Highly accurate diagnosis of cancer in thyroid nodules with follicular neoplasm/suspicious for a follicular neoplasm cytology by ThyroSeq v2 next-generation sequencing assay

Diagnostic accuracy of Afirma gene expression classifier, Afirma gene sequencing classifier, ThyroSeq v2 and ThyroSeq v3 for indeterminate (Bethesda III and IV) thyroid nodules: a meta-analysis

Objective

The management of thyroid nodules with indeterminate cytology (ITN) is still a challenge. To evaluate the performance of commercial molecular tests for ITN, we performed this comprehensive meta-analysis.

Methods

We performed an electronic search using PubMed/Medline, Embase, and the Cochrane Library. Studies assessing the diagnostic accuracy of Afirma gene expression classifier (GEC), Afirma gene sequencing classifier (GSC), ThyroSeq v2 (TSv2), or ThyroSeq v3 (TSv3) in patients with ITN (only Bethesda category III or IV) were selected; Statistical analyses were performed by using Stata.

Results

Seventy-one samples (GEC, n = 38; GSC, n = 16; TSv2, n = 9; TSv3, n = 8) in 53 studies, involving 6490 fine needle aspirations (FNAs) with ITN cytology with molecular diagnostics (GEC, GSC, TSv2, or TSv3), were included in the study. The meta-analysis showed the following pooled estimates: sensitivity 0.95 (95% CI: 0.94-0.97), specificity 0.35 (0.28-0.43), positive likelihood ratio (LR+) 1.5 (1.3-1.6), and negative likelihood ratio (LR-) 0.13 (0.09-0.19), with the best performance for TSv3 (area under the ROC curve 0.95 (0.93-0.96), followed by TSv2 (0.90 (0.87-0.92)), GSC (0.86 (0.82-0.88)), and GEC (0.82 (0.78-0.85)); the best rule-out property was observed for GSC (LR-, 0.07 (0.02-0.19)), followed by TSv3 (0.11 (0.05-0.24)) and GEC (0.16 (0.10-0.28), and the best rule-in was observed for TSv2 (LR+, 2,9 (1.4-4.6)), followed by GSC (1.9 (1.6-2.4)). A meta-regression analysis revealed that study design, Bethesda category, and type of molecular test were independent factors.

Conclusion

We showed that in patients with ITN, TSv3 has the best molecular diagnostic performance, followed by TSv2, GSC, and GEC. As regards rule-out malignancy, GSC, and rule-in, TSV2 is superior to other tests.

ThyroSeq overview on indeterminate thyroid nodules: An institutional experience

BACKGROUND

Molecular triage of indeterminate thyroid aspirates offers the opportunity to stratify the risk of malignancy (ROM) more accurately. Here we examine our experience with ThyroSeq v3 testing.

METHODS

We analyzed 276 of 658 (42%) fine needle aspiration samples classified as indeterminate thyroid nodules using ThyroSeq v3 (Sept 2017-Dec 2019). The test provides a ROM and detects specific mutations. Surgical diagnoses were reviewed.

RESULTS

Of 276 ThyroSeq-tested cases, 42% (n = 116) harbored genetic alterations, whereas 64% (n = 74) had surgical follow-up. Notably, 79% cases within intermediate to higher risk mutations were highly associated with surgical intervention, resulting in a 77.5% ROM when including both cancer and noninvasive follicular thyroid neoplasia with papillary-like features (cancer+NIFTP) and 68% malignant diagnosis when excluding NIFTP. RAS-like alterations were most common (66%), exhibiting a 73.4% ROM and a 59% malignant diagnosis. Interestingly, this group included 24 encapsulated follicular variant papillary thyroid carcinomas (EFVPTCs), 1 infiltrative FVPTC, 9 follicular carcinomas, and 7 NIFTP. Additionally, three high-risk mutations and eight BRAF/V600E mutations had a 100% ROM, all diagnosed as classic-type papillary thyroid carcinoma (cPTC). Combined analysis of thyroid nodules from Bethesda III and IV categories revealed a 78.2% positive predictive value (PPV) and a 75.9% negative predictive value (NPV).

CONCLUSION

ThyroSeq v3 effectively stratifies the ROM in indeterminate thyroid nodules based on specific genetic alterations, guiding appropriate surgical management. Notably, the BRAFV600E/high-risk group and RAS-like groups exhibited ROM of 100% and 77.5%, respectively, with promising predictive accuracy (PPV of 78.2% and NPV of 75.9%).

RAS-Mutant Follicular Thyroid Tumors: A Continuous Challenge for Pathologists

The classification of thyroid nodules, particularly those with a follicular growth pattern, has significantly evolved. These tumors, enriched with RAS or RAS-like mutations, remain challenging for pathologists due to variables such as nuclear atypia, invasion, mitotic activity, and tumor necrosis. This review addresses the histological correlates of benign, low-risk, and malignant RAS-mutant thyroid tumors, as well as some difficult-to-classify follicular nodules with worrisome features. One prototypical RAS-mutant nodule is non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). The assessment of nuclear characteristics in encapsulated/well-demarcated non-invasive RAS-mutant follicular-patterned tumors helps distinguish between follicular thyroid adenoma (FTA) and NIFTP. Despite this straightforward concept, questions about the degree of nuclear atypia necessary for the diagnosis of NIFTP are common in clinical practice. The nomenclature of follicular nodules lacking clear invasive features with increased mitotic activity, tumor necrosis, and/or high-risk mutations (e.g., TERT promoter or TP53) remains debated. Invasion, particularly angioinvasion, is the current hallmark of malignancy in RAS-mutant follicular-patterned neoplasms, with follicular thyroid carcinoma (FTC) as the model. Assessing the tumor interface is critical, though full capsule evaluation can be challenging. Multiple levels and NRASQ61R-specific immunohistochemistry can aid in identifying invasion. Controversies around vascular invasion persist, with ancillary stains like CD31, ERG, and CD61 aiding in its evaluation. Moreover, the review highlights that invasive encapsulated follicular variant papillary thyroid carcinoma (IEFVPTC) is closely associated with FTC, suggesting the need for better nomenclature. The concept of "high-grade" differentiated carcinomas, applicable to FTC or IEFVPTC with necrosis and/or high mitotic activity, is also discussed.

The value of ACR, European, Korean, and ATA ultrasound risk stratification systems combined with RAS mutations for detecting thyroid carcinoma in cytologically indeterminate and suspicious for malignancy thyroid nodules

PURPOSE

The aim of this study was to evaluate the diagnostic value of four commonly utilized ultrasound (US) RSSs, namely, the American College of Radiology [ACR], European [EU], Korean [K] TI-RADSs and American Thyroid Association [ATA] US-based RSS criteria, in combination with activating point mutations of the RAS genes (NRAS, HRAS, and KRAS) for detection of thyroid carcinoma in cytologically indeterminate and suspicious for malignancy thyroid nodules.

METHODS

We retrospectively analyzed cytologically indeterminate and suspicious for malignancy thyroid nodules which underwent US, molecular testing and surgery between September 1, 2018, and December 31, 2023. Receiver operating characteristic (ROC) curves were generated, and the area under the curve (AUC, 95% confidence interval [CI]) was calculated.

RESULTS

A total of 100 cytologically indeterminate and 24 suspicious for malignancy thyroid nodules were analyzed. Compared to the four US-based RSSs alone, the diagnostic value of the four US-based RSSs combined with RAS mutations did not significantly improved (cytologically indeterminate, AUC [95% CI] 0.6 [0.5-0.7] and 0.6 [0.5-0.7], respectively, p = 0.70; cytologically suspicious for malignancy, AUC [95% CI] 0.7 [0.5-0.9] and 0.8 [0.6-0.9], respectively, p = 0.23).

CONCLUSIONS

The diagnostic value of the four main US-based RSSs (ACR, EU, K, and ATA) was not improved in conjunction with the evaluation of RAS mutations for preoperative risk stratification of cytologically indeterminate thyroid nodules.

CLINICAL RELEVANCE STATEMENT

In cytologically indeterminate nodules categorized according to US-based RSSs, isolated RAS positivity does not reliably distinguish between benignity and malignancy.

Molecular Pathology of Thyroid Tumors: Old Problems and New Concepts

The molecular signatures of many thyroid tumors have been uncovered. These discoveries have translated into clinical practice and are changing diagnostic and tumor classification paradigms. Here, the findings of recent studies are presented with special emphasis on how molecular insights are impacting the understating of RAS mutant thyroid nodules, Hürthel cell neoplasms, and unusual thyroid tumors, such as hyalinizing trabecular tumor, secretory carcinoma of the thyroid, and sclerosing mucoepidermoid carcinoma with eosinophilia. In addition, the utility of detecting actionable molecular alterations by immunohistochemistry in advanced and aggressive thyroid cancer is also discussed.

Next-generation sequencing identified that RET variation associates with lymph node metastasis and the immune microenvironment in thyroid papillary carcinoma

BACKGROUND

To date, although most thyroid carcinoma (THCA) achieves an excellent prognosis, some patients experience a rapid progression episode, even with differentiated THCA. Nodal metastasis is an unfavorable predictor. Exploring the underlying mechanism may bring a deep insight into THCA.

METHODS

A total of 108 THCA from Chinese patients with next-generation sequencing (NGS) were recruited. It was used to explore the gene alteration spectrum of THCA and identify gene alterations related to nodal metastasis in papillary thyroid carcinoma (PTC). The Cancer Genome Atlas THCA cohort was further studied to elucidate the relationship between specific gene alterations and tumor microenvironment. A pathway enrichment analysis was used to explore the underlying mechanism.

RESULTS

Gene alteration was frequent in THCA. BRAF, RET, POLE, ATM, and BRCA1 were the five most common altered genes. RET variation was positively related to nodal metastasis in PTC. RET variation is associated with immune cell infiltration levels, including CD8 naïve, CD4 T and CD8 T cells, etc. Moreover, Step 3 and Step 4 of the cancer immunity cycle (CIC) were activated, whereas Step 6 was suppressed in PTC with RET variation. A pathway enrichment analysis showed that RET variation was associated with several immune-related pathways.

CONCLUSION

RET variation is positively related to nodal metastasis in Chinese PTC, and anti-tumor immune response may play a role in nodal metastasis triggered by RET variation.

A case of hyalinizing trabecular tumor of the thyroid: diagnostic significance of PAX8-GLIS3 fusion

BACKGROUND

Hyalinizing trabecular tumor (HTT) is an uncommon follicular cell-derived thyroid tumor classified as a low-risk neoplasm by the World Health Organization Classification of Tumors of Endocrine Organs, 5th edition. The PAX8-GLIS3 gene fusion is reportedly a pathognomonic genetic alteration of HTT.

CASE PRESENTATION

A 43-year-old Japanese female was incidentally discovered to have an 8-mm, well-defined, hypoechoic mass in the left lobe of the thyroid gland by ultrasound examination. Contrast-enhanced computed tomography scan revealed a solid mass exhibiting slight homogeneous enhancement in the lower pole of the thyroid gland. The mass was diagnosed as atypia of undetermined significance by fine-needle aspiration cytology. The patient underwent left hemithyroidectomy with routine central compartment dissection. Histologic findings revealed tumor cells with elongated nuclei and intranuclear pseudoinclusions arranged with trabeculae architecture or small nests in hyalinized stroma. Weak membranous and cytoplasmic staining was found by MIB1 (Ki-67) immunostaining. The final diagnosis was HTT of the thyroid gland. Next-generation sequencing genetic analysis of a surgical specimen revealed no pathologic mutations, including BRAF, H/K/NRAS, or RET-PTC fusions. The PAX8-GLIS3 fusion was detected by RT-PCR.

CONCLUSIONS

A rare case of HTT was demonstrated through imaging, cytologic, histologic and molecular investigations. PAX8-GLIS3 fusion detected by RT-PCR and Sanger sequencing was confirmed to be a genetic hallmark of HTT.

The prognostic power of gene mutations in thyroid cancer

The introduction and generalization of next-generation sequencing techniques have significantly increased the identification of mutations in thyroid tumors from multiple patient cohorts. The understanding of the association between specific mutations and clinical outcomes is gradually leading to individualizing the care of patients with thyroid cancer. BRAFV600 is the most common mutation seen in thyroid cancer patients and unequivocally predicts malignancy, but when considered in isolation, it is not recommended to be used as an independent prognostic factor. Mutations in RAS are the second most common alterations in thyroid cancer but can be found in benign and malignant lesions. Rearrangements involving receptor tyrosine kinases, primarily RET, are found in a subset of thyroid tumors without mutations in either BRAF or RAS. The assessment of additional mutations is increasingly employed in thyroid cancer prognostication. The coexistence of BRAF with alterations in genes such as PIK3CA, TERT promoter, or TP53 is associated with less favorable outcomes. Similar studies have also shown that additional oncogenic mutations in RAS-mutant thyroid carcinoma, such as those affecting the EIF1AX gene, likely predict a more aggressive clinicopathologic behavior. Overall, emerging evidence suggests that the co-occurrence of specific alterations in defined genes with BRAF or RAS mutations can become prognostic tools and useful predictors of thyroid tumor aggressiveness.

Approach to Thyroid Nodules: Diagnosis and Treatment

Thyroid nodules (TNs) are prevalent and found in up to 50% of individuals. While most TNs are benign, some can be malignant. The evaluation of TNs is crucial to rule out malignancy and identify those requiring surgical intervention. This study aimed to clarify the reported prevalence of TNs, focusing specifically on their various types, assessment and diagnostic processes, current evaluation methods, and evidence-based management. It also provides recommendations for follow-up. TNs are typically found during physical exams or incidentally during imaging procedures. Routine laboratory and clinical evaluations of TNs are common. Ultrasound is the preferred imaging method to determine if a TN needs a biopsy. Fine-needle aspiration (FNA) is crucial in deciding whether surgery or surveillance is necessary. TNs that show suspicious features on the ultrasound may require cytologic analysis to assess the risk of malignancy. The effectiveness of several supplementary molecular tests is still uncertain, although some studies report promising results. The management and treatment approach for TNs primarily depends on the results of FNA cytology and ultrasound characteristics. The optimal treatment strategy for TNs ranges from straightforward follow-ups for low-risk cases to surgical intervention for high-risk patients. Rather than adopting a uniform approach, clinicians should assess each patient on a case-by-case basis using current knowledge and a collaborative, multidisciplinary method.

Role of Genetic Testing in the Management of Indeterminate Thyroid Nodules in the Indian Setting

The increased detection of thyroid nodules in the human population has led to an increase in the number of thyroid surgeries without an improvement in survival outcomes. Though the choice for surgery is straightforward in malignant thyroid nodules, the decision is far more complex in those nodules that get categorized into indeterminate thyroid nodules (ITN) by fine needle aspiration. Therefore, there is a pressing need to develop a tool that will aid in decision-making among the ITN. In this context, the development of various molecular testing (MT) panels has helped to confirm or rule out malignancy, reducing unnecessary surgeries and potentially guiding the extent of surgery as well. Currently, such tests are widely used among the Western population but these MT panels are not used by the South Asian population because of non-availability of validated panels and the high cost involved. There is a need to develop a suitable panel which is population-specific and validate the same. In this review, we would focus on current trends in the management of ITN among the South Asian population and how to develop a novel MT panel which is cost-effective, with high diagnostic accuracy obviating the need for expensive panels that already exist.

Diagnostic performance of molecular testing in indeterminate (Bethesda III and IV) thyroid nodules with Hürthle cell cytology

BACKGROUND

Indeterminate thyroid nodules with Hürthle cell cytology remain a diagnostic challenge. The low benign call rate and positive predictive value of first-generation molecular tests precluded their use to rule out malignancy. We examined the diagnostic performance of current tests.

METHOD

This subset analysis of our prospective randomized trial compared the benign call rate and positive predictive value of Afirma Gene Sequencing Classifier and Thyroseq v3 in Bethesda III and IV nodules with Hürthle cell cytology. Molecular test samples were obtained at initial fine-needle aspiration (8/2017-7/2022) and reflexively sent for processing.

RESULTS

Molecular testing was performed on 140 Hürthle cell nodules. Of 79 nodules tested with the Afirma Gene Sequencing Classifier, the benign call rate was 84% (66/79). Nine of 66 nodules with benign results were resected, with no malignancies. Twelve of 13 nodules with suspicious results were resected, revealing 3 malignancies-2 papillary thyroid carcinomas and one Hürthle cell carcinoma (positive predictive value 25%). Of 61 nodules tested with Thyroseq v3, the benign call rate was 56% (34/61; (P < .01 versus Afirma Gene Sequencing Classifier). Five of 34 nodules with negative results were resected, with no malignancies. Nineteen of 27 nodules with positive results were resected, revealing 3 malignancies-2 papillary thyroid carcinomas and 1 Hürthle cell carcinoma (positive predictive value 16%).

CONCLUSION

The high benign call rate of current molecular tests in Hürthle cell nodules strengthens their value in enabling patients to avoid surgery.

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.

Progress in Thyroid Cancer Genomics: A 40-Year Journey

Background: Very little was known about the molecular pathogenesis of thyroid cancer until the late 1980s. As part of the Centennial celebration of the American Thyroid Association, we review the historical discoveries that contributed to our current understanding of the genetic underpinnings of thyroid cancer. Summary: The pace of discovery was heavily dependent on scientific breakthroughs in nucleic acid sequencing technology, cancer biology, thyroid development, thyroid cell signaling, and growth regulation. Accordingly, we attempt to link the primary observations on thyroid cancer molecular genetics with the methodological and scientific advances that made them possible. Conclusions: The major genetic drivers of the common forms of thyroid cancer are now quite well established and contribute to a significant extent to how we diagnose and treat the disease. However, many challenges remain. Future work will need to unravel the complexity of thyroid cancer ecosystems, which is likely to be a major determinant of their biological behavior and on how they respond to therapy.

Clinical use of Molecular Data in Thyroid Nodules and Cancer

Over the past 3 decades, advances in the molecular genetics of thyroid cancer (TC) have been translated into diagnostic tests, prognostic markers, and therapeutic agents. The main drivers in differentiated TC pathogenesis are single-point mutations and gene fusions in components of the Mitogen-activated protein kinase (MAPK) and phosphoinositide-3-kinase-protein kinase B/Akt (PI3K/Akt) pathways. Other important genetic alterations in the more advanced types of TC include TERT promoter, TP53, EIF1AX, and epigenetic alterations. Using this knowledge, several molecular tests have been developed for cytologically indeterminate thyroid nodules. Currently, 3 commercially available tests are in use including a DNA/RNA-based test (ThyroSeq v.3), an RNA-based test (Afirma Gene Sequencing Classifier), and a hybrid DNA/miRNA test, ThyGeNEXT/ThyraMIR. These tests are mostly used to rule out malignancy in Bethesda III and IV thyroid nodules because they all have high sensitivities and negative predictive values. Their common use, predominantly in the United States, has resulted in a significant reduction in unnecessary thyroid surgeries for benign nodules. Some of these tests also provide information on the underlying molecular drivers of TC; this may support decision making in initial TC management planning, although this practice has not yet been widely adopted. More importantly, molecular testing is essential in patients with advanced disease before using specific mono-kinase inhibitors (eg, selpercatinib for RET-altered TC) because these drugs are ineffective in the absence of a specific molecular target. This mini-review discusses the utilization of molecular data in the clinical management of patients with thyroid nodules and TC in these different clinical situations.

Molecular testing for indeterminate thyroid nodules: past, present, and future

PURPOSE OF REVIEW

To examine the origin, current progress, and future directions of molecular testing in indeterminate Bethesda III and Bethesda IV thyroid nodules.

RECENT FINDINGS

The diagnostic performance of current genomic tests shows improved benign call rates, specificity and positive-predictive values over prior test versions. The choice of test platform for clinical use should consider test performance, institutional rate of malignancy, nodule cytology and the potential for prognostication to help guide decision-making. Current challenges include test reliability, defining the optimal duration of surveillance, and improving test performance in challenging cytology, such as oncocytic nodules and NIFTP. Opportunities also remain to optimize cost-effectiveness across multiple clinical and practice settings and to refine the use of molecular testing for dynamic risk stratification, such as with BRAF V600E mutation testing.

SUMMARY

Molecular testing of indeterminate thyroid nodules has helped to reduce the burden of diagnostic surgery, associated healthcare costs, and potential complications. Current-generation tests have demonstrated improvement in diagnostic performance, but challenges remain in improving test performance and refining the scope of testing in care. Decision-making for the management of indeterminate thyroid nodules should consider cytology, clinical and sonographic features, patient values and preferences and molecular testing results, whenever available.

European experience with the Afirma Gene Expression Classifier for indeterminate thyroid nodules: A clinical utility study in the Netherlands

BACKGROUND

The Gene Expression Classifier (GEC) and Genomic Sequencing Classifier (GSC) were developed to improve risk stratification of indeterminate nodules. Our aim was to assess the clinical utility in a European population with restrictive diagnostic workup.

METHODS

Clinical utility of the GEC was assessed in a prospective multicenter cohort of 68 indeterminate nodules. Diagnostic surgical rates for Bethesda III and IV nodules were compared to a historical cohort of 171 indeterminate nodules. Samples were post hoc tested with the GSC.

RESULTS

The GEC classified 26% as benign. Surgical rates between the prospective and historical cohort did not differ (72.1% vs. 76.6%). The GSC classified 59% as benign, but misclassified six malignant lesions as benign.

CONCLUSION

Implementation of GEC in management of indeterminate nodules in a European country with restrictive diagnostic workup is currently not supported, especially in oncocytic nodules. Prospective studies with the GSC in European countries are needed to determine the clinical utility.

Bethesda III and IV Thyroid Nodules Managed Nonoperatively After Molecular Testing With Afirma GSC or Thyroseq v3

CONTEXT

Molecular testing has improved risk stratification and increased nonoperative management for patients with indeterminate thyroid nodules, but data on the long-term outcomes of current molecular tests Afirma Gene Sequencing Classifier (GSC) and Thyroseq v3 are limited.

OBJECTIVE

To determine the rate of delayed operation and the false negative rate of the Afirma GSC and Thyroseq v3 in Bethesda III and IV thyroid nodules.

METHODS

Prospective follow-up of a single center, randomized, clinical trial comparing the performance of Afirma GSC and Thyroseq v3 in the diagnosis of indeterminate thyroid nodules at the University of California, Los Angeles (UCLA). Consecutive participants who underwent thyroid biopsy in the UCLA health system with Bethesda III and IV cytology from August 2017 to November 2019. The main outcome measure was false negative rate of molecular testing.

RESULTS

Of 176 indeterminate nodules with negative or benign molecular test results, 14 (8%) nodules underwent immediate resection, with no malignancies found on surgical pathology. Nonoperative management with active surveillance was pursued for 162 (92%) nodules with benign or negative test results. The median surveillance was 34 months (range 12-60 months), and 44 patients were lost to follow-up. Of 15 nodules resected during surveillance, 1 malignancy was found (overall false negative rate of 0.6%). This was a 2.7 cm minimally invasive Hurthle cell carcinoma that initially tested negative with Thyroseq v3 and underwent delayed resection due to sonographic growth during surveillance.

CONCLUSIONS

The majority of Bethesda III/IV thyroid nodules with negative or benign molecular test results are stable over 3 years of follow-up. These findings support the high sensitivity of current molecular tests and their role in ruling out malignancy in indeterminate thyroid nodules.

An overview of the role of telomeres and telomerase in pre‑neoplastic lesions (Review)

Telomeres are tandem repeats of DNA sequences protecting the end of linear chromosomes. Replicative senescence due to telomere attrition is considered a tumor-preventing mechanism in differentiated somatic cells. However, telomere shortening is associated with genome instability and several disease entities. During carcinogenesis, the development of a telomere maintenance mechanism, predominately through the activation of the telomerase enzyme, represents a hallmark of cancer, since it enables cancer cells to avert senescence and divide indefinitely. Although research of the involvement of telomeres and telomerase in various malignant neoplasms has gained a large amount of interest, the timing and relevance of their role in pre-neoplastic lesions remain to be determined. The present narrative review aims to summarize the evidence regarding the role of telomeres and telomerase in pre-neoplasia across different types of tissues.

Molecular testing in indeterminate thyroid nodules: an additional tool for clinical decision-making

Thyroid nodules are commonly encountered in clinical practice, affecting up to 50% of the population. The large majority of thyroid lumps are benign incidental findings detected by imaging, while approximately 5-15% harbor malignancy. For a target patient's care, it is of paramount importance to identify and treat thyroid malignancy, while preventing unnecessary invasive surgery in patients with benign lesions. Although fine needle aspiration (FNA) associated with cytological examination provides malignant risk information, 20-30% of diagnoses fall into the "indeterminate thyroid nodule" (ITN) category. ITN clinical management remains a challenging issue for physicians since the ITN risk of malignancy varies from 5% to 40% and most thyroid nodules undergo overtreatment with surgery procedures. ITN molecular testing may better define malignant risk in the single nodule and is able to discriminate with accuracy benign from malignant nodules. Nowadays there are different technologies and different molecular panels, each with its own specificity, sensitivity and predictive values. In view of widespread introduction of molecular testing , some outstanding questions remain and are addressed in the present review such as the presence of molecular panels acting as "rule in" or "rule out" tools, the effective impact of testing results in the clinical decision-making process, and the prohibitive cost of commercial assays associated with the lack of test reimbursement in national health systems.

The Difference in Clinical Behavior of Gene Fusions Involving RET/PTC Fusions and THADA/IGF2BP3 Fusions in Thyroid Nodules

BACKGROUND

Molecular testing has been used as an adjunct to morphological evaluation in the workup of thyroid nodules. This study investigated the impact of two gene fusions, RET/PTC and THADA/IGF2BP3, that have been described as oncogenic events in thyroid neoplasms.

METHODS

We performed a retrospective, single-centered study at a McGill University teaching hospital in Montreal, Canada, from January 2016 to August 2021. We included patients who underwent surgery for thyroid nodules that pre-operatively underwent molecular testing showing either RET/PTC or THADA/IGF2BP3 gene fusion.

RESULTS

This study included 697 consecutive operated thyroid nodules assessed using molecular testing, of which five had the RET/PTC fusion and seven had the THADA/IGF2BP3 fusion. Of the five nodules in the RET/PTC group, 100% were malignant and presented as Bethesda V/VI. Eighty percent (4/5) were found to have lymph node metastasis. Twenty percent (1/5) had extrathyroidal extensions. Sixty percent (3/5) were a diffuse sclerosing variant of papillary thyroid carcinoma, and the rest were the classical variant. Of the seven THADA/IGF2BP3 nodules, all presented as Bethesda III/IV and 71.4% (5/7) were malignant based on the final pathology analysis, and 28.6% (2/7) were NIFTP. All the THADA/IGF2BP3 fusion malignancies were a follicular variant of papillary thyroid carcinoma. None had lymph node metastasis or displayed extrathyroidal extensions.

CONCLUSIONS

RET/PTC nodules presented as Bethesda V/VI and potentially had more aggressive features, whereas THADA/IGF2BP3 nodules presented as Bethesda III/IV and had more indolent behavior. This understanding may allow clinicians to develop more targeted treatment plans, such as the extent of surgery and adjuvant radioactive iodine treatment.

AI-Assisted Ultrasound for the Early Diagnosis of Antibody-Negative Autoimmune Thyroiditis

The prevalence of antibody-negative chronic autoimmune thyroiditis (SN-CAT) is increasing. The early diagnosis of SN-CAT can effectively prevent its further development. Thyroid ultrasound can diagnose autoimmune thyroiditis and predict hypothyroidism. Primary hypothyroidism with a hypoechoic pattern suggested by thyroid ultrasound and negative thyroid serum antibodies is the main basis for the diagnosis of SN-CAT. However, for early SN-CAT, only hypoechoic thyroid changes and serological antibodies are currently available. This study explored how to achieve an accurate and early diagnosis of SN-CAT and prevent the development of SN-CAT combined with hypothyroidism. The diagnosis of a hypoechoic thyroid by artificial intelligence is expected to be a breakthrough in the accurate diagnosis of SN-CAT.

Molecular profile of follicular tumors of the thyroid gland

More than 90 % of newly diagnosed cases of endocrine cancer occur in the thyroid gland. Introduction of fine needle puncture of the thyroid gland, with the classification of cytological material according to the Bethesda system, has become the cornerstone of the diagnosis of malignant neoplasms of the thyroid gland. However, traditionally in this classification there remains a weak link called a follicular tumor (category IV). The detection of a follicular tumor in the cytological material does not allow one to reliably classify the mass as benign or malignant and requires surgical intervention with morphological verification. In recent years, the possibilities of molecular genetic testing have improved markedly. Follicular tumors tend to accumulate mutations, which over time can lead to malignant transformation, but can also be used as a method of timely diagnosis. This review analyzes the literature on the possibilities of molecular genetic testing in assessing the malignant potential of follicular formations of the thyroid gland.

InTERTwined: how TERT promoter mutations impact BRAFV600E-driven thyroid cancers

Thyroid cancers are often initiated by the acquisition of a BRAFV600E mutation. BRAFV600E-driven thyroid tumors display a wide range of behaviors, from the slow-growing papillary carcinomas to the highly aggressive anaplastic. Mutations in the promoter of TERT (telomerase reverse transcriptase) gene were discovered a decade ago and identified as prevalent events in thyroid cancers. Multiple studies showed that TERT promoter mutations, particularly when co-occurring with BRAFV600E, are markers of poor prognosis across thyroid cancer subtypes, and can be implemented for routine clinical stratification. Mechanistically, TERT promoter mutations reactivate telomerase expression via the differential recruitment of transcriptional complexes. Re-expression of TERT impacts tumor biology, plausibly via both the well-known function of telomerase maintaining telomeres and by affecting other cancer-relevant processes.

Approach to risk stratification for papillary thyroid carcinoma based on molecular profiling: institutional analysis

BACKGROUND

Currently, treatment recommendations for papillary thyroid carcinoma are not based on the genetic background causing tumourigenesis. The aim of the present study was to correlate the mutational profile of papillary thyroid carcinoma with clinical parameters of tumour aggressiveness, to establish recommendations for risk-stratified surgical treatment.

METHOD

Papillary thyroid carcinoma tumour tissue of patients undergoing thyroid surgery at the University Medical Centre Mainz underwent analysis of BRAF, TERT promoter and RAS mutational status as well as potential RET and NTRK rearrangements. Mutation status was correlated with clinical course of disease.

RESULTS

One hundred and seventy-one patients operated for papillary thyroid carcinoma were included. The median age was 48 years (range 8-85) and 69 per cent (118/171) of patients were females. One hundred and nine papillary thyroid carcinomas were BRAF-V600E mutant, 16 TERT promotor mutant and 12 RAS mutant; 12 papillary thyroid carcinomas harboured RET rearrangements and two papillary thyroid carcinomas showed NTRK rearrangements. TERT promoter mutant papillary thyroid carcinomas had a higher risk of distant metastasis (OR 51.3, 7.0 to 1048.2, P < 0.001) and radioiodine-refractory disease (OR 37.8, 9.9 to 169.5, P < 0.001). Concomitant BRAF and TERT promoter mutations increased the risk of radioiodine-refractory disease in papillary thyroid carcinoma (OR 21.7, 5.6 to 88.9, P < 0.001). RET rearrangements were associated with a higher count of tumour-affected lymph nodes (OR 7950.9, 233.7 to 270495.7, P < 0.001) but did not influence distant metastasis or radioiodine-refractory disease.

CONCLUSIONS

Papillary thyroid carcinoma with concomitant BRAF-V600E and TERT promoter mutations demonstrated an aggressive course of disease, suggesting the need for a more extensive surgical strategy. RET rearrangement-positive papillary thyroid carcinoma did not affect the clinical outcome, potentially obviating the need for prophylactic lymphadenectomy.

Histology-based and cytology-based needle sampling for targeted next-generation sequencing in the indeterminate thyroid tumors

PURPOSE

To establish the optimal and minimally invasive diagnostic approach for targeted next-generation sequencing (NGS) in the indeterminate thyroid tumors.

METHODS

The patients with indeterminate thyroid tumors were prospectively recruited and analyzed in a single tertiary medical center. We performed FNA and core needle biopsy (CNB) at the surgical specimens to confirm the quality of each sampling procedure. Cytological diagnosis by FNA, histological diagnosis by CNB and confirmed diagnosis by final surgery were compared to demonstrate the agreement among these approaches for the indeterminate thyroid tumors. The quality of the samples from FNA and CNB was evaluated, respectively to determine the optimal approach for targeted NGS. Finally, we performed ultrasound-guided CNB and FNA (US-CNB and US-FNA) on one case to confirm the clinical feasibility of being a pre-operative minimally invasive diagnostic approach.

RESULTS

A total of 6 female patients (average age: 50.83 ± 15.18 years) with indeterminate thyroid tumors (average size: 1.79 ± 0.91 cm) were recruited for further analyses. The pathological diagnoses could be obtained by CNB in the first five cases, and the sample quality of CNB for targeted NGS was better than that of FNA, even after 10X dilution. The gene mutations associated with thyroid malignancy could be detected by NGS. In the case treated with US-CNB, the pathological and targeted NGS results were successfully obtained, which suggested the possibility of thyroid malignancy to facilitate immediate decision of subsequent treatment.

CONCLUSION

CNB could serve as a minimally invasive diagnostic approach in the indeterminate thyroid tumors by providing pathological diagnoses and qualified samples for detection of mutated genes, which facilitates appropriate and immediate management.

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.

A Triumvirate:: Correlating Thyroid Cytopathology, Molecular Testing, and Histopathology

Risk stratification is essential in the preoperative evaluation and management of thyroid nodules, most of which are benign. Advances in DNA and RNA sequencing have shed light on the molecular drivers of thyroid cancer. Molecular testing of cytologically indeterminate nodules has helped refine risk stratification, triage patients for surgery, and determine the extent of surgery. Molecular platforms with high negative predictive values can help identify nodules that may be spared surgery and can be managed conservatively. Here we discuss the importance of integrating cytomorphologic, molecular, and histologic features to help avoid errors and improve patient management.

How Effective is the Use of Molecular Testing in Preoperative Decision Making for Management of Indeterminate Thyroid Nodules?

INTRODUCTION

We performed Thyroseq v2 molecular testing on indeterminate thyroid nodules and evaluated whether they underwent a management change from the standard of thyroid lobectomy.

METHODS

We conducted a retrospective analysis of all indeterminate thyroid nodules that underwent Thyroseq v2 molecular testing from 2014 to 2019 at a large academic center. Pathology was reviewed by thyroid cytopathologists. Thyroseq results were reported benign (malignancy probability less than 10%) or suspicious (malignancy probability greater than 30%). The primary endpoint was a management change from a diagnostic lobectomy.

RESULTS

A total of 142 nodules were included: 113 (80%) Bethesda III and 29 (20%) Bethesda IV. Seventy-three nodules underwent surgical management and 69 did not. We noted a change in management in 64% (91/142) of nodules. Patients who underwent a change in management to no surgery had a significantly higher rate of benign Thyroseq result than those without a change (75.8% vs. 49.0%, p = 0.001). On logistic regression analysis, a benign Thyroseq result was a positive independent predictor of a change to no surgery (OR 3.87, 95% CI 1.69-8.89). Nodule size, multiple nodules, compressive symptoms, and history of hypothyroidism were not significant. Of the 91 patients who underwent a management change, 71% (65/91) did not undergo surgery. On follow-up (average 985 ± 615 days), 12% (8/65) of those nodules were growing or developed suspicious features requiring surgery.

CONCLUSIONS

Molecular testing helped avoid surgery in almost half our population with indeterminate thyroid nodules, and benign results may help avoid surgery in asymptomatic patients with indeterminate thyroid nodules.

SFE-AFCE-SFMN 2022 Consensus on the management of thyroid nodules : Role of molecular tests for cytologically indeterminate thyroid nodules

The SFE-AFCE-SFMN 2022 consensus deals with the management of thyroid nodules, a condition that is a frequent reason for consultation in endocrinology. In more than 90% of cases, patients are euthyroid, with benign non-progressive nodules that do not warrant specific treatment. The clinician's objective is to detect malignant thyroid nodules at risk of recurrence and death, toxic nodules responsible for hyperthyroidism or compressive nodules warranting treatment. The diagnosis and treatment of thyroid nodules requires close collaboration between endocrinologists, nuclear medicine physicians and surgeons, but also involves other specialists. Therefore, this consensus statement was established jointly by 3 societies: the French Society of Endocrinology (SFE), French Association of Endocrine Surgery (AFCE) and French Society of Nuclear Medicine (SFMN); the various working groups included experts from other specialties (pathologists, radiologists, pediatricians, biologists, etc.). Because of the emerging role of molecular fine-needle cytology diagnostics, the French Endocrine Society convened a panel of experts to review the evidence for the diagnostic value of molecular tests performed on cytologically indeterminate thyroid nodules.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution

BACKGROUND

The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations.

METHODS

The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients.

RESULTS

The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories.

CONCLUSIONS

In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Development of a Machine Learning-Based Screening Method for Thyroid Nodules Classification by Solving the Imbalance Challenge in Thyroid Nodules Data

BACKGROUND

This study aims to show the impact of imbalanced data and the typical evaluation methods in developing and misleading assessments of machine learning-based models for preoperative thyroid nodules screening.

STUDY DESIGN

A retrospective study.

METHODS

The ultrasonography features for 431 thyroid nodules cases were extracted from medical records of 313 patients in Babol, Iran. Since thyroid nodules are commonly benign, the relevant data are usually unbalanced in classes. It can lead to the bias of learning models toward the majority class. To solve it, a hybrid resampling method called the Smote-was used to creating balance data. Following that, the support vector classification (SVC) algorithm was trained by balance and unbalanced datasets as Models 2 and 3, respectively, in Python language programming. Their performance was then compared with the logistic regression model as Model 1 that fitted traditionally.

RESULTS

The prevalence of malignant nodules was obtained at 14% (n = 61). In addition, 87% of the patients in this study were women. However, there was no difference in the prevalence of malignancy for gender. Furthermore, the accuracy, area under the curve, and geometric mean values were estimated at 92.1%, 93.2%, and 76.8% for Model 1, 91.3%, 93%, and 77.6% for Model 2, and finally, 91%, 92.6% and 84.2% for Model 3, respectively. Similarly, the results identified Micro calcification, Taller than wide shape, as well as lack of ISO and hyperechogenicity features as the most effective malignant variables.

CONCLUSION

Paying attention to data challenges, such as data imbalances, and using proper criteria measures can improve the performance of machine learning models for preoperative thyroid nodules screening.

Assessing Bias and Limitations of Clinical Validation Studies of Molecular Diagnostic Tests for Indeterminate Thyroid Nodules: Systematic Review and Meta-Analysis

Background: Molecular tests for thyroid nodules with indeterminate fine needle aspiration results are increasingly used in clinical practice; however, true diagnostic summaries of these tests are unknown. A systematic review and meta-analysis were completed to (1) evaluate the accuracy of commercially available molecular tests for malignancy in indeterminate thyroid nodules and (2) quantify biases and limitations in studies that validate those tests. Summary: PubMed, EMBASE, and Web of Science were systematically searched through July 2021. English language articles that reported original clinical validation attempts of molecular tests for indeterminate thyroid nodules were included if they reported counts of true-negative, true-positive, false-negative, and false-positive results. We performed screening and full-text review, followed by assessment of eight common biases and limitations, extraction of diagnostic and histopathological information, and meta-analysis of clinical validity using a bivariate linear mixed-effects model. Forty-nine studies were included. Meta-analysis of Afirma Gene expression classifiers (GEC; n = 38 studies) revealed a sensitivity of 0.92 (confidence interval: 0.90-0.94), specificity of 0.26 (0.20-0.32), negative likelihood ratio (LR-) of 0.32 (0.23-0.44), positive LR+ of 1.24 (1.15-1.35), and area under the curve (AUC) of 0.83 (0.74-0.89). Afirma Genomic Sequencing Classifier (GSC; n = 10) had a sensitivity of 0.94 (0.89-0.96), specificity of 0.38 (0.27-0.50), LR- of 0.18 (0.10-0.30), LR+ of 1.52 (1.28-1.87), and AUC of 0.91 (0.62-0.92). ThyroSeq v1 and v2 (n = 10) had a sensitivity of 0.86 (0.82-0.90), specificity of 0.74 (0.59-0.85), LR- of 0.19 (0.13-0.26), LR+ of 3.52 (2.08-5.92), and AUC of 0.86 (0.81-0.90). ThyroSeq v3 (n = 6) had a sensitivity of 0.92 (0.86-0.95), specificity of 0.41 (0.18-0.69), LR- of 0.24 (0.09-0.62), LR+ of 1.67 (1.09-2.98), and AUC of 0.90 (0.63-0.92). Fourteen percent of studies conducted a blinded histopathologic review of excised thyroid nodules, and 8% made the decision to go to surgery blind to molecular test results. Conclusions: Meta-analyses reveal a high diagnostic accuracy of molecular tests for thyroid nodule assessment of malignancy risk; however, these studies are subject to several limitations. Limitations and their potential clinical impacts must be addressed and, when feasible, adjusted for using valid statistical methodologies.

Clinicopathologic features of thyroid nodules with PTEN mutations on preoperative testing

The incidence of cancer in thyroid nodules carrying germline or somatic phosphatase and tensin homolog (PTEN) mutations is not well-defined. This study characterizes the clinical and histopathologic features of thyroid nodules with preoperatively detected PTEN mutations and their impact on management. Thyroid nodules with PTEN mutations on molecular testing of fine-needle aspiration (FNA) specimens from November 2017 to July 2020 at our institution were included. Demographic and clinicopathologic data were obtained through retrospective chart review. We identified 49 PTEN mutation-positive nodules from 48 patients. Surveillance was pursued for 28 patients and surgery for 20 patients. There were 14 follicular adenomas (FA), 4 oncocytic adenomas, 1 oncocytic hyperplastic nodule, and 1 encapsulated follicular variant papillary thyroid carcinoma (EFVPTC). The EFVPTC had two somatic PTEN mutations, an NRAS mutation, and was a low-risk tumor with capsular but no angiolymphatic invasion. Four patients, all with multiple nodules, had PTEN hamartoma syndrome (PHTS) with germline mutations or a clinical diagnosis of Cowden syndrome (CS); two had surgery finding FAs, and one previously had follicular carcinoma removed. Among surveillance patients, 1/20 had a significant increase in the size of the thyroid nodule and underwent repeat FNA, and no thyroid malignancy was found with a mean of 1.77 years of follow-up (range 1.00-2.78). Thyroid nodules with isolated somatic PTEN mutations are primarily benign and unlikely to grow at a high rate, at least on short-term follow-up. About 8% of patients with PTEN mutations may have PHTS or CS, which should be suspected in younger patients with multiple thyroid nodules.

Clinicopathological features and outcomes of thyroid nodules with EIF1AX mutations

EIF1AX gene mutations are reported in both benign and malignant thyroid tumors, with unclear outcomes when detected preoperatively. The aim of this study was to determine the features and outcomes of thyroid nodules with various types of mutation identified in cytologic (fine-needle aspiration) samples on preoperative ThyroSeq testing and with surgical outcomes. In this single-institution retrospective study of 31 consecutive patients, 77% were female and nodule size ranged from 1.5 to 9.4 cm with widely varying cytologic and TI-RADS ultrasound categorizations. Among two main mutational hotspots, 55% were located in exon 2 and 45% at the intron 5/exon 6 splice site. On histology, 45% of -positive nodules were cancer/noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) including 19% encapsulated follicular variant papillary thyroid carcinoma, 10% follicular carcinoma, 10% anaplastic carcinoma (ATC), and 7% NIFTP. Almost half (48%) of patients had one or more coexisting mutations, most frequently RAS. The prevalence of cancer/NIFTP was 80% for mutation with coexisting molecular alteration vs 13% with an isolated mutation (P = 0.0002). Cancer probability was associated with mutation type and was 64% for splice-site mutation and 29% for non-splice mutation (P = 0.075). All 3 nodules with EIF1AX+RAS+TERT+TP53 mutations were ATC. In summary, in this study, all nodules with an isolated non-splice mutation were benign, one-third of those with an isolated splice mutation were cancer, and most nodules with coexisting with RAS or other alterations were malignant. These findings suggest that clinical management decisions for patients with EIF1AX-mutant nodules should consider both the type of mutation and its co-occurrence with other genetic alterations.

Molecular Testing for Indeterminate Thyroid Nodules: Association of Negative Predictive Value With Nodule Size

BACKGROUND

Molecular testing helps stratify risk of malignancy in indeterminate thyroid nodules, but it may be limited in its ability to rule out malignancy in large nodules.

METHODS

We compared small thyroid nodules (<4 cm) to large thyroid nodules (4 cm or greater) in a retrospective, single center, cohort study of indeterminate thyroid nodules analyzed with ThyroSeq from 10/2015 through 4/2020. Our primary outcome was negative predictive value.

RESULTS

A total of 204 thyroid nodules were analyzed with ThyroSeq and 62 underwent resection allowing comparison to final pathology for 48 small nodules and 14 large nodules. A greater proportion of large nodules were observed in men (50.0% vs 18.8% in small nodules, P = .02), but median age was similar between the groups (49.0 vs 52.5 years, P = .95). False negative results comprised a higher proportion of tests for large nodules (14.3%) than small nodules (0%, P = .01). The negative predictive value of ThyroSeq in small nodules was 1 indicating a negative test reliably predicted a benign nodule, compared to .5 in large nodules indicating a negative test in this cohort was reliable in predicting benignity. Applying the same negative predictive value to the cohort of large nodules that did not undergo resection after negative molecular testing (n = 16), it is possible that 8 large thyroid malignancies were missed at our institution during the study period.

CONCLUSIONS

Large thyroid nodules are associated with a higher rate of false negative results and a lower negative predictive value during molecular analysis of indeterminate thyroid nodules.

American Head and Neck Society Endocrine Surgery Section and International Thyroid Oncology Group consensus statement on mutational testing in thyroid cancer: Defining advanced thyroid cancer and its targeted treatment

BACKGROUND

The development of systemic treatment options leveraging the molecular landscape of advanced thyroid cancer is a burgeoning field. This is a multidisciplinary evidence-based statement on the definition of advanced thyroid cancer and its targeted systemic treatment.

METHODS

An expert panel was assembled, a literature review was conducted, and best practice statements were developed. The modified Delphi method was applied to assess the degree of consensus for the statements developed by the author panel.

RESULTS

A review of the current understanding of thyroid oncogenesis at a molecular level is presented and characteristics of advanced thyroid cancer are defined. Twenty statements in topics including the multidisciplinary management, molecular evaluation, and targeted systemic treatment of advanced thyroid cancer are provided.

CONCLUSIONS

With the growth in targeted treatment options for thyroid cancer, a consensus definition of advanced disease and statements regarding the utility of molecular testing and available targeted systemic therapy is warranted.

Diagnostic performance of next-generation sequencing and genetic profiling in thyroid nodules from a single center in China

Objective

The data regarding the mutation landscape in Chinese patients with thyroid cancer are limited. The diagnostic performance of thyroid nodules by fine-needle aspiration (FNA) cytology needs optimization, especially in indeterminate nodules.

Methods

A total of 1039 FNA and surgical resection samples tested using the targeted multigene next-generation sequencing (NGS) panel were retrospectively collected. The features of gene alterations in different thyroid tumors were analyzed, and the diagnostic efficacy was evaluated.

Results

Among 1039 samples, there were 822 FNA and 217 surgical FFPE samples. Among 207 malignant thyroid resections, a total of 181 out of 193 papillary thyroid carcinomas (PTCs) were NGS-positive (93.8%), with a high prevalence of BRAF mutations (81.9%, 158/193) and a low prevalence of RAS (1.0%, 2/193) and TERT promoter mutations (3.6%, 7/193). Gene fusions, involving the RET and NTRK3 genes, were present in 20 PTCs (10.4%) and mutually exclusive with other driver mutations. Two of three follicular thyroid carcinomas harbored multiple mutations. RET gene point mutations were common in medullary thyroid carcinoma (8/11, 72.7%). The combination of cytology and DNA-RNA-based NGS analysis demonstrated superior diagnostic value (98.0%) in FNA samples. For indeterminate thyroid nodules, the diagnostic sensitivity and specificity of NGS testing were 79.2 (38/48) and 80.0% (8/10), respectively. Two mutation-positive benign cases harbored NRAS and TSHR mutations, respectively.

Conclusions

Our study revealed the distinct molecular profile of thyroid tumors in the Chinese population. The combination of NGS testing and FNA cytology could facilitate the accurate diagnosis of thyroid nodules, especially for indeterminate nodules.

Is molecular testing in patients with low risk papillary thyroid carcinoma justified? A Markovian model

BACKGROUND

Current guidelines consider all cases of papillary thyroid carcinoma (PTC) smaller than 4 cm and without extrathyroidal extension (ETE) and/or lymph node metastases as belonging to the same prognostic group, and therefore the recommendation is for uniform treatment. Xing draws our attention to a small subgroup with Duet Mutations (BRAF E600 and TERT 3636 genes) that are aggressive biologically and should be treated differently. Thus the aim of the present study is to test the validity of this recommendation.

METHODS

A Markovian Model is used to evaluate the above hypothesis.

RESULTS

A Monte Carlo sensitivity test shows a 5.6 year survival advantage for patients with low-grade PTC, who have the Duet Mutations, and were treated by total thyroidectomy rather than hemithyroidectomy.

CONCLUSIONS

We conclude that there is a place for routine molecular tests in low-risk patients with PTC.

PAPPA Expression in Indeterminate Thyroid Nodules as Screening Test to Select Patients for Molecular Testing

Pregnancy-associated plasma protein A (PAPPA) acts as an oncogene, and its expression is increased in multiple malignancies, including thyroid cancer. Molecular tests represent a useful tool in the management of indeterminate thyroid nodules; however, they are not conducted in all centers, and they contribute to increase the per-patient cost of nodule evaluation. In this study, we examined whether PAPPA expression could represent a promising new screening test in the management of indeterminate thyroid nodules. Toward this aim, PAPPA expression was evaluated in 107 fine needle aspiration cytologies (FNAC) belonging to Bethesda III–IV categories that had been sent to molecular biology to discriminate the nature of the nodules. We found that the PAPPA expression increased and showed an elevated sensitivity (97.14%) and negative predictive value (98%) in indeterminate cytological samples positive for mutations. The enhanced expression was not linked to a specific oncogene. Our findings demonstrated that assessing the PAPPA expression in indeterminate thyroid cytologies could represent a useful screening tool to select all patients that effectively need to be sent to molecular testing, thereby, leading to a potential cost reduction in the management of patients.

Molecular profiling of papillary thyroid carcinomas in healthcare workers exposed to low dose radiation at the workplace

PURPOSE

Exposure to ionizing radiation, especially during childhood, is a well-established risk factor for thyroid cancer. The vast majority of radiation-induced cancers are papillary carcinomas (PTCs). These tumors typically have gene fusions in contrast to point mutations prevalent in sporadic PTCs. The aim of this study was to investigate the molecular profiles of PTC patients with workplace exposure to ionizing radiation.

METHODS

A retrospective review of 543 patients who underwent surgery with diagnosis of PTC was performed. A cohort of nine healthcare specialists previously exposed to radiation sources during their professional practice was selected and analyzed using the ThyroSeq mutation panel for point mutations and gene fusions associated with thyroid cancer.

RESULTS

The molecular analysis of surgical samples of PTCs was informative and revealed genetic alterations in five patients. BRAF V600E was found in four (67%) cases whereas RET/PTC1 fusion in one (17%) and one sample (17%) was wild type for point mutations and fusions. One sample completely failed molecular analysis while two others were negative for genes fusions but failed DNA analysis; these three samples were excluded.

CONCLUSIONS

In this limited cohort of healthcare workers exposed to low dose of ionizing radiation at the workplace and developed PTC, the molecular profiling determined BRAF V600E point mutation as the most common event, arguing against the role of workplace radiation exposure in the etiology of these tumors.

Risk stratification of indeterminate thyroid nodules using ultrasound and machine learning algorithms

BACKGROUND

Indeterminate thyroid nodules (Bethesda III) are challenging to characterize without diagnostic surgery. Auxiliary strategies including molecular analysis, machine learning models, and ultrasound grading with Thyroid Imaging, Reporting and Data System (TI-RADS) can help to triage accordingly, but further refinement is needed to prevent unnecessary surgeries and increase positive predictive values.

DESIGN

Retrospective review of 88 patients with Bethesda III nodules who had diagnostic surgery with final pathological diagnosis.

MEASUREMENTS

Each nodule was retrospectively scored through TI-RADS. Two deep learning models were tested, one previously developed and trained on another data set, mainly containing determinate cases and then validated on our data set while the other one trained and tested on our data set (indeterminate cases).

RESULTS

The mean TI-RADS score was 3 for benign and 4 for malignant nodules (p = .0022). Radiological high risk (TI-RADS 4,5) and low risk (TI-RADS 2,3) categories were established. The PPV for the high radiological risk category in those with >10 mm nodules was 85% (CI: 70%-93%). The NPV for low radiological risk in patients >60 years (mean age was 100% (CI: 83%-100%). The area under the curve (AUC) value of our novel classifier was 0.75 (CI: 0.62-0.84) and differed significantly from the chance-level (p < .00001).

CONCLUSIONS

Novel radiomic and radiologic strategies can be employed to assist with preoperative diagnosis of indeterminate thyroid nodules.

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.

The emerging roles of NGS in clinical oncology and personalized medicine

Next-generation sequencing (NGS) has been increasingly popular in genomics studies over the last decade, as new sequencing technology has been created and improved. Recently, NGS started to be used in clinical oncology to improve cancer therapy through diverse modalities ranging from finding novel and rare cancer mutations, discovering cancer mutation carriers to reaching specific therapeutic approaches known as personalized medicine (PM). PM has the potential to minimize medical expenses by shifting the current traditional medical approach of treating cancer and other diseases to an individualized preventive and predictive approach. Currently, NGS can speed up in the early diagnosis of diseases and discover pharmacogenetic markers that help in personalizing therapies. Despite the tremendous growth in our understanding of genetics, NGS holds the added advantage of providing more comprehensive picture of cancer landscape and uncovering cancer development pathways. In this review, we provided a complete overview of potential NGS applications in scientific and clinical oncology, with a particular emphasis on pharmacogenomics in the direction of precision medicine treatment options.

Risk of malignancy in cytologically indeterminate thyroid nodules harboring thyroid stimulating hormone receptor mutations

OBJECTIVES

To evaluate the frequency and risk of malignancy of TSHRpI568T mutations discovered in indeterminate thyroid nodules (ITN) within the Veracyte CLIA laboratory undergoing Afirma^® Genomic Sequencing Classifier (GSC) testing, and to evaluate a broader cohort of TSHR variants and their categorization as Afirma GSC benign (GSC-B) or suspicious (GSC-S). Finally, we seek to assess the risk of malignancy (ROM) of this group of TSHR mutated ITN in the GSC-S category.

METHODS

ITN submitted to Veracyte for Afirma GSC testing between October 2017 and February 2022 were analyzed for TSHR variants and rates of GSC-B and GSC-S were calculated based upon BIII or IV cytology, by TSHR variant codon amino acid (AA) substitution, age, and gender. For GSC-S samples, surgical pathology reports were requested, and the rate of malignancy was calculated.

RESULTS

Five percent of the ITN samples harbored an isolated TSHR variant and 5% of those were classified as GSC-S. Among TSHRpI568T samples, 96% were GSC-B and of the GSC-S samples, 21% were malignant. Among an unselected group of TSHR, absent TSHRpI568T mutations, 16.3% of GSC-S samples were malignant, all but one with codon mutations in the transmembrane subdomains of the TSHR. This prompted a dedicated evaluation of transmembrane codons which revealed a malignancy rate of 10.7% among GSC-S nodules. In total, 13/85 (15.3%) TSHR mutated ITN with Afirma GSC-S results were found to be malignant.

CONCLUSIONS

TSHR variants are rare in ITN, and most are categorized as benign under Afirma GSC testing which carries a < 4% risk of malignancy. For GSC-S ITN with TSHR mutations, the risk of malignancy is ≥= 15%, which is clinically meaningful and may alter treatment or monitoring recommendations for patients.

Identification of benign and malignant thyroid nodules based on dynamic AI ultrasound intelligent auxiliary diagnosis system

BACKGROUND

Dynamic artificial intelligence (AI) ultrasound intelligent auxiliary diagnosis system (Dynamic AI) is a joint application of AI technology and medical imaging data, which can perform a real-time synchronous dynamic analysis of nodules. The aim of this study is to investigate the value of dynamic AI in differentiating benign and malignant thyroid nodules and its guiding significance for treatment strategies.

METHODS

The data of 607 patients with 1007 thyroid nodules who underwent surgical treatment were reviewed and analyzed, retrospectively. Dynamic AI was used to differentiate benign and malignant nodules. The diagnostic efficacy of dynamic AI was evaluated by comparing the results of dynamic AI examination, preoperative fine needle aspiration cytology (FNAC) and postoperative pathology of nodules with different sizes and properties in patients of different sexes and ages.

RESULTS

The sensitivity, specificity and accuracy of dynamic AI in the diagnosis of thyroid nodules were 92.21%, 83.20% and 89.97%, respectively, which were highly consistent with the postoperative pathological results (kappa = 0.737, p < 0.001). There is no statistical difference in accuracy between people with different ages and sexes and nodules of different sizes, which showed the good stability. The accuracy of dynamic AI in malignant nodules (92.21%) was significantly higher than that in benign nodules (83.20%) (p < 0.001). The specificity and positive predictive value were significantly higher, and the misdiagnosis rate was significantly lower in dynamic AI than that of preoperative ultrasound ACR TI-RADS (p < 0.001). The accuracy of dynamic AI in nodules with diameter ≤ 0.50 cm was significantly higher than that of preoperative ultrasound (p = 0.044). Compared with FNAC, the sensitivity (96.58%) and accuracy (94.06%) of dynamic AI were similar.

CONCLUSIONS

The dynamic AI examination has high diagnostic value for benign and malignant thyroid nodules, which can effectively assist surgeons in formulating scientific and reasonable individualized diagnosis and treatment strategies for patients.

LINC01087 Promotes the Proliferation, Migration, and Invasion of Thyroid Cancer Cells by Upregulating PPM1E

This study is aimed at investigating the effect and mechanism of LINC01087 on the malignant evolution of thyroid cancer cells. The expression levels of LINC01087, miR-135a-5p, and PPM1E in thyroid carcinoma tissues were detected by QRT-PCR. Cell viability was detected using the CCK-8 method. Transwell assay was used to assess the ability of cells to invade. The targeting relationship between LINC01087 and miR-135a-5p was detected by dual luciferase reporting assay. In comparison with normal thyroid tissues and cells, the expression level of LINC01087 in thyroid cancer tissues and TPC-1 and K1 cells increased, and the expression level of miR-135a-5p in thyroid cancer tissues and TPC-1 and K1 cells decreased. LINC01087 knockdown and the high expression of miR-143-3p inhibited the proliferation, invasion, and EMT processes of TPC-1 and K1 in thyroid cancer cells. LINC01087 negatively targeted miR-135a-5p. Has-miR-135a-5p inhibited the malignant evolution and EMT of thyroid cancer by targeting PPM1E. The PPM1E overexpression can reverse the inhibitory effect of LINC01087 gene knockdown on the proliferation, migration, and invasion of thyroid cancer cells. LINC01087 can promote the proliferation and apoptosis of thyroid cancer cells, and its mechanism may be related to the miR-135a-5p/PPM1E axis.

Molecular Characterization of Thyroid Follicular Lesions in the Era of "Next-Generation" Techniques

It is unequivocally recognized that thyroid nodules are frequently detected in the adult population and mostly characterized by benign lesions (up to 70% of them), with only 5%-15% malignant lesions. The evaluation of thyroid lesions with fine-needle aspiration cytology (FNAC) represents one of the first and most useful diagnostic tools in the definition of their nature. Despite the fact that the majority of thyroid lesions are correctly diagnosed as either benign (70%-75%) or malignant (5%-10%) entities, the remaining nodules (20%-25%) represent the "gray zone" of follicular lesions, which belong to indeterminate categories, according to the different classification systems. This indeterminate group of lesions includes both benign and malignant entities, which cannot be easily discriminate with morphology alone. In these last decades, the increasing role of molecular testings, feasibly performed on cytological material combined with the discoveries of specific genetic alterations in the field of thyroid pathology, has opened the pace to their more accurate and specific contribution on cytology. In fact, in 2015, in the revised management guidelines for patients with thyroid nodules and well-differentiated thyroid cancers (WDTCs), the American Thyroid Association (ATA) confirmed the performance of molecular testing in thyroid indeterminate cytology, and the same performance was addressed in recent update of the management of thyroid nodules in the second edition of the Bethesda system for reporting thyroid cytopathology (TBSRTC). In the current review, we discuss the role of molecular tests for the different thyroid diagnostic categories of the Bethesda system for reporting thyroid cytopathology, mostly focusing our attention on the follicular and indeterminate lesions.

Combination of ultrasound and molecular testing in malignancy risk estimate of Bethesda category IV thyroid nodules: results from a single-institution prospective study

PURPOSE

Malignancy prediction in indeterminate thyroid nodules is still challenging. We prospectively evaluated whether the combination of ultrasound (US) risk stratification and molecular testing improves the assessment of malignancy risk in Bethesda Category IV thyroid nodules.

METHODS

Ninety-one consecutively diagnosed Bethesda Category IV thyroid nodules were prospectively evaluated before surgery by both ACR- and EU-TIRADS US risk-stratification systems and by a further US-guided fine-needle aspiration cytology (FNAC) for the following molecular testing: BRAFV600E, N-RAS codons 12/13, N-RAS codon 61, H-RAS codons 12/13, H-RAS codon 61, K-RAS codons 12/13, and K-RAS codon 61 point-mutations, as well as PAX8/PPARγ, RET/PC1, and RET/PTC 3 rearrangements.

RESULTS

At histology, 37% of nodules were malignant. No significant association was found between malignancy and either EU- or ACR-TIRADS. In total, 58 somatic mutations were identified, including 3 BRAFV600E (5%), 5 N-RAS 12/13 (9%), 13 N-RAS 61 (22%), 7 H-RAS 12/13 (12%), 11 H-RAS 61 (19%), 6 K-RAS 12/13 (10%), 8 K-RAS 61 (14%) mutations and 2 RET/PTC1 (4%), 0 RET/PTC 3 (0%), 3 PAX8/PPARγ (5%) rearrangements. At least one somatic mutation was found in 28% and 44% of benign and malignant nodules, respectively, although malignancy was not statistically associated with the outcome of the mutational test. However, the combination of ACR-, but not EU-, TIRADS with the presence of at least one somatic mutation, was significantly associated with malignant histology (P = 0.03).

CONCLUSION

US risk stratification and FNAC molecular testing may synergistically contribute to improve malignancy risk estimate of Bethesda category IV thyroid nodules.

Preoperative detection of the TERT promoter mutations in papillary thyroid carcinomas

OBJECTIVE

Telomerase reverse transcriptase promoter (TERT-p) mutations are strongly associated with tumour aggressiveness and worse prognosis in papillary thyroid carcinomas (PTCs). Since the TERT-p mutations have been reported to be subclonal, it is unclear how accurately they can be detected by preoperative fine-needle aspiration (FNA). The objective of this study was to analyse the concordance rate of the TERT-p mutations between preoperative FNA and corresponding postoperative surgical specimens.

DESIGN AND PATIENTS

Ninety-six cases of PTC aged 55 years or older were studied. The mutational status of TERT-p was detected by droplet digital polymerase chain reaction assay.

RESULTS

The mutational status of the TERT-p in FNA samples was highly concordant with that in postoperative formalin-fixed and paraffin-embedded (FFPE) specimens. The TERT-p mutation was significantly associated with age, tumour size, extrathyroidal extension and the Ki-67 labelling index in multivariate analysis in both FNA and FFPE samples.

CONCLUSIONS

The detection of the TERT-p mutations using FNA samples has a good ability to predict disease aggressiveness and, therefore, could be clinically useful in the determination of PTC management.