Incidentally Discovered Papillary Thyroid Microcarcinomas Are More Frequently Found in Patients with Chronic Lymphocytic Thyroiditis Than with Multinodular Goiter or Graves' Disease

Autoimmune Thyroid Disease and Differentiated Thyroid Carcinoma: A Review of the Mechanisms That Explain an Intriguing and Exciting Relationship

Autoimmune thyroid disease is a complex and highly frequent disease, where a wide variety of genetic, epigenetic and environmental factors (among others) come together and interact, and is characterized by the presence of two clinical outcomes: hypothyroidism (in Hashimoto's thyroiditis) and hyperthyroidism (in Graves-Basedow disease). For its part, differentiated thyroid carcinoma (mainly papillary carcinoma) is the most common type of cancer affecting the thyroid (and one of the most prevalent worldwide). An important co-occurrence between autoimmune thyroid disease and differentiated thyroid carcinoma has been documented. In this article, studies that have evaluated possible associations and relationships between autoimmune thyroid disease and differentiated thyroid cancer are systematically described and summarized. To date, the underlying mechanism that explains this association is inflammation; however, the characteristics and designs of the studies evaluated do not yet allow a causal relationship between the two entities to be established. These aspects have made it difficult to establish "causality" in the continuum of the pathogenesis between both conditions.

Elevated Preoperative TPO Ab Titers Decrease Risk for DTC in a Linear Fashion: A Retrospective Analysis of 1635 Cases

CONTEXT

For some, chronic lymphocytic thyroiditis (Hashimoto thyroiditis) is an important risk factor for differentiated thyroid cancer (DTC). Surgical cohort studies even suggested a potential role for thyroid peroxidase antibodies (TPO-Abs) on that risk.

OBJECTIVE

Our clinical observations argued against that possibility. We designed the present study to evaluate the relationship of TPO-Abs and DTC in a large patient population.

METHODS

We recruited individuals who underwent thyroidectomies at 4 different clinical sites (USA: 1 clinic, 2000-2013, and Greece: 3 clinics, 2007-2021). We gathered data on TPO-Abs titers measured with commercially available chemiluminescence immunoassays, and reviewed patients' data including surgical pathology. TPO-Abs of 34 IU/mL or greater was deemed positive (TPO+) and TPO-Abs less than 34 IU/mL was deemed negative (TPO-). Odds ratios (OR) for DTC were calculated with the Fisher exact test and P less than .05 was deemed significant.

RESULTS

We reviewed data from 8461 consecutive thyroid surgery cases. TPO-Abs titers were available for 1635 individuals: DTC n = 716 (43.8%), benign pathology n = 919 (56.2%), TPO+ n = 540 (33.0%), and TPO- n = 1095 (67.0%). DTC was found at a lower frequency in TPO+ (198/540, 36.7%) compared to TPO- (518/1095, 47.3%) patients, OR 0.64 (0.52-0.80; P < .0001). Rising TPO-Abs titers conferred protection against DTC in a linear fashion: TPO-Abs less than 10 IU/mL: 59.3%, TPO-Abs less than 34 IU/mL: 47.4%, TPO-Abs 34 to 100 IU/mL: 42.6%, TPO-Abs 100 to 500 IU/mL: 32.0%, TPO-Abs greater than 1000 IU/mL: 19.4%; P less than .0001.

CONCLUSION

Higher TPO-Ab titers appear protective against DTC in our large multicenter cohort of patients who underwent thyroidectomies. Rising preoperative TPO-Abs titers conferred linearly increasing protection against DTC.

The role of vascular endothelial growth factor in the development of papillary thyroid carcinoma in patients with lymphocytic thyroiditis

BACKGROUND

Vascular endothelial growth factor (VEGF) plays a pivotal role in the pathogenesis of autoimmune chronic inflammatory conditions and papillary thyroid carcinoma (PTC). We hypothesized that, as VEGF expression is increased both in PTC and in lymphocytic thyroiditis (LT), it may stimulate the development of PTC in patients with LT. To evaluate this, we examined both tumor and adjacent non-tumoral tissues of PTC patients with and without LT.

METHODS

A total of 50 patients with PTC (52.50±7.41 years) and 17 patients with nodular goiter (NG) (50.47±10.38 years) were included in the study. According to the presence of LT, patients with PTC were further divided into two groups. Immunohistochemical analyses of VEGF were conducted in all patients and for PTC patients, both tumor tissue and adjacent non-tumoral tissue were evaluated.

RESULTS

The scores for intensity of staining and percentage of labeled thyrocytes for VEGF were found to be significantly higher in the PTC patients than in the NG patients (P<0.001, P<0.001, respectively). The tumor tissue revealed similar scores for PTC patients with LT and without LT. However, the scores in adjacent non-tumoral tissue were higher in PTC patients with LT than in patients without LT (P=0.004, P=0.01, respectively).

CONCLUSIONS

To the best of our knowledge, our results are the first to demonstrate that the expression of VEGF in adjacent non-tumoral tissue were higher in PTC patients with LT than in those without, which shows a possible role of VEGF expression in the progression of PTC in the presence of LT.

Outcomes of Surgical Treatment for Graves' Disease: A Single-Center Experience of 216 Cases

BACKGROUND

The role of surgery in the treatment of Graves' disease (GD) needs to be revisited. The aims of the present retrospective study were to evaluate the outcomes of the current surgical strategy as a definitive treatment of GD at our center and to explore the clinical association between GD and thyroid cancer.

METHODS

A patient cohort of 216 cases from 2013 to 2020 was involved in this retrospective study. The data of the clinical characteristics and follow-up results were collected and analyzed.

RESULTS

There were 182 female and 34 male patients. The mean age was 43.9 ± 15.0 years old. The mean duration of GD reached 72.2 ± 92.7 months. Of the 216 cases, 211 had been treated with antithyroid drugs (ATDs) and hyperthyroidism had been completely controlled in 198 cases. A total (75%) or near-total (23.6%) thyroidectomy was performed. Intraoperative neural monitoring (IONM) was applied to 37 patients. The failure of ATD therapy (52.3%) was the most common surgical indication, followed by suspicion of a malignant nodule (45.8%). A total of 24 (11.1%) patients had hoarseness after the operation and 15 (6.9%) patients had transient vocal cord paralysis; 3 (1.4%) had this problem permanently. No bilateral RLN paralysis occurred. A total of 45 patients had hypoparathyroidism and 42 of them recovered within 6 months. Sex showed a correlation with hypoparathyroidism through a univariate analysis. A total of 2 (0.9%) patients underwent a reoperation because of hematomas. A total of 104 (48.1%) cases were diagnosed as thyroid cancer. In most cases (72.1%), the malignant nodules were microcarcinomas. A total of 38 patients had a central compartment node metastasis. A lateral lymph node metastasis occurred in 10 patients. Thyroid carcinomas were incidentally discovered in the specimens of 7 cases. The patients with concomitant thyroid cancer had a significant difference in body mass index, duration of GD, gland size, thyrotropin receptor antibodies and nodule(s) detected.

CONCLUSION

Surgical treatments for GD were effective, with a relatively low incidence of complications at this high-volume center. Concomitant thyroid cancer is one of the most important surgical indications for GD patients. Careful ultrasonic screening is necessary to exclude the presence of malignancies and to determine the therapeutic plan.

Clinicopathologic characteristics of incidental thyroid carcinoma in euthyroid patients receiving total thyroidectomy for multinodular goiter: A retrospective cohort study

BACKGROUND

Total thyroidectomy is the treatment of choice for multinodular goiter (MNG). In some of these cases, incidental thyroid cancer (ITC) is detected postoperatively. Papillary thyroid microcarcinoma (PTMC), the most common type of ITC, has clinical factors and pathologic similarities with ITC that have not been well clarified previously. We investigated the incidence and characteristics of ITC and PTMC in euthyroid patients undergoing total thyroidectomy for MNG.

METHODS

We retrospectively investigated the data of 151 euthyroid patients who underwent total thyroidectomy for MNG between January 2016 and December 2020. Patients with PTMC were then selected from among those with ITC for further data analysis.

RESULTS

The incidence rates of ITC and PTMC were 31.1% (47/151) and 21.1% (32/151), respectively. The mean age of patients with ITC was 52.8 ± 11.7 years, which was younger than that of patients with benign MNG (57.2 ± 12.5 years, p < 0.05). Bilateral cancer was observed in 17 patients with ITC (17/47, 36.2%) and nine with PTMC (9/32, 28.1%). The numbers of patients in the ITC and PTMC groups whose cancer was not on the side comprising the dominant tumor were 15 (15/47, 31.9%) and 13 (13/32, 40.6%), respectively. The multivariate analysis demonstrated that younger age was a clinical factor associated with ITC and PTMC.

CONCLUSION

Younger age is a clinical factor for ITC and PTMC. We recommend taking considering clinical factors and pathologic characteristics of ITC and PTC when considering total thyroidectomy in euthyroid patients with MNG.

Benign and malignant thyroid nodules with autoimmune thyroiditis

Objective

The prevalence of autoimmune thyroiditis (AT) in papillary thyroid carcinoma (PTC) is still controversial. The aim of this study was to investigate the frequency of coexistence of PTC with AT versus that of the coexistence of benign nodules with AT.

Materials and methods

This was a cross-sectional retrospective study including patients operated on for thyroid nodules from January 2011, to April 2021. The frequency of papillary carcinomas cooccurring with AT was compared to that of benign nodules cooccurring with AT, which was assessed based on cytopathological diagnosis after thyroidectomy.

Results

The study included 668 cases of benign nodules and 420 cases with PTC. No statistically significant difference was observed between cases of benign and PTC nodules regarding the presence of AT (25% vs. 28%, respectively, p = 0.177). The size of the PTC compared to that of the benign predominant nodules was significantly smaller both in the absence (0.96 ± 1.09 cm vs. 2.19 ± 1.06 cm, p < 0.05) and in the presence (0.77 ± 0.76 cm vs. 1.67 ± 1.08 cm, p < 0.01) of AT. In the binary logistic regression analysis of the PTC, the only variable associated with AT was multifocality (odds ratio: 1.750, 95% confidence intervals: 1.131-2.706, p = 0.013). The incidences of lymph node involvement and advanced stage PTC were very low both in the presence and absence of AT.

Conclusion

The nodules present with PTC were not more likely to coexist with AT than benign nodules were. The small incidence of advanced PTC indicates a significant improvement in early-stage diagnosis.

Preoperative Thyroid Peroxidase Antibody Predicts Recurrence in Papillary Thyroid Carcinoma: A Consecutive Study With 5,770 Cases

Background

Thyroid autoimmunity is common in papillary thyroid carcinoma (PTC) and was believed to confer a better prognosis; however, controversy still remains. This study aimed to investigate the prognostic value of chronic lymphocytic thyroiditis (CLT) and preoperative thyroid peroxidase antibody (TPOAb) in PTC patients.

Methods

A retrospective analysis was performed on 5,770 PTC patients who underwent surgical treatment with pathologically confirmed PTC in our institution between 2012 to 2016. The patients were divided into groups with respect to the coexistence of CLT or preoperative TPOAb levels. The clinicopathological characteristics and disease-free survival (DFS) rates were compared between the groups.

Results

The coexistence of CLT was likely to have bilateral, multifocal tumors. Particularly, PTC patients with TPOAb++ (&gt;1,000 IU/L) had a larger tumor size (p = 0.007) and higher rates of bilaterality and multifocality than those with TPOAb− (TPOAb&lt; 100 IU/L), while for lymph node metastasis and extrathyroidal extension, there is no statistical difference. Tumor recurrence was found in 15 of 425 (3.5%), 9 of 436 (2.1%), and 56 of 3,519 (1.6%) patients with TPOAb++, TPOAb+, and TPOAb−, respectively (p = 0.017). On univariate analysis, TPOAb++ was correlated with tumor recurrence, with a hazard ratio of 2.20 [95% confidence interval (CI), 1.25–3.89], which remained as an independent risk factor at 1.98 (95% CI, 1.10–3.55) on multivariate analysis. PTC patients with TPOAb++ had the lowest DFS rates (96.5 vs. 97.9 vs. 98.4%, p = 0.020).

Conclusion

CLT is not a protective factor in PTC patients. We provide initial evidence that the preoperative TPOAb instead predicts recurrence in papillary thyroid carcinoma.

Risk Factors for Contralateral Occult Papillary Thyroid Carcinoma in Patients with Clinical Unilateral Papillary Thyroid Carcinoma: A Case-Control Study

INTRODUCTION

Papillary thyroid cancer (PTC) is one of the most prevalent endocrine malignancies that has increased in recent decades around the world. Although the indicator for navigating the surgical extent in PTC patients is still in debate, a key issue is how to predict that there are undetected preoperative tumors in the contralateral thyroid lobe. This study aims to find risk factors for contralateral occult papillary thyroid cancer (COPTC) to facilitate more accurate surgical decisions made for patients with PTC.

MATERIALS AND METHODS

In our study, we included 229 patients who underwent total thyroidectomy plus central and ipsilateral lateral lymph nodes dissection from January 1, 2019, to September 1, 2021. Univariate and multivariate logistic regression analyses were conducted to assess the association between COPTC and clinical-pathological characteristics, as well as the relation between the diameter of the occult lesions and predictors. The forest plot was plotted to visualize the prediction factors from the output of the multivariate regression analysis. A ROC curve was used to evaluate the combining potency of all the risk factors.

RESULTS

Of the 229 patients included in our study, 46 with COPTC were assigned to the case group, representing 20.1% in this study. Multifocality in one lobe (OR = 2.21, P=0.03), intact capsule (OR = 2.54, P=0.01), central lymph node metastasis (OR = 3.00, P=0.02), and Hashimoto's thyroiditis (OR = 2.08, P = 0.04) are more prone to present contralateral occult papillary thyroid carcinoma. The ROC curve of the aggregate potency of the risk factors presents AUC = 0.701 (P < 0.001), and the best cutoff value was 2.02, with a sensitivity of 78.3% and specificity of 55.2%. Furthermore, there was no statistical correlation between the diameter of the occult tumor and the four obtained variables.

CONCLUSION

Patients with multifocality in one lobe, intact capsule, central lymph node metastasis, and HT may harbor contralateral papillary thyroid carcinoma. It is essential to be prudent to make a surgical or follow-up decision on these patients. In addition, more clinical rather than postoperative pathological indicators need to be revealed in the future.

Cancer Risk in Hashimoto's Thyroiditis: a Systematic Review and Meta-Analysis

OBJECTIVE

Research data suggest that patients with Hashimoto's thyroiditis may increase the risk of cancer. However, existing research is inconsistent with this view. Therefore, to investigate the effect of Hashimoto's thyroiditis on the risk of developing cancer, we conducted this study.

METHODS

We searched the PubMed and Embase databases from database establishment until March 2022. After rigorous literature screening by two authors, 23 studies that met the inclusion criteria were identified, and the required data were independently extracted.

RESULTS

We retrieved 3591 records, and after the screening, 11 case-control studies and 12 cohort studies were included in the analysis. Data analysis suggested that patients with Hashimoto's thyroiditis had an increased risk of developing breast cancer, urogenital cancer, digestive organs cancer, hematologic cancer, and a low risk of respiratory cancers.

CONCLUSIONS

This systematic review and meta-analysis showed that patients with HT may have a significantly increased risk of thyroid cancer, breast cancers, lung cancer, digestive system cancer, urogenital cancers, blood cancers, and prolactinoma people without HT.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD 42022320741.

Clinical Characteristics and Prognosis of Coexisting Thyroid Cancer in Patients with Graves' Disease: A Retrospective Multicenter Study

BACKGROUND

The association between Graves' disease (GD) and co-existing thyroid cancer is still controversial and most of the previously reported data have been based on surgically treated GD patients. This study investigated the clinicopathological findings and prognosis of concomitant thyroid cancer in GD patients in the era of widespread application of ultrasonography.

METHODS

Data of GD patients who underwent thyroidectomy for thyroid cancer between 2010 and 2019 in three tertiary hospitals in South Korea (Asan Medical Center, Chonnam National University Hwasun Hospital, and Pusan National University Hospital) were collected and analyzed retrospectively. In the subgroup analysis, aggressiveness and clinical outcomes of thyroid cancer were compared nodular GD and non-nodular GD groups according to the presence or absence of the thyroid nodules other than thyroid cancer (index nodules).

RESULTS

Of the 15,159 GD patients treated at the hospitals during the study period, 262 (1.7%) underwent thyroidectomy for coexisting thyroid cancer. Eleven patients (4.2%) were diagnosed with occult thyroid cancer and 182 patients (69.5%) had microcarcinomas. No differences in thyroid cancer aggressiveness, ultrasonographic findings, or prognosis were observed between the nodular GD and non-nodular GD groups except the cancer subtype. In the multivariate analysis, only lymph node (LN) metastasis was an independent prognostic factor for recurrent/persistent disease of thyroid cancer arising in GD (P=0.020).

CONCLUSION

The prevalence of concomitant thyroid cancer in GD patients was considerably lower than in previous reports. The clinical outcomes of thyroid cancer in GD patients were also excellent but, more cautious follow-up is necessary for patients with LN metastasis in the same way as for thyroid cancer in non-GD patients.

Clinical Significance of Coexistence of Hashimoto Thyroiditis and Graves' Disease with Differentiated and Medullary Thyroid Cancer

The association of Hashimoto thyroiditis and Graves' disease with papillary, follicular, and medullary thyroid cancer has not been comprehensively investigated until now. This comparative clinicopathological study of consecutive patients thyroidectomized at a surgical referral center aimed to explore interdependencies between chronic autoimmune thyroiditis and thyroid cancer. Altogether, there were 852 (58.4%) patients with papillary thyroid cancer, 181 (12.4%) patients with follicular thyroid cancer, and 426 (29.2%) patients with sporadic medullary thyroid cancer, of whom 75 (5.1%) patients also had Hashimoto thyroiditis and 40 (2.7%) patients also had Graves' disease. Patients with papillary (medians of 42 vs. 48 years; P =0.008) and follicular (medians of 33 vs. 63 years; P=0.022) thyroid cancer, unlike patients with medullary thyroid cancer (medians of 57.5 vs. 57 years; P=0.989), were younger at thyroidectomy when they had Hashimoto thyroiditis concomitantly. No such associations were seen with Graves' disease. Primary thyroid cancers tended to be more localized in conjunction with Hashimoto thyroiditis, and less so with Graves' disease, although patterns were not consistent across tumor types. In conclusion, Hashimoto thyroiditis, but not Graves' disease, may be associated with differentiated (papillary and follicular) thyroid cancer but not with medullary thyroid cancer.

Thyroid Microcarcinoma in Pediatric Population in Romania

Thyroid microcarcinoma in pediatric population in Romania Non-medullary thyroid cancer (TC) is the most common endocrine malignancy, with an increasing incidence in the recent years, due to the increase of the thyroid microcarcinoma. Thyroid microcarcinoma (mTC) is defined, according to WHO criteria, as ≤1 cm dimension thyroid carcinoma, being a rare disease in children population. In adults, the current guidelines recommend a limited surgical approach. In children, however, there are no specific guidelines for mTC. Due to the scarcity of these tumors, mTC in children have largely been understudied, to our knowledge with only one previous publication reporting on the outcomes of a large historic series of patients with mTC from the USA. In Romania, the incidence of TC is rising, one of the reason may be the effect of Chernobyl nuclear accident in the past and the iodine deficiency. The purpose of this study was to describe the characteristics and outcome of children diagnosed with mTC in Romania diagnosed from 1 January 2000 to 31 December 2018. During the study period we identified 77 cases of differentiated TC (papillary and follicular) and of these 20 cases (19.4%) were mTC. The mTC represented roughly one fifth of our nationwide pediatric population diagnosed in the last 20 years, the majority of cases being recorded in adolescents aged between 15–18 years. Although patients with apparently more unfavorable local phenotype were identified, this was not reflected in the outcome of the patients in terms of remission of the disease and survival. Our study illustrates the heterogeneity of the real-life practice with respect to the pediatric mTC, and underscores the need for carefully designed multicenter international studies, including larger cohorts of patients in order to provide the data required for establishing evidence based uniform protocols. The European Reference Networks (ERN), such as the ERN for Rare Endocrine Diseases (Endo-ERN) provides an ideal platform to initiate such collaborative studies.

Influence Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: Hashimoto's Thyroiditis Has a Weak Effect on Central or Lateral Lymph Node Metastasis

Purpose

To analyze the effect of Hashimoto’s thyroiditis (HT) concurrent with papillary thyroid cancer (PTC) on cervical lymph node metastasis (LNM).

Methods

Two thousand nine hundred twenty-six patients who underwent thyroidectomy and lymph node dissection between January 2015 and December 2018 were enrolled in this study. Patient demographics and clinicopathologic features were analyzed.

Results

Of the total enrolled patients, 598 (20.4%) had concurrent HT. There were 1482 PTC cases with N0, 1033 cases with N1a, and 411 cases with N1b. Patients with HT had lower frequency of extrathyroidal extension (ETE), lymphatic vascular (LV) invasion, high pathological T stage (III+IV) and central LNM rate. Stratifying central LNM by non-ETE or without intrathyroidal spreading, it was further found that central LNM rate in patients with HT was lower than that of patients without HT. However, there was no significant difference in the central LNM rate in patients with PTC stratified by ETE or intrathyroidal spreading. HT with PTC played a weak protective role in N1a, reducing the risk of N1a by 16.4%. Conversely, HT is a risk factor for N1b, increasing the risk by 1.336 times compared to patients without HT. TgAb is an independent risk factor for N1b, which appears related to the promotion of N1b by HT.

Conclusion

In PTC, HT has a protective effect on central LNM and a risk effect on lateral LNM, although the difference was not significant. This weak protective effect on N1a is more obvious in PTC with less aggressive clinicopathologic characteristics. The risk effect of HT on N1b may be associated with TgAb.

Oxidative Stress-Induced Sirtuin1 Downregulation Correlates to HIF-1α, GLUT-1, and VEGF-A Upregulation in Th1 Autoimmune Hashimoto's Thyroiditis

In Hashimoto’s thyroiditis (HT), oxidative stress (OS) is driven by Th1 cytokines’ response interfering with the normal function of thyrocytes. OS results from an imbalance between an excessive production of reactive oxygen species (ROS) and a lowering of antioxidant production. Moreover, OS has been shown to inhibit Sirtuin 1 (SIRT1), which is able to prevent hypoxia-inducible factor (HIF)-1α stabilization. The aims of this study were to determine the involvement of NADPH-oxidases (NOX), SIRT1, and HIF-1α in HT pathophysiology as well as the status of antioxidant proteins such as peroxiredoxin 1 (PRDX1), catalase, and superoxide dismutase 1 (SOD1). The protein expressions of NOX2, NOX4, antioxidant enzymes, SIRT1, and HIF-1α, as well as glucose transporter-1 (GLUT-1) and vascular endothelial growth factor A (VEGF-A), were analyzed by Western blot in primary cultures of human thyrocytes that were or were not incubated with Th1 cytokines. The same proteins were also analyzed by immunohistochemistry in thyroid samples from control and HT patients. In human thyrocytes incubated with Th1 cytokines, NOX4 expression was increased whereas antioxidants, such as PRDX1, catalase, and SOD1, were reduced. Th1 cytokines also induced a significant decrease of SIRT1 protein expression associated with an upregulation of HIF-1α, GLUT-1, and VEGF-A proteins. With the exception of PRDX1 and SOD1, similar results were obtained in HT thyroids. OS due to an increase of ROS produced by NOX4 and a loss of antioxidant defenses (PRDX1, catalase, SOD1) correlates to a reduction of SIRT1 and an upregulation of HIF 1α, GLUT-1, and VEGF-A. Our study placed SIRT1 as a key regulator of OS and we, therefore, believe it could be considered as a potential therapeutic target in HT.

Molecular Pathology of Non-familial Follicular Epithelial-Derived Thyroid Cancer in Adults: From RAS/BRAF-like Tumor Designations to Molecular Risk Stratification

This review addresses the impact of molecular alterations on the diagnosis and prognosis of differentiated thyroid carcinoma (DTC), including papillary, follicular, and well-differentiated carcinoma NOS, as well as oncocytic neoplasms. The molecular characterization of DTC is based upon the well-established dichotomy of BRAF-like and RAS-like designations, together with a remaining third group, less homogeneous, composed of non-BRAF-/non-RAS-like tumors. The role of BRAF V600E mutation in risk stratification is discussed in the clinico-pathological context, namely, staging and invasive features of classic papillary thyroid carcinoma (PTC) and histopathological variants carrying an excellent prognosis (microPTC) or a guarded prognosis, including the aggressive variants tall cell and hobnail cell PTCs. In follicular patterned tumors, namely, follicular thyroid carcinoma (FTC), with or without oncocytic features, the most prevalent molecular alteration are RAS mutations that do not carry prognostic significance. The only genetic alteration that has been proven to play a role in risk stratification of PTC and FTC is TERT promoter (TERTp) mutation.

Shared and unique metabolic features of the malignant and benign thyroid lesions determined with use of 1H HR MAS NMR spectroscopy

The purpose of this work was to investigate the distinct and common metabolic features of the malignant and benign thyroid lesions in reference to the non-transformed tissue from the contralateral gland (chronic thyroiditis and colloid goiter). 1H HR MAS NMR spectra of 38 malignant lesions, 32 benign lesions and 112 samples from the non-tumoral tissue (32 from chronic thyroiditis and 80 samples from colloid goiter) were subjected both to multivariate and univariate analysis. The increased succinate, glutamine, glutathione, serine/cysteine, ascorbate, lactate, taurine, threonine, glycine, phosphocholine/glycerophosphocholine and decreased lipids were found in both lesion types in comparison to either colloid goiter or chronic thyroiditis. The elevated glutamate and choline, and reduced citrate and glucose were additionally evident in these lesions in reference to goiter, while the increased myo-inositol-in comparison to thyroiditis. The malignant lesions were characterized by the higher alanine and lysine levels than colloid goiter and thyroiditis, while scyllo-inositol was uniquely increased in the benign lesions (not in cancer) in comparison to both non-tumoral tissue types. Moreover, the benign lesions presented with the unique increase of choline in reference to thyroiditis (not observed in the cancerous tissue). The metabolic heterogeneity of the non-tumoral tissue should be considered in the analysis of metabolic reprogramming in the thyroid lesions.

Hashimoto's thyroiditis as a risk factor for thyroid cancer

PURPOSE OF REVIEW

To summarize the recent developments in considering Hashimoto's thyroiditis as a risk factor for thyroid cancer.

RECENT FINDINGS

Modern approaches to understanding the co-occurrence of Hashimoto's thyroiditis and thyroid cancer have consistently found increased prevalence of both conditions, separately as well as of their coexistence. The inflammatory process in Hashimoto's thyroiditis is understood as a potential risk factor for thyroid cancer development. This has also provided a better understanding of the limitations in the current diagnostic and follow-up armamentarium for both conditions, resulting in international guidelines from the clinical and scientific societies. Other recent developments call for a paradigm shift in guidelines on thyroid carcinomas when lymphocytic infiltration is present, which potentially should always be considered the case at least in areas of sufficient iodine intake.

SUMMARY

The literature of Hashimoto's thyroiditis as a risk factor for thyroid cancer is reviewed over the last year to highlight new developments in the understanding of their association and future clinical implications.

Higher TSH Is Not Associated With Thyroid Cancer Risk in the Presence of Thyroid Autoimmunity

BACKGROUND

Higher-but-within-normal thyrotropin (thyroid-stimulating hormone, TSH) is associated with higher risk for differentiated thyroid cancer (DTC) in surgical series. Our recent clinical observations suggest that this is not the case in the presence of autoimmune thyroid disease (AITD). We designed the present study to clarify this controversy.

METHODS

We analyzed our prospectively collected database of patients referred for thyroid surgery at 2 tertiary care referral centers in Greece and the United States. We collected data for preoperative TSH, postoperative pathology, and thyroid peroxidase (TPO) antibodies titers. Subjects were subdivided into 2 groups, those with AITD (i.e., lymphocytic thyroiditis) and non-AITD. We excluded subjects with Graves disease, abnormal TSH (< 0.40 or > 4.50 mIU/mL), or recent use of levothyroxine. We compared the serum TSH among different groups using the Mann-Whitney test.

RESULTS

A total of 3973 subjects were screened; 1357 met exclusion criteria. After all exclusions, data from 1731 non-AITD subjects and 329 AITD subjects were included in the analysis. AITD subjects had higher TSH than non-AITD subjects (2.09 vs 1.48; P < 0.0001). TSH values were higher in DTC compared with benign histology only in non-AITD subjects (1.65 vs 1.40; P < 0.0001). Progressively higher TSH was associated with higher incidence of DTC only in non-AITD subjects (P < 0.0001). In AITD subjects, TSH was similar between groups with or without DTC (2.02 vs 2.14; P = 0.21).

CONCLUSIONS

TSH concentrations are not associated with the risk of developing DTC in the presence of thyroid autoimmunity, even though this seems to be the case for all other patients.