The changing characteristics and molecular profiles of papillary thyroid carcinoma over time: a systematic review

Clinical value of multi-gene testing in distinguishing benign and malignant thyroid nodules

BACKGROUND

The newly released 2022 WHO Classification of Neuroendocrine Neoplasms (version 5) and a recent update on thyroid tumor classifications have emphasized genetic testing to an unprecedented level. Fine needle aspiration (FNA) has been widely applied for the preoperative diagnosis of thyroid nodules. However, it is limited mainly to testing for a single gene-BRAFV600E, whereas multi-gene testing data are scarce, especially in the Asian population. This study aimed to explore the clinical value of multi-gene testing in the differential diagnosis of benign and malignant thyroid nodules based on the 2023 Bethesda System for Reporting Thyroid Cytopathology (BSRTC).

METHODS

A total of 615 thyroid nodules underwent ultrasound-guided fine-needle aspiration cytology (FNAC) were collected from Sir Run Run Shaw Hospital, Zhejiang University School of Medicine. The next-generation sequencing platform was applied for multi-gene testing. A panel of well-recognized commonly mutated genes in thyroid cancer were analyzed, including BRAFV600E, KRAS, NRAS, HRAS, TERT, TP53, PAX8/PPARG, CCDC6/ RET and NCOA4/ RET.

RESULTS

Gene mutations were identified in 324 nodules (52.7%), with BRAFV600E being the most prevalent driver gene alteration observed in this cohort (233/324; 79.1%), followed by RAS (77/324, 23.8%). The overall malignancy rate of gene mutations was 89.7% in our cohort, of which the lymph node metastasis rate was 45.3%. The combination of multi-gene testing and cytology resulted in 89.3% sensitivity, 95.2% specificity, 98.9% positive predictive value, 64.5% negative predictive value and 90.3% accuracy, which were significantly higher than those from mere cytology (sensitivity 68.6%, specificity 87.5%, positive predictive value 95.9%, negative predictive value 39.8%, accuracy 72.2%).

CONCLUSIONS

Multi-gene testing could substantially enhance the detection rate of malignant thyroid nodules and protect patients with benign nodules from unnecessary surgeries. Multi-gene testing provides a valuable reference for individualized preoperative decision-making, which may serve as a crucial method for postoperative treatment and prognosis assessment.

A Shift in Molecular Drivers of Papillary Thyroid Carcinoma Following the 2017 World Health Organization Classification: Characterization of 554 Consecutive Tumors With Emphasis on BRAF-Negative Cases

Most studies for comprehensive molecular profiling of papillary thyroid carcinoma (PTC) have been performed before the 2017 World Health Organization (WHO) classification, in which the diagnostic criteria of follicular variants of PTC have been modified and noninvasive follicular thyroid neoplasm with papillary-like nuclear features has been introduced. This study aims to investigate the shift in the incidence of BRAF V600E mutations in PTCs following the 2017 WHO classification and to further characterize the histologic subtypes and molecular drivers in BRAF-negative cases. The study cohort consisted of 554 consecutive PTCs larger than 0.5 cm between January 2019 and May 2022. Immunohistochemistry for BRAF VE1 was performed for all cases. Compared with a historical cohort of 509 PTCs from November 2013 to April 2018, the incidence of BRAF V600E mutations was significantly higher in the study cohort (86.8% vs 78.8%, P = .0006). Targeted RNA-based next-generation sequencing using a FusionPlex Pan Solid Tumor v2 panel (ArcherDX) was performed for BRAF-negative PTCs from the study cohort. Eight cribriform-morular thyroid carcinomas and 3 cases with suboptimal RNA quality were excluded from next-generation sequencing. A total of 62 BRAF-negative PTCs were successfully sequenced, including 19 classic follicular predominant PTCs, 16 classic PTCs, 14 infiltrative follicular PTCs, 7 encapsulated follicular PTCs, 3 diffuse sclerosing PTCs, 1 tall cell PTC, 1 solid PTC, and 1 diffuse follicular PTC. Among them, RET fusions were identified in 25 cases, NTRK3 fusions in 13 cases, BRAF fusions in 5 cases including a novel TNS1::BRAF fusion, NRAS Q61R mutations in 3 cases, KRAS Q61K mutations in 2 cases, NTRK1 fusions in 2 cases, an ALK fusion in 1 case, an FGFR1 fusion in 1 case, and an HRAS Q61R mutation in 1 case. No genetic variants, from our commercially employed assay, were detected in the remaining 9 cases. In summary, the incidence of BRAF V600E mutations in PTCs significantly increased from 78.8% to 86.8% in our post-2017 WHO classification cohort. RAS mutations accounted for only 1.1% of the cases. Driver gene fusions were identified in 8.5% of PTCs and were clinically relevant given the emerging targeted kinase inhibitor therapy. Of the 1.6% of cases for which no driver alteration was detected, the specificity of drivers tested and tumor classification require further investigation.

A new paradigm for epidermal growth factor receptor expression exists in PTC and NIFTP regulated by microRNAs

Intoduction

Identification of molecular alterations associated with tumor behavior is necessary to guide clinical management. The 2022 WHO classification has organized the thyroid follicular cell-derived neoplasms into benign, low-risk and high-risk neoplasms, and emphasized the value of biomarkers that may provide differential diagnostic and prognostic information to avoid overtreatment of low risk neoplasms. This work aims to study the epidermal growth factor receptor (EGFR) expression, functional and spatial dynamics in relation to specific miRNAs alterations in papillary thyroid cancer (PTC) and in non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) considered as models of high-risk and low-risk thyroid tumors respectively.

Methods

Primary thyroid cultured cells were used for miRNA gain/loss of function and luciferase reporter assays. Paraffin embedded tissues were used for real time PCR, immuno-fluorescence stain and confocal microscopy experiments.

Results

Our results showed that in PTC, EGFR mRNA is reduced as an effect of miR-146b-5p upregulation. The EGF expression is low and the ERK pathway is inhibited. The EGFR protein high cytoplasmic expression and colocalization with the endosomal/exosomal markers, ALIX and CD63, suggest the occurrence of stress-induced EGFR internalization, accumulation in endosomal vesicles and secretion via exosomes. In NIFTP EGFR transcription is increased in association with downregulation of miR-7-5p and the EGFR/ERK pathway is active indicating dependence on the canonical EGFR pathway for growth.

Conclusion

Downregulation of transcript level along with cytoplasmic accumulation of undegraded protein is a new pattern of EGFR regulation associated with malignancy in thyroid. Further research is needed to elucidate the intracellular trafficking defects responsible for this specific EGFR dynamic in PTC.

Clinicopathological Implications of the BRAF V600E Mutation in Papillary Thyroid Carcinoma of Ukrainian Patients Exposed to the Chernobyl Radiation in Childhood: A Study for 30 Years After the Accident

With time after the Chernobyl accident, the number of papillary thyroid carcinomas (PTCs) driven by the BRAF^V600E oncoprotein is growing in patients exposed to radiation at a young age. Clinicopathological associations of BRAF^V600E in PTCs from patients with internal radiation history have not been sufficiently studied so far. This work analyzes the structural characteristics, proliferative activity, invasive features, clinical information, and dosimetric data in the BRAF^V600E-positive and BRAF^V600E-negative PTCs from the Ukrainian patients exposed to Chernobyl radiation and treated over 30 years after the accident. The study included 428 PTCs from patients aged 4-49 years at surgery who lived in the six northern regions of Ukraine most contaminated by ¹³¹I, were ≤18 years of age at the time of exposure, and were operated on from 1990 to 2017. Immunohistochemical staining for BRAF^V600E was performed with the VE1 antibody. The probability of causation (POC) of a tumor due to radiation was determined using an interactive online NIH/NCI software. BRAF^V600E was detected in 136/428 (31.8%) PTCs. In comparison with the BRAF^V600E-negative PTCs, the BRAF^V600E-positivity was associated with older patient age at the accident and at surgery, a longer period of latency, and lower POC. The BRAF^V600E-positive PTCs were characterized by smaller tumor size, higher Ki67 labeling index, more frequent oncocytic changes, multifocality, and dominant papillary growth pattern. Tumor invasive features were less frequent in the BRAF^V600E-positive PTCs and did not change with POC level. Despite a less aggressive tumor phenotype, BRAF^V600E was a risk factor for recurrence, namely radioiodine-refractory (RAI-R) recurrent metastases. Multivariate models of RAI-R included BRAF^V600E and/or histopathological parameters closely correlating with BRAF^V600E such as tumor size, multifocality, dominant papillary growth pattern, or oncocytic changes. Thus, the BRAF^V600E-positive PTCs from patients from a high-risk group for radiogenic thyroid cancer diagnosed in the 30 years after the Chernobyl accident did not display higher invasiveness regardless of POC level, but in view of the prognostic impact of this genetic alteration, knowledge of the BRAF status may be beneficial for middle-aged patients with radiogenic PTC considered for RAI therapy, and suggests more careful follow-up of patients with the BRAF^V600E-positive tumors.

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.

The relationship of the clinicopathological characteristics and treatment results of post-Chornobyl papillary thyroid microcarcinomas with the latency period and radiation exposure

INTRODUCTION

A worldwide increase in the incidence of thyroid cancer during the last decades is largely due to papillary thyroid microcarcinomas (MPTCs), which are mostly low-risk tumors. In view of recent clinical recommendations to reduce the extent of surgery for low-risk thyroid cancer, and persisting uncertainty about the impact of radiation history, we set out to address whether clinicopathological characteristics and prognosis of post-Chornobyl MPTCs were changing with regard to: i) the latency period, ii) probability of causation (POC) of a tumor due to radiation, and iii) tumor size.

METHODS

Patients (n = 465) aged up to 50 years at diagnosis who lived in April, 1986 in six northern, most radiocontaminated regions of Ukraine were studied.

RESULTS

Latency period was statistically significantly associated with the reduction of POC level, tumor size and the frequency of fully encapsulated MPTCs. In contrast, the frequency of oncocytic changes and the BRAF^V600E mutation increased. Invasive properties and clinical follow-up results did not depend on latency except for a lower frequency of complete remission after postsurgical radioiodine therapy. The POC level was associated with more frequent extrathyroidal extension, and lymphatic/vascular invasion, less frequent oncocytic changes and BRAF^V600E , and did not associate with any clinical indicator. Tumor size was negatively associated with the latency period and BRAF^V600E , and had a statistically significant effect on invasive properties of MPTCs: both the integrative invasiveness score and its components such as lymphatic/vascular invasion, extrathyroidal extension and lymph node metastases increased. The frequency of total thyroidectomy, neck lymph node dissection and radioiodine therapy also increased with the larger tumor size. The duration of the latency period, POC level or tumor size did not associate with the chance of disease recurrence.

DISCUSSION

In summary, we did not observe overall worsening of the clinicopathological features or treatment results of radiogenic MPTCs that could be associated with the latency period or POC level, suggesting that radiation history did not strongly affect those in the analyzed MPTC patients. However, the increase in the invasive properties with tumor size indicates the need for individual risk stratification for each MPTC patient, regardless of radiation history, for treatment decision-making.

LncRNA-PANDAR regulates the progression of thyroid carcinoma by targeting miR-637/KLK4

Thyroid gland carcinoma (TC) originates from follicular or parafollicular thyroid cells and is one of the most common endocrine organ malignancies. To explore the molecular mechanism by which long-chain non-coding RNAs regulate the growth and metastasis of thyroid gland carcinoma, in this study we focused on long non-coding RNAs (lncRNAs) that have been reported to be involved in tumorigenesis. We identified Promoter Region of CDKN 1A antisense DNA damage-activated RNA (PANDAR), which was positively correlated with thyroid gland carcinoma risk. PANDAR could promote thyroid gland carcinoma cell proliferation and metastasis. PANDAR negatively correlated with miR-637, and miR-637 overexpression suppressed thyroid gland carcinoma progression, which could be reversed by PANDAR. MiR-637 could target Kallikrein-related peptidases 4 (KLK4) to inhibit its expression, which was high in thyroid gland carcinoma. KLK4 inhibited cell progression in thyroid gland carcinoma cells. Knockdown of PANDAR expression inhibited cancer progression in nude mice. Overall, PANDAR can suppress miR-637 and induce KLK4 to regulate invasion and migration in thyroid gland carcinoma. Additionally, we identified miR-637 as a target of PANDAR in thyroid gland carcinoma, and PANDAR can be used as a novel therapeutic target for the treatment of thyroid gland carcinoma.

Magnetic resonance imaging (MRI) radiomics of papillary thyroid cancer (PTC): a comparison of predictive performance of multiple classifiers modeling to identify cervical lymph node metastases before surgery

PURPOSE

To compare predictive efficiency of multiple classifiers modeling and establish a combined magnetic resonance imaging (MRI) radiomics model for identifying lymph node (LN) metastases of papillary thyroid cancer (PTC) preoperatively.

MATERIALS AND METHODS

A retrospective analysis based on the preoperative MRI scans of 109 PTC patients including 77 patients with LN metastases and 32 patients without metastases was conducted, and we divided enroll cases into trained group and validation group. Radiomics signatures were selected from fat-suppressed T2-weighted MRI images, and the optimal characteristics were confirmed by spearman correlation test, hypothesis testing and random forest methods, and then, eight predictive models were constructed by eight classifiers. The receiver operating characteristic (ROC) curves analysis were performed to demonstrate the effectiveness of the models.

RESULTS

The area under the curve (AUC) of ROC based on MRI texture diagnosed LN status by naked eye was 0.739 (sensitivity = 0.571, specificity = 0.906). Based on the 5 optimal signatures, the best AUC of MRI radiomics model by logistics regression classifier had a considerable prediction performance with AUCs 0.805 in trained group and 0.760 in validation group, respectively, and a combination of best radiomics model with visual diagnosis of MRI texture had a high AUC as 0.969 (sensitivity = 0.938, specificity = 1.000), suggesting combined model had a preferable diagnostic efficiency in evaluating LN metastases of PTC.

CONCLUSION

Our combined radiomics model with visual diagnosis could be a potentially effective strategy to preoperatively predict LN metastases in PTC patients before clinical intervention.

Impact of Molecular Testing on the Management of Indeterminate Thyroid Nodules Among Western and Asian Countries: a Systematic Review and Meta-analysis

Molecular testing has a potential to improve the management of patients with indeterminate thyroid nodules considered for surgery. This study examined the influence of molecular tests on the treatment of indeterminate nodules, particularly the differences between Western and Asian countries. Electronic databases including PubMed and Web of Science were searched for relevant articles from 2010 to March 2019. We computed meta-analysis of proportion and their 95% confidence intervals (CIs) utilizing the random-effect model. We used independent samples t test to compare the resection rate (RR), rate of malignancy (ROM), rate of preoperative molecular testing (RMT), and rate of positive test (RP) between subgroups. We included a total of 34 studies with 7976 indeterminate nodules. The multigene panel testing methods were exclusively used in the USA. Compared with the non-molecular era, molecular testing was associated with a significantly increased ROM (47.9% versus 32.1%; p = 0.001). The ROM of indeterminate nodules in Asian institutes was significantly higher than that in Western countries (75.3% versus 36.6%; p < 0.001, respectively). Institutes employing single-gene tests achieved a higher ROM (59.8% versus 37.9%; p = 0.013). Molecular testing is a promising method to tailor the clinical management for indeterminate thyroid FNA. Certain differences in routine thyroid cytopathology practice among the West and the East are still present. The combination of molecular testing and active surveillance enhances the accuracy of case selection for surgery in Asian countries.

Research trends for papillary thyroid carcinoma from 2010 to 2019: A systematic review and bibliometrics analysis

BACKGROUND

Thyroid carcinoma comprises the fastest rising incidence of carcinomas over the past decade. Papillary thyroid carcinoma (PTC) is the most predominant type of thyroid carcinoma. This study aimed to assess the research trends in the field of PTC.

METHODS

Publications from January 2010 to December 2019 were retrieved from the Web of Science Core Collection database using Thompson Reuters. Searching strategies were determined according to Medical Subject Heading terms. Different kinds of bibliometrics software, such as HistCite and VOSviewer, and online bibliometrics analysis platforms were utilized to evaluate and visualize the results.

RESULTS

A total of 8102 publications across 93 countries were identified, with the annual number of publications showing an increasing trend. The United States, China, and South Korea showed their dominant position in PTC publication outputs, H-index, total citations, and international collaborations. Thyroid was the most productive journal. Akira Miyauchi published the most articles, and the most productive institution was Yonsei University. The hotspots keywords proliferation, invasion and metastasis, diagnoses and prognoses, therapeutic resistance, recurrence, and microcarcinomas appeared earlier and were sustained over the last 3 years.

CONCLUSIONS

This bibliometric study provides a comprehensive analysis delineating the scientific productivity, collaboration, and research hotspots within the PTC field, which will be very helpful when focusing on the direction of research over the next few years.

A Narrative Review of Genetic Alterations in Primary Thyroid Epithelial Cancer

Thyroid carcinoma is the most frequent endocrine neoplasia. Different types of thyroid carcinoma are described: well-differentiated papillary thyroid carcinoma (PTC), poorly differentiated thyroid carcinoma (PDTC), follicular thyroid carcinoma (FTC), anaplastic thyroid carcinoma (ATC), and medullary thyroid carcinoma (MTC). MTC is inherited as an autosomal dominant trait in 25% of cases. The genetic landscape of thyroid carcinoma has been largely deciphered. In PTC, genetic alterations have been found in about 95% of tumors: BRAF mutations and RET rearrangements are the main genetic alterations. BRAF and RAS mutations have been confirmed to play an important role also in PDTC and ATC, together with TP53 mutations that are fundamental in tumor progression. It has also been clearly demonstrated that telomerase reverse transcriptase (TERT) promoter mutations and TP53 mutations are present with a high-frequency in more advanced tumors, frequently associated with other mutations, and their presence, especially if simultaneous, is a signature of aggressiveness. In MTC, next-generation sequencing confirmed that mutations in the RET gene are the most common molecular events followed by H-RAS and K-RAS mutations. The comprehensive knowledge of the genetic events responsible for thyroid tumorigenesis is important to better predict the biological behavior and better plan the therapeutic strategy for specific treatment of the malignancy based on its molecular profile.

Do BRAFV600E mutation and sodium-iodide symporter expression affect the response to radioactive iodine therapy in patients with papillary thyroid carcinoma?

OBJECTIVE

To report on the associations between BRAF and sodium iodide symporter expressions and treatment outcomes in patients with papillary thyroid carcinoma.

METHODS

Inclusion criteria included a pathologic diagnosis of papillary thyroid carcinoma of any stage, thyroidectomy followed by radioactive iodine therapy, and follow-up for at least 12 months after initial therapy. Events were classified as persistent or recurrent disease based on a clinical or investigational evidence of disease within or after, respectively, 1 year from initial therapy. Disease-free survival was calculated between the dates of surgery and confirmed event. Patients with no evidence of disease were censored at their last follow-up (censored group). BRAF mutation and sodium-iodide symporter expressions were evaluated using immunohistochemistry.

RESULTS

The study included 78 patients (60 females, 18 males) with median age 36 years (range: 20-70 years). BRAF was positive in 78%, equivocal in 13%, and negative in 9%. Sodium-iodide symporter was positive in 88%. BRAF mutation was significantly associated with increasing tumor size, presence of lymphovascular invasion, classic subtype of papillary thyroid carcinoma, thyroid capsular infiltration, and lymph node metastasis. Sodium-iodide symporter expression was not associated with any clinical or pathologic characteristics. Patients with negative or equivocal BRAF had significantly better disease-free survival (82%, 3 events) compared to the positive group (41%, 33 events; P=0.02).

CONCLUSION

In patients with papillary thyroid carcinoma, BRAF mutation is associated with high-risk pathological characteristics and worsened disease-free survival.

Characterizing the function of EPB41L4A in the predisposition to papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common histotype of thyroid carcinoma. The heritability of PTC is high compared to other cancers, but its underlying causes are unknown. A recent genome-wide association study revealed the association of a variant at the 5q22 locus, rs73227498, with PTC predisposition. We report that rs17134155, a variant in high linkage disequilibrium with rs73227498, is located in an enhancer region downstream of coding transcripts of EPB41L4A. Rs17134155 showed significant enhancer activity in luciferase assays, and haplotypes containing the protective allele of this variant conferred a significantly lower risk of PTC. While the index SNP, rs73227498, acted as a significant cis-eQTL for expression of EPB41L4A, rs17134155 was a significant cis-sQTL for the alternative splicing of a non-coding transcript of EPB41L4A, called EPB41L4A-203. We also performed knockdown of EPB41L4A followed by microarray analysis. Some of the top differentially-expressed genes were represented among regulators of the WNT/β-catenin signaling pathway. Our results indicate that an enhancer region at 5q22 regulates the expression and splicing of EPB41L4A transcripts. We also provide evidence that EPB41L4A expression is involved in regulating growth and differentiation pathways, suggesting that decreased expression of EPB41L4A is a mechanism in the predisposition to PTC.

The Coexistence of Genetic Mutations in Thyroid Carcinoma Predicts Histopathological Factors Associated With a Poor Prognosis: A Systematic Review and Network Meta-Analysis

PURPOSE

Genetic mutations may play an important role in the progression and invasion of thyroid carcinoma (TC), and their coexistence may result in mutational synergy. The presence of the BRAFV600E mutation, as well as mutations affecting the TERT promoter, RAS, CHEK2 and RET/PTC, may all have an impact on prognosis. The aim of this study was to explore whether synergy between the coexistent mutations predicts histopathological prognostic factors that influence disease outcome.

METHODS

A comprehensive literature search of PubMed, Embase and the Cochrane Library, from their inception until January 2020. Primary outcomes included: disease stage, lymph node metastasis, extrathyroidal extension and distant metastasis; while, secondary outcomes included: tumor recurrence, mortality, invasion of thyroid capsule, multiplicity, presented as an odds ratio (OR) with 95% credible intervals (CrI).

RESULTS

27 publications (comprising 9 active intervention arms), involving 8,388 TC patients, were selected. Network meta-analytic estimates of active interventions contrasted with other active interventions, with random effects, were calculated. In terms of outcomes focus on overall TC, BRAFV600E + TERT co-mutation ranked highest for diseases stage (OR = 5.74, 95% CrI: 3.09-10.66), as well as lymph node metastasis, extrathyroidal extension (5.74, 4.06-8.10), tumor recurrence (7.21, 3.59-14.47), and invasion of the thyroid capsule (3.11, 1.95-4.95). BRAFV600E + TERT co-mutation ranked secondary in distant metastasis, mortality, and multiplicity that ranked highest was TERT+RAS or RAS. When we were limited to the study of patients with papillary TC (PTC), BRAFV600E + TERT always ranked highest for primary outcomes: disease stage (6.39, 3.13-13.04), lymph node metastasis, extrathyroidal extension (5.80,3.89-8.64) and distant metastasis (7.33, 3.00-17.89), while BRAFV600E + TERT again ranked highest in secondary outcomes: tumor recurrence (7.23,3.37-15.51), mortality (9.26, 3.02-28.42), invasion of thyroid capsule (3.20,2.01-5.11), and multiplicity.

CONCLUSIONS

In this molecular marker mutation-based systematic review and network meta-analysis, we found that coexistent BRAFV600E + TERT genetic co-mutations predicted poor histopathological prognosis, including progression, invasion, and metastasis, especially in PTC. For the overall TC, the BRAFV600E + TERT + RAS triple mutations may have a greater impact on the prognosis, and further research should related to potentially important features. This study is registered with PROSPERO, number CRD42019143242.

The diversities in thyroid cytopathology practices among Asian countries using the Bethesda system for reporting thyroid cytopathology

Background

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) has been adopted and widely used among Asian countries. This study aims to investigate the application of TBSRTC in thyroid cytology practice among Asian countries.

Methods

We searched electronic databases including PubMed and Web of Science from 2010 to 2019. Meta-analysis of proportion and their 95% confidence intervals (CIs) were calculated using the random-effect model. Meta-regression and subgroup analysis were used to search for heterogeneity origins.

Results

We included 42 Asian studies with 84.953 fine-needle aspirations. Among six categories, benign was the most commonly diagnosed category. The resection rate (RR) and risk of malignancy (ROM) were highest in malignant and SM categories, and lowest among benign nodules. Thyroid cytology practice in Asia was characterized by a low RR and high ROM in patients with indeterminate thyroid nodules. There was a significant amount of heterogeneities of TBSRTC outputs (frequency, resection rate, and malignancy risk) among Asian countries. Meta-regression showed that the sources of heterogeneity might stem from the differences in study origin and the application of molecular testing. We highlighted the usefulness of preoperative molecular testing to select patients for surgery.

Conclusions

Our study provided insight regarding thyroid cytology practice among Asian countries. Active surveillance is commonly used in Asian practice resulting in a low RR and high ROM for indeterminate nodules. There are still variations in general thyroid cytology practice in Asia. Future guidelines and consensus regarding the application of TBSRTC in thyroid cytology practice among Asian countries are required.

Clinical, Pathological, and Molecular Characteristics Correlating to the Occurrence of Radioiodine Refractory Differentiated Thyroid Carcinoma: A Systematic Review and Meta-Analysis

Background: Recently, radioiodine refractory differentiated thyroid cancer (RR-DTC) has received increasing attention due to its poor prognosis. The roles of clinical, pathological, and molecular features in the development of RR-DTC remain controversial and require additional investigation. This study aimed to evaluate the association between these risk factors and the occurrence of RR-DTC.

Methods: We performed a systematic search for relevant literature following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) in PubMed, EMBASE, Medline, SCOPUS, and Web of Science up to the July 15, 2020. Observational studies that investigated the risk factors for RR-DTC were included. Fixed- or random-effects models were used to calculate pooled odds ratios (ORs) or mean differences (MD) with corresponding 95% confidence intervals.

Results: We included 13 eligible studies incorporating 1,431 cases, of which 603 were patients with RR-DTC. The pooled analysis indicated that four parameters significantly increased the risk of RR-DTC: extrathyroidal extension (ETE) (OR: 2.28, 95% CI: 1.43–3.64, I² = 14%), BRAF^V600E mutation (OR: 3.60, 95% CI: 1.74–7.46, I² = 69%), TERT promoter mutation (OR: 9.84, 95% CI: 3.60–26.89, I² = 61%) and high-risk histological subtype (OR: 1.94, 95% CI: 1.15–3.27, I² = 15%), including tall cell variant papillary thyroid carcinoma (PTC), sclerosing diffuse PTC, hobnail variant PTC, follicular thyroid carcinoma (FTC) (including Hürthle cell), and poorly differentiated thyroid carcinoma (PDTC). However, there was no statistical significance regarding sex, age, tumor size, multifocality, or lateral lymph node metastasis. Subgroup and sensitivity analyses were conducted to further confirm the robustness of the results.

Conclusions: Histological subtype, ETE, BRAF^V600E mutation, and TERT promoter mutation could be considered clinicopathological factors and biomarkers. They could assist in risk stratification, prognostic prediction, and individual therapy options for RR-DTC.

BRAFV600E, hypothyroidism, and human relaxin in thyroid carcinogenesis

PURPOSE

BRAF^V600E, a major driver of thyroid cancer, evaluated in the context of thyroid hormones and human relaxin.

METHODS

Immunohistochemical expressions of BRAF^V600E, TSH, TSH receptor (TSHR), T4, T3 receptor (T3R), RLNH2, and its receptor, RXFP1, were evaluated in thyroid tumors from a retrospective U.S. population of 481 cancer cases diagnosed in 1983-2004.

RESULTS

BRAF^V600E was expressed in 52% of all thyroid tumors; expression of other markers ranged from 25% for T4 to 98% for RLNH2. Tumors predominantly exhibited hypothyroid-like conditions characterized by elevated TSH and TSHR and reduced T4. BRAF^V600E prevalence was significantly higher in tumors expressing TSH, TSHR, T3R, and RXFP1 and lower in tumors expressing T4. The proportion of BRAF^V600E mutation in classic papillary tumors significantly increased from 56 to 72% over the 21-year period of diagnoses, while expression of RXFP1, TSH, TSHR, and T3R decreased in non-tumor. Racial/ethnic differences were observed in thyroid hormone marker expression. Non-tumor expression of TSH, TSHR, and T3R were each associated with shorter overall survival, but did not remain significant after adjustment for demographic and clinical factors.

CONCLUSIONS

Our study provides the first evidence of the potential interaction of BRAF^V600E mutation, relaxin, and thyroid hormones in thyroid carcinogenesis. Moreover, our results suggest that hypothyroidism, influenced by RLNH2 activity, may underlie the development of the majority of thyroid cancers and mediate the role of BRAF^V600E in thyroid carcinogenesis. BRAF^V600E mutation is increasing in papillary thyroid cancers and may be contributing to the rising incidence of this malignancy.

Growth factor receptor bound protein-7 regulates proliferation, cell cycle, and mitochondrial apoptosis of thyroid cancer cells via MAPK/ERK signaling

It is of great significance to explore the molecular mechanism of thyroid cancer (TC) pathogenesis for its improvement and therapy. Growth factor receptor bound protein-7 (GRB7) has been regarded as an important regulatory gene in the developments of various malignant tumors. Our study aimed to illustrate the role of GRB7 in the TC pathology mechanism. Firstly, GRB7 was found to be significantly upregulated in 49 cases of TC tissues and 5 TC cell lines by using real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting. Silencing GRB7 with siRNA dramatically inhibited proliferation and induced cell cycle arrest in TC cells. Besides, GRB7 silence resulted in the decrease of adenosine triphosphate content, glucose uptake, and lactose production in TC cells and attenuated the activity and expression of mitochondrial respiratory complex. We also demonstrated that GRB7 downregulation increased the levels of Bax and caspase 3, and inhibited the expression of Bcl-2, suggesting the induced mitochondrial apoptosis. More importantly, our study proved that mitogen-activated protein kinase/extracellular-regulated protein kinases (MAPK/ERK) signaling played a crucial role in the regulation of GRB7 on TC cell functions. In general, the present research verified that GRB7 was upregulated during TC development and modulated the proliferation, cell cycle, and mitochondrial apoptosis of TC cells by activating MAPK/ERK pathway. This may provide a novel target for the therapeutic strategy of TC.

High Preponderance of BRAF V600E Mutation in Papillary Thyroid Carcinoma Among Filipinos: A Clinicopathologic Study

Purpose

BRAF mutation in papillary thyroid carcinoma (PTC) is associated with an aggressive phenotype, with varying incidence. We evaluated the prevalence of BRAF mutations in PTC among Filipino patients and their correlation with clinicopathologic characteristics.

Patients and Methods

Clinicopathologic data were retrieved from 64 sequential patients who underwent thyroidectomy from June 2016 to December 2016. BRAF mutation testing was performed using Sanger sequencing.

Results

Eighteen (28%) of 64 patients were diagnosed with PTC; 12 (70.59%) of 17 harbored a BRAF V600E mutation (no amplification in one patient). Demographics of patients with PTC were as follows: 13 women and five men, with median age of 46 years (range, 25 to 74 years). Fourteen patients had conventional subtype PTC; two, follicular variant; one, oncocytic variant; and one, tall-cell features. Tumor size ranged from 0.8 to 7.0 cm (median, 2.4 cm); extrathyroidal extension was present in seven (38.9%) of 18 patients, multifocality in six (33.33%) of eight, and lymph node involvement in eight (44.4%) of 18. Significant association between presence of a BRAF mutation and presence of extrathyroidal extension or lymph node involvement was not determined due to the limited sample size.

Conclusion

The high preponderance of BRAF mutation (70.59%) suggests some correlation with the previously reported lower 5-year survival among Filipinos. This warrants further investigation in a larger-cohort prospective study.

Downregulation of miR‑193a‑3p via targeting cyclin D1 in thyroid cancer

Thyroid cancer (TC) is a frequently occurring malignant tumor with a rising steadily incidence. microRNA (miRNA/miR)‑193a‑3p is an miRNA that is associated with tumors, playing a crucial role in the genesis and progression of various cancers. However, the expression levels of miR‑193a‑3p and its molecular mechanisms in TC remain to be elucidated. The present study aimed to probe the expression of miR‑193a‑3p and its clinical significance in TC, including its underlying molecular mechanisms. Microarray and RNA sequencing data gathered from three major databases, specifically Gene Expression Omnibus (GEO), ArrayExpress and The Cancer Genome Atlas (TCGA) databases, and the relevant data from the literature were used to examine miR‑193a‑3p expression. Meta‑analysis was also conducted to evaluate the association between clinicopathological parameters and miR‑193a‑3p in 510 TC and 59 normal samples from the TCGA database. miRWalk 3.0, and the TCGA and GEO databases were used to predict the candidate target genes of miR‑193a‑3p. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and protein‑protein interaction network enrichment analyses were conducted by using the predicted candidate target genes to investigate the underlying carcinogenic mechanisms. A dual luciferase assay was performed to validate the targeting regulatory association between the most important hub gene cyclin D1 (CCND1) and miR‑193a‑3p. miR‑193a‑3p expression was considerably downregulated in TC compared with in the non‑cancer controls (P<0.001). The area under the curve of the summary receiver operating characteristic was 0.80. Downregulation of miR‑193a‑3p was also significantly associated with age, sex and metastasis (P=0.020, 0.044 and 0.048, respectively). Bioinformatics analysis indicated that a low miR‑193a‑3p expression may augment CCND1 expression to affect the biological processes of TC. In addition, CCND1, as a straightforward target, was validated through a dual luciferase assay. miR‑193a‑3p and CCND1 may serve as prognostic biomarkers of TC. Finally, miR‑193a‑3p may possess a crucial role in the genesis and progression of TC by altering the CCND1 expression.

ARV-825-induced BRD4 protein degradation as a therapy for thyroid carcinoma

Bromodomain-containing protein 4 (BRD4) is overexpressed in thyroid carcinoma, represents as an important therapeutic target. ARV-825 is a novel cereblon-based PROTAC (Proteolysis Targeting Chsimera) compound. It can induce fast and sustained BRD4 protein degradation. Its potential effect in human thyroid carcinoma cells was studied here. In TPC-1 cells and primary human thyroid carcinoma cells, ARV-825 potently inhibited cell viability, proliferation and migration. Furthermore, ARV-825 induced robust apoptosis activation in the thyroid carcinoma cells. ARV-825 induced BRD4 protein degradation and downregulation of its targets, including c-Myc, Bcl-xL and cyclin D1 in thyroid carcinoma cells. It was significantly more potent in inhibiting thyroid carcinoma cells than the known small molecule BRD4 inhibitors. In vivo studies demonstrated that ARV-825 oral administration potently suppressed TPC-1 xenograft tumor growth in severe combined immunodeficient mice. BRD4 protein degradation as well as c-Myc, Bcl-xL and cyclin D1 downregulation were detected in ARV-825-treated TPC-1 tumor tissues. Taken together, ARV-825 induces BRD4 protein degradation and inhibits thyroid carcinoma cell growth in vitro and in vivo.

MiR-1256 inhibits cell proliferation and cell cycle progression in papillary thyroid cancer by targeting 5-hydroxy tryptamine receptor 3A

Aberrant expression of miR-1256 has been reported to be closely associated with the development and progression of tumors, including colon cancer and lung cancer. However, study of its expression pattern and functional role in papillary thyroid cancer (PTC) is rare. Using quantitative real time PCR analysis, we found miR-1256 was significantly down-regulated in PTC tissues and cell lines. The correlation of miR-1256 expression with clinicopathological features was statistically analyzed. The results showed miR-1256 expression was significantly correlated with tumor size (p = 0.0124) and TNM stage (p = 0.0032). Restoring miR-1256 expression significantly inhibited proliferation and cell cycle progression of PTC cells demonstrated by CCK-8 and flow cytometry assays. Luciferase reporter assay and biotin-avidin pull-down assay showed miR-1256 can directly target 5-hydroxytryptamine receptor 3A (HTR3A) in PTC cells. The expression of miR-1256 was inversely correlated with HTR3A expression in PTC tissues. Knockdown of HTR3A imitated the suppressive effects of miR-1256 in PTC cells. Ectopic expression of HTR3A can antagonize the effects of miR-1256 on PTC cells. Furthermore, the suppressive effects of miR-1256 on the expression of PCNA, CDK4, Cyclin D1, and p21 were partially reversed by HTR3A overexpression in PTC cells. In summary, our data suggested that miR-1256 could suppress PTC cellular function by targeting HTR3A, which might be a potential therapeutic target for patients with PTC.

The stress-activated protein kinase pathway and the expression of stanniocalcin-1 are regulated by miR-146b-5p in papillary thyroid carcinogenesis

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Deciphering the pathophysiological mechanisms that contribute to PTC development is essential to the discovery of optimal diagnostic and therapeutic approaches. MiR-146b-5p has been identified as a cancer-associated microRNA highly up-regulated in PTC. This study explores the hypothesis that miR-146b-5p contributes to papillary thyroid carcinogenesis through regulation of cell signaling pathways in a manner that overcomes the cellular growth suppressive events and provides survival advantage. The effect of miR-146b-5p inhibition on major cancer related signaling pathways and expression of Stanniocalcin-1 (STC1), an emerging molecule associated with stress response and carcinogenesis, was tested in cultured primary thyroid cells using luciferase reporter assays, quantitative real-time PCR, immunofluorescence staining, and flow cytometry. Our results demonstrated that miR-146b-5p inhibits the JNK/AP1 pathway activity and down-regulates the expression of STC-1 in thyroid-cultured cells and in thyroid tissue samples. In the presence of miR-146b-5p, PTC cells were resistant to cell death in response to oxidative stress. This is a novel report that miR-146b-5p directly targets STC1 and regulates the activity of JNK/AP1 pathway. Considering the importance of the JNK/AP1 pathway and STC1 in mediating many physiological and pathological processes like apoptosis, stress response and cellular metabolism, a biological regulator of these pathways would have a great scientific and clinical significance.

Differences in surgical resection rate and risk of malignancy in thyroid cytopathology practice between Western and Asian countries: A systematic review and meta-analysis

There is increasing evidence showing that clinicians employ different management strategies in their use of The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC). In this meta-analysis, we investigated the differences in diagnosis frequency, resection rate (RR), and risk of malignancy (ROM) between Western (ie, American and European) and Asian cytopathology practices. We searched PubMed and Web of Science from January 2010 to January 2019. Proportion and 95% CIs were calculated using a random-effect model. We used independent sample t tests to compare frequencies, RR, and ROM between Western and Asian practices. We analyzed a total of 38 studies with 145,066 fine-needle aspirations. Compared with Asian practice, Western series had a significantly lower ROM in most of TBSRTC categories, whereas the RR was not statistically different. Focusing on indeterminate nodules, the RR in Western series was significantly higher (51.3% vs 37.6%; P = .048), whereas the ROM was significantly lower (25.4% vs 41.9%; P = .002) compared with those in Asian series. The addition of Asian cohorts increased ROM for most of diagnostic categories compared with the original TBSRTC. In conclusion, this study demonstrates a difference in Western and Asian thyroid cytology practice, especially regarding the indeterminate categories. Lower RR and higher ROM suggest that Asian clinicians adopt a more conservative approach, whereas immediate diagnostic surgery is favored in Western practice for indeterminate nodules. The addition of Asian series into a meta-analysis of TBSRTC altered ROM for several categories, which should be considered in future revisions of TBSRTC.

Incidence of Thyroid Cancer Among Children and Young Adults in Fukushima, Japan, Screened With 2 Rounds of Ultrasonography Within 5 Years of the 2011 Fukushima Daiichi Nuclear Power Station Accident

Importance

Ultrasonographic (US) screening for thyroid cancer was performed in the Fukushima Health Management Survey after the 2011 Fukushima Daiichi nuclear power station accident. Clinical characteristics of thyroid cancers screened by US among children and young adults during the first 5 years after the accident were analyzed.

Objectives

To evaluate the number of detected thyroid cancers by age group within 5 years of the Fukushima Daiichi nuclear power station accident and to compare the basic clinical characteristics and demographic patterns in first- and second-round examinations.

Design, Setting, and Participants

In this observational study, 324 301 individuals 18 years or younger at the time of accident were included. Patients received a cytologic diagnosis of malignant or suspected malignant thyroid cancer during the first (fiscal years 2011-2013) or second round (fiscal years 2014-2015) of screening. Number of detected cases of cancer was evaluated, correcting for the number of examinees by age group at the time of the accident and for the incidence of detected cancers according to age group at the time of the screening (age groups were divided into 3-year intervals). Results were compared using the age-specific incidence of unscreened cancers from a national cancer registry.

Main Outcomes and Measures

Clinical baseline characteristics of the patients and the age-specific number and incidence of thyroid cancers detected during the second round.

Results

Among 299 905 individuals screened in the first round (50.5% male; mean [SD] age at screening, 14.9 [2.6] years), malignant or suspected thyroid cancer was diagnosed in 116. Among 271 083 individuals screened in the second round (50.4% male; age at screening, 12.6 [3.2] years), malignant or suspected thyroid cancer was diagnosed in 71. The most common pathologic diagnosis in surgical cases was papillary thyroid cancer (149 of 152 [98.0%]). The distribution pattern by age group at the time of the accident, where the number of detected thyroid cancer cases was corrected by the number of examinees, increased with older age in both screening rounds. This demographic pattern was similar between the first and second examinations. The distribution pattern of the incidence rate by age group at the time of screening in the second round also increased with older age. The incidence rate detected by screening was 29 cases per 100 000 person-years for those aged 15 to 17 years, 48 cases per 100 000 person-years for those aged 18 to 20 years, and 64 cases per 100 000 person-years for those aged 21 to 22 years.

Conclusions and Relevance

Large-scale mass US screening of young people resulted in the diagnosis of a number of thyroid cancers, with no major changes in overall characteristics within 5 years of the 2011 Fukushima nuclear power station accident. These results suggest that US screening can identify many detectable cancers from a large pool of nonclinical and subclinical thyroid cancers among individuals of a relatively young age, in an age-dependent manner.

Radiation-Induced Thyroid Cancers: Overview of Molecular Signatures

Enormous amounts of childhood thyroid cancers, mostly childhood papillary thyroid carcinomas (PTCs), after the Chernobyl nuclear power plant accident have revealed a mutual relationship between the radiation exposure and thyroid cancer development. While the internal exposure to radioactive ¹³¹I is involved in the childhood thyroid cancers after the Chernobyl accident, people exposed to the external radiation, such as atomic-bomb (A-bomb) survivors, and the patients who received radiation therapy, have also been epidemiologically demonstrated to develop thyroid cancers. In order to elucidate the mechanisms of radiation-induced carcinogenesis, studies have aimed at defining the molecular changes associated with the thyroid cancer development. Here, we overview the literatures towards the identification of oncogenic alterations, particularly gene rearrangements, and discuss the existence of radiation signatures associated with radiation-induced thyroid cancers.

A Systematic Review and Meta-Analysis of the Diagnostic Performance of BRAF V600E Immunohistochemistry in Thyroid Histopathology

Immunohistochemistry (IHC) in evaluating thyroid surgical specimens may facilitate diagnostic and prognostic evaluation, with potential therapeutic implications. We performed a systematic review and meta-analysis examining the analytic validity of IHC in detecting BRAFV600E mutations in thyroid cancer (primary or metastatic). We screened citations from three electronic databases (until December 20, 2018), supplemented by a hand search of authors' files and cross-references of reviews. Citations and full-text papers were independently reviewed in duplicate, and consensus was achieved on inclusion of papers. Two reviewers independently critically appraised and abstracted data from included papers. Random-effect meta-analyses were conducted for sensitivity and specificity estimates. We reviewed 1499 unique citations and 93 full-text articles. We included 1 systematic review and 30 original articles. The published review (from 2015) needed to be updated as there were multiple subsequent original studies. The pooled sensitivity of IHC in detecting a BRAFV600E mutation was 96.8% (95% confidence interval [CI] at 94.1%, 98.3%) (29 studies, including 2659 BRAFV600E mutant tumors). The IHC pooled specificity was 86.3% (95% CI 80.7%, 90.4%) (28 studies, including 1107 BRAFV600E wild-type specimens). These meta-analyses were subject to statistically significant heterogeneity, partly explained by antibody type (sensitivity and specificity) and tissue/tumor type (specificity). In conclusion, BRAF IHC is highly sensitive and reasonably specific in detecting the BRAFV600E mutation; however, there is some variability in analytic performance.

Physical activity participation and the risk of chronic diseases among South Asian adults: a systematic review and meta-analysis

South Asia specific reviews on the role of physical activity (PA) domains on chronic disease prevention are lacking. This study aimed to systematically review published literature to identify the association between PA domains and chronic diseases and to provide summary estimates of the strength of association. Nine electronic databases were searched using the predefined inclusion criteria which included population (South Asian adults 40 years or older), exposure (PA or sedentary behaviour) and outcome (type 2 diabetes mellitus, breast cancer, colorectal cancer, coronary heart disease, stroke, vascular disease and musculoskeletal diseases and their markers). A random-effects meta-analysis was carried out for cardiometabolic outcomes whereas narrative synthesis was completed for other outcome variables. Inactive or less active South Asian adults were at 31% higher risk of being hypertensive. Likewise, the risk of cardiometabolic outcomes was 1.34 times higher among inactive adults. Household PA was found to have a protective effect  on breast cancer risk. Total and leisure time PA had a protective effect on osteoporosis among males and females respectively. Contemporary studies with a longitudinal design, representative samples, valid and reliable assessment of different domains are needed to establish the role of PA in chronic disease prevention in the region.

Relationship between BRAF V600E and clinical features in papillary thyroid carcinoma

OBJECTIVE

To investigate the mutant status of BRAF gene and analyze its relationship to epidemiological risk factors and clinical outcomes among patients with papillary thyroid cancer (PTC) in the largest, single-institution Chinese cohort to date.

METHODS

The medical records of 2048 PTC patients were reviewed in this retrospective study. Single-factor and multiple logistic regression analyses were applied to identify risk factors for BRAF V600E mutation. Survival outcomes including distant metastatic and persistent or recurrent PTC were examined, with a mean follow-up time of 23.4 (5-47) months.

RESULTS

The BRAF V600E mutation was present in 83.7% of patients (1715 of 2048). Correlation was found between BRAF V600E mutation and several epidemiological features, including age, concomitant hypertension and Hashimoto thyroiditis (HT). For the clinicopathological features, BRAF V600E was significantly associated with bilateral multifocality (odds ratio (OR) 1.233, 95% confidence interval (CI) 1.063-1.431, P < 0.01) and less lateral lymph node metastases (OR 0.496, 95% CI 0.357-0.689, P < 0.01). Smaller tumor size and advanced disease stage were significant in single-factor analyses but became insignificant after multivariate adjustment. No association was found between BRAF V600E mutation and extrathyroidal invasion, distant metastatic and disease persistence or recurrence.

CONCLUSION

Part of epidemiological features are independent risk or protective factors for BRAF V600E mutation. The presence of BRAF V600E mutation is not an aggressive prognosis on poor clinical outcomes in PTC. However, the high prevalence of BRAF V600E may provide guidance for surgery strategy and opportunity for targeted treatment in recurrent and advanced stage disease.

LncRNA HOXA-AS2 Facilitates Tumorigenesis and Progression of Papillary Thyroid Cancer by Modulating the miR-15a-5p/HOXA3 Axis

The long non-coding RNA HOXA-AS2 has been found to be an oncogene in several types of human malignant tumors. However, its role in regulating the occurrence and development of papillary thyroid cancer (PTC) is still unclear. The present study investigated the function and mechanism(s) of HOXA-AS2 in PTC progression. Using quantitative real-time polymerase chain reaction, HOXA-AS2 was found to be differentially expressed in PTC tissues and cell lines. Kaplan-Meier analysis indicated that the overall survival rate of patients with higher levels of HOXA-AS2 was lower than those with relatively lower levels. Loss-of-function assays revealed that HOXA-AS2 knockdown inhibited PTC progression by inhibiting cellular proliferation, migration, and invasion and accelerating apoptosis. Mechanistically, loss-of-function assays showed a positive correlation between HOXA3 and HOXA-AS2 expression. Subcellular fractionation assay results revealed abundant HOXA-AS2 expression in the cytoplasm of PTC cells. Additionally, FOXD2-AS1 was found to upregulate HOXA3 expression by binding to miR-15a-5p. Finally, rescue assays demonstrated the overall function of the HOXA-AS2/miR-15a-5p/HOXA3 axis in PTC progression. These findings will significantly contribute to further research and the development of more efficient treatments for thyroid cancer in the future.

Risk Factors for Predicting Lymph Nodes Posterior to Right Recurrent Laryngeal Nerve (LN-prRLN) Metastasis in Thyroid Papillary Carcinoma: A Meta-Analysis

OBJECTIVE

To evaluate the risk factors for predicting lymph nodes (LN) posterior to right recurrent laryngeal nerve metastasis in thyroid papillary carcinoma.

METHODS

PubMed, PMC, EMBASE, and the Cochrane Library were systematically searched for articles published spanning 30/06/2009-30/8/2018 using multiple search terms. Thirteen articles involving 10,014 patients were reviewed in our meta-analysis. Stata 15.1 software was used for the meta-analysis.

RESULTS

The rate of LN posterior to right recurrent laryngeal nerve (LN-prRLN) metastasis was 8.65%. Univariate analysis showed that age (P = 0.001), gender (P < 0.001), tumour size (P < 0.001), lateral LN metastasis (P < 0.001), extrathyroidal invasion (P < 0.001), multifocality (P = 0.005), capsule invasion (P < 0.001), tumour location (P = 0.076), lymph nodes anterior to right recurrent laryngeal nerve (LN-arRLN) metastasis (P < 0.001), and central LN metastasis (P < 0.001) were significantly associated with the increased incidence of LN-prRLN metastasis in thyroid papillary carcinoma.

CONCLUSION

PTC patients aged <45, male, and with tumours > 1 cm, lateral LN metastasis, extrathyroidal invasion, multifocality, capsule invasion, LN-arRLN metastasis, or central LN metastasis were significantly correlated with lymph nodes posterior to right recurrent laryngeal nerve metastasis, indicating LN-prRLN dissection.

Physical activity participation and the risk of chronic diseases among South Asian adults: protocol for a systematic review and meta-analysis

BACKGROUND

Chronic diseases contribute to about half of the adult disease burden in the South Asian region. Meanwhile, physical activity levels are declining despite the global evidence of its role in the prevention of chronic diseases. While there are a plethora of systematic reviews on the effects of physical activity on chronic diseases, there has not yet been a synthesis of the evidence concerning the nature of this relationship among people living in South Asian countries incorporating multiple chronic diseases and a focus on physical activity domains. The aim of this protocol is to describe the rationale and methods for a systematic review of published research to identify the association between physical activity and selected chronic diseases and their markers and analysis of the strength of association with a focus on physical activity domains among South Asian adults 40 years and older.

METHODS

Nine electronic databases including Medline, PsycINFO, Embase, CENTRAL, CINAHL Plus, AgeLine, SPORTDiscus, Scopus and Web of Science will be systematically searched for papers reporting the association between physical activity and selected chronic diseases (type 2 diabetes mellitus, breast cancer, colorectal cancer, coronary heart disease, stroke, vascular diseases and musculoskeletal diseases (osteoarthritis, osteoporosis, back and neck pain)) and their markers using predefined search terms. Searches will be limited to peer-reviewed, English language papers with a quantitative design. In addition, a manual search of references of relevant systematic reviews as well as citations and references of eligible studies will also be carried out. The methodological appraisal will be performed using the National Institutes of Health quality assessment checklist for observational studies and the Effective Public Health Practice Project quality assessment tool for intervention studies. The overall quality of evidence for the study outcomes across the study designs will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. The review results will be presented in the form of narrative synthesis, and a random effects meta-analysis is planned depending on the nature of included studies and available data.

DISCUSSION

This review will summarise the strength of the association between physical activity and selected chronic diseases and their markers among South Asian adults 40 years or older. The findings will provide an evidence base to guide public health policy and interventions in the South Asian region and to inform future research to address the rising burden of chronic diseases.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018096505.

Targeted next-generation sequencing of cancer-related genes in thyroid carcinoma: A single institution's experience

Thyroid carcinoma (TC) has characteristic genetic alterations, including point mutations in proto-oncogenes and chromosomal rearrangements that vary by histologic subtype. Recent developments in next-generation sequencing (NGS) technology enable simultaneous analysis of cancer-associated genes of interest, thus improving diagnostic accuracy and allowing precise personalized treatment for human cancer. A total of 50 patients who underwent thyroidectomy between 2014 and 2016 at Hokuto Hospital were enrolled. Total DNA was extracted from formalin-fixed, paraffin-embedded tissue sections and quantified. Targeted regions of 24 cancer-associated genes were amplified by PCR, barcoded and sequenced using an Illumina MiSeq platform. Subjects included 30 patients with papillary carcinoma (PC), two with PC tall cell variant (TVPC), two with PC follicular variant (FVPC), eight with follicular carcinoma, seven with poorly differentiated carcinoma (PDC), and one with anaplastic carcinoma (AC). The BRAF V600E mutation was present in 25 of 30 (83%) patients with PC, 2 of 2 (100%) patients with TVPC, 6 of 7 (86%) patients of PDC, and one patient with AC. PIK3CA mutations were present in 3 of 30 (delPV104P, A1046T and C420R; 10%) patients with PC and 1 of 7 (H1047R; 14%) patients with PDC. The TP53 mutation was present in 1 of 30 (R306*; 3.3%) patients with PC and 1 of 7 (Q152*; 14%) patients with PDC. The NRAS mutation was present in 1 of 2 (Q61K, 50%) patients with FVPC. Statistical analysis showed that patients without the BRAF V600E mutation had advanced pathologic T and N stages compared with those with the mutation (P=0.047 and P=0.019, respectively). The BRAF V600E mutation was not correlated with overall and disease-free survival in patients with PC. A patient with PC with a mutation in EGFR (K852Q) and the PIK3CA mutation had an aggressive course with multiple bone and lung metastases. Detection of mutations in cancer-associated genes using NGS could enhance the understanding of the clinical behavior of TC.

Clinicopathological Risk Factors for Distant Metastasis in Differentiated Thyroid Carcinoma: A Meta-analysis

INTRODUCTION

Distant metastasis (DM) is not a frequent event in differentiated thyroid carcinoma (DTC) but has an adverse impact on mortality of patients with DTC. In the current study, we aimed to conduct a comprehensive systematic review and meta-analysis to investigate the risk factors for DM in DTCs and for each histological subtype.

METHODS

Five electronic databases were searched from inception to December 2016 for relevant articles. Pooled odd ratios and 95% confidence interval were calculated using random-effect model.

RESULTS

Thirty-four articles with 73,219 patients were included for meta-analyses. In DTCs, male gender, age ≥45 years, tumor size ≥4 cm, multifocality, vascular invasion (VI), extrathyroidal extension (ETE), lymph node metastasis (LNM), and lateral LNM were demonstrated to be associated with significant risks for DM. In addition, several clinicopathological factors such as age ≥45 years, VI, ETE, and LNM were shown to be significant risk factors for DM in both PTC and FTC subgroups.

CONCLUSION

Our study demonstrated the promising value of several clinicopathological factors such as male gender, older age, VI, ETE, and LNM in predicting DM in PTCs and FTCs. Our study affirms the value of the selected clinicopathological factors for tumor risk stratification and assessment of patients' prognosis.

Detection of BRAF V600E Mutations With Next-Generation Sequencing in Infarcted Thyroid Carcinomas After Fine-Needle Aspiration

OBJECTIVES

Fine-needle aspiration (FNA) of thyroid lesions may result in infarction and diagnostic difficulties on subsequent thyroidectomy specimens. Next-generation sequencing (NGS) methods for detection of hallmark driver BRAF V600E mutations may help characterize such tumors in which histologic alterations preclude definitive tissue diagnosis.

METHODS

Thyroidectomy specimens with both malignant FNA diagnoses and resultant infarction were identified from our institutional database. NGS methods were used to detect BRAF V600E mutations in the infarcted thyroid carcinomas.

RESULTS

Nine thyroid carcinomas with infarction were characterized as BRAF-like papillary thyroid carcinoma based on molecular driver categorization and histologic diagnosis. BRAF V600E mutations were detected in the infarcted tissue in four (67%) of six lesions.

CONCLUSIONS

We demonstrate detection of hallmark BRAF V600E mutations by NGS within infarcted tissue of thyroid carcinomas after FNA. This suggests a potential ancillary method of characterizing infarcted thyroid carcinomas whose altered histology may be nondiagnostic.

Mutational Profile of Papillary Thyroid Carcinoma in an Endemic Goiter Region of North India

INTRODUCTION

Mitogen activated protein kinase (MAPK) pathway is regularly altered in papillary thyroid carcinomas (PTCs). Serine/threonine-protein kinase B-Raf (BRAF) V600E mutations were observed very frequently in PTC along with less frequent rat sarcoma (RAS) and rearranged during transfection (RET) gene, also known as RET/PTC translocation. The present study aimed to analyze the mutational profile of PTCs from an endemic Goiter area of North India.

METHODOLOGY

Tissues from 109 PTC patients were used to isolate DNA and RNA. BRAF V600E was detected by restriction fragment length polymorphism-polymerase chain reaction (PCR). RAS mutations were screened by using Sanger's sequencing method. RET/PTC rearrangements were analyzed by real-time PCR.

RESULTS

BRAF V600E mutation was detected in 51.38% (56/109) of PTCs, whereas RAS mutations were less frequent. No RET/PTC rearrangements were observed. BRAF V600E was found to be associated with the aggressive clinicopathological features such as lymph node metastasis, distant metastasis, higher tumor-node-metastasis stages, and high-risk groups.

CONCLUSION

The prevalence of BRAF V600E is high in patients from Indian Subcontinent and found to be associated with aggressive features of PTC. Concomitant mutations of BRAF V600E and RAS mutations impart more aggressiveness to PTCs.

Reconsideration of tumor size threshold for total thyroidectomy in differentiated thyroid cancer

BACKGROUND

The optimal extent of surgery for differentiated thyroid cancer may not be well recognized initially. Identification of intermediate-risk features on surgical pathology may prompt the need for completion thyroidectomy if a lobectomy is performed. In this study, we examined the factors in relation to the need for completion thyroidectomy.

METHODS

We studied consecutive patients who underwent thyroidectomy for differentiated thyroid cancer from 2008 to 2017. Total thyroidectomy was indicated when tumor size >4 cm, clinical extrathyroidal extension, clinical lymph node metastasis, or distant metastasis was present. The need for completion thyroidectomy was defined as the presence of aggressive histology, extrathyroidal extension, lymphovascular invasion, or non-low-risk nodal metastasis.

RESULTS

Among 771 patients, 155 (20%) were definitely indicated for total thyroidectomy. The need for completion thyroidectomy was identified in 273 (44%) of the 616 patients initially eligible for lobectomy. The proportions of patients requiring completion thyroidectomy were 18% and 57% for microcarcinomas and tumors of 1-4 cm, respectively. Receiver operating characteristic curve analysis indicated that tumor size ≥1.1 cm had the highest accuracy of prediction. Multivariate logistic regression revealed that tumor size and BRAF V600E mutation were independent factors predicting the risk of requiring completion thyroidectomy.

CONCLUSION

A substantial portion of patients with differentiated thyroid cancer who are preoperatively eligible for lobectomy would be found to have intermediate-risk pathologic features. This should be incorporated into the shared decision making before surgery.

AZD5153, a novel BRD4 inhibitor, suppresses human thyroid carcinoma cell growth in vitro and in vivo

The development of novel anti-papillary thyroid carcinoma agents is urgent. AZD5153 is a novel and specific Bromodomain-containing protein 4 (BRD4) inhibitor. Here, we show that AZD5153 dose-dependently inhibited survival, proliferation and cell cycle progression in TPC-1 cells and primary human thyroid carcinoma cells. Yet, it was non-cytotoxic to the primary thyroid epithelial cells. AZD5153 induced caspase-3/-9 and apoptosis activation in TPC-1 cells and primary cancer cells. Its cytotoxicity in TPC-1 cells was significantly attenuated with co-treatment of the caspase inhibitors. BRD4 expression was elevated in TPC-1 and primary human thyroid carcinoma cells, but was low in the thyroid epithelial cells. BRD4-regulated proteins, including c-Myc, Bcl-2 and cyclin D1, were significantly downregulated following AZD5153 treatment in TPC-1 and primary cancer cells. In vivo, oral administration of AZD5153 at well-tolerated doses significantly inhibited TPC-1 xenograft growth in severe combined immunodeficient (SCID) mice. BRD4-dependent proteins, Myc, Bcl-2 and cyclin D1, were also downregulated in AZD5153-treated tumor tissues. Collectively, the results suggest that targeting BRD4 by AZD5153 inhibits human thyroid carcinoma cell growth in vitro and in vivo.

Long non-coding PANDAR as a novel biomarker in human cancer: A systematic review

OBJECTIVES

Long non-coding RNAs (lncRNAs) are characterized as a group of RNAs that more than 200 nucleotides in length and have no protein-coding function. More and more evidences provided that lncRNAs serve as key molecules in the development of cancer. Deregulation of lncRNAs functions as either oncogenes or tumour suppressor genes in various diseases. Recently, increasing studies about PANDAR in cancer progression were reported. In our review, we will focus on the current research on the character of PANDAR include the clinical management, tumour progression and molecular mechanisms in human cancers.

MATERIALS AND METHODS

We summarize and analyze current studies concerning the biological functions and mechanisms of lncRNA PANDA in tumour development. The related studies were obtained through a systematic search of Pubmed.

RESULTS

PANDAR was a well-characterized oncogenic lncRNA and widely overexpressed in many tumours. PANDAR is upregulated in many types of cancer, including colorectal cancer, lung cancer, renal cell carcinoma, cholangiocarcinoma, osteosarcoma, thyroid cancer and other cancers. Upregulation of PANDAR was significantly associated with advanced tumour weights, TNM stage and overall survival. Furthermore, repressed of PANDAR would restrain proliferation, migration and invasion.

CONCLUSION

PANDAR may act as a powerful tumour biomarker for cancer diagnosis and treatment.

RNA-sequencing investigation identifies an effective risk score generated by three novel lncRNAs for the survival of papillary thyroid cancer patients

Scholars are striving to apply molecular biology involving long non-coding RNA (lncRNA) in the prognostication of papillary thyroid cancer (PTC). However, the clinical role of lncRNAs in the prognostic setting of PTC is still unclear. Herein, a comprehensive inquiry was performed to screen lncRNA expression profiling with 507 PTC patients from The Cancer Genome Atlas RNA-sequencing datasets. A total of 734 lncRNAs were detected to be aberrantly expressed, among which three novel lncRNAs including AC079630.2, CRNDE and CTD-2171N6.1 were markedly related to the progression and survival of PTC. Furthermore, the aberrant expression of these lncRNAs could be verified by other cohorts from gene expression omnibus (GEO) as detected by microarrays. Next, we established a three-lncRNA signature and divided the PTC patients into two subgroups of high- and low-risk. Interestingly, patients with high-risk tended to gain obviously poorer outcome. Most importantly, this three-lncRNA signature was an independent biomarker to predict the patient survival of PTC. The accurate molecular roles of these three lncRNAs remains unclarified and warrants further characterization, but our current data propose that they might play pivotal roles in PTC tumorigenesis and more importantly, these novel lncRNAs are closely related to patients' survival. These discoveries will have far-reaching consequences with respect to molecular prediction of PTC.

Knockdown of lncRNA-PANDAR suppresses the proliferation, cell cycle and promotes apoptosis in thyroid cancer cells

Long non-coding RNAs (lncRNAs) have been found to show important regulatory roles in various human cancers. Lnc-RNA PANDAR is a novel identified lncRNA that was previously reported to show abnormal expression pattern in various cancers. However, little is known of its expression and biological function in thyroid cancer. Here, we used the quantitative real-time PCR (qRT-PCR) to determine the expression of PANDAR in 64 thyroid cancer tissues. We found that expression of PANDAR was up-regulated in thyroid cancer tissues compared with adjacent non-tumor tissues. Functional assays in vitro demonstrated that knockdown of PANDAR could inhibit proliferation, cell cycle progression, induces the apoptosis, inhibit invasion of thyroid cancer cells. Thus, our study provides evidence that PANDAR may function as a potential target for treatment for patients with thyroid cancer.