism or did not know that cigarette smoking is associated with more severe TED (21%TED, 33% GD). CONCLUSIONS: TED patients had equivalent levels of TED knowledge compared to GD patients without orbitopathy. While subjects in both disease groups had greater knowledge than controls, each had significant misconceptions regarding aspects of TED diagnosis, management, and treatment. These findings should guide the future provision of patient information for TED, with educational materials being targeted to address existing gaps in knowledge.

PTTG and PBF Functionally Interact with p53 and Predict Overall Survival in Head and Neck Cancer.

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common cancer worldwide and poses a significant health burden due to its rising incidence. Although the proto-oncogene pituitary tumor-transforming gene 1 (PTTG) predicts poor patient outcome, its mechanisms of action are incompletely understood. We show here that the protein PBF modulates PTTG function, is overexpressed in HNSCC tumors, and correlates with significantly reduced survival. Lentiviral shRNA attenuation of PTTG or PBF expression in HNSCC cells with either wild-type or mutant p53, and with and without HPV infection, led to dysregulated expression of p53 target genes involved in DNA repair and apoptosis. Mechanistically, PTTG and PBF affected each other's interaction with p53 and cooperated to reduce p53 protein stability in HNSCC cells independently of HPV. Depletion of either PTTG or PBF significantly repressed cellular migration and invasion and impaired colony formation in HNSCC cells, implicating both proto-oncogenes in basic mechanisms of tumorigenesis. Patients with HNSCC with high tumoral PBF and PTTG had the poorest overall survival, which reflects a marked impairment of p53-dependent signaling.Significance: These findings reveal a complex and novel interrelationship between the expression and function of PTTG, PBF, and p53 in human HNSCC that significantly influences patient outcome. Cancer Res; 78(20); 5863-76. ©2018 AACR.

The Clinical Utility of Cell-Free DNA Measurement in Differentiated Thyroid Cancer: A Systematic Review.

BACKGROUND: Cell-free DNA (cfDNA) can be detected in the circulation of healthy individuals, but is found in higher concentrations in cancer patients. Furthermore, mutations in tumor cells can be identified in circulating DNA fragments. This has been the subject of significant interest in the field of cancer research, but little has been published in thyroid cancer. OBJECTIVES: To assess all available evidence on the use of circulating cfDNA in the diagnosis, management and surveillance of patients with differentiated thyroid cancer, and collate it into a systematic review to guide future research. METHODS: A comprehensive literature search on the measurement of cfDNA in thyroid cancer was undertaken, and results from relevant studies collated into a systematic review. RESULTS: Nine studies were identified, with varying methodologies and findings. Key techniques and findings are summarized. CONCLUSION: There is limited but promising evidence that somatic mutations in thyroid cancer can be detected in circulating cfDNA and are associated with more advanced disease. Further research is required to develop a clinically useful tool based on cfDNA to improve the management of thyroid cancers.

MANAGEMENT OF ENDOCRINE DISEASE: Subclinical thyrotoxicosis: prevalence, causes and choice of therapy.

Subclinical thyrotoxicosis is a condition affecting up to 10% of the population in some studies. We have reviewed literature and identified studies describing prevalences, causes and outcomes of this condition. Treatment should be considered in all subjects if this biochemical abnormality is persistent, especially in case of symptoms of thyrotoxicosis or in the presence of any complication. In particular, treatment should be offered in those subclinically thyrotoxic patients with a sustained serum TSH below 0.1 U/L. However it is important to recognise that there are no large controlled intervention studies in the field and thus there is no high quality evidence to guide treatment recommendations. In particular, there is no evidence for therapy and there is weak evidence of harm from thyrotoxicosis if serum TSH is in the 0.1-0.4 IU/L range. In this review, we describe the different causes of subclinical thyrotoxicosis, and how treatment should be tailored to the specific cause. We advocate radioactive iodine treatment to be the first-line treatment in majority of patients suffering from subclinical thyrotoxicosis due to multinodular toxic goitre and solitary toxic adenoma, but we do generally not recommend it as the first-line treatment in patients suffering from subclinical Graves' hyperthyroidism. Such patients may benefit mostly from antithyroid drug therapy. Subclinical thyrotoxicosis in early pregnancy should in general be observed, not treated. Moreover, we advocate a general restriction of therapy in cases where no specific cause for the presumed thyroid hyperactivity has been proven.