TERT promoter mutations and their association with BRAF V600E mutation and aggressive clinicopathological characteristics of thyroid cancer

TERT Promoter Mutations Increase Tumor Aggressiveness by Altering TERT mRNA Splicing in Papillary Thyroid Carcinoma

CONTEXT

Telomerase reverse transcriptase promoter (TERT-p) mutations, which upregulate TERT expression, are strongly associated with tumor aggressiveness and worse prognosis in papillary thyroid carcinomas (PTCs). TERT expression is also observed in a proportion of PTCs without TERT-p mutations, but such tumors show less aggressiveness and better prognosis than TERT-p mutation-positive tumors.

OBJECTIVE

TERT has multiple splicing variants whose relationships with the TERT-p status and clinicopathological characteristics remain poorly understood. We examined the relationship between the TERT-p mutational status, the TERT splicing pattern, and clinicopathological features.

METHODS

We investigated the expression of 2 major variants, α deletion (dA) and β deletion (dB), in a series of 207 PTCs operated on between November 2001 and March 2020 in Nagasaki University Hospital and Kuma Hospital.

RESULTS

The TERT-p mutations were found in 33 cases, and among 174 mutation-negative cases, 24 showed TERT expression. All cases were classified into 3 groups: the TERT-p mutation-negative/expression-negative group (mut-/exp-), the TERT-p mutation-negative/expression-positive group (mut-/exp+), and the TERT-p mutation-positive group (mut+/exp+). The +A+B/dB ratio in mut+/exp+ was significantly higher than that in mut-/exp+ PTCs. Analysis with clinicopathological data revealed that +A+B expression was associated with higher PTC aggressiveness, whereas dB expression counteracted this effect. Functional in vitro study demonstrated that dB strongly inhibited cell growth, migration, and clonogenicity, suggesting its tumor-suppressive role.

CONCLUSION

These results provide evidence that the TERT-p mutations alter the expression of different TERT splice variants, which, in turn, associates with different tumor aggressiveness.

TERT promoter mutations and additional molecular alterations in thyroid fine-needle aspiration specimens: A multi-institutional study with histopathologic follow-up

OBJECTIVES

TERT promoter mutations are not infrequently encountered in thyroid carcinomas; however, it is unclear if additional molecular alterations may play a role in determining tumor behavior.

METHODS

Fine-needle aspiration (FNA) specimens from 32 patients with TERT promoter mutations detected by ThyroSeq v3 from 4 institutions were included in the study. FNA diagnoses, molecular results, and surgical follow-up were retrospectively reviewed and analyzed.

RESULTS

There were 5 benign and 27 malignant neoplasms, including 7 high-grade thyroid carcinomas (HGCs) on histopathologic follow-up. Of 4 cases with an isolated TERT mutation, 3 (75%) cases were malignant. Of 17 cases harboring a co-occurring TERT mutation with 1 additional molecular alteration, 13 (76%) displayed malignancy on histopathologic follow-up. All 11 cases with TERT mutations plus 2 or more additional molecular alterations were malignant on follow-up. Furthermore, HGC was not seen in cases with an isolated TERT mutation, while 80% of cases harboring TERT mutations plus 3 additional molecular alterations showed HGC.

CONCLUSIONS

TERT promoter mutations are commonly associated with malignancy, particularly HGCs, when multiple co-occurring molecular alterations are present. However, TERT promoter mutations may occasionally be detected in benign thyroid neoplasms when encountered in isolation or with fewer than 2 additional molecular alterations.

The Long Journey towards Personalized Targeted Therapy in Poorly Differentiated Thyroid Carcinoma (PDTC): A Case Report and Systematic Review

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) has an intermediate prognosis between indolent well-differentiated thyroid carcinoma (TC) and anaplastic carcinoma. Herein, we present a case report with a PDTC component, along with a systematic review of the literature.

CASE REPORT

We report a case of a 45-year-old man diagnosed with a PDTC component, along with hobnail and tall-cell variant features positive for BRAFV600E mutation, after a total thyroidectomy and neck dissection. Radioactive iodine (RAI)-131 therapy was applied, but an early recurrence led to complementary surgeries. The anti-Tg rise, the presence of new lymph nodes, and the negative whole-bodyradioiodine scan were suggestive of a radioiodine-resistant tumor. Lenvatinib, sorafenib, dabrafenib/trametinib, cabozantinib and radiotherapy were all administered, controlling the tumor for a period of time before the patient ultimately died post-COVID infection. Systematic Review: We searched PubMed, Scopus, and WebofScience to identify studies reporting clinicopathological characteristics, molecular marker expression, and management of non-anaplastic TC with any proportion of PDTC in adult patients. Of the 2007 records retrieved, 82were included in our review (PROSPERO-ID545847).

CONCLUSIONS

Our case, together with the systematic review, imply that a combination of molecular-targetedtreatments may be safe and effective in patients with RAI-resistantBRAF-mutated advanced PDTC when surgery has failed to control tumor progression.

Genetic trio of BRAF and TERT alterations and rs2853669TT in papillary thyroid cancer aggressiveness

BACKGROUND

BRAF V600E and TERT promoter alterations are core components in current genetics-based risk assessment for precision management of papillary thyroid cancer. It remains unknown whether this approach could achieve even better precision through a widely recognized prognostic single-nucleotide variation (SNV, formerly SNP), rs2853669T>C, in the TERT promoter.

METHODS

The genetic status of alterations and SNV were examined by sequencing genomic DNA from papillary thyroid cancer in 608 patients (427 women and 181 men) aged 47 years (interquartile range = 37-57), with a median follow-up time of 75 months (interquartile range = 36-123), and their relationship with clinical outcomes was analyzed. A luciferase reporter assay was performed to examine TERT promoter activities.

RESULTS

TERT promoter alterations showed a strong association with papillary thyroid cancer recurrence in the presence of genotype TT of rs2853669 (adjusted hazard ratio [HR] = 2.12, 95% confidence interval [CI] = 1.10 to 4.12) but not TC/CC (adjusted HR = 1.17, 95% CI = 0.56 to 2.41). TERT and BRAF alterations commonly coexisted and synergistically promoted papillary thyroid cancer recurrence. With this genetic duet, TT of rs2853669 showed a robustly higher disease recurrence than TC/CC (adjusted HR = 14.26, 95% CI = 2.86 to 71.25). Patients with the genetic trio of BRAF V600E, TERT alteration, and TT of rs2853669 had a recurrence of 76.5% vs recurrence of 8.4% with neither variation and with TC/CC (HR = 13.48, 95% CI = 6.44 to 28.21). T allele of rs2853669 strongly increased TERT promoter activities, particularly the variant promoters.

CONCLUSIONS

The SNV rs2853669T>C dramatically refines the prognostic power of BRAF V600E and TERT promoter alterations to a higher precision, suggesting the need for including this SNV in the current genetics-based risk prognostication of papillary thyroid cancer.

TERT RNAscope analysis of sub-centimetric papillary thyroid carcinomas and synchronous lymph node metastases

BACKGROUND

Sub-centrimetric papillary thyroid carcinomas usually have a good prognosis with a cancer specific survival of > 99%, however in up to 65% of patients, lymph node metastases can be observed. Molecular alterations in BRAF, TERT and TP53 are associated with worse clinicopathological outcome in patients with papillary thyroid carcinoma.

MATERIAL AND METHODS

Twenty-two cases of papillary thyroid carcinomas measuring ≤ 1 cm with synchronous lymph node metastases were examined regarding morphological patterns and immunohistochemical status of p53, Ki-67, and BRAF V600E status. TERT RNA expression in lymph node metastases were evaluated by RNAScope®.

RESULTS

Morphological patterns were heterogeneous in both primary tumors and lymph node metastases. Proliferation indices measured by Ki-67 were low. Both primary and lymph node metastases were wild type for p53 by immunohistochemical analysis. No lymph node metastasis showed TERT expression by RNAScope®.

CONCLUSIONS

Our data indicate that TERT expression is not involved in the development early lymph node metastasis in patients with sub-centimetric PTC.

Integrated proteogenomic and metabolomic characterization of papillary thyroid cancer with different recurrence risks

Although papillary thyroid cancer (PTC) has a good prognosis, its recurrence rate is high and remains a core concern in the clinic. Molecular factors contributing to different recurrence risks (RRs) remain poorly defined. Here, we perform an integrative proteogenomic and metabolomic characterization of 102 Chinese PTC patients with different RRs. Genomic profiling reveals that mutations in MUC16 and TERT promoter as well as multiple gene fusions like NCOA4-RET are enriched by the high RR. Integrative multi-omics analyses further describe the multi-dimensional characteristics of PTC, especially in metabolism pathways, and delineate dominated molecular patterns of different RRs. Moreover, the PTC patients are clustered into four subtypes (CS1: low RR and BRAF-like; CS2: high RR and metabolism type, worst prognosis; CS3: high RR and immune type, better prognosis; CS4: high RR and BRAF-like) based on the omics data. Notably, the subtypes display significant differences considering BRAF and TERT promoter mutations, metabolism and immune pathway profiles, epithelial cell compositions, and various clinical factors (especially RRs and prognosis) as well as druggable targets. This study can provide insights into the complex molecular characteristics of PTC recurrences and help promote early diagnosis and precision treatment of recurrent PTC.

BRAF and RET polymorphism association with thyroid cancer risk, a preliminary study from Khyber Pakhtunkhwa population

BACKGROUND

Thyroid cancer, originating in the neck's thyroid gland, encompasses various types. Genetic mutations, particularly in BRAF and RET genes are crucial in its development. This study investigates the association between BRAF (rs113488022) and RET (rs77709286) polymorphisms and thyroid cancer risk in the Khyber Pakhtunkhwa (KP) population.

METHODS

Blood samples from 100 thyroid cancer patients and 100 healthy controls were genotyped using ARMS-PCR followed by gel electrophoresis and statistical analysis.

RESULTS

Analysis revealed a significant association between the minor allele T of BRAF (rs113488022) and thyroid cancer risk (P = 0.0001). Both genotypes of BRAF (rs113488022) showed significant associations with thyroid cancer risk (AT; P = 0.0012 and TT; P = 0.045). Conversely, the minor allele G of RET (rs77709286) exhibited a non-significant association with thyroid cancer risk (P = 0.2614), and neither genotype showed significant associations (CG; P = 0.317, GG; P = 0.651). Demographic and clinical parameters analysis using SPSS showed a non-significant association between BRAF and RET variants and age group (P = 0.878 and P = 0.536), gender (P = 0.587 and P = 0.21), tumor size (P = 0.796 and P = 0.765), or tumor localization (P = 0.689 and P = 0.727).

CONCLUSION

In conclusion, this study emphasizes the significant association between BRAF polymorphism and thyroid cancer risk, while RET polymorphism showed a less pronounced impact. Further validation using larger and specific datasets is essential to establish conclusive results.

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.

Genomic alterations in thyroid cancer: biological and clinical insights

Tumours can arise from thyroid follicular cells if they acquire driver mutations that constitutively activate the MAPK signalling pathway. In addition, a limited set of additional mutations in key genes drive tumour progression towards more aggressive and less differentiated disease. Unprecedented insights into thyroid tumour biology have come from the breadth of thyroid tumour sequencing data from patients and the wide range of mutation-specific mechanisms identified in experimental models, in combination with the genomic simplicity of thyroid cancers. This knowledge is gradually being translated into refined strategies to stratify, manage and treat patients with thyroid cancer. This Review summarizes the biological underpinnings of the genetic alterations involved in thyroid cancer initiation and progression. We also provide a rationale for and discuss specific examples of how to implement genomic information to inform both recommended and investigational approaches to improve thyroid cancer prognosis, redifferentiation strategies and targeted therapies.

Reactivation of telomerase reverse transcriptase expression in cancer: the role of TERT promoter mutations

Telomerase activity and telomere elongation are essential conditions for the unlimited proliferation of neoplastic cells. Point mutations in the core promoter region of the telomerase reverse transcriptase (TERT) gene have been found to occur at high frequencies in several tumour types and considered a primary cause of telomerase reactivation in cancer cells. These mutations promote TERT gene expression by multiple mechanisms, including the generation of novel binding sites for nuclear transcription factors, displacement of negative regulators from DNA G-quadruplexes, recruitment of epigenetic activators and disruption of long-range interactions between TERT locus and telomeres. Furthermore, TERT promoter mutations cooperate with TPP1 promoter nucleotide changes to lengthen telomeres and with mutated BRAF and FGFR3 oncoproteins to enhance oncogenic signalling in cancer cells. TERT promoter mutations have been recognized as an early marker of tumour development or a major indicator of poor outcome and reduced patients survival in several cancer types. In this review, we summarize recent findings on the role of TERT promoter mutations, telomerase expression and telomeres elongation in cancer development, their clinical significance and therapeutic opportunities.

Age-associated mortality is partially mediated by TERT promoter mutation status in differentiated thyroid carcinoma

BACKGROUND

Age at diagnosis (AAD) and telomerase reverse transcriptase (TERT) promoter mutations are prognostic factors in differentiated thyroid carcinoma (DTC), and the prevalence of the mutations increases with AAD. Considering this correlation, we investigated whether an interaction between AAD and the mutations is present and whether the mutation mediates the effect of AAD on the mortality rate in DTC.

METHODS

The study included 393 patients with DTC who were followed-up after thyroidectomy at a single medical center in Korea from 1994 to 2004. Multivariable Cox regression was used to investigate the interaction of AAD and TERT promoter mutation. Mediation analysis was conducted using a regression-based causal mediation model.

RESULTS

The age-associated mortality rate increased progressively in all DTC patients and wild-type TERT group (WT-TERT) with a linear trend (p < 0.001) contrary to mutant TERT group (M-TERT) (p = 0.301). Kaplan-Meier curves declined progressively with increasing AAD in the entire group, but the change was without significance in M-TERT. The effect of AAD on mortality was not significant (adjusted HR: 1.07, 95% CI 0.38-3.05) in M-TERT. An interaction between AAD and TERT promoter mutation (p = 0.005) was found in a multivariable Cox regression. TERT promoter mutations mediated the effect of AAD on the mortality rate by 36% in DTC in a mediation analysis.

CONCLUSIONS

Considering the mediation of TERT promoter mutation on the effect of AAD on mortality, inclusion of TERT promoter mutation in a stage classification to achieve further individualized prediction in DTC is necessary.

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.

TERT expression is associated with metastasis from thin primaries, exhausted CD4+ T cells in melanoma and with DNA repair across cancer entities

Telomerase reverse transcriptase (TERT) promoter mutations occur frequently in cancer, have been associated with increased TERT expression and cell proliferation, and could potentially influence therapeutic regimens for melanoma. As the role of TERT expression in malignant melanoma and the non-canonical functions of TERT remain understudied, we aimed to extend the current knowledge on the impact of TERT promoter mutations and expression alterations in tumor progression by analyzing several highly annotated melanoma cohorts. Using multivariate models, we found no consistent association for TERT promoter mutations or TERT expression with the survival rate in melanoma cohorts under immune checkpoint inhibition. However, the presence of CD4+ T cells increased with TERT expression and correlated with the expression of exhaustion markers. While the frequency of promoter mutations did not change with Breslow thickness, TERT expression was increased in metastases arising from thinner primaries. As single-cell RNA-sequencing (RNA-seq) showed that TERT expression was associated with genes involved in cell migration and dynamics of the extracellular matrix, this suggests a role of TERT during invasion and metastasis. Co-regulated genes found in several bulk tumors and single-cell RNA-seq cohorts also indicated non-canonical functions of TERT related to mitochondrial DNA stability and nuclear DNA repair. This pattern was also evident in glioblastoma and across other entities. Hence, our study adds to the role of TERT expression in cancer metastasis and potentially also immune resistance.

Review article: new treatments for advanced differentiated thyroid cancers and potential mechanisms of drug resistance

The treatment of advanced, radioiodine refractory, differentiated thyroid cancers (RR-DTCs) has undergone major advancements in the last decade, causing a paradigm shift in the management and prognosis of these patients. Better understanding of the molecular drivers of tumorigenesis and access to next generation sequencing of tumors have led to the development and Food and Drug Administration (FDA)-approval of numerous targeted therapies for RR-DTCs, including antiangiogenic multikinase inhibitors, and more recently, fusion-specific kinase inhibitors such as RET inhibitors and NTRK inhibitors. BRAF + MEK inhibitors have also been approved for BRAF-mutated solid tumors and are routinely used in RR-DTCs in many centers. However, none of the currently available treatments are curative, and most patients will ultimately show progression. Current research efforts are therefore focused on identifying resistance mechanisms to tyrosine kinase inhibitors and ways to overcome them. Various novel treatment strategies are under investigation, including immunotherapy, redifferentiation therapy, and second-generation kinase inhibitors. In this review, we will discuss currently available drugs for advanced RR-DTCs, potential mechanisms of drug resistance and future therapeutic avenues.

TERT Mutations in Non-Small Cell Lung Cancer: Clinicopathologic Features and Prognostic Implications

Introduction

The associations between the clinical characteristics of non-small cell lung cancer (NSCLC) and mutations in telomerase reverse transcriptase (TERT) gene remain unclear. In this study, we used next-generation sequencing (NGS) to investigate the incidence rate and clinical correlates of TERT mutations in patients with NSCLC.

Methods

In total, 283 tumor samples from patients with NSCLC were tested using an NGS panel from September 2017 to May 2020. The genetic testing results and clinical data of all patients were collected.

Results

TERT mutations were found in 30 patients, which were significantly associated with age, smoking history, sex, and metastasis (P < 0.05). Survival analyses showed that patients who carried TERT mutations had a poorer prognosis. Of the 30 TERT-mutation carriers, 17 harbored epidermal growth factor receptor (EGFR) mutations, which were significantly associated with sex, histopathology type, and metastasis (P < 0.05; overall survival [OS], 21 months; 95% confidence interval [CI], 8.153-33.847 months). Three TERT mutation patients harbored Kirsten rat sarcoma virus (KRAS) mutations, which were significantly associated with metastasis risk (P < 0.05), KRAS mutations carriers had a worse prognosis, with an OS of 10 months (95% CI, 8.153-33.847 months). Multivariate Cox regression analyses showed that age, cancer stage, and TERT mutation carrier status were independent risk factors for NSCLC, and the TERT mutation was 2.731 times higher than that without TERT mutation (95% CI, 1.689-4.418, P < 0.001).

Conclusions

TERT mutations were present in 11% of patients with NSCLC. TERT mutations were associated with age, smoking history, sex, and distant metastasis. Co-mutations in TERT and EGFR/KRAS indicated a poor prognosis. The co-mutations of TERT and EGFR differed according to sex, histopathology type, and metastasis, whereas TERT and KRAS co-mutations were only associated with patient metastasis. Age, cancer stage, and TERT mutation carrier status were independent risk factors for poor prognosis in patients with NSCLC.

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

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

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.

Iodine nutritional status is not a direct factor in the prevalence of the BRAFV600E mutation in papillary thyroid cancer

Objective

Papillary thyroid carcinoma (PTC) accounts for approximately 85%-90% of all thyroid cancers. Of the iodine-metabolizing genes, BRAFV600E is a highly specific target for PTC and may have a reciprocal causative relationship with iodide-metabolizing genes.

Materials and methods

In this study, we performed a data analysis of selected quantitative studies to determine the relationship between iodine nutritional status and the prevalence of the BRAF600E mutation in patients with PTC. Five studies were selected for meta-analysis based on the selection criteria.

Results

A total of 2,068 patients were divided into three groups: low (urinary iodine concentration [UIC] < 100 µg/L), adequate (UIC 100-200 µg/L), and high (UIC ≥ 200 µg/L). The results were obtained using RevMan software, and the pooled odds ratios (ORs) were calculated using Mantel-Haenszel statistics with a 95% confidence interval (CI). The OR for the prevalence of the BRAFV600E mutation between the high and adequate groups was 1.25 (95% CI 0.64-2.43, p = 0.51), and the OR between the low and adequate groups was 0.98 (95% CI 0.42-2.31, p = 0.96). The BRAFV600E mutation risk did not change significantly at different levels of iodine nutrition (p = 0.33) in statistical analyses.

Conclusion

We conducted preliminary research on dietary iodine intake and the BRAFV600E mutation in PTC. The results suggested that abnormal iodine intake might not directly influence the prevalence of the BRAFV600E mutation in these patients. Further research into the associations between dietary iodine intake and the BRAFV600E mutation in PTC, including the underlying mechanisms, is required.

Deep Learning Prediction of TERT Promoter Mutation Status in Thyroid Cancer Using Histologic Images

Background and objectives: Telomerase reverse transcriptase (TERT) promoter mutation, found in a subset of patients with thyroid cancer, is strongly associated with aggressive biologic behavior. Predicting TERT promoter mutation is thus necessary for the prognostic stratification of thyroid cancer patients. Materials and Methods: In this study, we evaluate TERT promoter mutation status in thyroid cancer through the deep learning approach using histologic images. Our analysis included 13 consecutive surgically resected thyroid cancers with TERT promoter mutations (either C228T or C250T) and 12 randomly selected surgically resected thyroid cancers with a wild-type TERT promoter. Our deep learning model was created using a two-step cascade approach. First, tumor areas were identified using convolutional neural networks (CNNs), and then TERT promoter mutations within tumor areas were predicted using the CNN–recurrent neural network (CRNN) model. Results: Using the hue–saturation–value (HSV)-strong color transformation scheme, the overall experiment results show 99.9% sensitivity and 60% specificity (improvements of approximately 25% and 37%, respectively, compared to image normalization as a baseline model) in predicting TERT mutations. Conclusions: Highly sensitive screening for TERT promoter mutations is possible using histologic image analysis based on deep learning. This approach will help improve the classification of thyroid cancer patients according to the biologic behavior of tumors.

BRAFV600E and TERT promoter C228T mutations on ThyroSeq v3 analysis of delayed skin metastasis from papillary thyroid cancer: a case report and literature review

BACKGROUND

Skin metastasis from papillary thyroid cancer (PTC) is a rare entity that can occur up to decades after treatment of the primary tumor. Here, we present a patient who developed skin metastasis 10 years after treatment of her primary tumor and describe the molecular findings of the metastatic lesion.

CASE PRESENTATION

A 44-year-old female with a history of PTC who underwent a total thyroidectomy and radioactive iodine (RAI) treatment 10 years ago presented with a 1.3-cm skin lesion along the prior thyroidectomy scar. A biopsy revealed metastatic PTC, and the patient underwent surgical excision of the lesion. ThyroSeq molecular testing showed the copresence of BRAF^V600E mutation and TERT promoter C228T mutation. The patient subsequently received one round of adjuvant RAI therapy.

CONCLUSIONS

A high index of suspicion is warranted in patients with a history of PTC who develop a skin lesion, even several years after remission of the primary disease. In patients with high-risk mutations, such as BRAF^V600E and TERT promoter C228T mutations, long-term surveillance of disease recurrence is particularly important.

Genetic analysis and clinicopathologic features of locally advanced papillary thyroid cancers: a prospective observational study

PURPOSE

Locally advanced papillary thyroid cancer (LAPTC) has poor prognosis. Large-scale genomic testing has revealed multiple oncogenic drivers which may be essential for understanding tumor progression. However, the accurate identification of high recurrence risk and poor prognosis in thyroid carcinoma remains unclear. The objective of this study was to analyze genetic profile and clinicopathologic features of locally advanced papillary thyroid cancers.

METHODS

An observational cohort study was performed to identify molecular characteristics of LAPTC and a prognosis comparison of LAPTC with different genetic mutations. ThyroSeq v2 next-generation sequencing (57-gene panel) was performed on fresh tumor tissue. Then, the clinicopathological features between tumors with different genetic mutations were compared. Additionally, correlations of tumor recurrence and disease free survival with different genetic alterations were analyzed.

RESULTS

This study showed that the main mutation is common BRAF^V600E (66.2%, 43/65) in LAPTC, followed by the TERT promoter mutations (38.5%, 25/65). Synergetic mutations of BRAF^V600E and TERT promoters (B&T) were identified in 26.2% LAPTC (17/65), which is associated with tall-cell variant, extrathyroidal invasion and advanced tumor stage (III/IV). The synergetic mutations of B&T are also significantly associated with higher risk of recurrence (hazard ratio [HR], 6.0; 95% confidence interval, CI 1.26-28.55, P = 0.02) and mortality (17.6%, 3/17).

CONCLUSIONS

Synergetic mutations of B&T are common in LAPTC, which is associated with the aggressive clinicopathologic features and an increased risk of recurrence and mortality. This finding may help to predict aggressive behavior of LAPTC and to assist in clinical decision-making.

TERT genetic polymorphism rs2736100 is associated with an aggressive manifestation of papillary thyroid carcinoma

Objectives

TERT rs2736100 genetic polymorphism is commonly found in human malignancies, indicating its key role in cancer cell transformation. The aim of this study is to investigate the effects of the functional TERT rs2736100 genetic polymorphism on the outcomes of papillary thyroid carcinoma (PTC) patients.

Materials and methods

We performed a retrospective study on the relationship between rs2736100 and clinicopathological outcomes of PTC in 500 patients (378 females and 122 males) aged 43.8 ± 11.4 years (range 15-74 years) with a median follow-up of 60 months (range, 1-455 months).

Results

TERT rs2736100 genetic polymorphism (TG/GG vs. TT) was significantly associated with several high-risk clinicopathological features such as tumor spread, extrathyroidal extension, central/lateral lymph node metastases, and Stage T III or IV disease. However, in Kaplan-Meier survival analyses, the rs2736100 mutation was unrelated to overall disease-free survival with a log-rank value of p > 0.05. In Cox-regression analyses, the overall survival rate of recurrence/neo-metastasis was related to a larger tumor size, younger age, and tumor spread but unrelated to the rs2736100 mutation.

Conclusions and significance

TERT rs2736100 genetic polymorphism mutation is more likely to manifest with aggressive clinicopathological characteristics but cannot worsen prognosis in PTC.

Effect of Having Concurrent Mutations on the Degree of Aggressiveness in Patients with Thyroid Cancer Positive for TERT Promoter Mutations

This study aimed to examine whether concurrent mutations with a TERT promoter mutation are associated with a greater likelihood of more aggressive disease than a TERT promoter mutation alone. The medical records of 1477 patients who underwent thyroid surgery at two tertiary hospitals between 2017 and 2022 were reviewed. Twenty-four patients had TERT promoter mutations based on molecular profile testing. Clinicodemographic data, mutational profiles, and histopathological features were assessed. Descriptive analysis, Fisher's exact test, and binary logistic regression were performed. Seven patients had single-gene TERT promoter mutations, and 17 had concurrent mutations, including BRAF V600E, HRAS, NRAS, PIK3CA, and EIF1AX. The overall prevalence of malignancy was 95.8%, of which 78.3% were aggressive thyroid cancers. There was a statistically significant association between concurrent mutations and disease aggressiveness. The odds of having aggressive disease were 10 times higher in patients with a TERT promoter mutation and a concurrent molecular alteration than in those with a TERT promoter mutation alone. This is an important finding for thyroid specialists to consider when counseling patients concerning risk stratification and management options.

Molecular and clinical features of papillary thyroid cancer in adult patients with a non-classical phenotype

Purpose

Genotyping is fundamental in papillary thyroid cancer (PTC) and helps to enhance diagnosis and prognosis and determine appropriate treatments. The phenotype-genotype association in PTC was previously studied, with BRAF V600E characterizing classic PTC and tall-cell PTC and RAS mutations characterizing follicular-variant PTC. In clinic, some non-classical histological subtypes of PTC were also identified, however, their genotype remains unclear. In this study, we collected samples of these non-classical PTC after the exclusion of classic phenotypes and examined their phenotypes, genotype and the relationship between phenotype and genotype.

Methods

We screened out non-classical PTC by excluding classical PTC from 1,059 different thyroid samples, and a total of 24 cases was obtained and described from the morphological features, which is rare in differentiated PTC. DNA/RNA sequencing was performed using 18 available samples to describe the genetic features.

Results

PTC with the non-classical phenotype were characterized cuboidal to low columnar tumor cells with subtle nuclear features of PTC and without discernible nuclear elongation, concurrently with dense microfollicles, delicate papillae or solid nodules with delicate fibrovascular cores. They were associated with lymphatic vessel invasion (P<0.001) but not with a worse prognosis (P=0.791). Gene fusions were identified in 14 of 18 (77.8%) cases, including eight fusions of NTRK and six fusions of RET. The high percentage of fusions in this papillary thyroid cancer subgroup suggested a correlation of gene fusions with the phenotype that does not belong to the BRAF V600E-mutant or RAS-mutant group.

Conclusions

Our study retrospectively screened a large cohort of different thyroid tissue samples, and presented the histopathological and genetic features of a non-classical phenotype of PTC from 24 patients. It may contribute to diagnose in PTC, and patients of these non-classical phenotype may benefit from targeted therapy, compared to a natural patient cohort without selection.

Molecular testing in thyroid cancer diagnosis and management

Molecular diagnostic testing has had a profound impact on the diagnosis and management of thyroid nodules and thyroid cancer. Based on the tremendous expansion of knowledge of the genomic landscape of thyroid cancer over the past few decades, tests have been developed, analyzed, modified, and implemented into clinical practice. Genomic testing of thyroid nodules to improve preoperative diagnosis has become an important component supporting decision-making in clinical care, reducing the need for diagnostic surgeries and improving accuracy of cancer risk assessment. In addition, a role for molecular testing of established thyroid cancers to assist in selection of therapeutic options for patients with advanced and/or progressive disease has been established. Research is ongoing to determine if molecular results should affect management of less aggressive forms of thyroid cancer earlier in clinical management. This review will outline the various commercial platforms for molecular diagnostics for nodules emphasizing their performance parameters and indications for use, as well as discuss the use of genomic analysis for progressive thyroid cancer and highlight opportunities for further research.

Radiomics Analysis of Gray-Scale Ultrasonographic Images of Papillary Thyroid Carcinoma > 1 cm: Potential Biomarker for the Prediction of Lymph Node Metastasis

Purpose

This study aimed to investigate radiomics analysis of ultrasonographic images to develop a potential biomarker for predicting lymph node metastasis in papillary thyroid carcinoma (PTC) patients.

Materials and Methods

This study included 431 PTC patients from August 2013 to May 2014 and classified them into the training and validation sets. A total of 730 radiomics features, including texture matrices of gray-level co-occurrence matrix and gray-level run-length matrix and single-level discrete two-dimensional wavelet transform and other functions, were obtained. The least absolute shrinkage and selection operator method was used for selecting the most predictive features in the training data set.

Results

Lymph node metastasis was associated with the radiomics score (p < 0.001). It was also associated with other clinical variables such as young age (p = 0.007) and large tumor size (p = 0.007). The area under the receiver operating characteristic curve was 0.687 (95% confidence interval: 0.616-0.759) for the training set and 0.650 (95% confidence interval: 0.575-0.726) for the validation set.

Conclusion

This study showed the potential of ultrasonography-based radiomics to predict cervical lymph node metastasis in patients with PTC; thus, ultrasonography-based radiomics can act as a biomarker for PTC.

Targeting Diagnosis of High-Risk Papillary Thyroid Carcinoma Using Ultrasound Contrast Agent With the BRAFV600E Mutation: An Experimental Study

OBJECTIVE

High-risk papillary thyroid carcinoma (PTC) patients with BRAF mutation have lymph node and distant metastases and poor prognosis. Therefore, this study aims to develop a targeted ultrasound contrast agent for the BRAF^V600E mutation to screen high-risk PTC at early stage.

METHODS

The targeted lipid nanobubbles carrying BRAF^V600E antibody were prepared using thin film hydration-sonication and avidin-biotin binding methods. The physicochemical properties and stability of the targeted nanobubbles were detected by transmission electron microscopy, atomic force microscopy, and confocal laser scanning microscopy. The target binding abilities of the targeted nanobubbles in the PTC cells (B-CPAP) overexpressed mutant BRAF^V600E were evaluated by immunofluorescence staining, quantitative real-time polymerase chain reaction, western blot, and fluorescence microscopy. After PTC tumor models overexpressed mutant BRAF^V600E were established, the enhanced images of targeted lipid nanobubbles and untargeted lipid nanobubbles on PTC tumors in nude mice were observed using contrast-enhanced ultrasound imaging.

RESULTS

The targeted lipid nanobubbles revealed uniform, round morphology, and good stability with a nanoscale size. Besides, BRAF^V600E monoclonal antibody was observed to be combined on the surface of lipid nanobubbles. Furthermore, the targeted nanobubbles had a good targeting diagnosis ability in PTC cells with BRAF^V600E overexpression. Moreover, the targeted nanobubbles had better ultrasound enhancement and peak intensity of the time-intensity curve (P < .001) in PTC tumors with BRAF^V600E overexpression as compared to the untargeted lipid nanobubbles.

CONCLUSION

The targeted lipid nanobubbles carrying BRAF^V600E antibody could be regarded as a potential targeted ultrasound contrast agent for the diagnosis of high-risk PTC.

Thyroid carcinoma-featured telomerase activation and telomere maintenance: Biology and translational/clinical significance

BACKGROUND

Telomerase is a ribonucleoprotein complex consisting of a catalytic component telomerase reverse transcriptase (TERT), internal RNA template and other co-factors, and its essential function is to synthesize telomeric DNA, repetitive TTAGGG sequences at the termini of linear chromosomes. Telomerase is silent in normal human follicular thyroid cells, primarily due to the TERT gene being tightly repressed. During the development and progression of thyroid carcinomas (TCs), TERT induction and telomerase activation is in general required to maintain telomere length, thereby conferring TC cells with immortal and aggressive phenotypes.

METHODS

The genomic alterations of the TERT loci including TERT promoter's gain-of-function mutations, copy number gain, fusion and rearrangements, have recently been identified in TCs as mechanisms to induce TERT expression and to activate telomerase. Importantly, numerous studies have consistently shown that TERT promoter mutations and TERT expression occur in all TC subtypes, and are robustly associated with TC malignancy, aggressiveness, treatment failure and poor outcomes. Therefore, the assessment of TERT promoter mutations and TERT expression is highly valuable in TC diagnostics, prognosis, treatment decision, and follow-up design. In addition, the TERT promoter is frequently hypermethylated in TC cells and tumors, which is required to activate TERT transcription and telomerase. Dysregulation of other components in the telomerase complex similarly upregulate telomerase. Moreover, shortened telomeres lead to altered gene expression and metabolism, thereby actively promoting TC aggressiveness. Here we summarize recent findings in TCs to provide the landscape of TC-featured telomere/telomerase biology and discuss underlying implications in TC precision medicine.

CONCLUSION

Mechanistic insights into telomerase activation and TERT induction in TCs are important both biologically and clinically. The TERT gene aberration and expression-based molecular classification of TCs is proposed, and for such a purpose, the standardization of the assay and evaluation system is required. Moreover, the TERT-based system and 2022 WHO TC classification may be combined to improve TC care.

Implications of TERT promoter mutations and telomerase activity in solid tumors with a focus on genitourinary cancers

INTRODUCTION

The reactivation of telomerase represents a key moment in the carcinogenesis process. Mutations in the central promoter region of the telomerase reverse transcriptase (TERT) gene cause telomerase reactivation in approximately 90% of solid tumors. In some of these, its prognostic and predictive role in response to treatments has already been demonstrated, in others (such as tumors of the genitourinary tract like urothelial carcinoma) data are controversial and the research is still ongoing. In the future, TERT promoter mutations and telomerase activity could have diagnostic, prognostic, and therapeutic applications in many types of cancer.

AREAS COVERED

We performed a review the literature with the aim of describing the current evidence on the prognostic and predictive role of TERT promoter mutations. In some tumor types, TERT promoter mutations have been associated with a worse prognosis and could have a potential value as biomarkers to guide therapeutic decisions. Mutations in TERT promoter seems to make the tumor particularly immunogenic and more responsive to immunotherapy, although data is controversial.

EXPERT OPINION

We described the role of TERT promoter mutations in solid tumors with a particular focus in genitourinary cancers, considering their frequency in this tract.

Tumor mutation burden-assisted risk stratification for papillary thyroid cancer

PURPOSE

Although papillary thyroid cancer (PTC) has a low mortality rate, the rate of recurrence remains relatively high. This study aims to develop a molecular signature to predict the recurrence of PTC.

METHODS

A total of 333 PTC patients' data from The Cancer Genome Atlas (TCGA) were included. We calculated tumor mutation burden (TMB) and analyzed the mutation status of BRAF and TERT promoter.

RESULTS

Tumor recurrence occurred in 17 of 263 cases in TMB-L patients versus 14 of 70 cases in TMB-H patients (hazard ratio [HR], 3.55; 95% confidence interval [CI], 1.75-7.21; P &lt; 0.001). The HR for recurrence in TMB-H patients remained significant after adjustment for classical clinicopathologic factors (patient age, gender, extrathyroidal extension and lymph node metastasis). These clinical factors had no effect on recurrence rate in TMB-L patients, but had a strong adverse effect on the prognosis of TMB-H patients. Compared with TMB-L patients lacking mutation, the HR (95% CI) of recurrence for TMB-H patients with coexisting BRAF V600E and/or TERT C228/250 T mutations was 6.68 (2.41-18.57), which remained significant after adjustment for clinicopathological factors. The mutation status of BRAF V600E and TERT C228/250 T had little effect on PTC recurrence in TMB-L patients. Either of the mutation was associated with high recurrence rate in TMB-H patients.

CONCLUSIONS

The presence of BRAF V600E and/or TERT promoter mutations denotes a high risk of recurrence in TMB-H patients. This represents a powerful molecular prognostic genotype that can help predict patients with the highest risk of recurrence.

A Significance of Concomitant BRAFV600E and TERT Mutations in Polish Patients with Papillary Thyroid Microcarcinoma: A Retrospective Cohort Study Based on 430 Cases

Background: The incidence of papillary thyroid cancer is increasing worldwide due to more frequent pathological detection of papillary thyroid microcarcinomas (PTMC), which are cancers measuring 1 cm or less in diameter. In rare cases, the course of PTMC can be aggressive, with an increased risk of recurrence/persistent disease. The aim of this study of Polish patients diagnosed with PTMC was to assess the impact of concomitant B-type Raf kinas-activating mutation in codon 600 of exon 15 (BRAF^V600E) and telomerase reverse transcriptase (TERT) hotspot mutations on clinicopathological features, response to treatment, potential recurrence, and the final outcome. Methods: A retrospective analysis of the 430 PTMC cases diagnosed during 2001-2020 at a single center was performed. All PTMC cases were assessed histopathologically, and analyses of BRAF^V600E and TERT promoter were performed based on DNA isolated from tumor blocks. Results: There were 29/430 (6.7% [confidence interval: 4.6-9.5]) patients in whom the TERT^C228T and/or TERT^C250T mutations coexisted with the BRAF^V600E mutation. A statistical comparison between PTMC cases with concomitant BRAF^V600E and TERT hotspot mutations and those without any of those mutations revealed no significant differences between the two groups with respect to risk stratification, response to primary treatment, clinical course, or final disease status. Conclusion: Regardless of the molecular background of PTMC, the overall response to therapy is excellent, and long-term disease-free survival rates can be achieved by most patients.

Three-dimensional fractal dimension and lacunarity features may noninvasively predict TERT promoter mutation status in grade 2 meningiomas

PURPOSE

The 2021 World Health Organization classification includes telomerase reverse transcriptase promoter (TERTp) mutation status as a factor for differentiating meningioma grades. Therefore, preoperative prediction of TERTp mutation may assist in clinical decision making. However, no previous study has applied fractal analysis for TERTp mutation status prediction in meningiomas. The purpose of this study was to assess the utility of three-dimensional (3D) fractal analysis for predicting the TERTp mutation status in grade 2 meningiomas.

METHODS

Forty-eight patients with surgically confirmed grade 2 meningiomas (41 TERTp-wildtype and 7 TERTp-mutant) were included. 3D fractal dimension (FD) and lacunarity values were extracted from the fractal analysis. A predictive model combining clinical, conventional, and fractal parameters was built using logistic regression analysis. Receiver operating characteristic curve analysis was used to assess the ability of the model to predict TERTp mutation status.

RESULTS

Patients with TERTp-mutant grade 2 meningiomas were older (P = 0.029) and had higher 3D FD (P = 0.026) and lacunarity (P = 0.004) values than patients with TERTp-wildtype grade 2 meningiomas. On multivariable logistic analysis, higher 3D FD values (odds ratio = 32.50, P = 0.039) and higher 3D lacunarity values (odds ratio = 20.54, P = 0.014) were significant predictors of TERTp mutation status. The area under the curve, accuracy, sensitivity, and specificity of the multivariable model were 0.84 (95% confidence interval 0.71-0.93), 83.3%, 71.4%, and 85.4%, respectively.

CONCLUSION

3D FD and lacunarity may be useful imaging biomarkers for predicting TERTp mutation status in grade 2 meningiomas.

Associations between TERT Promoter Mutations and Survival in Superficial Spreading and Nodular Melanomas in a Large Prospective Patient Cohort

Survival outcomes in melanoma and their association with mutations in the telomerase reverse transcriptase gene TERT promoter remain uncertain. In addition, few studies have examined whether these associations are affected by a nearby common germline polymorphism or vary on the basis of melanoma histopathological subtype. We analyzed 408 primary tumors from a prospective melanoma cohort for somatic TERT-124[C>T] and TERT-146[C>T] mutations, the germline polymorphism rs2853669, and BRAFV600 and NRASQ61 mutations. We tested the associations between these variants and clinicopathologic factors and survival outcomes. TERT-124[C>T] was associated with thicker tumors, ulceration, mitoses (>0/mm2), nodular histotype, and CNS involvement. In a multivariable model controlling for the American Joint Committee on Cancer stage, TERT-124[C>T] was an independent predictor of shorter recurrence-free survival (hazard ratio = 2.58, P = 0.001) and overall survival (hazard ratio = 2.47, P = 0.029). Patients with the germline variant and TERT-124[C>T]-mutant melanomas had significantly shorter recurrence-free survival than those lacking either or both sequence variants (P < 0.04). The impact of the germline variant appeared to be more pronounced in superficial spreading than in nodular melanoma. No associations were found between survival and TERT-146[C>T], BRAF, or NRAS mutations. These findings strongly suggest that TERT-124[C>T] mutation is a biomarker of aggressive primary melanomas, an effect that may be modulated by rs2853669.

Frequency of TERT Promoter Mutations in Real-World Analysis of 2,092 Thyroid Carcinoma Patients

BACKGRUOUND

Telomerase reverse transcriptase (TERT) promoter mutations are associated with increased recurrence and mortality in patients with thyroid carcinoma. Previous studies on TERT promoter mutations were retrospectively conducted on a limited number of patients.

METHODS

We prospectively collected data on all consecutive patients who underwent thyroid carcinoma surgery between January 2019 and December 2020 at the Samsung Medical Center, Seoul, Korea. We included 2,092 patients with thyroid carcinoma.

RESULTS

Of 2,092 patients, 72 patients (3.4%) had TERT promoter mutations. However, the frequency of TERT promoter mutations was 0.5% in papillary thyroid microcarcinoma (PTMC) ≤1 cm and it was 5.8% in papillary thyroid carcinoma (PTC) >1 cm. The frequency of TERT promoter mutations was significantly associated with older age at diagnosis (odds ratio [OR], 1.12; P<0.001), larger primary tumor size (OR, 2.02; P<0.001), and aggressive histological type (OR, 7.78 in follicular thyroid carcinoma; OR, 10.33 in poorly differentiated thyroid carcinoma; OR, 45.92 in anaplastic thyroid carcinoma; P<0.001). Advanced T stage, advanced N stage, and distant metastasis at diagnosis were highly prevalent in mutated thyroid cancers. However, initial distant metastasis was not present in patients with TERT promoter mutations in PTMC. Although the C228T mutation was more highly detected than the C250T mutation (64 cases vs. 7 cases), there were no significant clinicopathological differences.

CONCLUSION

This study is the first attempt to investigate the frequency of TERT promoter mutations in a real-world setting. The frequency of TERT promoter mutations in PTC was lower than expected, and in PTMC, young patients, and female patients, the frequency was very low.

Case report: response to the ERK1/2 inhibitor ulixertinib in BRAF D594G cutaneous melanoma

Melanoma is characterized by oncogenic mutations in pathways regulating cell growth, proliferation, and metabolism. Greater than 80% of primary melanoma cases harbor aberrant activation of the mitogen-activated protein kinase kinase/extracellular-signal-regulated kinase (MEK/ERK) pathway, with oncogenic mutations in BRAF, most notably BRAF V600E, being the most common. Significant progress has been made in BRAF-mutant melanoma using BRAF and MEK inhibitors; however, non-V600 BRAF mutations remain a challenge with limited treatment options. We report the case of an individual diagnosed with stage III BRAF D594G-mutant melanoma who experienced an extraordinary response to the ERK1/2 inhibitor ulixertinib as fourth-line therapy. Ulixertinib was obtained via an intermediate expanded access protocol with unique flexibility to permit both single-agent and combination treatments, dose adjustments, breaks in treatment to undergo surgery, and long-term preventive treatment following surgical resection offering this patient the potential for curative treatment.

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.

Emerging mechanisms of telomerase reactivation in cancer

Mutations in the promoter of human telomerase reverse transcriptase (hTERT) result in hyperactivation of hTERT. Notably, all mutations are G>A transitions, frequently found in a wide range of cancer types, and causally associated with cancer progression. Initially, the mutations were understood to reactivate hTERT by generating novel E26 transformation-specific (ETS) binding sites. Recent work reveals the role of DNA secondary structure G-quadruplexes, telomere binding factor(s), and chromatin looping in hTERT regulation. Here, we discuss these emerging findings in relation to the clinically significant promoter mutations to provide a broader understanding of the context-dependent outcomes that result in hTERT activation in normal and pathogenic conditions.

Risk Factors for TERT Promoter Mutations with Papillary Thyroid Carcinoma Patients: A Meta-Analysis and Systematic Review

Whether TERT promoter mutation is related to more aggressive clinicopathologic features and worse outcomes in papillary thyroid carcinoma patients (PTCs) is still variable and controversial. Our intention was to investigate the risk or prognostic factors that may additionally predict the TERT promoter mutation doable of these lesions and new prevention techniques in PTCs. A total of 2,539 PTC patients with 11.50% TERT mutation have been analyzed using Revman 5.3 software in this study. The PubMed and Embase databases were systematically searched for works published until November 9, 2021. The following variables had been associated with an extended chance of TERT promoter mutation in PTC patients: age < 45 years (MD = 10.93, 95%CI = 7.25-14.61); gender = male (pooled OR = 1.63, 95%CI = 1.17-2.28); tumor size > 1 cm (MD = 0.56, 95%CI = 0.34-0.77); lymph node metastasis (pooled OR = 1.29, 95%CI = 0.93-1.79); vascular invasion (pooled OR = 1.78, 95%CI = 0.83-3.84); extrathyroidal extension (pooled OR = 2.00, 95%CI = 1.32-3.02); distant metastasis (pooled OR = 1.46, 95%CI = 1.04-2.04); advanced TNM stage (pooled OR = 3.19, 95%CI = 2.28-4.45). In addition, multifocality (pooled OR = 0.67, 95%CI = 0.14-3.24) had no affiliation with TERT promoter mutation in PTC patients. Our finding showed that age < 45 years, male, tumor size > 1 cm, lymph node metastasis, vascular invasion, and superior/advanced TNM stage were dangerous elements for TERT promoter mutation of worse effect in PTCs while that multifocality was once negatively correlated. TERT promoter mutation is drastically associated with recurrence and PTC-related mortality.

Overview of the 2022 WHO Classification of Thyroid Neoplasms

This review summarizes the changes in the 5th edition of the WHO Classification of Endocrine and Neuroendocrine Tumors that relate to the thyroid gland. The new classification has divided thyroid tumors into several new categories that allow for a clearer understanding of the cell of origin, pathologic features (cytopathology and histopathology), molecular classification, and biological behavior. Follicular cell-derived tumors constitute the majority of thyroid neoplasms. In this new classification, they are divided into benign, low-risk, and malignant neoplasms. Benign tumors include not only follicular adenoma but also variants of adenoma that are of diagnostic and clinical significance, including the ones with papillary architecture, which are often hyperfunctional and oncocytic adenomas. For the first time, there is a detailed account of the multifocal hyperplastic/neoplastic lesions that commonly occur in the clinical setting of multinodular goiter; the term thyroid follicular nodular disease (FND) achieved consensus as the best to describe this enigmatic entity. Low-risk follicular cell-derived neoplasms include non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), thyroid tumors of uncertain malignant potential, and hyalinizing trabecular tumor. Malignant follicular cell-derived neoplasms are stratified based on molecular profiles and aggressiveness. Papillary thyroid carcinomas (PTCs), with many morphological subtypes, represent the BRAF-like malignancies, whereas invasive encapsulated follicular variant PTC and follicular thyroid carcinoma represent the RAS-like malignancies. This new classification requires detailed subtyping of papillary microcarcinomas similar to their counterparts that exceed 1.0 cm and recommends not designating them as a subtype of PTC. The criteria of the tall cell subtype of PTC have been revisited. Cribriform-morular thyroid carcinoma is no longer classified as a subtype of PTC. The term "Hürthle cell" is discouraged, since it is a misnomer. Oncocytic carcinoma is discussed as a distinct entity with the clear recognition that it refers to oncocytic follicular cell-derived neoplasms (composed of > 75% oncocytic cells) that lack characteristic nuclear features of PTC (those would be oncocytic PTCs) and high-grade features (necrosis and ≥ 5 mitoses per 2 mm²). High-grade follicular cell-derived malignancies now include both the traditional poorly differentiated carcinoma as well as high-grade differentiated thyroid carcinomas, since both are characterized by increased mitotic activity and tumor necrosis without anaplastic histology and clinically behave in a similar manner. Anaplastic thyroid carcinoma remains the most undifferentiated form; squamous cell carcinoma of the thyroid is now considered as a subtype of anaplastic carcinoma. Medullary thyroid carcinomas derived from thyroid C cells retain their distinct section, and there is a separate section for mixed tumors composed of both C cells and any follicular cell-derived malignancy. A grading system for medullary thyroid carcinomas is also introduced based on mitotic count, tumor necrosis, and Ki67 labeling index. A number of unusual neoplasms that occur in the thyroid have been placed into new sections based on their cytogenesis. Mucoepidermoid carcinoma and secretory carcinoma of the salivary gland type are now included in one section classified as "salivary gland-type carcinomas of the thyroid." Thymomas, thymic carcinomas and spindle epithelial tumor with thymus-like elements are classified as "thymic tumors within the thyroid." There remain several tumors whose cell lineage is unclear, and they are listed as such; these include sclerosing mucoepidermoid carcinoma with eosinophilia and cribriform-morular thyroid carcinoma. Another important addition is thyroblastoma, an unusual embryonal tumor associated with DICER1 mutations. As in all the WHO books in the 5th edition, mesenchymal and stromal tumors, hematolymphoid neoplasms, germ cell tumors, and metastatic malignancies are discussed separately. The current classification also emphasizes the value of biomarkers that may aid diagnosis and provide prognostic information.

Advances in pharmacotherapy for advanced thyroid cancer of follicular origin (PTC, FTC). New approved drugs and future therapies

INTRODUCTION

The most common altered signaling found in aggressive iodine-refractory Thyroid cancer derived from follicular cells (RAI-TC) are RTK, MAPK, PI3K, WNT, BRAF, RAS, RET, and TP53. Tyrosine Kinase Inhibitors (TKI) are multi-kinase inhibitors able to act against different pathways, that elicit an anti-neoplastic activity.

AREAS COVERED

The aim of this paper is to review recent novel molecular therapies of RAI-TC. Recently, sorafenib and lenvatinib, have been approved for the treatment of aggressive RAI-TC. Other studies are evaluating vandetanib and selumetinib in RAI-TC. Furthermore, preliminary studies have evaluated dabrafenib, and vemurafenib in BRAF mutated RAI-TC patients to re-induce 131-iodine uptake. The interplay between cells of the immune system and cancer cells can be altered by immune checkpoints inhibitors. The expression of PDL1 in RAI-TC was related to tumor recurrence and poor survival. Several clinical trials are investigating a combination of different therapies, such as lenvatinib and pembrolizumab.

EXPERT OPINION

Mechanisms of resistance to TKIs inhibitors can be of intrinsic or acquired origin. An acquired resistance to lenvatinib, or sorafenib can be due to upregulation of FGFR; therefore anti-FGFR agents are evaluated. A new strategy is to combine TKIs with immunotherapy. Several studies are evaluating lenvatinib and pembrolizumab in RAI-TC patients.

Bibliometric insights in advances of papillary thyroid microcarcinoma: Research situation, hot points, and global trends

BACKGROUND

Thyroid cancer has been on the rise over the last decade. Papillary thyroid microcarcinoma (PTMC) accounts for more than half of all thyroid cancers. Micropapillary carcinoma of the thyroid is a common but non-fatal form of thyroid cancer. To better comprehend, nearly two decades of scientific outputs were analyzed and summarized using bibliometric methods in this study.

METHODS

Approximately 1098 publications from 2000 and 2021 were included in WoS database through systematic retrieval. The general information was characterized, and developmental skeleton and research frontiers were explored. CiteSpace, VOSviewer, and R, Tableau were used to evaluate and visualize the results.

RESULTS

A total of 1098 publications from across 75 countries were identified. The annual number of publications showed an increasing trend in the past 21 years. China, Korea, the United States of America (USA), Italy, and Japan made remarkable contributions to the research of PTMC. Thyroid was the most productive journal. Miyauchi Akira published maximum articles. The utmost productive institution was the University of Ulsan. Risk stratification, active surveillance, and thermal ablation garnered the attention of researchers leading to novel approaches in the clinical diagnosis and treatment of micropapillary thyroid carcinoma.

CONCLUSIONS

This bibliometric study provides a comprehensive analysis of global productivity, collaboration, and research hotspots within PTMC field, which will aid in directing research toward PTMC in the coming years.

Genomic and Transcriptomic Correlates of Thyroid Carcinoma Evolution after BRAF Inhibitor Therapy

Targeted inhibition of BRAF V600E achieves tumor control in a subset of advanced thyroid tumors. Nearly all tumors develop resistance, and some have been observed to subsequently undergo dedifferentiation. The molecular alterations associated with thyroid cancer dedifferentiation in the setting of BRAF inhibition are unknown. We analyzed targeted next-generation sequencing data from 639 advanced, recurrent and/or metastatic thyroid carcinomas, including 15 tumors that were treated with BRAF inhibitor drugs and had tissue sampled during or posttreatment, 8 of which had matched pretherapy samples. Pre- and posttherapy tissues from one additional patient were profiled with whole-exome sequencing and RNA expression profiling. Mutations in genes comprising the SWI/SNF chromatin remodeling complex and the PI3K-AKT-mTOR, MAPK, and JAK-STAT pathways all increased in prevalence across more dedifferentiated thyroid cancer histologies. Of 7 thyroid cancers that dedifferentiated after BRAF inhibition, 6 had mutations in these pathways. These mutations were mostly absent from matched pretreatment samples and were rarely detected in tumors that did not dedifferentiate. Additional analyses in one of the vemurafenib-treated tumors before and after anaplastic transformation revealed the emergence of an oncogenic PIK3CA mutation, activation of ERK signaling, dedifferentiation, and development of an immunosuppressive tumor microenvironment. These findings validate earlier preclinical data implicating these genetic pathways in resistance to BRAF inhibitors, and suggest that genetic alterations mediating acquired drug resistance may also promote thyroid tumor dedifferentiation. IMPLICATIONS: The possibility that thyroid cancer dedifferentiation may be attributed to selective pressure applied by BRAF inhibitor-targeted therapy should be investigated further.

BRAF Mutations in Papillary Thyroid Carcinoma: A Genomic Approach Using Probe-Based DNA Capture for Next-Generation Sequencing

The BRAF V600E mutation in papillary thyroid carcinoma is the major mutation in classical subtype of papillary thyroid carcinoma and other cancers. It is the most studied predictor of clinical and pathological characteristics as well as molecular targets for cancer therapy. On the other hand, there is potential for many more forms of activating mutation in BRAF that are not detectable by simple assays to detect V600E, or even simple polymerase chain reaction (PCR)-based sequencing for full-length BRAF. Such activating mutations could arise from larger-scale rearrangements which may apparently leave no sequence change to BRAF while causing increased expression or activation by unusual means, such as gene fusion. Detection of these kinds of changes can take place using a variety of methods, though capture-based sequencing can identify the existence of such forms of mutant BRAF without needing foreknowledge of the loci involved in these kinds of mutation. In this chapter, we detail a method for capture of specific DNA sequences and their amplification to prepare for massively parallel sequencing.

The Prognostic Implication of the BRAF V600E Mutation in Papillary Thyroid Cancer in a Chinese Population

BACKGROUND

The BRAF V600E mutation is an important genetic event in papillary thyroid cancer (PTC). This study aimed to provide additional information regarding the association of the BRAF V600E mutation with PTC prognosis.

METHODS

A retrospective single-center study based on a Chinese population was performed to analyze the association of the BRAF V600E mutation with several clinicopathological features. Kaplan-Meier survival curves and Cox proportional hazards regression analysis were applied to implement the survival analysis.

RESULTS

The BRAF V600E mutation was present in 1102 (87.7%) of the 1257 patients and was significantly associated with older age, conventional subtype, multifocality, advanced TNM stage, and a reduced prevalence of Hashimoto's thyroiditis. The Kaplan-Meier survival curves demonstrated that the difference between the BRAF V600E-positive and BRAF V600E-negative groups was significant with a log-rank P-value of 0.048. The Cox proportional hazards regression analysis adjusted HR was 3.731 (95% CI, 1.457 to 9.554). We further demonstrated that larger tumor size (>1 cm), extrathyroidal extension (ETE), and lateral lymph node metastasis (LNM) were associated with a higher probability of PTC recurrence in patients harboring the BRAF V600E mutation.

CONCLUSIONS

The BRAF V600E mutation remains an independent risk factor for PTC recurrence and may be useful for clinical decisions when it combines with some pathological factors.

TERT Promoter Mutations Increase Sense and Antisense Transcription from the TERT Promoter

Background: Chief among mechanisms of telomerase reverse transcriptase (TERT) reactivation is the appearance of mutations in the TERT promoter. The two main TERT promoter mutations are C>T transitions located −146C>T and −124C>T upstream from the translational start site. They generate a novel Ets/TCF binding site. Both mutations are mutually exclusive and −124C>T is strikingly overrepresented in most cancers. We investigated whether this mutational bias and mutual exclusion could be due to transcriptional constraints. Methods: We compared sense and antisense transcription of a panel of TERT promoter-luciferase vectors harboring the −124C>T and -146C>T mutations alone or together. lncRNA TAPAS levels were measured by RT-PCR. Results: Both mutations generally increased TERT transcription by 2–4-fold regardless of upstream and downstream regulatory elements. The double mutant increased transcription in an additive fashion, arguing against a direct transcriptional constraint. The −146C>T mutation, alone or in combination with −124C>T, also unleashed antisense transcription. In line with this finding, lncRNA TAPAS was higher in cells with mutated TERT promoter (T98G and U87) than in cells with wild-type promoter, suggesting that lncRNA TAPAS may balance the effect of TERT promoter mutations. Conclusions: −146C>T and −124C>T TERT promoter mutations increase TERT sense and antisense transcription, and the double mutant features higher transcription levels. Increased antisense transcription may contain TERT expression within sustainable levels.

PRDM16 Inhibits Cell Proliferation and Migration via Epithelial-to-Mesenchymal Transition by Directly Targeting Pyruvate Carboxylase in Papillary Thyroid Cancer

PRDM16 (known as MEL1), a member of the PR domain zinc finger family, has been implicated in multiple biological processes, including cancers. It is not clear yet whether PRDM16 is involved in tumor progress of papillary thyroid cancer (PTC). We identified the PRDM16 expression level in PTC tissues by qRT-PCR and analyzed its relationship with clinical characteristics in both Fudan University Shanghai Cancer Center (FUSCC) and TCGA cohorts. We tested the function of PRDM16 in PTC cells both in vivo and in vitro. We found a direct downstream target of PRDM16, pyruvate carboxylase (PC), by RNA-sequencing, rescue experiments, luciferase assay, and chromatin immunoprecipitation assay. PRDM16 was downregulated in papillary thyroid cancer tissues and was significantly related with lymph node metastases and extrathyroidal extension in both FUSCC and TCGA cohorts. Overexpression of PRDM16 could attenuate proliferation and migration of PTC cells via inhibiting the epithelial-to-mesenchymal transition process. PC was upregulated in papillary thyroid cancer tissues. Knockdown of PC could inhibit proliferation and migration in TPC-1 and K1 cells. The repression effect on cell proliferation and migration from PRDM16 was PC dependent. PRDM16 could directly bind to the PC promoter and inhibit its expression at the transcription level. Moreover, the mRNA expression level of PRDM16 and PC was negatively related in human PTC tissues. In conclusion, PRDM16 exhibited an antitumor effect and EMT inhibition function in PTC by directly binding with the PC promoter. PRDM16 may be a novel therapeutic target in papillary thyroid cancer.

Solid Thyroid Follicular Nodules With Longitudinal Nuclear Grooves: Clinicopathologic, Immunohistochemical, and Molecular Genetic Study of 18 Cases

CONTEXT.—

Follicular thyroid nodules can be a source of diagnostic difficulties, particularly when they display atypical features commonly associated with malignancy, such as nuclear grooves.

OBJECTIVE.—

To differentiate lesions with atypical features from similar-appearing benign and malignant lesions.

DESIGN.—

Eighteen cases of atypical follicular thyroid nodules characterized by a solid growth pattern and prominent longitudinal nuclear grooves were studied and examined for clinicopathologic characteristics.

RESULTS.—

The lesions occurred in 16 women and 2 men aged 36 to 88 years and measured from 0.2 to 1.5 cm. The tumors were well circumscribed and noninvasive, and histologically characterized by a predominantly solid growth pattern with rare scattered follicles or a combination of solid growth pattern with minor follicular areas. A striking feature seen in all cases was the occurrence of longitudinal nuclear grooves. Immunohistochemical stains showed negativity for cytokeratin 19 (CK19) and HBME-1 in 8 cases; in the other 10, there was focal positivity for HBME-1 in 4 cases and diffuse positivity in 6. All cases were negative for galectin-3 and for CK19, with the exception of 1 case, which was CK19+/HBME-1-. Next-generation sequencing of 16 cases with a 161-gene panel detected 14 single nucleotide variants in 12 cases, predominantly NRAS and HRAS mutations. Clinical follow-up ranging from 18 to 72 months (median, 43.7 months) did not disclose any evidence of recurrence or metastases.

CONCLUSIONS.—

We interpret these lesions as low-grade, indolent follicular proliferations that need to be distinguished from papillary thyroid carcinoma, follicular adenoma, and noninvasive follicular thyroid neoplasms with papillary-like nuclear features.

Papillary Thyroid Cancer Prognosis: An Evolving Field

Simple Summary

Over the last couple of decades, the prognostic stratification systems of differentiated thyroid cancer (DTC) patients have been revised several times in an attempt to achieve a tailored clinical management reflecting the single patients’ needs. Such revisions are likely to continue in the near future, since the prognostic value of a number of promising clinicopathological features and new molecular biomarkers are being evaluated. Here, we will review the current staging systems of thyroid cancer patients and discuss the most relevant clinicopathological parameters and new molecular markers that are potentially capable of refining the prognosis.

Abstract

Over the last few years, a great advance has been made in the comprehension of the molecular pathogenesis underlying thyroid cancer progression, particularly for the papillary thyroid cancer (PTC), which represents the most common thyroid malignancy. Putative cancer driver mutations have been identified in more than 98% of PTC, and a new PTC classification into molecular subtypes has been proposed in order to resolve clinical uncertainties still present in the clinical management of patients. Additionally, the prognostic stratification systems have been profoundly modified over the last decade, with a view to refine patients’ staging and being able to choose a clinical approach tailored on single patient’s needs. Here, we will briefly discuss the recent changes in the clinical management of thyroid nodules, and review the current staging systems of thyroid cancer patients by analyzing promising clinicopathological features (i.e., gender, thyroid auto-immunity, multifocality, PTC histological variants, and vascular invasion) as well as new molecular markers (i.e., BRAF/TERT promoter mutations, miRNAs, and components of the plasminogen activating system) potentially capable of ameliorating the prognosis of PTC patients.

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.