Molecular profiling of thyroid nodule fine-needle aspiration cytology

An enzyme-free sensing platform for miRNA detection and in situ imaging in clinical samples based on DNAzyme cleavage-triggered catalytic hairpin assembly

MicroRNA (miRNA) is demonstrated to be associated with the occurrence and development of various diseases including cancer. Currently, most miRNA detection methods are confined to in vitro detection and cannot obtain information on the temporal and spatial expression of miRNA in relevant tissues and cells. In this work, we established a novel enzyme-free method that can be applied to both in vitro detection and in situ imaging of miRNA by integrating DNAzyme and catalytic hairpin assembly (CHA) circuits. This developed CHA-Amplified DNAzyme miRNA (CHAzymi) detection system can realize the quantitively in vitro detection of miR-146b (the biomarker of papillary thyroid carcinoma, PTC) ranging from 25 fmol to 625 fmol. This strategy has also been successfully applied to in situ imaging of miR-146b both in human PTC cell TPC-1 and clinical samples, showing its capacity as an alternative diagnostic method for PTC. Furthermore, this CHAzymi system can be employed as a versatile sensing platform for various miRNAs by revising the relevant sequences. The results imply that this system may expand the modality of miRNA detection and show promise as a novel diagnostic tool in clinical settings, providing valuable insights for effective treatment and management of the disease.

BRAF Detection in FNAC Combined with Semi-Quantitative 99mTc-MIBI Technique and AI Model, an Economic and Efficient Predicting Tool for Malignancy in Thyroid Nodules

BACKGROUND

Technology allows us to predict a histopathological diagnosis, but the high costs prevent the large-scale use of these possibilities. The current liberal indication for surgery in benign thyroid conditions led to a rising frequency of incidental thyroid carcinoma, especially low-risk papillary micro-carcinomas.

METHODS

We selected a cohort of 148 patients with thyroid nodules by ultrasound characteristics and investigated them by fine needle aspiration cytology (FNAC)and prospective BRAF collection for 70 patients. Also, we selected 44 patients with thyroid nodules using semi-quantitative functional imaging with an oncological, 99mTc-methoxy-isobutyl-isonitrile (99mTc-MIBI) radiotracer.

RESULTS

Following a correlation with final histopathological reports in patients who underwent thyroidectomy, we introduced the results in a machine learning program (AI) in order to obtain a pattern. For semi-quantitative functional visual pattern imaging, we found a sensitivity of 33%, a specificity of 66.67%, an accuracy of 60% and a negative predicting value (NPV) of 88.6%. For the wash-out index (WOind), we found a sensitivity of 57.14%, a specificity of 50%, an accuracy of 70% and an NPV of 90.06%.The results of BRAF in FNAC included 87.50% sensitivity, 75.00% specificity, 83.33% accuracy, 75.00% NPV and 87.50% PPV. The prevalence of malignancy in our small cohort was 11.4%.

CONCLUSIONS

We intend to continue combining preoperative investigations such as molecular detection in FNAC, 99mTc-MIBI scanning and AI training with the obtained results on a larger cohort. The combination of these investigations may generate an efficient and cost-effective diagnostic tool, but confirmation of the results on a larger scale is necessary.

GeneAI 3.0: powerful, novel, generalized hybrid and ensemble deep learning frameworks for miRNA species classification of stationary patterns from nucleotides

Due to the intricate relationship between the small non-coding ribonucleic acid (miRNA) sequences, the classification of miRNA species, namely Human, Gorilla, Rat, and Mouse is challenging. Previous methods are not robust and accurate. In this study, we present AtheroPoint's GeneAI 3.0, a powerful, novel, and generalized method for extracting features from the fixed patterns of purines and pyrimidines in each miRNA sequence in ensemble paradigms in machine learning (EML) and convolutional neural network (CNN)-based deep learning (EDL) frameworks. GeneAI 3.0 utilized five conventional (Entropy, Dissimilarity, Energy, Homogeneity, and Contrast), and three contemporary (Shannon entropy, Hurst exponent, Fractal dimension) features, to generate a composite feature set from given miRNA sequences which were then passed into our ML and DL classification framework. A set of 11 new classifiers was designed consisting of 5 EML and 6 EDL for binary/multiclass classification. It was benchmarked against 9 solo ML (SML), 6 solo DL (SDL), 12 hybrid DL (HDL) models, resulting in a total of 11 + 27 = 38 models were designed. Four hypotheses were formulated and validated using explainable AI (XAI) as well as reliability/statistical tests. The order of the mean performance using accuracy (ACC)/area-under-the-curve (AUC) of the 24 DL classifiers was: EDL > HDL > SDL. The mean performance of EDL models with CNN layers was superior to that without CNN layers by 0.73%/0.92%. Mean performance of EML models was superior to SML models with improvements of ACC/AUC by 6.24%/6.46%. EDL models performed significantly better than EML models, with a mean increase in ACC/AUC of 7.09%/6.96%. The GeneAI 3.0 tool produced expected XAI feature plots, and the statistical tests showed significant p-values. Ensemble models with composite features are highly effective and generalized models for effectively classifying miRNA sequences.

[Molecular and other ancillary tests proposed by The Bethesda system for reporting thyroid cytopathology 2023]

For the first time the 2023 version of The Bethesda System for Reporting Thyroid Cytology dedicates a whole chapter (chapter 14) to ancillary studies almost exclusively represented by molecular testing. The latest data reported bring some evidence that molecular testing could help to optimize the diagnostic performance of « indeterminate » categories (AUS and NF). Other studies suggest a promising role to guide the management of suspicious of malignancy and malignant categories. Indeed, the recognition of prognostic and predictive biomarkers analyzed on cytological samples, regardless of how it is collected, has progressed thanks to advances in our knowledge of molecular abnormalities of thyroid tumors. The chapter 14 is presented here highlighting the current and emerging roles of « in-house » and commercialized molecular testing as presented by TSBRTC.

Thyroid Nodules: Emerging Trends in Detection and Visualization based on Citespace

BACKGROUND

Thyroid nodule (TN) is a highly prevalent clinical endocrine disease. Many countries have formed guidelines on the prevention and treatment of TN based on extensive research. However, there is a scarcity of TN-related literature based on bibliometrics.

OBJECTIVES

This study aimed to evaluate the scientific achievements and progress of TN research from a global perspective by investigating the literature for 20 years through bibliometrics.

METHODS

We searched the literature on TN in the core collection of the Web of Science database from 2002 to 2021 and used the Citespace software to analyze the co-authorship, co-citation, and co-occurrence of countries, institutions, authors, keywords, and co-cited literature.

RESULTS

We retrieved 12319 documents related to TN. The literature on TN has been growing since 2002. The United States has contributed the largest proportion of TN papers (20.64%), followed by China, Italy, and South Korea. The United States ranked first in terms of centrality (0.38). Haugen BR, Gharib H, and Cibas ES are the top three most cited authors. The papers published in Thyroid were cited most frequently (7952 times). The most prominent keywords were management, cancer, fine needle aspiration, diagnosis, malignant tumor, thyroid cancer, ultrasound, biopsy, benign, surgery, ablation, and cytology. All keywords could be divided into three categories: diagnosis stratification, treatment, and cancer. As far as potential hot spots are concerned, the keywords that have recently burst strongly and are still continuing are: "Association Guideline" (2018-2021), "Radiofrequency Ablation" (2017-2021), "Classification" (2019-2021), and "Data System" (2017-2021).

CONCLUSION

Based on the current trends, the number of publications on TN will continue to increase. The United States is the most active contributor to research in this field. Previous literature focused on stratification, cancer, surgery, and ablation, and there were different opinions on the stratification of diagnosis. There were relatively few studies on pathogenesis and treatment using medicine. More focus will be placed on association guidelines, radiofrequency ablation, classification, and data system, which may be the next popular topics in TN research.

Case Report: Giant abdominal hemangioma originating from the liver

Background

Hepatic hemangioma is among the most common benign liver lesions. However, giant pedunculated hepatic hemangiomas are exceptionally rare and associated with additional risks, such as torsion.

Case presentation

We present the case of a 63-year-old female patient who presented with abdominal distension and pain. Barium meal examination and gastroscopy revealed a large, smooth-surfaced submucosal bulge located at the fundus of the stomach. Subsequent MRI examination identified a mass measuring approximately 6.4 x 7 cm in the left upper abdomen. Surgical intervention was planned for mass removal. However, intraoperative exploration revealed the origin of the mass to be the liver, and subsequent histopathological examination confirmed it as a hemangioma.

Conclusion

We systematically summarized the characteristics of our case along with 31 previously reported cases. Giant pedunculated hepatic hemangiomas typically occur in the left lobe of the liver. Due to their atypical presentation, a combination of imaging methods such as ultrasound, CT, and/or MRI is essential for accurate diagnosis. Furthermore, surgical intervention is recommended due to the potential risks of bleeding, rupture, and torsion.

Molecular Testing Results for Indeterminate Thyroid Nodules and Social Habits

INTRODUCTION

The effects of smoking and alcohol use on the risk of thyroid cancer remain unclear. We sought to investigate the association between these social habits, molecular testing results, and the risk of thyroid cancer.

METHODS

We conducted a retrospective chart review of patients with indeterminate thyroid nodules (Bethesda III and IV) who underwent molecular testing. The frequency of abnormal molecular testing results was compared among patients with varying smoking and alcohol consumption habits.

RESULTS

Of 460 patients, median age was 51.8 y, 78.3% were female, 60.7% were White, and 79.8% presented with Bethesda III nodules. The rate of malignancy was 42.6% overall; 73.4% of molecular testing was performed with Afirma, 20.1% with ThyroSeq, and 5.0% with ThyGeNEXT. For social habits, 72.2% never smoked and 40.9% never drank alcohol. Never/rare drinkers were less likely to have abnormal results compared to routine drinkers when considering all types of molecular testing together (83.2% versus 91.3%, P = 0.046), as were those who underwent ThyroSeq molecular testing (71.8% versus 94.4%, P = 0.045). Multivariable analysis revealed that being a routine drinker (adjusted OR 2.19, 95% CI 1.08-4.88), having a larger lesion (adjusted OR 0.65, 95% CI 0.54-0.77), being tested by ThyroSeq (adjusted OR 0.41, 95% CI 0.22-0.76), and other commercial panels (adjusted OR 0.12, 95% CI 0.02-0.64) were independent predictors of abnormal molecular testing results.

CONCLUSIONS

Our patients' social habits may be associated with the molecular testing results of their indeterminate thyroid nodules but not with their surgical pathology results.

Diagnostic Performance of Afirma and Interpace Diagnostics Genetic Testing in Indeterminate Thyroid Nodules: A Single Center Study

Indeterminate thyroid nodules (ITN) represent 20–30% of biopsied nodules, with a 10–60% risk of malignancy. Molecular testing can stratify the risk of malignancy among ITNs, and subsequently reduce the need for unnecessary diagnostic surgery. We aimed to assess the performance of these molecular tests at a single institution. Patients with Bethesda III, IV, and V nodules with Afirma and Interpace Diagnostics genetic testing data from November 2013 to November 2021 were included. Three cohorts were formed, including GSC + XA, ThyGeNEXT + ThyraMIR, and GSC + GEC. Statistical analysis determined the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and accuracy of each type of testing. The PPV of nodules undergoing genetic testing by ThyGeNEXT + ThyraMIR (45.00%, 95%CI: 28.28–62.93%, p = 0.032) and GSC + XA (57.14%, 95%CI: 29.32–81.08%, p < 0.001) were superior to that of GEC + GSC (30.72%, 95%CI: 26.83–34.90%). The NPV was above 85% in all cohorts, suggesting overall suitable rule-out tests. The Afirma platform (GSC + XA) had the highest NPV at 96.97%. The overall accuracy for nodules undergoing ThyGeNEXT + ThyraMIR was 81.42% (95%CI: 73.01–88.11%, p < 0.001). A total of 230 patients underwent thyroidectomy, including less than 60% of each of the ThyGeNEXT + ThyraMIR and GSC + XA cohorts. Specifically, only 25% of patients in the GSC + XA cohort underwent surgery, considerably decreasing the rate of unnecessary surgical intervention. Sub-group analysis, including only patients with surgical pathology, found that PPV tended to be higher in the GSC + XA cohort, at 66.67% (95%CI: 37.28–87.06%), as compared to the ThyGeNEXT + ThyraMIR cohort, at 52.94% (95%CI: 35.25–69.92%). The Afirma genetic testing platform GSC + XA outperformed the other platforms with regards to both PPV and NPV and decreased the rate of surgery in patients with ITNs by 75%, significantly preventing unnecessary surgical intervention.

Longitudinal liver sampling in patients with chronic hepatitis B starting antiviral therapy reveals hepatotoxic CD8+ T cells

Accumulation of activated immune cells results in nonspecific hepatocyte killing in chronic hepatitis B (CHB), leading to fibrosis and cirrhosis. This study aims to understand the underlying mechanisms in humans and to define whether these are driven by widespread activation or a subpopulation of immune cells. We enrolled CHB patients with active liver damage to receive antiviral therapy and performed longitudinal liver sampling using fine-needle aspiration to investigate mechanisms of CHB pathogenesis in the human liver. Single-cell sequencing of total liver cells revealed a distinct liver-resident, polyclonal CD8+ T cell population that was enriched at baseline and displayed a highly activated immune signature during liver damage. Cytokine combinations, identified by in silico prediction of ligand-receptor interaction, induced the activated phenotype in healthy liver CD8+ T cells, resulting in nonspecific Fas ligand-mediated killing of target cells. These results define a CD8+ T cell population in the human liver that can drive pathogenesis and a key pathway involved in their function in CHB patients.

Thyroid cancer under the scope of emerging technologies

The vast majority of thyroid cancers originate from follicular cells. We outline outstanding issues at each step along the path of cancer patient care, from prevention to post-treatment follow-up and highlight how emerging technologies will help address them in the coming years. Three directions will dominate the coming technological landscape. Genomics will reveal tumoral evolutionary history and shed light on how these cancers arise from the normal epithelium and the genomics alteration driving their progression. Transcriptomics will gain cellular and spatial resolution providing a full account of intra-tumor heterogeneity and opening a window on the microenvironment supporting thyroid tumor growth. Artificial intelligence will set morphological analysis on an objective quantitative ground laying the foundations of a systematic thyroid tumor classification system. It will also integrate into unified representations the molecular and morphological perspectives on thyroid cancer.

Testing of mutations on thyroid nodules with indeterminate cytology: A prospective study of 112 patients in Argentina

BACKGROUND

The study of genetic mutations in thyroid nodules makes it possible to improve the preoperative diagnosis of and reduce unnecessary surgeries on benign nodules. In this study, we analysed the impact of implementing a 7-gene mutation panel that enables mutations to be detected in BRAF and RAS (H/N/K) and the gene fusions PAX8/PPARG, RET/PTC1 and RET/PTC2, in a population in northern Argentina.

METHODS

We performed a prospective analysis of 112 fine needle aspirations diagnosed as having indeterminate cytology according to the Bethesda classification system. These include the Bethesda III or atypia of unknown significance/follicular lesion of unknown significance and Bethesda IV or follicular neoplasm/suspicious for follicular neoplasm categories. The mutations of the 7-gene panel were analysed and this information was linked to the available histology and ultrasound monitoring.

RESULTS

The BRAF V600E and RET/PTC1 mutations were associated with carcinoma in 100% of cases (n = 8), whereas only 37.5% (n = 3) of the nodules with RAS and 17% (n = 1) with PAX8/PPARG mutations were associated with carcinoma. From the histological diagnosis and ultrasound monitoring of patients, we can estimate that this panel has a sensitivity of 86% in detecting malignant carcinoma, a specificity of 77%, a positive predictive value (PPV) of 54% and a negative predictive value (NPV) of 94%. In this study, it was possible to reduce the number of surgeries by 48% in the patients analysed.

CONCLUSION

The implementation of the mutation panel allowed the appropriate surgical strategy to be selected for each patient, the number of two-step surgeries to be reduced, and active follow-up to be established in low-risk patients.

Do ACR TI-RADS scores demonstrate unique thyroid molecular profiles?

Purpose

The present study aimed to examine the molecular profiles of cytologically indeterminate thyroid nodules stratified by American College of Radiology Thyroid Imaging Reporting and Data System (TI-RADS) categories and to determine whether certain ultrasonographic features display particular molecular alterations.

Methods

A retrospective review was conducted of cases from January 1, 2016 to April 1, 2018. Cases with in-house ultrasonography, fine-needle aspiration Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) diagnoses, molecular testing, and surgery were included. All cases were diagnosed as TBSRTC indeterminate categories. The ultrasound studies were retrospectively reviewed and assigned TI-RADS scores (TR1-TR5) by board-certified radiologists. The final diagnoses were determined based on the surgical resection pathology. Binary logistic regression analysis was used to study whether demographic characteristics, TI-RADS levels, and TBSRTC diagnoses were associated with ThyroSeq molecular results.

Results

Eighty-one cases met the inclusion criteria. RAS mutations were the most common alteration across all TI-RADS categories (TR2 2/2; TR3 10/19, TR4 13/44, and TR5 8/16), and did not stratify with any particular TI-RADS category. Only TR4 and TR5 categories displayed more aggressive mutations such as BRAF^V600E; and TERT. ThyroSeq results were positively correlated with thyroid malignancy when non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was categorized in the malignant category (odds ratio [OR], 6.859; P<0.01), but not when NIFTP was removed from the malignancy category. Echogenicity scores were found to be negatively correlated with ThyroSeq results in thyroid nodules (OR, 0.162; P<0.01).

Conclusion

Higher-risk molecular alterations tended to stratify with the higher TI-RADS categories.

LncRNA-MIAT promotes thyroid cancer progression and function as ceRNA to target EZH2 by sponging miR-150-5p

While long noncoding RNAs (lncRNAs) have been reported to play an important role in human cancer types, they remain poorly understood in papillary thyroid carcinoma (PTC). The aim of this study was to use genome-wide expression profiling to identify lncRNAs acting as competing endogenous RNAs (ceRNAs) in PTC. We constructed a ceRNA network based on our lncRNA microarray data and validated the correlation between myocardial infarction-associated transcript lncRNA (MIAT), miRNA-150-5p, and EZH2 in vitro and in vivo. We found 15 lncRNAs, 28 miRNAs, and hundreds of mRNAs involved in this ceRNA network. Splendid positive correlations were found between the MIAT and EZH2 expression in types of cancer in TCGA data. Besides, significant differences in MIAT/EZH2 expression were found among various clinicopathological features. Gain- and loss-of-function experiments revealed that MIAT inhibited cell proliferation and migration in vitro. Moreover, EZH2 was identified as a direct downstream target of miR-150-5p in PTC cells. Restoration of EZH2 expression partially abolished the biological effects of miR-150-5p. Furthermore, overexpression of MIAT was inversely correlated with miR-150-5p expression. Knockdown of MIAT produced significant behavioral alter maybe partly due to the function of the MIAT-150-5p-EZH2 network. Our findings suggest MIAT may inhibit EZH2 expression and promote PTC cell invasion via the miR-150/EZH2 pathway. Therefore, MIAT may serve as a valuable prognostic biomarker and therapeutic target for PTC.

Are the anatomical, clinical, and ultrasound characteristics of thyroid nodules with Bethesda III or IV cytology and ACR TI-RADS 3, 4, or 5 able to refine the indications for molecular diagnostic tests?

OBJECTIVE

To analyze the association of clinical, anatomical, and ultrasound (US) characteristics of malignancies in Bethesda III or IV (III-B or IV-B) thyroid nodules.

METHODS

The association between malignancies and the following variables were analyzed: III-B or IV-B, age < 55 years and ≥ 55 years, sex, family history of thyroid cancer, history of irradiation, nodule size, and ACR TI-RADS classification in 62 participants who underwent thyroidectomy.

RESULTS

Of the 62 participants, 87.1% (54/62) were women, 74.2% were < 55 years old, 95.2% had no family history of thyroid cancer, 56.5% had nodules < 2 cm in size, 62.9% were IV-B, and 69.4% were ACR TI-RADS 4. Thirty-two patients had thyroid carcinoma, and 30 had benign histology. Among all factors associated with malignancy, only ACR TI-RADS 5 classification on US was found to be statistically significant (p = 0.014), while III-B with architectural atypia cytological classification was the only one significantly associated with benign status (p = 0.004).

CONCLUSION

Only a high risk of malignancy as assessed using US was able to refine the indication for molecular tests in a group of patients with indeterminate nodules. We found 85% (53/62) of III-B or IV-B thyroid nodules would benefit from available molecular diagnostic tests.

Comprehensive analysis of aberrant alternative splicing related to carcinogenesis and prognosis of papillary thyroid cancer

As a key mechanism, alternative splicing (AS) plays a role in the cancer initiation and development. However, in papillary thyroid cancer (PTC), data for the comprehensive AS event profile and its clinical implications are lacking. Herein, a genome-wide AS event profiling using RNA-Seq data and its correlation with matched clinical information was performed using a 389 PTC patient cohort from the project of The Cancer Genome Atlas (TCGA). We identified 1,925 cancer-associated AS events (CASEs) by comparing paired tumors and neighboring healthy tissues. Parent genes with CASEs remarkably enriched in the pathways were linked with carcinogenesis, such as P53, KRAS, IL6-JAK-STAT3, apoptosis, and MYC signaling. The regulatory networks of AS implied an obvious correlation between the expression of splicing factor and CASE. We identified eight CASEs as predictors for overall survival (OS) and disease-free survival (DFS). The established risk score model based on DFS-associated CASEs successfully predicted the prognosis of PTC patients. From the unsupervised clustering analysis results, it is found that different clusters based on AS correlated with prognosis, molecular features, and immune characteristics. Taken together, the comprehensive genome-wide AS landscape analysis in PTC showed new AS events linked with tumorigenesis and prognosis, which provide new insights for clinical monitoring and therapy for PTC.

Testing of mutations on thyroid nodules with indeterminate cytology: A prospective study of 112 patients in Argentina

BACKGROUND

The study of genetic mutations in thyroid nodules makes it possible to improve the preoperative diagnosis of and reduce unnecessary surgeries on benign nodules. In this study, we analysed the impact of implementing a 7-gene mutation panel that enables mutations to be detected in BRAF and RAS (H/N/K) and the gene fusions PAX8/PPARG, RET/PTC1 and RET/PTC2, in a population in northern Argentina.

METHOD

We performed a prospective analysis of 112 fine needle aspirations diagnosed as having indeterminate cytology according to the Bethesda classification system. These include the Bethesda III or atypia of unknown significance/follicular lesion of unknown significance and Bethesda IV or follicular neoplasm/suspicious for follicular neoplasm categories. The mutations of the 7-gene panel were analysed and this information was linked to the available histology and ultrasound monitoring.

RESULTS

The BRAF V600E and RET/PTC1 mutations were associated with carcinoma in 100% of cases (n=8), whereas only 37.5% (n=3) of the nodules with RAS and 17% (n=1) with PAX8/PPARG mutations were associated with carcinoma. From the histological diagnosis and ultrasound monitoring of patients, we can estimate that this panel has a sensitivity of 86% in detecting malignant carcinoma, a specificity of 77%, a positive predictive value (PPV) of 54% and a negative predictive value (NPV) of 94%. In this study, it was possible to reduce the number of surgeries by 48% in the patients analysed.

CONCLUSION

The implementation of the mutation panel allowed the appropriate surgical strategy to be selected for each patient, the number of two-step surgeries to be reduced, and active follow-up to be established in low-risk patients.

Pathological findings of the retrospective diagnosis of NIFTP (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) in 84 cases from Turkey and systematic review

AIM

The terminology of "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was introduced in 2016; and estimated to cause significant effects in the clinical management of thyroid nodules. The aim of our study is to review our cases that were previously diagnosed as non-invasive encapsulated follicular variant PTC (NI/E-FVPTC) which are compatible with NIFTP and to correlate their follow-up.

METHOD

All thyroidectomy cases evaluated in the last 15 years were screened, and possible NIFTP cases were determined among patients with NI/E-FVPTC and they were re-examined microscopically. Revised histopathological criteria were used for the retrospective diagnosis of NIFTP. Histopathological findings were correlated to follow up information.

RESULTS

Totally 2138 cases had been previously diagnosed with PTC; 481 (22.5%) of them were FVPTC. After microscopic reevaluation of potential NIFTP cases, 84 cases (3.9%) received final diagnosis of NIFTP. 78.6% of NIFTP patients were female (F/M: 66/18); mean age was 49.0, tumor diameter was 22.7 mm and follow-up time was 66.4 months. 17.9% of NIFTP cases were multifocal and 13.1% were bilateral. No recurrence, lymph node involvement or distant metastasis was detected in any of the patients who were followed up. The mean age of the patients who had total thyroidectomy and received RAI was significantly higher than those who did not.

CONCLUSION

Although conservative treatment of NIFTP with lobectomy is recommended, age of the patients has been continuing to be the most important determinant for the clinicians to decide on total thyroidectomy and RAI ablation therapy at our institution.

Value of Pyruvate Carboxylase in Thyroid Fine-Needle Aspiration Wash-Out Fluid for Predicting Papillary Thyroid Cancer Lymph Node Metastasis

The incidence of papillary thyroid carcinoma (PTC) is increasing. Lymph node metastatic status of PTC is a major factor for decision marking of surgery and surgical extend, however, no reliable tool exists for prediction of PTC nodal metastasis, for example, ultrasound cannot qualitatively diagnose and effectively detect central lymph node metastasis (CLNM). Therefore, the development of a new diagnostic biomarker is crucial for CLNM. Metabolic dysregulation is an important factor associated with malignancy and metastasis of tumors. Pyruvate carboxylase (PC) is a major anaplerotic enzyme that catalyzes the carboxylation of pyruvate to form oxaloacetate, which has been suggested to be involved in the tumorigenesis of several cancers, including PTC. This study aimed to explore the role of PC expression in thyroid fine-needle aspiration (FNA) wash-out fluid for predicting CLNM in PTC, and to explore how PC is involved in PTC development. The expression levels of PC in PTC tissues and normal thyroid tissues were first compared based on bioinformatics analysis of public databases, including the Gene Expression Profiling (GEPIA), Oncomine and Gene Expression Omnibus (GEO) databases. Then, the PC mRNA and protein expression levels were measured by RT-PCR and Immunohistochemistry (IHC) in surgical tissues from a total of 42 patients with surgically confirmed PTC, and compared in patients with and without CLNM. Further, to assess PC expression in diagnostic biopsies, a total of 71 thyroid nodule patients with ultrasound-guided FNA wash-out fluid samples and cytological diagnosis were prospectively enrolled in the study. Then, we analyzed the mechanism of PC-mediated PTC progression in vitro. This study showed that PC expression was higher in PTC tissues and thyroid FNA wash-out fluid samples from patients with CLNM than those from patients without CLNM, and that PC-induced PTC metastasis may occur through the TGF-β/Smad-regulated epithelial-mesenchymal transition (EMT) pathway.

The role of ThyroSeq V3 testing in the management of patients with indeterminate thyroid nodules on fine needle aspiration

BACKGROUND

The multigene genomic classifier ThyroSeq V3 has proven to be an effective triage modality in the management of indeterminate thyroid nodules. This study reports on the clinical management of patients with indeterminate thyroid nodules.

METHODS

ThyroSeq V3 testing at our institution was implemented April 1, 2019. Over a 17-month period (1 April 2019 through 31 August 2020). Thirty five indeterminate thyroid nodules were sent for testing; diagnoses included FLUS, suspicious for a follicular/Hurthle cell neoplasm (SFN/SHCN) and suspicious for papillary thyroid carcinoma (SPTC). There were 26 females, nine males; mean age 56 years. Aspirated nodules, mean size of 2 cm, were evaluated by rapid on site evaluation with adequacy assessed by the cytopathologist via telecytology.

RESULTS

Of the 35 nodules, 17 (49%) were positive and 18 (51%) were negative on ThyroSeq Testing. All of the 17 positive nodules (four FLUS, 10 SFN/SHCN, three SPTC) showed neoplastic lesions; five adenomas, one NIFTP and 11 carcinomas on surgical resection. Only 4 (22%) of the 18 nodules that were negative were resected and showed two colloid/adenomatous nodules, one NIFTP and one follicular variant of papillary thyroid carcinoma. As FLUS FNAs were the majority of the indeterminate nodules, a comparison was made pre-and post ThyroSeq testing. Prior to ThyroSeq testing the majority (69%) of the nodules were resected as compared to 36% post implementation; a statistically significant value (P < .005). Surgical resection yielded a majority of benign nodules pre-ThyroSeq testing, 68%, as compared to post-ThyroSeq testing, 25%.

CONCLUSION

Implementation of ThyroSeq V3 testing has led to improvements in clinical management of patients with indeterminate thyroid nodules.

Malignancy risk of hyperfunctioning thyroid nodules compared with non-toxic nodules: systematic review and a meta-analysis

Background

Hyperfunctioning or hot nodules are thought to be rarely malignant. As such, current guidelines recommend that hot nodules be excluded from further malignancy risk stratification. The objective of this systematic review and meta-analysis is to compare the malignancy risk in hot nodules and non-toxic nodules in observational studies.

Methods

Ovid MEDLINE Daily and Ovid MEDLINE, EMBASE, Scopus, and Web of Science databases were searched. Observational studies which met all of the following were included: (1) use thyroid scintigraphy for nodule assessment, (2) inclusion of both hyperfunctioning and non-functioning nodules based on scintigraphy, (3) available postoperative histopathologic nodule results, (4) published up to November 12, 2020 in either English or French. The following data was extracted: malignancy outcomes include malignancy rate, mapping of the carcinoma within the hot nodule, inclusion of microcarcinomas, and presence of gene mutations.

Results

Among the seven included studies, overall incidence of malignancy in all hot thyroid nodules ranged from 5 to 100% in comparison with non-toxic nodules, 3.8–46%. Odds of malignancy were also compared between hot and non-toxic thyroid nodules, separated into solitary nodules, multiple nodules and combination of the two. Pooled odds ratio (OR) of solitary thyroid nodules revealed a single hot nodule OR of 0.38 (95% confidence interval (CI) 0.25, 0.59), toxic multinodular goiter OR of 0.51 (95% CI 0.34, 0.75), and a combined hot nodule OR of 0.45 (95% CI 0.31, 0.65). The odds of malignancy are reduced by 55% in hot nodules; however, the incidence was not zero.

Conclusions

Odds of malignancy of hot nodules is reduced compared with non-toxic nodules; however, the incidence of malignancy reported in hot nodules was higher than expected. These findings highlight the need for further studies into the malignancy risk of hot nodules.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13044-021-00094-1.

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.

Genetic alterations in cfDNA of benign and malignant thyroid nodules based on amplicon-based next-generation sequencing

Background

Circulating cell-free DNA (cfDNA) serves as a biomarker in multiple malignant diseases. However, controversy still surrounds the role of cfDNA detection in the diagnosis and monitoring of papillary thyroid carcinoma (PTC). This study set out to identify the role of cfDNA detection in distinguishing between benign and malignant thyroid nodules.

Methods

Tissue, blood cell, and plasma samples were collected from 10 patients with benign nodules and 10 patients with malignant nodules. The DNA isolated from these samples was subject to PCR-based amplification using primers designed for 50 proto-oncogenes and tumor suppressor genes. PCR products were sequenced using Illumina technology, and the mutations were detected with varScan among sequencing data for each sample and comparative analysis was carried out.

Results

Through amplicon sequencing, we found one non-synonymous somatic mutation in the benign nodules and three in the malignant nodules. Among these four mutations, BRAF^V600E mutation was detected in the tissue samples of 8 out of the 10 PTC patients, but it was not detected in the benign nodules. However, no BRAF^V600E mutation was detected in cfDNA. Further differential analysis of cfDNA indicated that some genes had more mutations in benign patients than in malignant patients, such as MET and IDH, and some genes had more mutations in malignant patients, such as PIK3CA and EZH2.

Conclusions

We found that BRAF^V600E mutation was a credible disease-related mutation in PTC; however, it could not be detected in cfDNA. Moreover, there was a large difference in mutation gene distribution between benign and malignant thyroid nodules.

DNA FISH Diagnostic Assay on Cytological Samples of Thyroid Follicular Neoplasms

Simple Summary

Cytopathology cannot distinguish benign from malignant follicular lesions in 20–30% of cases. These indeterminate cases includes the so-called follicular neoplasms (FNs) according to The Bethesda System for Reporting Thyroid Cytopathology. Frozen samples from 66 classic follicular adenomas (cFAs) and carcinomas (cFTCs) studied by array-comparative genomic hybridization identified three specific alterations of cFTCs (losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X) confirmed by fluorescent in situ hybridization (FISH) in a second independent series of 60 touch preparations from frozen samples of cFAs and cFTCs. In a third independent set of 27 cases of already stained pre-operative fine-needle aspiration cytology samples diagnosed as FNs and histologically verified, FISH analysis using these three markers identified half of cFTCs. Specificity of our assay for identifying cFTCs is higher than 98% which might be comparable with BRAF^600E testing in cases of suspicion of classic papillary thyroid carcinomas.

Abstract

Although fine-needle aspiration cytology (FNAC) is helpful in determining whether thyroid nodules are benign or malignant, this distinction remains a cytological challenge in follicular neoplasms. Identification of genomic alterations in cytological specimens with direct and routine techniques would therefore have great clinical value. A series of 153 cases consisting of 72 and 81 histopathologically confirmed classic follicular adenomas (cFAs) and classic follicular thyroid carcinomas (cFTCs), respectively, was studied by means of different molecular techniques in three different cohorts of patients (pts). In the first cohort (training set) of 66 pts, three specific alterations characterized by array comparative genomic hybridization (aCGH) were exclusively found in half of cFTCs. These structural abnormalities corresponded to losses of 1p36.33-35.1 and 22q13.2-13.31, and gain of whole chromosome X. The second independent cohort (validation set) of 60 pts confirmed these data on touch preparations of frozen follicular neoplasms by triple DNA fluorescent in situ hybridization using selected commercially available probes. The third cohort, consisting of 27 archived cytological samples from an equal number of pts that had been obtained for preoperative FNAC and morphologically classified as and histologically verified to be follicular neoplasms, confirmed our previous findings and showed the feasibility of the DNA FISH (DNA fluorescent in situ hybridization) assay. All together, these data suggest that our triple DNA FISH diagnostic assay may detect 50% of cFTCs with a specificity higher than 98% and be useful as a low-cost adjunct to cytomorphology to help further classify follicular neoplasms on already routinely stained cytological specimens.

MiR-221/222 promote migration and invasion, and inhibit autophagy and apoptosis by modulating ATG10 in aggressive papillary thyroid carcinoma

MicroRNA (miRNA) has been reported to exert important functions in papillary thyroid carcinomas (PTC). However, the role of miRNA in aggressive PTC (APTC) remains unclear. Here, we investigated the diagnostic potentials and mechanisms of miR-221/222 in APTC. Results showed that miR-221/222 were markedly up-regulated in PTC, compared with the adjacent normal tissue (ANT). A high expression of miR-221/222 were associated with a primary tumor, regional lymph node, and distant metastasis (TNM) stage, multicentricity, lymph node metastasis, and extra-thyroidal extension. Receiver operating characteristic (ROC) curve analysis indicated that miR-221/222 could be used as APTC diagnostic markers. Moreover, miR-221/222 tremendously promoted migration and invasion and inhibited apoptosis and autophagy in PTC cells. A luciferase assay showed that miR-221/222 inhibited the fluorescent activity of autophagy-related protein 10 (ATG10). Furthermore, miR-221/222 decreased ATG10 mRNA and protein levels. Silencing of ATG10 significantly abrogated the effect of miR-221/222 on apoptosis and autophagy. We suggested that miR-221/222 can promote migration and invasion, and inhibit autophagy and apoptosis by targeting ATG10 in APTC.

Malignancy rates for Bethesda III and IV thyroid nodules: a retrospective study of the correlation between fine-needle aspiration cytology and histopathology

BACKGROUND

Fine-needle aspiration cytology (FNAC) has become a well-established modality in the diagnosis, staging and follow-up of thyroid nodules. FNAC outcomes are routinely classified using the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), facilitating appropriate clinical management. Bethesda categories III and IV encompass varying risks of malignancy. This retrospective study established a possible association between these cytological categories and malignancy rates in patients treated at a single institution.

METHODS

Over a 6-year period, 11,627 FNAC procedures were performed on thyroid nodules. Of these, 814 (59.63%) patients were submitted to thyroidectomy. The nodules of 108 patients were classified as Bethesda category III and 47 patients as Bethesda category IV. Patient data were reviewed to establish a correlation between the FNAC results and the final histopathological analyses.

RESULTS

The rates of malignancy among patients who underwent surgery were 25% for category III and 27.6% for category IV, with no significant differences between categories (p = 0.67). The pathological parameters of malignant nodules, namely tumour type, size, encapsulation, invasion into the thyroid capsule, extrathyroidal extension and lymphovascular invasion did not significantly differ between the groups (p > 0.05).

CONCLUSIONS

This paper provides a more precise correlation of malignancy rates with thyroid nodules classified as Bethesda categories III and IV, as our findings are comparable to the literature, giving malignancy rates ranging from 10 to 30% for category III and 25-40% for category IV. Use of the BSRTC is heterogeneous across institutions, and there is some degree of subjectivity in the distinction between categories III and IV; therefore, it is crucial to estimate the rates of malignancy at each institution. Molecular assays are of increasing importance in determining the need for surgical intervention for thyroid lesions. Gene expression assays using FNAC material may demonstrate a high predictive value for cytologically indeterminate thyroid nodules diagnosed as Bethesda classes III and IV.

Differential Diagnosis of Malignant Lymphadenopathy Using Flow Cytometry on Fine Needle Aspirate: Report on 269 Cases

Introduction: Fine needle aspiration (FNA) is frequently the first noninvasive test used for the diagnostic workup of lymphadenopathy. There have been many studies showing its usefulness, especially in conjunction with other techniques for the diagnosis of lymphoma, but it remains inferior to histological examination. The data regarding this subject have mostly been reported mostly from first-world countries, but are scarce for emerging economies. Thus, the current study assesses the agreement between fine needle aspiration flow cytometry (FNA FC) and histology in the aforementioned region. Material and Methods: We conducted a retrospective study including the FNA FC adenopathy diagnoses made between January 2011 and December 2016 at the Tygerberg Hospital, Cape Town, South Africa. Additional variables included were the histological diagnosis, sex and age of the included patients. Results: In the descriptive part of the current study, 269 FNA FC samples were included. The most frequent diagnoses made on these were represented by B-cell lymphoma, reactive adenopathy, no abnormality detected (NAD), and non-hematological malignancy. In the analytical part of the current study, there were 115 cases included that had both valid FNA FC and histological diagnoses. It could be observed that FNA FC can correctly diagnose B-cell lymphoma in most cases, but it is a poor diagnostic tool especially for Hodgkin lymphoma in this setting as only a four-color flow cytometer was available for diagnosis. Moreover, FNA FC diagnosis of reactive adenopathy and of no abnormalities detected was shown to frequently hide a malignant disease. Conclusion: In countries with scarce resources, FNA FC represents a useful diagnostic tool in the case of B-cell lymphoma, but may misdiagnose reactive adenopathy. Thus, FNA FC should be used in a case-specific manner, in addition to as a screening tool, with the knowledge that in cases with a high clinical suspicion of lymphoma, histological diagnosis is a necessity.

Thyroid Nodule Molecular Testing: Is It Ready for Prime Time?

Cytologically indeterminate thyroid nodules remain a diagnostic and clinical challenge, and molecular testing has been advocated and advanced as a diagnostic modality to help guide treatment. While studies have expounded on the improved diagnostic certainty with these tests, data demonstrating meaningful clinical impact and supporting their routine use is still limited at best. In this review, we discuss the limitations regarding diagnostic accuracy, impact on surgical decision-making and outcomes, and cost-effectiveness of molecular testing. By highlighting the limitations of these tests, we aim to promote more thoughtful utilization of these tools in the management of thyroid nodules going forward.

Performance of a Multigene Genomic Classifier in Thyroid Nodules With Indeterminate Cytology: A Prospective Blinded Multicenter Study

Question

Can the diagnosis of benign disease or cancer in thyroid nodules with indeterminate cytology be established by molecular testing instead of diagnostic surgery?

Findings

This prospective, blinded, multicenter cohort study of a multigene genomic classifier (ThyroSeq v3) test included 257 indeterminate cytology thyroid nodules with informative test results. It demonstrated a high sensitivity (94%) and reasonably high specificity (82%), with 61% of the nodules yielding a negative test result and only 3% residual cancer risk in these nodules.

Meanings

Up to 61% of patients with indeterminate cytology thyroid nodules may avoid diagnostic surgery by undergoing multigene genomic classifier testing.

Importance

Approximately 20% of fine-needle aspirations (FNA) of thyroid nodules have indeterminate cytology, most frequently Bethesda category III or IV. Diagnostic surgeries can be avoided for these patients if the nodules are reliably diagnosed as benign without surgery.

Objective

To determine the diagnostic accuracy of a multigene classifier (GC) test (ThyroSeq v3) for cytologically indeterminate thyroid nodules.

Design, Setting, and Participants

Prospective, blinded cohort study conducted at 10 medical centers, with 782 patients with 1013 nodules enrolled. Eligibility criteria were met in 256 patients with 286 nodules; central pathology review was performed on 274 nodules.

Interventions

A total of 286 FNA samples from thyroid nodules underwent molecular analysis using the multigene GC (ThyroSeq v3).

Main Outcomes and Measures

The primary outcome was diagnostic accuracy of the test for thyroid nodules with Bethesda III and IV cytology. The secondary outcome was prediction of cancer by specific genetic alterations in Bethesda III to V nodules.

Results

Of the 286 cytologically indeterminate nodules, 206 (72%) were benign, 69 (24%) malignant, and 11 (4%) noninvasive follicular thyroid neoplasms with papillary-like nuclei (NIFTP). A total of 257 (90%) nodules (154 Bethesda III, 93 Bethesda IV, and 10 Bethesda V) had informative GC analysis, with 61% classified as negative and 39% as positive. In Bethesda III and IV nodules combined, the test demonstrated a 94% (95% CI, 86%-98%) sensitivity and 82% (95% CI, 75%-87%) specificity. With a cancer/NIFTP prevalence of 28%, the negative predictive value (NPV) was 97% (95% CI, 93%-99%) and the positive predictive value (PPV) was 66% (95% CI, 56%-75%). The observed 3% false-negative rate was similar to that of benign cytology, and the missed cancers were all low-risk tumors. Among nodules testing positive, specific groups of genetic alterations had cancer probabilities varying from 59% to 100%.

Conclusions and Relevance

In this prospective, blinded, multicenter study, the multigene GC test demonstrated a high sensitivity/NPV and reasonably high specificity/PPV, which may obviate diagnostic surgery in up to 61% of patients with Bethesda III to IV indeterminate nodules, and up to 82% of all benign nodules with indeterminate cytology. Information on specific genetic alterations obtained from FNA may help inform individualized treatment of patients with a positive test result.

Digital Gene Expression Analysis on Cytology Smears Can Rule Out Malignancy in Follicular-Patterned Thyroid Tumors

Patients with indeterminate thyroid nodules (Bethesda III and IV) are often treated with diagnostic lobectomy, which in most cases represents an overtreatment. A reliable rule-out molecular test could spare patients unnecessary surgery. Stained smears of 88 indeterminate thyroid nodules with histologic diagnosis of follicular-patterned tumors were selected: 34 follicular adenomas (FAs), 34 follicular variant papillary thyroid carcinomas (FVPTCs), and 20 noninvasive follicular neoplasms with papillary-like nuclear features (NIFTPs). The expression level of 126 genes was measured by digital counting. Mutation testing was performed for the main gene mutations and fusions. Performance of gene expression and mutation tests was calculated by receiver operating characteristic analysis. The gene expression model showed an area under the curve (AUC) of 88%, with 91% negative predictive value in FAs and FVPTCs only. Part of NIFTPs was labeled as benign, and part was labeled as malignant; thus, the classifier performance worsened. Two FAs (5.9%), eight NIFTPs (40%), and 22 FVPTCs (64.7%) were mutation positive. Mutation testing AUC was 79% in FAs and FVPTCs, and decreased by including NIFTPs. This gene expression-based test was feasible in thyroid-stained smears, showed higher AUC than mutation test, and had a high negative predictive value-making it a good candidate as a rule-out test for indeterminate thyroid cytology. NIFTPs have a heterogeneous phenotype, and their preoperative diagnosis requires further investigation.

Nomogram for the diagnosis of suspected papillary thyroid carcinomas based on sonographic patterns: a retrospective study

Background

High resolution ultrasonography (US) is the first choice for diagnosis of thyroid cancer and is based on many sonographic features: composition, echogenicity, margins, calcifications, shape and vascularity. Here, we tried to develop a nomogram to evaluate papillary thyroid carcinoma (PTC) based on sonographic features.

Methods

From Aug 2016 to Dec 2017, a primary cohort of 382 patients with suspicious thyroid nodules and accepted US examinations were included in Gansu Provincial Hospital. Sonographic features were used to develop a nomogram with Cox regression analysis. The nomogram was validated using prospective data from 162 patients as the validation group.

Results

The primary and validation cohort showed comparable clinical and US features in all aspects. Univariate and multivariate analyses showed solid composition [odds ratio (OR): 3.785; 95% confidence interval (CI): 1.504-9.528, P=0.005], hypoechoic (OR: 15.840; 95% CI: 5.754-43.602, P<0.001) and irregular margins (OR: 15.953; 95% CI: 5.897-43.160, P<0.001), microcalcifications (OR: 21.730; 95% CI: 7.119-66.329, P<0.001), taller than wide shape (OR: 5.153; 95% CI: 1.997-13.311, P=0.001), internal high vascularization (OR: 6.288; 95% CI: 2.175-18.181, P=0.001), and obscure borders (OR: 5.648; 95% CI: 2.118-15.065, P=0.001) as risk factors for PTC. Based on the seven risk factors, nomogram was developed and validated by a prospective group, and discrimination and calibration were measured using the concordance index (C-index).

Conclusions

Our novel nomogram risk score model based on the US features accurately predicted PTC nodule diagnosis.

DNA Methylation-Based Method to Differentiate Malignant from Benign Thyroid Lesions

Background: The differential diagnosis of thyroid nodules using fine-needle aspiration biopsy (FNAB) is challenging due to the inherent limitation of the cytology tests. The use of molecular markers has potential to complement the FNAB-based diagnosis and avoid unnecessary surgeries. In this study, we aimed to identify DNA methylation biomarkers and to develop a diagnostic tool useful for thyroid lesions. Methods: Genome-wide DNA methylation profiles (Illumina 450K) of papillary thyroid carcinoma (PTC = 60) and follicular thyroid carcinoma (FTC = 10) were compared with non-neoplastic thyroid tissue samples (NT = 50) and benign thyroid lesions (BTL = 17). The results were confirmed in publicly available databases from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) using the same DNA methylation platform. Two classifiers were trained to discriminate FTC and PTC from BTL. To increase the applicability of the method, six differentially methylated CpGs were selected and evaluated in 161 thyroid tumors and 69 BTL postsurgical specimens and 55 prospectively collected FNAB using bisulfite-pyrosequencing. Results: DNA methylation analysis revealed 2130 and 19 differentially methylated CpGs in PTC and FTC, respectively. The CpGs confirmed by GEO and TCGA databases showing high areas under the receiver operating characteristic curve in all sample sets were used to train our diagnostic classifier. The model based on six CpGs was able to differentiate benign from malignant thyroid lesions with 94.3% sensitivity and 82.4% specificity. A similar performance was found applying the algorithm to TCGA and GEO external data sets (91.3-97.4% sensitivity and 87.5% specificity). We successfully evaluated the classifiers using a bisulfite-pyrosequencing technique, achieving 90.7% sensitivity and 75.4% specificity in surgical specimens (five of six CpGs). The study comprising FNAB cytology materials corroborated the applicability and performance of the methodology, demonstrating 86.7% sensitivity and 89.5% specificity in confirmed malignant tumors, and 100% sensitivity and 89% specificity in cases with indeterminate cytology. Conclusions: A novel diagnostic tool with potential application in preoperative screening of thyroid nodules is reported here. The proposed protocol has the potential to avoid unnecessary thyroidectomies.

Identification of a Five-CpG Signature with Diagnostic Value in Thyroid Cancer

Thyroid cancer (TC) ranks as the most common endocrine malignancy, and its incidence and mortality rates continue to rise annually. Increasing evidence have shown that DNA methylation, a kind of stable epigenetic modification, is associated with carcinogenesis, suggesting its potential as biomarkers for the early detection of tumors. With the aim of exploring likely DNA methylation biomarkers for TC diagnosis, we conducted a synthetic analysis of DNA methylation profiles based on 789 samples from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In the discovery phase, we identified five CpG probes (cg11228682, cg01291854, cg06778183, cg01668008, and cg01702055) on the condition of DNA methylation data from GSE86961 (n = 82) and constructed a five-CpG signature-based diagnostic model for TC. In addition, we validated the diagnostic score formula in two independent training cohorts, GSE97466 (n = 141) and TCGA (n = 566), as well as the previous developing cohort GSE86961. Receiver operating characteristic analysis revealed that the five-CpG signature had a good diagnostic performance to distinguish TC samples from benign samples. In conclusion, our findings suggest that the five-CpG signature could provide a novel biomarker with useful applications in TC diagnosis.

Concomitant Thyroid Cancer in Patients with Multiple Endocrine Neoplasia Type 1 Undergoing Surgery for Primary Hyperparathyroidism

BACKGROUND

Compared to those with sporadic primary hyperparathyroidism (SPHP), multiple endocrine neoplasia type 1 (MEN1) patients with primary hyperparathyroidism (MPHP) typically require more extensive dissection and have higher recurrence rates. Little is known about the risk of concomitant thyroid cancer in either setting. This study aimed to determine the rates and characteristics of thyroid cancer for MPHP versus SPHP patients undergoing parathyroidectomy.

METHODS

Patients with MPHP (diagnosed by clinical and/or genetic criteria) or SPHP who had initial or reoperative parathyroid exploration from 1967 to 2014 were identified via a prospective database. The thyroid cancer-specific data for MPHP patients (n = 29) were compared to a selected 2:1 age- and sex-matched SPHP cohort (n = 58) who all had concurrent thyroidectomy for any reason. Clinically significant thyroid cancer was defined as >1 cm in diameter.

RESULTS

In the MPHP group, 24/29 (83%) thyroidectomies were preoperatively unplanned versus 20/58 (34%) in the SPHP matched cohort (p < 0.01), and in this setting there was no difference in the rate of histologic thyroid cancer (3/24 [13%] vs. 5/20 [25%], p = 0.44). Histologic thyroid cancer was identified in 8/29 (28%) MPHP versus 27/58 (47%) SPHP patients (p = 0.11). Despite observed differences in the time period and extent of thyroidectomy, MPHP patients did not have an increased likelihood of thyroid cancer (surgery before 2005: odds ratio [OR] = 2.57, p = 0.09; total thyroidectomy: OR = 5.47, p < 0.01; MPHP: OR = 1.14, p = 0.83). All MPHP thyroid cancers were characterized as conventional papillary thyroid cancer (PTC), while thyroid cancers in SPHP patients included both PTC (66%) and follicular-variant PTC (34%). No MPHP patient had clinically significant thyroid cancer compared to an incidence of 15/58 (26%) in SPHP patients (p < 0.01).

CONCLUSIONS

Although patients with MEN1 have a substantial incidence of thyroid cancer (28%) and undergo more unplanned thyroidectomies during parathyroidectomy than do patients with SPHP, clinically significant thyroid cancer is proportionally uncommon.

TIRADS score is of limited clinical value for risk stratification of indeterminate cytological results

CONTEXT

Thyroid nodules with cytological indeterminate results represent a daily and recurrent issue for patient management.

OBJECTIVE

The primary aim of our study was to determine if TIRADS (Thyroid Imaging Reporting and Data System) could be used to stratify the malignancy risk of these nodules and to help in their clinical management. Secondary objective was to estimate if this risk stratification would change after reclassification of encapsulated non-invasive follicular variant of papillary carcinomas (FVPTC) as non-invasive follicular thyroid neoplasm (NIFTP).

PATIENTS AND METHODS

Single-center retrospective study of a cohort of 602 patients who were referred for ultrasound-guided fine-needle aspiration from January 2010 to December 2016 with an indeterminate cytological result and in whom histological results after surgery were available. TIRADS score was prospectively determined for all patients included. Nodules that had been classified as FVPTC were submitted to a rereading of histological report and reclassified as NIFTP when judged relevant. A table of malignancy risk crossing Bethesda and TIRADS results was built before and after this reclassification.

RESULTS

The study included 602 cytologically indeterminate nodules. TIRADS score was positively correlated with the malignancy rate (P < 0.0001). Risk stratification with TIRADS was significant only in Bethesda V nodules (P = 0.0004). However, the risk of malignancy in this Bethesda V category was always above 45%, whatever the TIRADS score.

CONCLUSION

For a clinician facing an indeterminate cytological result for a thyroid nodule, return to TIRADS score is of limited value in most conditions to rule in or rule out malignancy and to guide subsequent management of patients.

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP): impact on the reclassification of thyroid nodules

The 2017 edition of the WHO book on Classification of Tumours of Endocrine Organs includes a new section entitled 'Other encapsulated follicular-patterned thyroid tumours', in which the newly created NIFTP (non-invasive follicular thyroid neoplasm with papillary-like nuclear features) is identified and described in detail. Despite deleting the word 'carcinoma' from its name, NIFTP is not a benign tumor either and is best regarded as a neoplasm with 'very low malignant potential'. The main goal of the introduction of NIFTP category is to prevent overdiagnosis and overtreatment. Sampling constraints, especially when dealing with heterogeneous and/or large nodules, and difficulties in the invasiveness evaluation, are the major weaknesses of the histological characterization of NIFTP. At the cytological level, NIFTP can be separated from classic papillary carcinoma (cPTC) but not from encapsulated, invasive follicular variant PTC. The impact of NIFTP individualization for cytopathology is the drop of rates of malignancy for each Bethesda category in general and for indeterminate categories in particular. The biggest impact will be seen in institutions with a high frequency of FVPTC. The introduction of NIFTP has changed the utility of predictive values of molecular tests because RAS mutations and PAX8-PPARg rearrangements are frequently detected in NIFTP. This turns less promising the application of mutation detection panels as indicators of malignancy and will probably contribute to switch to a rule-out approach of molecular testing. Selection for surgery will go on being determined by a combined detection of clinical, cytological and ultrasound suspicious features.

Molecular Testing of Nodules with a Suspicious or Malignant Cytologic Diagnosis in the Setting of Non-Invasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features (NIFTP)

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is an indolent thyroid tumor characterized by frequent RAS mutations and an absence of the BRAF V600E mutation commonly seen in classical papillary thyroid carcinoma (cPTC). The ability to differentiate potential NIFTP/follicular variant of papillary thyroid carcinoma (FVPTC) from cPTC at the time of fine-needle aspiration (FNA) can facilitate conservative management of NIFTP. The aim of the current study was to investigate how molecular testing may add to cytologic assessment in the pre-operative differentiation of potential NIFTP/FVPTC and cPTC. We had previously evaluated cytologists' ability to prospectively distinguish potential NIFTP/FVPTC from cPTC in a cohort of 56 consecutive FNAs diagnosed as malignant or suspicious for malignancy. We utilized this cohort to perform molecular analysis. Detected molecular abnormalities were stratified into two groups: (1) those supporting malignancy and (2) those supporting a diagnosis of potential NIFTP/FVPTC. The cytologists' characterization of cases and the detected molecular alterations were correlated with the final histologic diagnoses. Molecular testing was performed in 52 (93%) of the 56 cases. For the 37 cases cytologists favored to be cPTC, 31 (84%) had a molecular result that supported malignancy (28 BRAF V600E mutations, 2 NTRK1 fusions, 1 AGK-BRAF fusion). For the 8 cases that were favored to be NIFTP/FVPTC by cytologists, 7 (88%) had a molecular result that supported conservative management (1 NRAS mutation, 6 wild-type result). Seven cases were designated as cytomorphologically indeterminate for NIFTP/FVPTC or cPTC, of which 6 (86%) had a molecular result that would have aided in the pre-operative assessment of potential NIFTP/FVPTC or cPTC/malignancy. These included 3 BRAF V600E mutations in nodules that were cPTC on resection, an HRAS mutation, and a wild-type result in the 2 nodules that were NIFTP, and a TERT promoter mutation along with an NRAS mutation in a poorly differentiated thyroid carcinoma. For nodules with an FNA diagnosis of suspicious for malignancy or malignant, cytologists can differentiate most cases of potential NIFTP/FVPTC from cPTC. However, molecular testing may be valuable for a subset of cases, especially those that are indeterminate for potential NIFTP/FVPTC versus cPTC based on cytologic features alone.