Emerging Biomarkers in Thyroid Practice and Research

PD-L1 Expression and Its Modulating Factors in Anaplastic Thyroid Carcinoma: A Multi-institutional Study

Anti-PD immunotherapy is currently under investigation in anaplastic thyroid carcinoma (ATC). Tumor cell surface PD-L1 expression is considered predictive of therapeutic response. Although papillary thyroid carcinoma has been widely studied for PD-L1 expression, there are limited data on ATC. In this retrospective multi-institutional study involving 9 centers across Asia, 179 ATCs were assessed for PD-L1 expression using the SP263 (Ventana) clone. A tumor proportion score (TPS) ≥1% was required to consider a case PD-L1-positive. PD-L1 expression was compared with the histological patterns, the type of specimen (small or large), tumor molecular profile (BRAF V600E and TERT promoter mutation status), and patient outcome. PD-L1 expression in any co-existent differentiated thyroid carcinoma (DTC) was evaluated separately and compared with ATC. Most ATCs (73.2%) were PD-L1-positive. The median TPS among positive cases was 36% (IQR 11% to 75%; range 1% to 99%). A high expression (TPS ≥ 50%) was noted in 30.7%. PD-L1-negative cases were more likely to be small specimens (P=0.01). A negative result on small samples, hence, may not preclude expression elsewhere. ATCs having epithelioid and pleomorphic histological patterns were more likely to be PD-L1-positive with higher TPS than sarcomatoid (P<0.01). DTCs were more frequently negative and had lower TPS than ATC (P<0.01). Such PD-L1 conversion from DTC-negative to ATC-positive was documented in 71% of cases with co-existent DTC. BRAF V600E, but not TERT promoter mutations, correlated significantly with PD-L1-positivity rate (P=0.039), reinforcing the potential of combining anti-PD and anti-BRAF V600E drugs. PD-L1 expression, however, did not impact the patient outcome.

Exploring the potential of genetic analysis in historical blood spots for patients with iodine-deficient goiter and thyroid carcinomas in Switzerland and Germany (1929-1989)

Iodine deficiency-induced goiter continues to be a global public health concern, with varying manifestations based on geography, patient's age, and sex. To gain insights into clinical occurrences, a retrospective study analyzed medical records from patients with iodine deficiency-induced goiter or thyroid cancer who underwent surgery at the Community Hospital in Riehen, Switzerland, between 1929 and 1989. Despite today's adequate iodine supplementation, a significant risk for iodine-independent goiter remains in Switzerland, suggesting that genetic factors, among others, might be involved. Thus, a pilot study exploring the feasibility of genetic analysis of blood spots from these medical records was conducted to investigate and enhance the understanding of goiter development, potentially identify genetic variations, and explore the influence of dietary habits and other environmental stimuli on the disease.Blood prints from goiter patients' enlarged organs were collected per decade from medical records. These prints had been made by pressing, drawing, or tracing (i.e., pressed and drawn) the removed organs onto paper sheets. DNA analysis revealed that its yields varied more between the prints than between years. A considerable proportion of the samples exhibited substantial DNA degradation unrelated to sample collection time and DNA mixtures of different contributors. Thus, each goiter imprint must be individually evaluated and cannot be used to predict the success rate of genetic analysis in general. Collecting a large sample or the entire blood ablation for genetic analysis is recommended to mitigate potential insufficient DNA quantities. Researchers should also consider degradation and external biological compounds' impact on the genetic analysis of interest, with the dominant contributor anticipated to originate from the patient's blood.

Exosome-Mediated Communication in Thyroid Cancer: Implications for Prognosis and Therapeutic Targets

Thyroid cancer (THCA) is one of the most common malignancies of the endocrine system. Exosomes have significant value in performing molecular treatments, evaluating the diagnosis and determining tumor prognosis. Thus, the identification of exosome-related genes could be valuable for the diagnosis and potential treatment of THCA. In this study, we examined a set of exosome-related differentially expressed genes (DEGs) (BIRC5, POSTN, TGFBR1, DUSP1, BID, and FGFR2) by taking the intersection between the DEGs of the TCGA-THCA and GeneCards datasets. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of the exosome-related DEGs indicated that these genes were involved in certain biological functions and pathways. Protein‒protein interaction (PPI), mRNA‒miRNA, and mRNA-TF interaction networks were constructed using the 6 exosome-related DEGs as hub genes. Furthermore, we analyzed the correlation between the 6 exosome-related DEGs and immune infiltration. The Genomics of Drug Sensitivity in Cancer (GDSC), the Cancer Cell Line Encyclopedia (CCLE), and the CellMiner database were used to elucidate the relationship between the exosome-related DEGs and drug sensitivity. In addition, we verified that both POSTN and BID were upregulated in papillary thyroid cancer (PTC) patients and that their expression was correlated with cancer progression. The POSTN and BID protein expression levels were further examined in THCA cell lines. These findings provide insights into exosome-related clinical trials and drug development.

Tumor microenvironment in thyroid cancer: Immune cells, patterns, and novel treatments

The tumor immune microenvironment of thyroid cancer is the heterogeneous histological space in which tumor cells coexist with host cells. Published data from this review were identified by search and selection database of Pubmed, Elsevier, and Science Direct. Searching was made in two steps using different keywords. In thyroid pathology, the inflammatory response is very important, and might have a key role finding new diagnostic and therapeutic methods, particularly in thyroid cancer. Different immune cells may be more or less present in different types of thyroid cancer and may even have different functions, hence the importance of knowing their presence in different thyroid tumor pathologies. Cancer-related inflammation could be a useful target for new diagnostic and therapeutic strategies by analyzing peritumoral and intratumoral immune cells in different types of thyroid tumors. Moreover, novel strategies for thyroid cancer treatments, such as monoclonal antibodies targeting checkpoint inhibitors, are emerging as promising alternatives.

Long-Term Changes of Urinary Exosomal Peptide Levels After Thyroidectomy in Patients with Thyroid Cancer: A Prospective Observational Study

Background

The recurrence rate of thyroid cancer can be as high as 30%. The purpose of this study was to examine changes of urine exosomal peptide levels after thyroidectomy in patients with thyroid cancer to determine if levels can predict the risk of recurrence.

Methods

Patients >20 years old as newly diagnosed with papillary thyroid cancer who had received a thyroidectomy were recruited. Urine samples were collected at 12 months after enrollment to the study, and 1 year later. Urine exosomes containing different peptides were identified and compared.

Results

A total of 70 patients were enrolled in the study, and were classified by the interval between surgery and enrollment: 42 patients with < 5 years between surgery and enrollment, 14 patients between 5-10 years, and 14 patients longer than 10 years. No recurrence was observed in any patient during the 2 years after enrollment. No significant differences were found in the levels of serum proteins or urine exosomal peptides between groups, or between intervals. Known risk factors for high-risk thyroid cancer had only a mild correlation with serum protein levels and urine exosomal peptides.

Conclusion

Our study revealed the long-term basal fluctuation ranges of serum proteins and urine exosomal peptides in patients with thyroid cancer who underwent thyroidectomy. For high-risk patients after thyroidectomy, concentrations of serum proteins or urine exosomal peptides within the ranges may indicate there is a lower risk of thyroid cancer recurrence during long-term follow-up.

Trial Registration

ClinicalTrials.gov: NCT03488134.

Identification of potential targetable genes in papillary, follicular, and anaplastic thyroid carcinoma using bioinformatics analysis

PURPOSE

To perform an extensive exploratory analysis to build a deeper insight into clinically relevant molecular biomarkers in Papillary, Follicular, and Anaplastic thyroid carcinomas (PTC, FTC, ATC).

METHODS

Thirteen Thyroid Cancer (THCA) datasets incorporating PTC, FTC, and ATC were derived from the Gene Expression Omnibus. Genes differentially expressed (DEGs) between THCA and normal were identified and subjected to GO and KEGG analyses. Multiple topological properties were harnessed and protein-protein interaction (PPI) networks were constructed to identify the hub genes followed by survival analysis and validation.

RESULTS

There were 70, 87, and 377 DEGs, and 23, 27, and 53 hub genes for PTC, FTC, and ATC samples, respectively. Survival analysis detected 39 overall and 49 relapse-free survival-relevant hub genes. Six hub genes, BCL2, FN1, ITPR1, LYVE1, NTRK2, TBC1D4, were found common to more than one THCA type. The most significant hub genes found in the study were: BCL2, CD44, DCN, FN1, IRS1, ITPR1, MFAP4, MKI67, NTRK2, PCLO, TGFA. The most enriched and significant GO terms were Melanocyte differentiation for PTC, Extracellular region for FTC, and Extracellular exosome for ATC. Prostate cancer for PTC was the most significantly enriched KEGG pathway. The results were validated using TCGA data.

CONCLUSIONS

The findings unravel potential biomarkers and therapeutic targets of thyroid carcinomas.

Differentiating BRAF V600E- and RAS-like alterations in encapsulated follicular patterned tumors through histologic features: a validation study

Differentiating BRAF V600E- and RAS-altered encapsulated follicular-patterned thyroid tumors based on morphology remains challenging. This study aimed to validate an 8-score scale nuclear scoring system and investigate the importance of nuclear pseudoinclusions (NPIs) in aiding this differentiation. A cohort of 44 encapsulated follicular-patterned tumors with varying degrees of nuclear atypia and confirmed BRAF V600E or RAS alterations was studied. Nuclear parameters (area, diameter, and optical density) were analyzed using a deep learning model. Twelve pathologists from eight Asian countries visually assessed 22 cases after excluding the cases with any papillae. Eight nuclear features were applied, yielding a semi-quantitative score from 0 to 24. A threshold score of 14 was used to distinguish between RAS- and BRAF V600E-altered tumors. BRAF V600E-altered tumors typically demonstrated higher nuclear scores and notable morphometric alterations. Specifically, the nuclear area and diameter were significantly larger, and nuclear optical density was much lower compared to RAS-altered tumors. Observer accuracy varied, with two pathologists correctly identifying genotype of all cases. Observers were categorized into proficiency groups, with the highest group maintaining consistent accuracy across both evaluation methods. The lower group showed a significant improvement in accuracy upon utilizing the 8-score scale nuclear scoring system, with notably increased sensitivity and negative predictive value in BRAF V600E tumor detection. BRAF V600E-altered tumors had higher median total nuclear scores. Detailed reevaluation revealed NPIs in all BRAF V600E-altered cases, but in only 2 of 14 RAS-altered cases. These results could significantly assist pathologists, particularly those not specializing in thyroid pathology, in making a more accurate diagnosis.

Diagnostic criteria and scoring systems for thyroid storm: An evaluation of their utility - comparative review

A thyroid storm is a life-threatening endocrine emergency characterized by severe hyperthyroidism and many systemic manifestations. Prompt recognition and treatment are essential for patient survival. This study evaluates the utility of existing diagnostic criteria and scoring systems for thyroid storm. A comprehensive literature review encompassed articles published up to December 2023. Various diagnostic criteria and scoring systems, such as the Burch-Wartofsky Point Scale and the Japanese Thyroid Association criteria, were critically assessed based on their sensitivity, specificity, and clinical applicability. Our findings reveal that existing diagnostic criteria and scoring systems, although valuable tools, exhibit limitations. They may lack sensitivity in identifying milder cases of thyroid storm or fail to differentiate it from other critical conditions. Furthermore, some criteria rely heavily on subjective clinical Judgment, which can vary among healthcare providers. Future research should focus on refining existing criteria and developing more objective and universally applicable diagnostic tools to address these limitations. Incorporating advanced laboratory markers and modern imaging techniques may enhance diagnostic accuracy. Additionally, a standardized scoring system approach could improve clinical practice consistency. In conclusion, while current diagnostic criteria and scoring systems provide a foundation for identifying thyroid storm, their utility has shortcomings. Advancements in diagnostic methods and a collaborative effort to establish standardized criteria are imperative to enhance the accuracy and reliability of thyroid storm diagnosis, ultimately improving patient outcomes.

Cyto-Histological Profile of MicroRNAs as Diagnostic Biomarkers in Differentiated Thyroid Carcinomas

INTRODUCTION

The repertoire of microRNAs (miRNAs) in thyroid carcinomas starts to be elucidated. Among differentiated thyroid carcinomas (DTCs), papillary thyroid carcinoma (PTC) is the most frequent. The assessment of miRNAs expression may contribute to refine the pre-surgical diagnosis in order to obtain a personalized and more effective treatment for patients.

AIMS

This study aims to evaluate (1) the miRNAs in a series of DTCs, and their association with the presence of selected genetic mutations in order to improve diagnosis and predict the biologic behavior of DTC/PTC. (2) The reliability of molecular tests in Ultrasound-guided Fine Needle Aspiration Cytology (US-FNAC) for a more precise preoperative diagnosis.

MATERIAL AND METHODS

This series includes 176 samples (98 cytology and 78 histology samples) obtained from 106 patients submitted to surgery, including 13 benign lesions (controls) and 93 DTCs (cases). The microRNA expression was assessed for miR-146b, miR-221, miR-222, and miR-15a through quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The results were analyzed by the 2-ΔΔCT method, using miR16 as an endogenous control. Regarding PTC diagnosis, the discriminative ability of miRNAs expression was assessed by the area under the Receiver Operating Characteristic Curve (AUC). In PTCs, the association of miRNAs expression, clinicopathological features, and genetic mutations (BRAF, RAS, and TERTp) was evaluated.

RESULTS/DISCUSSION

All the analyzed miRNAs presented a tendency to be overexpressed in DTCs/PTCs when compared with benign lesions, both in cytology and histology samples. In cytology, miRNAs expression levels were higher in malignant tumors than in benign tumors. In histology, the discriminative abilities regarding PTC diagnosis were as follows: miR-146b (AUC 0.94, 95% CI 0.87-1), miR-221 (AUC 0.79, 95% CI 0.68-0.9), miR-222 (AUC 0.76, 95% CI 0.63-0.89), and miR-15a (AUC 0.85, 95% CI 0.74-0.97). miR-146b showed 89% sensitivity (se) and 87% specificity (sp); miR-221 se = 68.4, sp = 90; miR-222 se = 73, sp = 70; and mi-R15a se = 72, sp = 80. MicroRNAs were associated with worst-prognosis clinicopathological characteristics in PTCs (p < 0.05), particularly for miR-222. Our data reveal a significant association between higher expression levels of miR-146b, miR-221, and miR-222 in the presence of the BRAF mutation (p < 0.001) and miR-146b (p = 0.016) and miR-221 (p = 0.010) with the RAS mutation, suggesting an interplay of these mutations with miRNAs expression. Despite this study having a relatively small sample size, overexpression of miRNAs in cytology may contribute to a more precise preoperative diagnosis. The miRNAs presented a good discriminative ability in PTC diagnosis. The association between the miRNAs expression profile and genetic alterations can be advantageous for an accurate diagnosis of DTCs/PTCs in FNAC.

Bioinformatics analysis for the identification of Sprouty-related EVH1 domain-containing protein 3 expression and its clinical significance in thyroid carcinoma

The poorly differentiated thyroid carcinoma (THCA) subtype is associated with an aggressive disease course, a less favorable overall prognosis, and an increased risk of distant organ metastasis. In this study, our objective was to explore the potential utility of the Sprouty-related EVH1 domain-containing protein 3 (SPRED3) as a biomarker for early diagnosis and prognosis in THCA patients. The differentially expressed prognostic-related genes associated with THCA were identified by querying The Cancer Genome Atlas (TCGA) database. The difference in the expression of the SPRED3 gene between thyroid carcinoma (THCA) tissues and normal tissues was analyzed using data from The Cancer Genome Atlas (TCGA) and further validated through immunohistochemistry. Univariate and multivariate Cox regression models were used, along with clinical information from THCA patients, to analyze the prognostic value of the SPRED3 gene in THCA patients. Functional enrichment analysis was subsequently performed to elucidate the molecular mechanisms underlying the regulatory effects of the SPRED3 gene on thyroid carcinoma. Additionally, we calculated the percentage of infiltrating immune cells in THCA patients and evaluated their correlation with SPRED3 gene expression. Compared with those in noncancerous thyroid tissue, the gene and protein expression levels of SPRED3 were found to be elevated in thyroid carcinoma tissues. Furthermore, the expression of SPRED3 in thyroid carcinoma exhibited significant correlations with tumor location, histological grade, pathological stage, and tumor node metastasis classification (TNM) stage. Univariate and multivariate Cox proportional hazards (Cox) regression analyses demonstrated that SPRED3 could serve as an independent prognostic factor for predicting the overall survival of THCA patients. The results of functional enrichment analysis suggested the potential involvement of SPRED3 in the regulation of extracellular matrix organization, epidermal development, signaling receptor activator activity, skin development, receptor ligand activity, glycosaminoglycan binding, neuroactive ligand‒receptor interaction, the IL-17 signaling pathway, and the PI3K-Akt signaling pathway. Additionally, there were significant correlations between the expression level of the SPRED3 gene and the infiltration of various immune cells (eosinophils, central memory T cells, neutrophils, macrophages, and NK cells) within the thyroid tumor microenvironment. SPRED3 can be used as a prognostic biomarker in patients with THCA could potentially be therapeutic target for THCA.

GPX4 inhibits apoptosis of thyroid cancer cells through regulating the FKBP8/Bcl-2 axis

GPX4 has attracted much attention as a key molecule of cell ferroptosis, but its role in cell apoptosis is rarely reported, and its role in apoptosis of thyroid cancer (TC) cell has not been reported. The analysis of TCGA database showed that both GPX4 and FKBP8 were highly expressed in TC tumor tissues; The expression of GPX4 and FKBP8 were positively correlated. The immunohistochemical analysis further confirmed that GPX4 and FKBP8 were highly expressed in TC tumor tissues. In addition, the high expression of GPX4 and FKBP8 were both significantly correlated with the poor prognosis of TC. Silencing GPX4 significantly inhibited the proliferation, induced apoptosis of TC cells, and reduced tumor growth in mice. The co-immunoprecipitation assay revealed a physical interaction between GPX4 and FKBP8 observed in the TC cells. Knockdown of FKBP8 significantly inhibited the proliferation and induced apoptosis of TC cells. Rescue experiments suggested that knockdown of FKBP8 could reverse the strengthens of cell proliferation and apoptosis and the higher expression of FKBP8 and Bcl-2 caused by overexpression of GPX4. Our results suggest that the GPX4/FKBP8/Bcl-2 axis promotes TC development by inhibiting TC cell apoptosis, which provides potential molecular targets for TC therapeutic strategies.

Advances and challenges in thyroid cancer: The interplay of genetic modulators, targeted therapies, and AI-driven approaches

Thyroid cancer continues to exhibit a rising incidence globally, predominantly affecting women. Despite stable mortality rates, the unique characteristics of thyroid carcinoma warrant a distinct approach. Differentiated thyroid cancer, comprising most cases, is effectively managed through standard treatments such as thyroidectomy and radioiodine therapy. However, rarer variants, including anaplastic thyroid carcinoma, necessitate specialized interventions, often employing targeted therapies. Although these drugs focus on symptom management, they are not curative. This review delves into the fundamental modulators of thyroid cancers, encompassing genetic, epigenetic, and non-coding RNA factors while exploring their intricate interplay and influence. Epigenetic modifications directly affect the expression of causal genes, while long non-coding RNAs impact the function and expression of micro-RNAs, culminating in tumorigenesis. Additionally, this article provides a concise overview of the advantages and disadvantages associated with pharmacological and non-pharmacological therapeutic interventions in thyroid cancer. Furthermore, with technological advancements, integrating modern software and computing into healthcare and medical practices has become increasingly prevalent. Artificial intelligence and machine learning techniques hold the potential to predict treatment outcomes, analyze data, and develop personalized therapeutic approaches catering to patient specificity. In thyroid cancer, cutting-edge machine learning and deep learning technologies analyze factors such as ultrasonography results for tumor textures and biopsy samples from fine needle aspirations, paving the way for a more accurate and effective therapeutic landscape in the near future.

An eXplainable Artificial Intelligence analysis of Raman spectra for thyroid cancer diagnosis

Raman spectroscopy shows great potential as a diagnostic tool for thyroid cancer due to its ability to detect biochemical changes during cancer development. This technique is particularly valuable because it is non-invasive and label/dye-free. Compared to molecular tests, Raman spectroscopy analyses can more effectively discriminate malignant features, thus reducing unnecessary surgeries. However, one major hurdle to using Raman spectroscopy as a diagnostic tool is the identification of significant patterns and peaks. In this study, we propose a Machine Learning procedure to discriminate healthy/benign versus malignant nodules that produces interpretable results. We collect Raman spectra obtained from histological samples, select a set of peaks with a data-driven and label independent approach and train the algorithms with the relative prominence of the peaks in the selected set. The performance of the considered models, quantified by area under the Receiver Operating Characteristic curve, exceeds 0.9. To enhance the interpretability of the results, we employ eXplainable Artificial Intelligence and compute the contribution of each feature to the prediction of each sample.

2023 European Thyroid Association Clinical Practice Guidelines for thyroid nodule management

With the widespread use of sensitive imaging techniques, which include neck visualization, a conspicuous number of thyroid nodules emerge and demand attention. Most lesions are benign, asymptomatic, and do not warrant treatment. In the case of cancer diagnosis, most are small, intrathyroidal and indolent neoplasms that can safely be managed conservatively. There is a pronounced need for more cost-effective, risk-adapted approaches to the management of this highly prevalent condition, taking the wishes of the patient into consideration. Thus, the present guidelines aim at providing a clinical practice guide for the initial workup and the subsequent management of adult individuals harboring thyroid nodules. Importantly, these guidelines are not intended to cover the management of thyroid malignancy. The manuscript and the specific recommendations were developed by reconciling the best available research evidence with the knowledge and clinical experience of the panelists and updating aspects of a number of previous European Thyroid Association guidelines.

Identification of NIFTP-Specific mRNA Markers for Reliable Molecular Diagnosis of Thyroid Tumors

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a low-risk thyroid tumor with a favorable prognosis. Nonetheless, differentiating NIFTP from other thyroid tumors remains challenging, necessitating reliable diagnostic markers. This study is aimed at discovering NIFTP-specific mRNA markers through RNA sequencing analysis of thyroid tumor tissues. We performed mRNA expression profiling for 74 fresh frozen thyroid tissue samples, including NIFTP and benign and malignant follicular-cell-derived tumors. NIFTP/malignant tumors showed 255 downregulated genes and 737 upregulated genes compared to benign tumors. Venn diagram analysis revealed 19 significantly upregulated and 7 downregulated mRNAs in NIFTP. Akaike information criterion analysis allowed us to select OCLN, ZNF423, LYG1, and AQP5 mRNA markers. We subsequently developed a predictive model based on logistic regression analysis using these four mRNAs, which we validated in independent samples (n = 90) using a qRT-PCR assay. This model demonstrated high accuracy in predicting NIFTP in discovery dataset (AUC (area under the receiver operating characteristic) = 0.960) and the validation dataset (AUC = 0.757). Our results suggest that OCLN, ZNF423, LYG1, and AQP5 mRNA markers might serve as reliable molecular markers for identifying NIFTP among other thyroid tumors, ultimately aiding in accurate diagnosis and management of NIFTP patients.

A Comparative Analysis of NOX4 Protein Expression in Malignant and Non-Malignant Thyroid Tumors

The comparative analysis of the expression of the reactive oxygen species-generating NADPH oxidase NOX4 from TCGA data shows that the NOX4 transcript is upregulated in papillary thyroid carcinomas (PTC)-BRAF^V600E tumors compared to PTC-BRAF^wt tumors. However, a comparative analysis of NOX4 at the protein level in malignant and non-malignant tumors is missing. We explored NOX4 protein expression by immunohistochemistry staining in malignant tumors (28 classical forms of PTC (C-PTC), 17 follicular variants of PTC (F-PTC), and three anaplastic thyroid carcinomas (ATCs)) and in non-malignant tumors (six lymphocytic thyroiditis, four Graves' disease, ten goiters, and 20 hyperplasias). We detected the BRAF^V600E mutation by Sanger sequencing and digital droplet PCR. The results show that NOX4 was found to be higher (score ≥ 2) in C-PTC (92.9%) compared to F-PTC (52.9%) and ATC (33.3%) concerning malignant tumors. Interestingly, all C-PTC-BRAF^V600E expressed a high score for NOX4 at the protein level, strengthening the positive correlation between the BRAF^V600E mutation and NOX4 expression. In addition, independent of the mutational status of BRAF, we observed that 90% of C-PTC infiltrating tumors showed high NOX4 expression, suggesting that NOX4 may be considered a complementary biomarker in PTC aggressiveness. Interestingly, NOX4 was highly expressed in non-malignant thyroid diseases with different subcellular localizations.

Reevaluating diagnostic categories and associated malignancy risks in thyroid core needle biopsy

As the application of core needle biopsy (CNB) in evaluating thyroid nodules rises in clinical practice, the 2023 Korean Thyroid Association Management Guidelines for Patients with Thyroid Nodules have officially recognized its value for the first time. CNB procures tissue samples preserving both histologic structure and cytologic detail, thereby supplying substantial material for an accurate diagnosis and reducing the necessity for repeated biopsies or subsequent surgical interventions. The current review introduces the risk of malignancy within distinct diagnostic categories, emphasizing the implications of noninvasive follicular thyroid neoplasm with papillary-like nuclear features on these malignancy risks. Prior research has indicated diagnostic challenges associated with follicular-patterned lesions, resulting in notable variation within indeterminate diagnostic categories. The utilization of mutation-specific immunostaining in CNB enhances the accuracy of lesion classification. This review underlines the essential role of a multidisciplinary approach in diagnosing follicular-patterned lesions and the potential of mutation-specific immunostaining to strengthen diagnostic consensus and inform patient management decisions.

The new insights into autophagy in thyroid cancer progression

In recent decades, the incidence of thyroid cancer keeps growing at a shocking rate, which has aroused increasing concerns worldwide. Autophagy is a fundamental and ubiquitous biological event conserved in mammals including humans. Basically, autophagy is a catabolic process that cellular components including small molecules and damaged organelles are degraded for recycle to meet the energy needs, especially under the extreme conditions. The dysregulated autophagy has indicated to be involved in thyroid cancer progression. The enhancement of autophagy can lead to autophagic cell death during the degradation while the produced energies can be utilized by the rest of the cancerous tissue, thus this influence could be bidirectional, which plays either a tumor-suppressive or oncogenic role. Accordingly, autophagy can be suppressed by therapeutic agents and is thus regarded as a drug target for thyroid cancer treatments. In the present review, a brief description of autophagy and roles of autophagy in tumor context are given. We have addressed summary of the mechanisms and functions of autophagy in thyroid cancer. Some potential autophagy-targeted treatments are also summarized. The aim of the review is linking autophagy to thyroid cancer, so as to develop novel approaches to better control cancer progression.

Advances in Molecular Profiling and Their Potential Influence on the Extent of Surgery in Well-Differentiated Thyroid Carcinoma (WDTC)

Thyroid cancer surgery has evolved dramatically with advances in our understanding of the biological behaviour of WDTC. Molecular profiling is shedding light on the subset that may behave aggressively. In an era when thyroid cancer management is becoming increasingly conservative, decision making regarding the extent of surgery must be objectively guided by molecular markers. The aim of the present article is to summarise the current published literature and provide possible practice recommendations. An online search for relevant published articles was performed using several databases. Title, abstract, and full-text screening, along with data extraction, was performed by two independent reviewers after the inclusion and exclusion criteria were defined. A total of 1241 articles were identified, and 82 relevant articles were extracted and scrutinised. BRAF V600E and TERT promoter mutations were found to be associated with an increased risk of disease recurrence and distant metastases. Several other mutations have been identified that enhance disease aggressiveness (such as RET/PTC, PTEN, and TP53). One of the most important determinants of the outcome in WDTC is the extent of surgical resection. The evolution of molecular testing has reached a stage of personalised incorporation into surgical practice. Guidelines for molecular testing and surgery in WDTC will need to be clearly defined, arguably representing the next chapter in the management of the disease.

Immunohistochemistry in the pathologic diagnosis and management of thyroid neoplasms

The use of immunohistochemistry cannot be underestimated in the everyday practice of thyroid pathology. It has evolved over the years beyond the traditional confirmation of thyroid origin to molecular profiling and the prediction of clinical behavior. In addition, immunohistochemistry has served to implement changes in the current thyroid tumor classification scheme. It is prudent to perform a panel of immunostains, and the immunoprofile should be interpreted in light of the cytologic and architectural features. Immunohistochemistry can also be easily performed in the limited cellularity specimen preparation generated from thyroid fine-needle aspiration and core biopsy; however, it will require laboratory validation of immunostains specific to these preparations to avoid diagnostic pitfalls. This review discusses the application of immunohistochemistry in thyroid pathology with a focus on limited cellularity preparations.

Recent Advances in the Surgical Management of Thyroid Cancer

A growing incidence of differentiated thyroid cancer (DTC) has been reported in most developed countries, corresponding mainly to incidentally discovered small papillary thyroid carcinomas. Given the excellent prognosis of most patients with DTC, optimal therapeutic management, minimizing complications, and preserving patient quality of life are essential. Thyroid surgery has a central role in both the diagnosis, staging, and treatment of patients with DTC. Thyroid surgery should be integrated into the global and multidisciplinary management of patients with DTC. However, the optimal surgical management of DTC patients is still controversial. In this review article, we discuss the recent advances and current debates in DTC surgery, including preoperative molecular testing, risk stratification, the extent of thyroid surgery, innovative surgical tools, and new surgical approaches.

Targeting Tumor Microenvironment Akt Signaling Represents a Potential Therapeutic Strategy for Aggressive Thyroid Cancer

Effects of the tumor microenvironment (TME) stromal cells on progression in thyroid cancer are largely unexplored. Elucidating the effects and underlying mechanisms may facilitate the development of targeting therapy for aggressive cases of this disease. In this study, we investigated the impact of TME stromal cells on cancer stem-like cells (CSCs) in patient-relevant contexts where applying in vitro assays and xenograft models uncovered contributions of TME stromal cells to thyroid cancer progression. We found that TME stromal cells can enhance CSC self-renewal and invasiveness mainly via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway. The disruption of Akt signaling could diminish the impact of TME stromal cells on CSC aggressiveness in vitro and reduce CSC tumorigenesis and metastasis in xenografts. Notably, disrupting Akt signaling did not cause detectable alterations in tumor histology and gene expression of major stromal components while it produced therapeutic benefits. In addition, using a clinical cohort, we discovered that papillary thyroid carcinomas with lymph node metastasis are more likely to have elevated Akt signaling compared with the ones without metastasis, suggesting the relevance of Akt-targeting. Overall, our results identify PI3K/Akt pathway-engaged contributions of TME stromal cells to thyroid tumor disease progression, illuminating TME Akt signaling as a therapeutic target in aggressive thyroid cancer.

Update on C-Cell Neuroendocrine Neoplasm: Prognostic and Predictive Histopathologic and Molecular Features of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a C-cell-derived epithelial neuroendocrine neoplasm. With the exception of rare examples, most are well-differentiated epithelial neuroendocrine neoplasms (also known as neuroendocrine tumors in the taxonomy of the International Agency for Research on Cancer [IARC] of the World Health Organization [WHO]). This review provides an overview and recent evidence-based data on the molecular genetics, disease risk stratification based on clinicopathologic variables including molecular profiling and histopathologic variables, and targeted molecular therapies in patients with advanced MTC. While MTC is not the only neuroendocrine neoplasm in the thyroid gland, other neuroendocrine neoplasms in the thyroid include intrathyroidal thymic neuroendocrine neoplasms, intrathyroidal parathyroid neoplasms, and primary thyroid paragangliomas as well as metastatic neuroendocrine neoplasms. Therefore, the first responsibility of a pathologist is to distinguish MTC from other mimics using appropriate biomarkers. The second responsibility includes meticulous assessment of the status of angioinvasion (defined as tumor cells invading through a vessel wall and forming tumor-fibrin complexes, or intravascular tumor cells admixed with fibrin/thrombus), tumor necrosis, proliferative rate (mitotic count and Ki67 labeling index), and tumor grade (low- or high-grade) along with the tumor stage and the resection margins. Given the morphologic and proliferative heterogeneity in these neoplasms, an exhaustive sampling is strongly recommended. Routine molecular testing for pathogenic germline RET variants is typically performed in all patients with a diagnosis of MTC; however, multifocal C-cell hyperplasia in association with at least a single focus of MTC and/or multifocal C-cell neoplasia are morphological harbingers of germline RET alterations. It is of interest to assess the status of pathogenic molecular alterations involving genes other than RET like the MET variants in MTC families with no pathogenic germline RET variants. Furthermore, the status of somatic RET alterations should be determined in all advanced/progressive or metastatic diseases, especially when selective RET inhibitor therapy (e.g., selpercatinib or pralsetinib) is considered. While the role of routine SSTR2/5 immunohistochemistry remains to be further clarified, evidence suggests that patients with somatostatin receptor (SSTR)-avid metastatic disease may also benefit from the option of ¹⁷⁷Lu-DOTATATE peptide radionuclide receptor therapy. Finally, the authors of this review make a call to support the nomenclature change of MTC to C-cell neuroendocrine neoplasm to align this entity with the IARC/WHO taxonomy since MTCs represent epithelial neuroendocrine neoplasms of endoderm-derived C-cells.

Risk assessment of cytologically indeterminate thyroid nodules with integrated molecular testing and repeat biopsy: a surgical decision-oriented tool

BACKGROUND

The preoperative diagnosis of cytologically indeterminate thyroid nodules (ITNs) is very challenging. In this study, we aim to provide an integrated risk assessment for thyroid nodules with indeterminate cytology to guide surgical decision-making, which includes results of blood tests, molecular tests, and repeat fine-needle aspiration biopsy (FNAB).

METHODS

The study retrospectively included 265 ITNs between June 2019 and April 2022. According to our integrated risk assessment process that starts with blood testing, followed by supplementary DNA mutation detection on the first FNAB, and finally repeat FNAB, we divided the ITNs into high-risk and low-risk groups. Performance was evaluated with sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under the receiver operating characteristic curve (AUC), and the consistency between the risk evaluation and histological results.

RESULTS

Of the 265 ITNs, 87 were included in the risk assessment process. The risk assessment had a sensitivity of 84.1%, specificity of 83.3%, PPV of 95.1%, NPV of 57.7%, and AUC of 0.837. The nodules with consistent results between the risk groups and histological outcomes, which included malignant cases in the high-risk group and benign cases in the low-risk group, accounted for 83.9% of all risk-assessed nodules.

CONCLUSIONS

These data suggest that the integrated risk assessment might provide proper information for surgical decision-making in patients with ITNs.

Application of dual-source computed tomography in the diagnosis of thyroid cancer and evaluation of biological behaviors

OBJECTIVE

Thyroid cancer (TC) is an extremely prevailing malignant endocrine tumor. Therefore, effective diagnostic tools are necessary. This study explored the application value of dual-source computed tomography (DSCT) in TC diagnosis and biological behavior assessment.

METHODS

This study retrospectively selected 68 TC patients and another 74 benign patients with thyroid adenoma, nodular goiter, or adenomatous hyperplasia. All patients were confirmed by pathological examination and underwent DSCT examination. The iodine concentration (IC) obtained from plain computed tomography (CT) scanning and normalized iodine concentration (NIC) in the arterial phase and venous phase were recorded. The positive expression rates of estrogen receptor alpha (ERα), estrogen receptors beta (ERβ), and Ki67 in pathological tissues were determined by immunohistochemistry, and their correlation with IC in plain CT was assessed by Pearson correlation analysis, respectively. The diagnostic values of IC in plain CT and venous phase NIC in TC patients were evaluated using the receiver operating characteristic curve.

RESULTS

Malignant patients had lower IC in plain DSCT scanning, venous phase NIC, and ERβ, and higher ERα and Ki67 than benign patients. IC level in plain DSCT scanning was inversely-correlated with ERα and Ki-67 positive expression rates, but positively-related to ERβ to different degrees. For the diagnosis of TC patients, the AUC of IC level in plain DSCT was 0.771, with a cut-off value of 1.250 (97.06% sensitivity and 41.89% specificity), and the AUC of venous phase NIC was 0.738, with a cut-off value of 0.825 (100% sensitivity and 43.24% specificity).

CONCLUSION

The IC level obtained from DSCT scanning could assist in the differential diagnosis of malignant and benign thyroid nodules and evaluation of biological behaviors.

Molecular Landscape of Pediatric Thyroid Cancer: A Review

Thyroid carcinomas (TC) are rare in the pediatric population; however, they constitute the most common endocrine malignancy. Despite some similarities with adult carcinomas, they have distinct clinical behavior and responses to therapy due to their unique pathology and molecular characteristics. The age cut-off used for defining the pediatric age group has been variable across different studies, and the universally accepted recommendations influence accurate interpretation of the available data. Moreover, factors such as radiation exposure and germline mutations have greater impact in children than in adults. Papillary TC is the most common and the most evaluated pediatric TC. Others, including follicular, poorly differentiated and medullary carcinomas, are rarer and have limited available literature. Most studies are from the West. Asian studies are primarily from Japan, with few from China, India, Saudi Arabia and Republic of Korea. This review provides a comprehensive account of the well-established and novel biomarkers in the field, including point mutations, fusions, miRNA, and thyroid differentiation genes. Familial and syndromic associations are also discussed. Current management guidelines for pediatric patients are largely derived from those for adults. An awareness of the molecular landscape is essential to acknowledge the uniqueness of these tumors and establish specific diagnostic and therapeutic guidelines.

Kinase Fusion-Related Thyroid Carcinomas: Towards Predictive Models for Advanced Actionable Diagnostics

The past decade has brought significant advances in our understanding of the molecular mechanisms of thyroid carcinogenesis. Among thyroid carcinomas, the most successful class of targeted therapeutics appears to be selective kinase inhibitors. Actionable kinase fusions arise in around 10-15% of cases of thyroid cancer, a significant subset. A cohort of molecular testing platforms, both commercial and laboratory-derived, has been introduced into clinical practice to identify patients with targetable tumors, requiring pathologists to develop an integrative approach that utilizes traditional diagnostic cytopathology and histopathology, immunohistochemistry, and cutting-edge molecular assays for optimal diagnostic, prognostic, and therapeutic efficiency. Furthermore, there has been increasing scrutiny of the clinical behavior of kinase fusion-driven thyroid carcinoma (KFTC), still regarded as papillary thyroid carcinomas, and in characterizing molecular predictors of kinase inhibitor resistance with an aim to establish standardized, evidence-based treatment regimens. This review presents an overview of the current literature on the clinicopathologic and molecular features of KFTC as well as the latest investigational progress and encountered challenges for this unique subset of thyroid neoplasias.

Immunohistochemical Profile of Parathyroid Tumours: A Comprehensive Review

Immunohistochemistry remains an indispensable tool in diagnostic surgical pathology. In parathyroid tumours, it has four main applications: to detect (1) loss of parafibromin; (2) other manifestations of an aberrant immunophenotype hinting towards carcinoma; (3) histogenesis of a neck mass and (4) pathogenetic events, including features of tumour microenvironment and immune landscape. Parafibromin stain is mandatory to identify the new entity of parafibromin-deficient parathyroid neoplasm, defined in the WHO classification (2022). Loss of parafibromin indicates a greater probability of malignant course and should trigger the search for inherited or somatic CDC73 mutations. Aberrant immunophenotype is characterised by a set of markers that are lost (parafibromin), down-regulated (e.g., APC protein, p27 protein, calcium-sensing receptor) or up-regulated (e.g., proliferation activity by Ki-67 exceeding 5%) in parathyroid carcinoma compared to benign parathyroid disease. Aberrant immunophenotype is not the final proof of malignancy but should prompt the search for the definitive criteria for carcinoma. Histogenetic studies can be necessary for differential diagnosis between thyroid vs. parathyroid origin of cervical or intrathyroidal mass; detection of parathyroid hormone (PTH), chromogranin A, TTF-1, calcitonin or CD56 can be helpful. Finally, immunohistochemistry is useful in pathogenetic studies due to its ability to highlight both the presence and the tissue location of certain proteins. The main markers and challenges (technological variations, heterogeneity) are discussed here in the light of the current WHO classification (2022) of parathyroid tumours.

Personalized Diagnosis in Differentiated Thyroid Cancers by Molecular and Functional Imaging Biomarkers: Present and Future

Personalized diagnosis can save unnecessary thyroid surgeries, in cases of indeterminate thyroid nodules, when clinicians tend to aggressively treat all these patients. Personalized diagnosis benefits from a combination of imagery and molecular biomarkers, as well as artificial intelligence algorithms, which are used more and more in our timeline. Functional imaging diagnosis such as SPECT, PET, or fused images (SPECT/CT, PET/CT, PET/MRI), is exploited at maximum in thyroid nodules, with a long history in the past and a bright future with many suitable radiotracers that could properly contribute to diagnosing malignancy in thyroid nodules. In this way, patients will be spared surgery complications, and apparently more expensive diagnostic workouts will financially compensate each patient and also the healthcare system. In this review we will summarize essential available diagnostic tools for malignant and benignant thyroid nodules, beginning with functional imaging, molecular analysis, and combinations of these two and other future strategies, including AI or NIS targeted gene therapy for thyroid carcinoma diagnosis and treatment as well.

S-100 Immunohistochemical Positivity in Rhabdomyoma: An Underestimated Potential Diagnostic Pitfall in Routine Practice

A 66-year-old man presented with a 2.8 cm lesion of the left vocal cord. On contrast-enhanced computed tomography scans, the tumor extended to the supraglottis, subglottis, paraglottic space and anterior commissure, causing partial obstruction of the laryngeal lumen. At another hospital, a fragmented incisional biopsy was diagnosed as a granular cell tumor, as to the S-100 immunohistochemical positivity. After excision, the tumor revealed to be an adult-type laryngeal rhabdomyoma. The typical cytoplasmic rod-like inclusions and cross striations were more evident in the second specimen. We confirmed the unusual S-100 immunohistochemical positivity (variable intensity, >90% of tumor cells). Muscle markers were not performed on the previous biopsy, resulting positive in our specimen (Desmin: strong, diffuse expression; Smooth Muscle Actin: strong staining in 10% of tumor cells). Melan-A, CD68, GFAP, pan-cytokeratins, CEA, calretinin and neurofilaments resulted negative. To our brief, systematic literature review, S-100 positivity (usually variable, often weak or patchy/focal) was globally found in 19/34 (56%) adult-type rhabdomyomas of the head and neck region. Especially on fragmented biopsy material, the differential diagnoses of laryngeal rhabdomyomas may include granular cell tumors, oncocytic tumors of the salivary glands or of different origin, and paragangliomas.

Molecular diagnosis and targeted treatment of advanced follicular cell-derived thyroid cancer in the precision medicine era

Most malignant thyroid tumours are initially treated with surgery or a combination of surgery and radioactive iodine (RAI) therapy. However, in patients with metastatic disease, many tumours become refractory to RAI, and these patients require alternative treatments, such as locoregional therapies and/or systemic treatment with multikinase inhibitors. Improvements in our understanding of the genetic alterations that occur in thyroid cancer have led to the discovery of several targeted therapies with clinical efficacy. These alterations include NTRK (neurotrophic tyrosine receptor kinase) gene fusions, with the tropomyosin receptor kinase inhibitors larotrectinib and entrectinib both approved by the European Medicines Agency and in other markets worldwide. Inhibitors of aberrant proteins resulting from alterations in RET (rearranged during transfection) and BRAF (B-Raf proto-oncogene) have also shown promising efficacy, and so far have received approval by the US Food and Drug Administration. Selpercatinib, a RET kinase inhibitor, was approved for use in Europe in early 2021. With the discovery of multiple actionable targets, it is imperative that effective testing strategies for these genetic alterations are integrated into the diagnostic armamentarium to ensure that patients who could potentially benefit from targeted treatments are identified. In this review, we offer our recommendations on the optimal testing strategies for detecting genetic alterations in thyroid cancer that have the potential to be targeted by molecular therapy. We also discuss the future of treatments for thyroid cancers, including the use of immune checkpoint inhibitors, and new generations of targeted treatments that are being developed to counter acquired tumour resistance.

Update on International Medical Taxonomies of Biomarkers and Their Applications in Management of Thyroid Cancers

Biomarkers (BMs) are medical signs which can be precisely measured and reproduced. Mainly, BMs provide information on the likely disease which can occur in an individual. On the other hand, BMs also signal disease recurrence in patients receiving therapy. The U.S. Food and Drug Administration coupled with the National Institutes of Health and the European Medicines Agency have proposed two distinct procedures to validate BMs. These agencies have elaborated two glossaries to describe the role of BMs. The aim of this study was to investigate medical taxonomies adopted by different governmental agencies for BM validation. Additional goals were to analyze efficiencies of the validated and candidate BMs for thyroid cancers (TCs). Currently, thyroglobulin is validated for monitoring TCs. Sorafenib-tosylate, Doxorubicin-hydrochloride, Vandetanib, Cabozantinib-s-malate, Dabrafenib-mesylate, Trametinib-dimethyl-sulfoxide, Lenvatinib-mesylate, Pralsetinib and Selpercatinib are validated for TC treatment. Among candidate BMs for TC diagnosis, there are molecular combinations including BRAF, RAS, RET/PTC and PAX8-PPARγ mutations. Noteworthy are BRAF and RET/PTC alterations already validated as targets of Dabrafenib-mesylate, Pralsetinib and Selpercatinib. Finally, cellular expressions of c-met in nodal TC metastases have diagnostic imaging applications. On the basis of this analysis, BM taxonomies should have common standards internationally recognized. BMs show different efficiencies depending on their diagnostic or therapeutic use.