Reappraising the role of thyroid scintigraphy in the era of TIRADS: A clinically-oriented viewpoint.

Thyroid nodules (TNs) are a common entity, with the majority being benign. Therefore, employing an accurate rule-out strategy in clinical practice is essential. In the thyroid field, the current era is significantly marked by the worldwide diffusion of ultrasound (US)-based malignancy risk stratification systems of TN, usually reported as Thyroid Imaging Reporting And Data System (TIRADS). With the advent of US (and later TIRADS), the role of thyroid scintigraphy (TS) in clinical practice has gradually diminished. The authors of the present paper believe that the role of TS should be reappraised, also considering its essential role in detecting autonomously functioning thyroid nodules and its limited contribution to detecting thyroid cancers. Thus, this document aims to furnish endocrinologists, radiologists, surgeons, and nuclear medicine physicians with practical information to appropriately use TS.

Papillary thyroid carcinoma: ≤ 10 mm does not always mean pN0. A multicentric real-world study.

The incidence of papillary thyroid carcinoma (PTC) is increasing and PTC ≤ 10 mm (PTMC) accounts for most new diagnoses. PTMCs are not always low risk, as detection of lymph nodes metastasis (LNM) may occur. The purpose of the study was to analyze the clinical pattern, frequency, and independent risk factors of patients with PTMC and LNM. From January 2022 to June 2023, PTCs managed at CTO Hospital, Rome; Policlinico Vanvitelli, Naples; and Garibaldi Nesima Hospital, Catania were included. PTC management followed the same diagnostic-therapeutic procedures according to the ATA guidelines. Variables such as age, sex, maximum diameter, histologic evidence of LNM (HELNM +), Hashimoto's thyroiditis (HT), multifocality, capsule invasion, and histological subtype were considered. PTCs were divided according to HELNM and size. Two hundred ninety-eight PTCs were included. PTMCs were 136 (45.6%) and LNM occurred in 27.2% of them. In the HELNM + group, analysis of PTMC vs 'MacroPTC' (PTC > 10 mm) did not show any statistical difference. Multivariate regression revealed that young age (OR 0.93; CI 95% 0.90-0.96; p < 0.01) and male sex (male OR 3.44; CI 95% 1.16-10.20; p = 0.03) were the only independent risk factors for HELNM + in PTMC. The risk of LNM in PTMC is not negligible; therefore, a careful evaluation by an expert thyroidologist is mandatory for patients with small thyroid nodule, especially in younger and male patients before excluding surgery. In the future, new tools are needed to detect early PTMC with LNM before surgery.

Head-to-head comparison of American, European, and Asian TIRADSs in thyroid nodule assessment: systematic review and meta-analysis.

Context: Ultrasound-based risk stratification systems (Thyroid Imaging Reporting and Data Systems (TIRADSs)) of thyroid nodules (TNs) have been implemented in clinical practice worldwide based on their high performance. However, it remains unexplored whether different TIRADSs perform uniformly across a range of TNs in routine practice. This issue is highly relevant today, given the ongoing international effort to establish a unified TIRADS (i.e. I-TIRADS), supported by the leading societies specializing in TNs. The study aimed to conduct a direct comparison among ACR-, EU-, and K-TIRADS in the distribution of TNs: (1) across the TIRADS categories, and (2) based on their estimated cancer risk. Methods: A search was conducted on PubMed and Embase until June 2023. Original studies that sequentially assessed TNs using TIRADSs, regardless of FNAC indication, were selected. General study characteristics and data on the distribution of TNs across TIRADSs were extracted. Results: Seven studies, reporting a total of 41,332 TNs, were included in the analysis. The prevalence of ACR-TIRADS 1-2 was significantly higher than that of EU-TIRADS 2 and K-TIRADS 2, with no significant difference observed among intermediate- and high-risk categories of TIRADSs. According to malignancy risk estimation, K-TIRADS often classified TNs as having more severe risk, ACR-TIRADS as having moderate risk, and EU-TIRADS classified TNs as having lower risk. Conclusion: ACR-, EU-, and K-TIRADS assess TNs similarly across their categories, with slight differences in low-risk classifications. Despite this, focusing on cancer risk estimation, the three TIRADSs assess TNs differently. These findings should be considered as a prerequisite for developing the I-TIRADS.

Determinants of circulating calcitonin value: analysis of thyroid features, demographic data, anthropometric characteristics, comorbidities, medications, and smoking habits in a population with histological full exclusion of medullary thyroid carcinoma.

Objective: Calcitonin (Ctn) measurement is crucial for the early diagnosis of medullary thyroid carcinoma (MTC). However, Ctn levels can be skewed/elevated due to other reasons, and the Ctn upper reference value remains controversial. In this field, studies have heterogeneous settings, published data are controversial, and no evidence has been achieved. The study's aim was to evaluate all previously investigated Ctn determinants in a population with histological exclusion of MTC. Methods: The institutional records from 2010 to 2022 were reviewed to select patients with thyroid nodules who had undergone total thyroidectomy with histological exclusion of MTC and who had tested for Ctn just before surgery. Thyroid features, demographic and anthropometric data, comorbidities, medications, and lifestyle information were collected. Univariate and multivariate analyses were performed. Results: A total of 127 cases were included. The median age for thyroidectomy was 51 years. Median Ctn was 1.04 pg/mL (interquartile range (IQR) 1.04-2.77), with two cases having values above 10 pg/mL. In univariate analysis, Ctn was correlated with gender (p < 0.001), body weight (p = 0.016), height (p = 0.031), body surface area (p = 0.016), thyroid size (p = 0.03), thyroglobulin (p < 0.001), and chronic kidney disease (p < 0.001). After multivariate analysis, the model with the highest accuracy included gender, chronic kidney disease, and thyroid-stimulating hormone (TSH) with an adjusted R-squared of 0.4. Conclusions: This study demonstrates, in a population histologically proven as MTC-free, that the Ctn value is mainly influenced by gender, anthropometric/thyroid features, and chronic kidney disease, with the further impact of TSH.

Inflammatory Profile Assessment in a Highly Selected Athyreotic Population Undergoing Controlled and Standardized Hypothyroidism.

Background: Hypothyroidism (hT) presents heterogeneous symptoms and findings. Evidence on this topic comes mainly from heterogeneous populations in terms of disease duration, residual thyroid function, and comorbidities. Therefore, it would be useful to assess systemic inflammation in a homogeneous hT population. The aim of this study was to investigate inflammation in a population that underwent standardized controlled hT. Methods: We recruited thyroidectomized patients diagnosed with thyroid cancer who were otherwise fit and healthy, showing hypothyroidism before I131 treatment using a standard protocol of LT4 withdrawal. The blood inflammatory indexes (BIIXs) (i.e., NLR, PLR, MLR, SII, SIRI, and AISI) were calculated using the blood tests collected just before I131 administration. Patients were divided according to sex, BMI, and thyroglobulin. The relationships between the BIIXs, age, and thyroid hormones were also investigated. Results: We included 143 patients. The median age of the sample was 43 years. The BIIX median values showed significant differences based on sex, BMI, and thyroglobulin levels (p < 0.05). No significant correlations were found between the BIIXs and age, TSH, FT4, and FT3. Conclusions: This study shows the BIIX median values of a population which underwent standardized hT. It suggests a role for some BIIXs in the evaluation of hypothyroidism in obese people and as hypothetical prognostic markers for thyroid cancer.

Lymph Node Ratio as a Predictive Factor of Persistent/Recurrent Disease in Patients With Medullary Thyroid Cancer: A Single-Center Retrospective Study.

OBJECTIVE: Thyroidectomy with neck lymph node dissection is curative for most patients with medullary thyroid cancer (MTC). Lymph node ratio (LNR, ie, the ratio between the metastatic and the removed lymph nodes) is a reliable parameter with which to estimate both disease extent and quality of neck dissection. The aim of this study was to investigate the prognostic role of LNR to predict persistent/recurrent disease in patients with MTC. METHODS: A single-center, retrospective study of a consecutive cohort of 95 patients with MTC treated with total thyroidectomy and neck dissection. Receiver operating characteristics curve analysis was performed to identify the LNR cut-off. RESULTS: LNR was positively associated with tumor size, preoperative and postoperative calcitonin values, postsurgery carcinoembryonic antigen values, persistent/recurrent disease, and the occurrence of distant metastases during follow-up. At multivariate analysis, persistent/recurrent disease was independently associated with the LNR value and was accurately predicted by a cut-off value of 0.12 (area under the curve = 0.85). Indeed, patients with LNR ≥0.12 had a higher probability of developing persistent/recurrent disease (79.3% vs 10.6%, odds ratio = 32.3, 95% CI = 9.8-106.4; P < .001) and distant metastasis (34.5% vs 3.0%, odds ratio = 16.8, 95% CI = 3.4-83.6; P < .001) than patients with LNR <0.12. The median time to progression was 15 months in patients with LNR ≥0.12 whereas it was not reached in patients with LNR <0.12 (hazard ratio: 7.18, 95% CI = 3.01-17.11, P < .001). CONCLUSIONS: LNR is a reliable prognostic factor to predict the risk of recurrence, persistence, and distant metastases in patients with MTC.

Effect of gluten-free diet on autoimmune thyroiditis progression in patients with no symptoms or histology of celiac disease: a meta-analysis.

Background: Hashimoto's thyroiditis (HT) is the most common autoimmune disease. HT may be associated with nonthyroidal autoimmune diseases, including celiac disease (CD) or other gluten-related conditions (GRC). In the last years, interest about gluten-free diet (GFD) has increased for its supposed extraintestinal anti-inflammatory effect; thus, many patients with HT initiate GFD on their own. Objectives: The aim of this meta-analysis is to examine all available data in literature about the effect of a GFD on TgAb, TPOAb, TSH, FT4, and FT3 levels in patients with HT and no symptoms or histology of CD. Methods: The study was conducted according to MOOSE (Meta-analysis Of Observational Studies in Epidemiology). The search was performed on databases PubMed and Scopus. The last search was performed on 7 February 2023. Quality assessment was performed. Meta-analyses were performed using the random-effect model. Hedges' g was used to measure the effect size (ES). Statistical analyses were performed using StataSE 17. Results: The online search retrieved 409 articles, and 4 studies with a total of 87 patients were finally included for quantitative analysis. The risk of bias was generally low. The mean period of GFD was almost 6 months. The meta-analyses showed reduction in antibody levels with ES: -0.39 for TgAb (95% CI: -0.81 to +0.02; p = 0.06; I² = 46.98%) and -0.40 for TPOAb (95% CI: -0.82 to +0.03; p = 0.07; I² = 47.58%). TSH showed a reduction with ES: -0.35 (95% CI: -0.64 to -0.05; p = 0.02; I² = 0%) and FT4 showed an increase with ES: +0.35% (95% CI: 0.06 to 0.64; p = 0.02; I² = 0%). FT3 did not display variations (ES: 0.05; 95% CI: -0.38 to +0.48; p = 0.82; I² = 51%). The heterogeneity of TgAb, TPOAb, and FT3 data was solved performing sub-analyses between patients with or without GRC (TgAb p = 0.02; TPOAb p = 0.02; FT3 p = 0.04) and only for FT3, performing a sub-analysis between patients taking and not taking LT4 (p = 0.03). Conclusion: This is the first meta-analysis investigating the effect of GFD on HT. Our results seem to indicate a positive effect of the gluten deprivation on thyroid function and its inflammation, particularly in patients with HT and GRC. However, current lines of evidence are not yet sufficient to recommend this dietary approach to all patients with a diagnosis of HT.

Prevalence and significance of indeterminate calcitonin values in patients with thyroid nodules: A systematic review and meta-analysis.

BACKGROUND: Although calcitonin (Ctn) measurement is recognized as the most accurate diagnostic test for medullary thyroid carcinoma (MTC), its routine execution is not universally accepted for several reasons, including the lack of recommendations for managing indeterminate Ctn values (ICV); such as 10-to-100 pg/mL. This study aimed to gather data on 1) the frequency of ICV among patients undergoing Ctn test and 2) the MTC rate among patients with ICV. METHODS: This review was conducted according to the Meta-analyses Of Observational Studies in Epidemiology guidelines. PubMed and Cochrane databases were searched, with no language restrictions. The final search was completed on January 2023. Then, quality assessment and proportion meta-analyses were performed. RESULTS: The online search retrieved 233 articles and 15 were included for quantitative analysis. The risk of bias was low. The number of patients undergone Ctn testing was 29,533. The pooled percentage of those with ICV was 1.7% (95% confidence interval [CI]:1.2-2.3). The pooled proportion of MTC incidence among patients with ICV was 9.6% (95% CI:5-14.1). Heterogeneity was explained by the covariates of Ctn assay sensitivity and the resection rate. The subgroup with Ctn 10-20 pg/mL showed a significantly lower MTC rate than the subgroup with Ctn 20-100 pg/mL. CONCLUSIONS: The percentage of ICV among patients with thyroid nodules who underwent Ctn testing is negligible. The rate of MTC in patients with ICV cannot be overlooked. Among the ICV intervals, the risk of MTC increases significantly when Ctn is above 20 pg/mL.

Early Massive Fibrosis of a Single Extraocular Muscle Causing Severe Unilateral Euthyroid Graves' Ophthalmopathy in a Patient with Hypercholesterolemia Who Smokes.

Background: Graves' ophthalmopathy (GO) is an autoimmune manifestation of orbit affecting approximately 25% of patients with Graves' disease (GD). Autoreactive T cells involved in thyroid autoimmunity can recognize the thyroid-stimulating receptor (TSHr) expressed in orbital tissues of GO patients. Clinical manifestations of GO are rather different depending on the presence of some risk factors, such as smoking, hyperthyroidism duration, age, biological activity of anti-TSHr antibodies (TSH-R-Ab) and metabolic diseases. Case Presentation: Here, we present a rare case of euthyroid single muscular GO in a 50-year-old patient who was a smoker and had dyslipidemia for several years. The patient experienced a very rapid and severe depression of ocular motility of the right eye that caused uncorrectable and constant diplopia, severely affecting his quality of life. He was euthyroid, and TSH-R-Ab plasmatic levels were only slightly elevated. Intravenous corticosteroid pulse therapy was partially effective, and two rounds of wall orbital surgical decompression were necessary. Massive mono-muscular fibrosis was evidenced by biopsy of the right inferior rectus muscle. Conclusion: Severe unilateral, mono-muscular GO in a euthyroid Graves' patient was found to be sustained by rapid and massive fibrosis of the inferior rectus muscle of the right orbit. Clarification of the pathogenetic mechanisms of these GO clinical forms requires further studies.

Levothyroxine therapy, calculated deiodinases activity and basal metabolic rate in obese or nonobese patients after total thyroidectomy for differentiated thyroid cancer, results of a retrospective observational study.

INTRODUCTION: Therapy for hypothyroid obese patients is still under definition since the thyrotropin-stimulating hormone (TSH) level is a less reliable marker of euthyroidism than nonobese patients. Indeed, TSH levels positively correlate with body mass index (BMI), and this increase may be a compensatory mechanism aimed at increasing energy expenditure in obese people. In contrast, the correlation of BMI with thyroid hormone levels is not completely clear, and conflicting results have been obtained by several studies. The L-T4 replacement dose is more variable in obese hypothyroid patients than in nonobese patients, and a recent study indicated that the L-T4 replacement dose is related to lean body mass in obese thyroidectomized patients. We aimed to study the correlations of L-T4-administered dose, thyroid hormone levels and TSH secretion with basal metabolic rate (BMR) and total calculated deiodinase activity (GD) in obese and nonobese athyreotic patients. We also looked for individualized L-T4 replacement dose set points to be used in clinical practice. METHODS: We studied retrospectively 160 athyreotic patients, 120 nonobese and 40 obese. GD was calculated by SPINA Thyr 4.2, the responsiveness of the hypothalamic/pituitary thyrotrope by Jostel's thyrotropin (TSH) index and BMR by the Mifflin-St. Jeor formula, the interplay of GD and BMR with L-T4, thyroid hormones and TSH index (TSHI) was also evaluated. RESULTS: In our study, the L-T4 dose was an independent predictor of GD, and approximately 30% of athyreotic patients under L-T4 therapy had a reduced GD; FT4 levels were higher and negatively modulated by BMR in obese athyreotic patients respect to nonobese, in these patients a T4 to T3 shunt, in terms of TSHI suppression is observed suggesting a defective hypothalamic pituitary T4 to T3 conversion and a resistance to L-T4 replacement therapy. CONCLUSIONS: L-t4 dose is the most important predictor of GD, BMR modulates T4 levels in obese athyreotic patients that are resistant to L-T4 replacement therapy.

Different FT3/TSH correlation in acquired and congenital hypothyroid patients reveals a different hypothalamic set-point.

OBJECTIVE: To understand differences in thyroid hormone replacement therapy with levo-thyroxine (l-T4) between acquired and congenital hypothyroid (CH) patients. DESIGN: We compared biochemical thyroid parameters between euthyroid subjects (EU) and both CH adult patients and thyroidectomized patients (TP) under replacement therapy. PATIENTS AND MEASUREMENTS: A retrospective analysis was performed on a series of 98 consecutive adult CH patients (27 males and 71 females) with a median age of 24 years (range 18-58). Serum TSH, FT3, FT4, l-T4 dose and body weight were assessed. For comparison purposes, large series of 461 TP for thyroid cancer and 1852 EU followed at our Thyroid Clinic were used as control groups. RESULTS: The daily weight-based l-T4 dose was significantly higher in CH than TP group (1.9 vs. 1.7 mcg/kg, p = .03). FT3/FT4 ratio was significantly higher in the EU group, intermediate in CH and lower in TP groups (0.32, 0.28 and 0.24, respectively). Linear regression analysis displayed an inverse correlation between FT4 and TSH in all the groups. An inverse correlation between FT3 and TSH was observed in the TP group, but not in the EU and CH group suggesting that CH patients, under replacement therapy, display biochemical thyroid parameters similar to EU subjects. CONCLUSIONS: Adult CH patients require a higher daily l-T4 dose than adult TP. However, the different correlation of TSH and FT3 values between CH and TP patients suggests an adaptive and different hypothalamic-pituitary-thyroid axis regulation that may depend on the early timing of the onset of hypothyroidism in CH.

Inflammasome activation as a link between obesity and thyroid disorders: Implications for an integrated clinical management.

Obesity is strongly associated with chronic low-grade inflammation. Obese patients have an increased risk to develop thyroid autoimmunity and to became hypothyroid, suggesting a pathogenetic link between obesity, inflammation and autoimmunity. Moreover, type 2 diabetes and dyslipidemia, also characterized by low-grade inflammation, were recently associated with more aggressive forms of Graves' ophthalmopathy. The association between obesity and autoimmune thyroid disorders may also go in the opposite direction, as treating autoimmune hyper and hypothyroidism can lead to weight gain. In addition, restoration of euthyroidism by L-T4 replacement therapy is more challenging in obese athyreotic patients, as it is difficult to maintain thyrotropin stimulation hormone (TSH) values within the normal range. Intriguingly, pro-inflammatory cytokines decrease in obese patients after bariatric surgery along with TSH levels. Moreover, the risk of thyroid cancer is increased in patients with thyroid autoimmune disorders, and is also related to the degree of obesity and inflammation. Molecular studies have shown a relationship between the low-grade inflammation of obesity and the activity of intracellular multiprotein complexes typical of immune cells (inflammasomes). We will now highlight some clinical implications of inflammasome activation in the relationship between obesity and thyroid disease.

Early detection of suspicious lymph nodes in differentiated thyroid cancer.

BACKGROUND: Early identification of cervical lymph node (LN) metastases cervical lymph node metastases (CLNM) is crucial in the management of differentiated thyroid cancer differentiated thyroid cancer (DTC) as it influences the indication and the extent of surgery with an impact on the recurrence risk and overall survival. The present review focused on novel sensitive and specific diagnostic techniques, by searching through online databases like MEDLINE and Scopus up to February 2022. AREAS COVERED: The techniques identified included contrast-enhanced ultrasound (CEUS), dosage of fragment 21-1 of cytokeratin 19 (CYFRA 21-1) in lymph node fine needle aspiration washout, sentinel LN biopsy (SNB), and artificial intelligence (AI) - deep learning applied to ultrasonography and computed tomography. These methods displayed widely varying sensitivity and specificity results, ranging from approximately 60-100%. This variability is mainly due to the operator's experience because of the great complexity of execution of these new techniques, which require a long-learning curve. EXPERT OPINION: Despite the appearance of many candidate methods to improve the detection of metastatic lymph nodes, none seem to be clearly superior to the tools currently used in clinical practice and FNA-Tg measurement remains the more accurate tool to detect neck recurrences and CLNM from DTC.

Impact of Chemical Endocrine Disruptors and Hormone Modulators on the Endocrine System.

There is growing concern regarding the health and safety issues of endocrine-disrupting chemicals (EDCs). Long-term exposure to EDCs has alarming adverse health effects through both hormone-direct and hormone-indirect pathways. Non-chemical agents, including physical agents such as artificial light, radiation, temperature, and stress exposure, are currently poorly investigated, even though they can seriously affect the endocrine system, by modulation of hormonal action. Several mechanisms have been suggested to explain the interference of EDCs with hormonal activity. However, difficulty in quantifying the exposure, low standardization of studies, and the presence of confounding factors do not allow the establishment of a causal relationship between endocrine disorders and exposure to specific toxic agents. In this review, we focus on recent findings on the effects of EDCs and hormone system modulators on the endocrine system, including the thyroid, parathyroid glands, adrenal steroidogenesis, beta-cell function, and male and female reproductive function.

Recent insights into the pathogenesis of autoimmune hypophysitis.

INTRODUCTION: Hypophysitis is an inflammation of the pituitary gland and a rare case of hypopituitarism. Despite the expanding spectrum of histological variants and causative agents, its pathogenesis is far to be fully understood. The present review is focused on recent evidence concerning the pathogenesis of autoimmune hypophysitis by searching through online databases like MEDLINE and Scopus up to May 2021. AREAS COVERED: Hypophysitis frequently develops in the context of a strong autoimmune background, including a wide spectrum of subtypes ranging from the commonest form of lymphocytic hypophysitis to the newly described and less common IgG4-, anti-PIT-1, and ICI-induced forms. A peculiar combination of genetic predisposition, pituitary damage and immunological setting represents the pathogenetic basis of autoimmune hypophysitis, which is characterized by diffuse infiltration of the gland by lymphocytes and variable degrees of fibrosis followed by pituitary cell destruction. Anti-pituitary antibodies (APA) have been described in sera from patients suffering from autoimmune hypophysitis, though their pathophysiological significance remains largely unknown and their diagnostic value limited. EXPERT OPINION: In recent years hypophysitis has gained interest due to the increased number of new diagnoses and the recognition of novel subtypes. Further studies could lead to improvements in biochemical/immunological diagnosis and targeted treatments.

Onset of Marine-Lenhart syndrome and Graves' ophthalmopathy in a female patient treated with alemtuzumab for multiple sclerosis.

BACKGROUND: Immune checkpoint blockade therapy may lead to thyroid dysfunction in 3-7% of treated patients. Alemtuzumab is a CD52 inhibitor leading to thyroid dysfunction in approximately 40% of patients. A female patient was affected by multiple sclerosis (MS) and subclinical hyperthyroidism due to an autonomously functioning thyroid nodule (AFTN). After alemtuzumab treatment, she developed aggressive clinical hyperthyroidism consistent with Marine-Lenhart syndrome. CASE PRESENTATION: A 36-year-old woman presented in July 2019 with symptoms of hyperthyroidism and eye complaints. Three years earlier, she was diagnosed with MS. Subclinical hyperthyroidism was diagnosed in April 2017. Thyroid scintigraphy showed an intranodular distribution of 99mTc-pertechnatate consisting of an AFTN in the right lobe of the thyroid. In June 2018, because of the MS, she was treated with alemtuzumab. In November 2018, she was started on methimazole treatment because of the symptoms of hyperthyroidism. In December 2018, thyroid function was normal under methimazole treatment. In June 2019, the patient received a second round of alemtuzumab administration. One month later, she developed symptoms of hyperthyroidism. These symptoms were accompanied by diplopia. Blood tests showed severe hyperthyroidism. Thyroid scintigraphy showed a diffuse distribution of 99mTc-pertechnatate and the presence of a "cool" area in the right lobe of the thyroid, confirmed by ultrasonography. The nodule was diagnosed as a low-risk indeterminate lesion. CONCLUSION: We present a case of Graves' disease with active, moderate-to-severe Graves' ophthalmopathy in a patient with pre-existing AFTN presenting with a coexisting, rare case of Marine-Lenhart syndrome associated with immune reconstitution after alemtuzumab treatment.

Thyroid Cancer and Circadian Clock Disruption.

Thyroid cancer (TC) represents the most common malignancy of the endocrine system, with an increased incidence across continents attributable to both improvement of diagnostic procedures and environmental factors. Among the modifiable risk factors, insulin resistance might influence the development of TC. A relationship between circadian clock machinery disfunction and TC has recently been proposed. The circadian clock machinery comprises a set of rhythmically expressed genes responsible for circadian rhythms. Perturbation of this system contributes to the development of pathological states such as cancer. Several clock genes have been found deregulated upon thyroid nodule malignant transformation. The molecular mechanisms linking circadian clock disruption and TC are still unknown but could include insulin resistance. Circadian misalignment occurring during shift work, jet lag, high fat food intake, is associated with increased insulin resistance. This metabolic alteration, in turn, is associated with a well-known risk factor for TC i.e., hyperthyrotropinemia, which could also be induced by sleep disturbances. In this review, we describe the mechanisms controlling the circadian clock function and its involvement in the cell cycle, stemness and cancer. Moreover, we discuss the evidence supporting the link between circadian clockwork disruption and TC development/progression, highlighting its potential implications for TC prevention, diagnosis and therapy.

The Possible Role of Cancer Stem Cells in the Resistance to Kinase Inhibitors of Advanced Thyroid Cancer.

Target therapy with various kinase inhibitors (KIs) has been extended to patients with advanced thyroid cancer, but only a subset of these compounds has displayed efficacy in clinical use. However, after an initial response to KIs, dramatic disease progression occurs in most cases. With the discovery of cancer stem cells (CSCs), it is possible to postulate that thyroid cancer resistance to KI therapies, both intrinsic and acquired, may be sustained by this cell subtype. Indeed, CSCs have been considered as the main drivers of metastatic activity and therapeutic resistance, because of their ability to generate heterogeneous secondary cell populations and survive treatment by remaining in a quiescent state. Hence, despite the impressive progress in understanding of the molecular basis of thyroid tumorigenesis, drug resistance is still the major challenge in advanced thyroid cancer management. In this view, definition of the role of CSCs in thyroid cancer resistance may be crucial to identifying new therapeutic targets and preventing resistance to anti-cancer treatments and tumor relapse. The aim of this review is to elucidate the possible role of CSCs in the development of resistance of advanced thyroid cancer to current anti-cancer therapies and their potential implications in the management of these patients.

Role of selenium and myo-inositol supplementation on autoimmune thyroiditis progression.

Previous reports indicate that selenium supplementation may be useful to reduce cell oxidative stress. In particular, selenium may decrease the level of thyroid autoantibodies in patients with Hashimoto's thyroiditis (HT). Recent studies also indicate that myo-inositol may have beneficial effects on thyroid function in patients with HT. Hence, the aim of the present study is to evaluate whether myo-inositol may enhance the protective effect of selenium on HT progression to hypothyroidism. The study was designed as observational and retrospective. Thyroid hormones were evaluated in patients with HT who were either euthyroid or subclinically hypothyroid. These patients were subdivided into three groups: untreated, treated with selenomethionine alone (Se-meth: 83 µg/day) and treated with Se-meth plus myo-inositol (Se-meth + Myo-I: 83 µg/day + 600 mg/day). Outcome evaluation was performed at baseline and after 6 and 12 months of treatment. High-resolution ultrasound of the thyroid gland was performed to evaluate changes in thyroid echoic pattern during the study. Compared to baseline, levels of thyroid-stimulating hormone (TSH) increased significantly in untreated patients but decreased by 31% and 38%, respectively, in those treated with Se-meth and Se-meth + Myo-I. Moreover, in the latter group the TSH reduction was observed earlier than in the Se-meth-treated group. Densitometric analysis of thyroid ultrasonography showed an echoic pattern improvement in both treated groups compared to untreated patients, although this difference was not statistically significant. Thus, Se-meth treatment is effective in patients with HT and its effect may be improved in combination with Myo-I through earlier achievement of TSH levels closer to physiological concentrations.