TERT, BRAF, and NRAS in Primary Thyroid Cancer and Metastatic Disease

BRAF mutation, selected miRNAs and genes expression in primary papillary thyroid carcinomas and local lymph node metastases

Mutations in cancer-related genes are now known to be accompanied by epigenetic events in carcinogenesis by modification of the regulatory pathways and expression of genes involved in the pathobiology. Such cancer-related mutations, miRNAs and gene expression may be promising molecular markers of the most common papillary thyroid carcinoma (PTC). However, there are limited data on their relationships. The aim of this study was to analyse the interactions between BRAF mutations, selected microRNAs (miR-21, miR-34a, miR-146b, and miR-9) and the expression of selected genes (LGALS3, NKX2-1, TACSTD2, TPO) involved in the pathogenesis of PTC. The study cohort included 60 primary papillary thyroid carcinomas (PTC) that were classified as classical (PTC/C; n=50) and invasive follicular variant (PTC/F; n=10), and 40 paired lymph node metastases (LNM). BRAF mutation status in primary and recurrent/persistent papillary thyroid carcinomas was determined. The mutation results were compared both between primary and metastatic cancer tissue, and between BRAF mutation status and selected genes and miRNA expression in primary PTC. Furthermore, miRNAs and gene expression were compared between primary PTCs and non-neoplastic tissue, and local lymph node metastatic tumor, respectively. All studied markers showed several significant mutual interactions and contexts. In conclusion, to the best our knowledge, this is the first integrated study of BRAF mutational status, the expression levels of mRNAs of selected genes and miRNAs in primary PTC, and paired LNM.

Predictors of treatment response in lymphogenic metastasized papillary thyroid cancer: a histopathological study

BACKGROUND

Lymph node metastases in papillary thyroid cancer (PTC) increase the risk for persistent and recurrent disease. Data on the predictive value of histopathological features of lymph node metastases, however, are inconsistent. The aim of this study was to evaluate the prognostic significance of known and new histopathological features of lymph node metastases in a well-defined cohort of PTC patients with clinically evident lymph node metastases.

METHODS

A total of 1042 lymph node metastases, derived from 129 PTC patients, were reexamined according to a predefined protocol and evaluated for diameter, extranodal extension, cystic changes, necrosis, calcifications, and the proportion of the lymph node taken up by tumor cells. Predictors for a failure to achieve a complete biochemical and structural response to treatment were determined.

RESULTS

The presence of more than 5 lymph node metastases was the only independent predictor for a failure to achieve a complete response to treatment (odds ratio [OR] 3.39 [95% CI, 1.57-7.33], P < .05). Diameter nor any of the other evaluated lymph node features were significantly associated with the response to treatment.

CONCLUSIONS

Detailed reexamination of lymph nodes revealed that only the presence of more than 5 lymph node metastases was an independent predictor of failure to achieve a complete response to treatment. No predictive value was found for other histopathological features, including the diameter of the lymph node metastases. These findings have the potential to improve risk stratification in patients with PTC and clinically evident lymph node metastases.

Comparative efficiency of differential diagnostic methods for the identification of BRAF V600E gene mutation in papillary thyroid cancer (Review)

V-Raf murine sarcoma viral oncogene homolog B1 (BRAF) encodes a serine-threonine kinase. The V600E point mutation in the BRAF gene is the most common mutation, predominantly occurring in melanoma, and colorectal, thyroid and non-small cell lung cancer. Particularly in the context of thyroid cancer research, it is routinely employed as a molecular biomarker to assist in diagnosing and predicting the prognosis of papillary thyroid cancer (PTC), and to formulate targeted therapeutic strategies. Currently, several methods are utilized in clinical settings to detect BRAF V600E mutations in patients with PTC. However, the sensitivity and specificity of various detection techniques vary significantly, resulting in diverse detection outcomes. The present review highlights the advantages and disadvantages of the methods currently employed in medical practice, with the aim of guiding clinicians and researchers in selecting the most suitable detection approach for its high sensitivity, reproducibility and potential to develop targeted therapeutic regimens for patients with BRAF gene mutation-associated PTC.

Gene mutations as predictors of central lymph mode metastasis in cN0 PTC: A meta-analysis

Gene mutations could predict the tumor progression and prognosis, which are us to predict CLNM in patients with cN0 PTC, however, these results are not consistent. This meta-analysis tried to identify gene mutations which could predict CLNM in patients with cN0 PTC. A systematic search was performed for identifying relevant literature published prior to July 2023 in three search engines: PubMed, EMBASE and Web of Science. Studies that investigated the gene mutations for CLNM in patients with cN0 PTC were included in our meta-analysis. Sixteen studies, including 6095 cN0 PTC with BRAF mutations were include in our meta-analysis. The prevalence of CLNM in cN0 PTC ranged from 13.7% to 50.6%. The pooled analysis demonstrated that BRAFV600E mutation is significantly associated with CLNM (OR = 2.01, 95% CI: 1.55-2.60, p < 0.001) in PTC and PTMC (OR = 1.70, 95% CI: 0.51-1.81, p < 0.001). Whereas, cN0 PTC with TERT (OR = 1.94, 95% CI: 0.51-7.36, p = 0.33) and KRAS (OR = 0.57, 95% CI: 0.51-1.81, p = 0.34) mutations might not contribute to predict CLNM. Our analysis identified that BRAF mutation was a predictive factor for cN0 PTC, as well as for cN0 PTMC, which could be useful for clinician to accurately choose prophylactic CLND and better manage cN0 PTC.

Comparative Cyto-Histological Genetic Profile in a Series of Differentiated Thyroid Carcinomas

INTRODUCTION

Molecular tests can contribute to improve the preoperative diagnosis of thyroid nodules. Tests available are expensive and not adapted to different populations.

AIM

This study aimed to compare the cyto-histological genetic profile and to evaluate the reliability of molecular tests using ultrasound-guided fine needle aspiration cytology (US-FNAC) in accurately diagnosing differentiated thyroid carcinomas (DTCs) and predicting biologic behavior of papillary thyroid carcinomas (PTCs).

MATERIALS AND METHODS

The series included 259 patients with paired cyto-histological samples totaling 518 samples. The genetic alterations were analyzed via PCR/Sanger sequencing. The association with clinicopathologic features was evaluated in PTCs.

RESULTS/DISCUSSION

From the 259 patients included, histologies were 50 (19.3%) benign controls and 209 (80.7%) DTC cases, from which 182 were PTCs; cytologies were 5.8% non-diagnostic, 18.2% benign, 39% indeterminate, and 37.1% malignant. In histology, indeterminate nodules (n = 101) were 22.8% benign and 77.2% malignant. Mutation frequencies in cytology and histology specimens were, respectively, TERTp: 3.7% vs. 7.9%; BRAF: 19.5% vs. 25.1%; and RAS: 11% vs. 17.5%. The overall cyto-histological agreement of the genetic mutations was 94.9%, with Cohen's k = 0.67, and in indeterminate nodules agreement was 95.7%, k = 0.64. The identified mutations exhibited a discriminative ability in diagnosing DTC with a specificity of 100% for TERTp and BRAF, and of 94% for RAS, albeit with low sensitivity. TERTp and BRAF mutations were associated with aggressive clinicopathological features and tumor progression in PTCs (p < 0.001). The obtained good cyto-histological agreement suggests that molecular analysis via US-FNAC may anticipate the genetic profile and the behavior of thyroid tumors, confirming malignancy and contributing to referring patients to surgery.

Clinical relevance of gene mutations and rearrangements in advanced differentiated thyroid cancer

BACKGROUND

Tumor genotyping is becoming crucial to optimize the clinical management of patients with advanced differentiated thyroid cancer (DTC); however, its implementation in clinical practice remains undefined. We herein report our single-center experience on molecular advanced DTC testing by next-generation sequencing approach, to better define how and when tumor genotyping can assist clinical decision making.

MATERIALS AND METHODS

We retrospectively collected data on all adult patients with advanced DTC who received molecular profiling at the IRCSS Sant'Orsola-Malpighi Hospital from 2008 to 2022. The genetic alterations were correlated with radioactive iodide refractory (RAI-R), RAI uptake/disease status, and time to RAI resistance (TTRR) development.

RESULTS

A significant correlation was found between RAI-R development and genetic alterations (P = 0.0001). About 48.7% of RAI-R cases were positive for TERT/TP53 mutations (as both a single event and comutations with other driver gene alterations, such as BRAF mutations, RAS mutations, or gene fusions), while the great majority of RAI-sensitive cases carried gene fusions (41.9%) or were wild type (WT; 41.9%). RAI uptake/disease status and time to TTRR were significantly associated with genetic alterations (P = 0.0001). In particular, DTC with TERT/TP53 mutations as a single event or as comutations displayed a shorter median TTRR of 35.4 months (range 15.0-55.8 months), in comparison to the other molecular subgroups. TERT/TP53 mutations as a single event or as comutations remained independently associated with RAI-R after Cox multivariate analysis (hazard ratio 4.14, 95% CI 1.51-11.32; P = 0.006).

CONCLUSIONS

Routine testing for genetic alterations should be included as part of the clinical workup, for identifying both the subset of more aggressive tumors and the subset of tumors harboring actionable gene fusions, thus ensuring the appropriate management for all patients with advanced DTC.

A phase I, single-center, open-label study to investigate the absorption, distribution, metabolism and excretion of encorafenib following a single oral dose of 100 mg [14 C] encorafenib in healthy male subjects

Encorafenib is a novel kinase inhibitor of BRAF V600E as well as wild-type BRAF and CRAF and has received approval, in combination with binimetinib, to treat BRAF V600E or V600K mutation-positive unresectable or metastatic melanoma or in combination with cetuximab to treat BRAF V600E mutation-positive colorectal cancer. The absorption, distribution, metabolism and excretion (ADME) of encorafenib was studied by administering [14 C] encorafenib (100 mg containing 90 μCi of radiolabeled material) to 4 healthy male subjects (NCT01436656). Following a single oral 100-mg dose of [14 C] encorafenib to healthy male subjects, the overall recovery of radioactivity in the excreta was ≥93.9% in all four subjects, indicating that good mass balance was achieved. An equal mean of 47.2% for the radioactivity dose was eliminated in the feces and urine. The percentage of the dose eliminated in the feces (5.0%) and urine (1.8%) as unchanged encorafenib was minor. Metabolism was found to be the major clearance pathway (~88% of the recovered radioactive dose) for encorafenib in humans and is predominantly mediated through N-dealkylation of the isopropyl carbamic acid methyl ester to form the primary phase 1 direct metabolite M42.5 (LHY746). Oral absorption was estimated from the radioactive dose recovered in the urine (47.2%) and the total radioactive dose recovered in the feces as metabolites (39%). Based on these values and the assumptions that encorafenib and its metabolites are stable in feces, the fraction of oral absorption was estimated to be at least ~86%.

The Role of Genetic Polymorphisms in Differentiated Thyroid Cancer: A 2023 Update

Thyroid cancer is the most common endocrine malignancy, with an increasing trend in the past decades. It has a variety of different histological subtypes, the most frequent one being differentiated thyroid cancer, which refers to papillary carcinoma, the most common histological type, followed by follicular carcinoma. Associations between genetic polymorphisms and thyroid cancer have been investigated over the years and are an intriguing topic for the scientific world. To date, the results of associations of single nucleotide polymorphisms, the most common genetic variations in the genome, with thyroid cancer have been inconsistent, but many promising results could potentially influence future research toward developing new targeted therapies and new prognostic biomarkers, thus consolidating a more personalized management for these patients. This review focuses on emphasizing the existing literature data regarding genetic polymorphisms investigated for their potential association with differentiated thyroid cancer and highlights the opportunity of using genetic variations as biomarkers of diagnosis and prognosis for thyroid cancer patients.

Papillary thyroid carcinoma with desmoid-type fibromatosis: the clinicopathological features with characteristic imaging and molecular correlation requiring comprehensive treatment

The pathogenesis and treatment of papillary thyroid cancer with desmoid-type fibromatosis (PTC-DTF), a rare subtype of papillary thyroid carcinoma characterized by a mixed epithelial-mesenchymal structure, are still ill-defined. Previous reports on PTC-DTF have had limited follow-up and recurrence has been rarely reported. To better understand this condition, we conducted a thorough analysis of five cases of PTC-DTF from our institute, including clinical and pathological examinations, imaging, immunohistochemistry, and molecular analysis. We also reviewed relevant literature. The mean age of the patients was 51.8 years, with three women and two men included in the group. Ultrasound often showed a hypoechogenic and well-defined nodule in the thyroid gland, except for one individual who had distant lung metastases detected by PET-CT. The nodules ranged in width from 0.5 to 5.0 cm and were excised in each case. Following surgery, ¹³¹I therapy was used in two cases. The overall number of PTC-DTF cases has risen from the previously reported 55 to 60, with females being the most commonly affected and ranging in age from 19 to 82. Most masses underwent a thyroidectomy, and approximately half of the patients had lymph node metastases. Histologically, PTC-DTFs were composed of a predominant stromal component (65% - 90%) and an intervening epithelial component. These spindle cells were arranged in parallel with abundant cytoplasm and vacuole-like nucleus but there wasn't evident atypia. The carcinoma cells were positively stained for CK and TTF-1 by immunohistochemistry, whereas mesenchymal cells were positive for SMA and displayed nuclear immunoreactivity for β-catenin. BRAF, NRAS, and CTNNB1 mutations were identified in the epithelial and mesenchymal components through molecular testing, respectively. Perhaps because the mesenchyme harbors aberrant nuclear β-catenin expression, PTC-DTF is more aggressive and prone to invasion and distant recurrence, as shown by our case 2, which is the first case to be reported thus far. PTC-DTF is typically treated with surgery, but clinicians may occasionally consider more holistic treatment plans that involve radioactive iodine and endocrine therapy.

Non-invasive follicular thyroid neoplasm with papillary-like nuclear feature: clinical, pathological, and molecular update 5 years after the nomenclature revision

The term non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was proposed in 2016 and incorporated as a new entity in the World Health Organization (WHO) classification of tumours of endocrine organs in 2017. Since then, there has been debate regarding the histological criteria for the diagnosis, the need for molecular studies or the risk of lymph node metastasis or recurrence associated with this entity. Over the years, the concept of NIFTP evolved, now including both small (<1 cm) and large (>4 cm) tumours and oncocytic lesions. On the other hand, recent data on NIFTP in the setting of thyroid follicular nodular disease or frequent coexistence of malignant tumours raised concerns regarding the follow-up of these patients. Today, both pathologists and clinicians still face several challenges in the diagnosis, treatment, and follow-up of patients with NIFTP.

Thyroglobulin expression, Ki-67 index, and lymph node ratio in the prognostic assessment of papillary thyroid cancer

The clinical significance of thyroglobulin (Tg) expression in papillary thyroid cancer (PTC) has not been systematically explored in relation to the Ki-67 index, lymph node ratio (LNR), or other conventional prognostic predictors. In this retrospective study of 327 patients with PTC, we investigated the immunohistochemical expression of Tg in both primary tumors and their matching lymph node metastases in relation to the Ki-67 index, LNR, and clinical data. Tumoral Tg immunoreactivity was inversely correlated to the Ki-67 index and tumor recurrence. The Ki-67 index was higher in lymph node metastases (mean 4%) than in the primary tumors (mean 3%). Reduced Tg expression, estimated as 0-25% Tg positive tumor cells, was more common in lymph node metastases compared to primary tumors. In addition to advanced metastatic burden (defined as N1b stage and LNR ≥ 21%), low Tg expression (0-25% positive tumor cells) in lymph node metastases had a significant prognostic impact with shorter recurrence-free survival. These findings support the potential value of histopathological assessment of Tg expression and Ki-67 index in lymph node metastases as complementary predictors to anticipate the prognosis of PTC patients better.

Genetic and clinical profiles of 160 papillary thyroid cancers with lateral neck lymph node metastasis

Background

Lymph node metastasis is widespread in papillary thyroid cancer (PTC). Patients are more vulnerable than those with central lymph node metastasis if they have lateral neck lymph node metastasis (LLNM). There are few researches focus on the correlation between clinical characteristics and genetic profile of PTC with LLNM. In this study, we aimed to analyze the clinical and genetic features of PTC with LLNM.

Methods

A total of 160 primary tumor samples derived from PTC patients with LLNM were involved. Targeted next-generation sequencing was carried out on all samples with 57 known thyroid-cancer-related genes. The associations between genomic alternations and clinical characteristics of PTC with LLNM were statistically evaluated.

Results

The median age of patients was 37 years, ranging from 5 to 77 years and the female/male ratio was 1.86. The most frequently altered genes in our series were BRAF mutation (68%), followed by RET fusion (17%), TERT promoter mutation (5%) and PIK3CA mutation (2%). To be noted, all PTC patients with LLNM of TERT promoter mutations appeared along with BRAF mutations (8/8) and half of them experienced a relapse. Intriguingly, we found more metastatic lymph nodes in patients with RET fusion, but there was no statistically significant difference in metastatic lymph node ratio than those with BRAF mutation or without mutation. A high rate of gene fusion (70%) was found in the pediatric population, with aggressive late-onset disease.

Conclusions

PTC patients with LLNM is characterized by a high rate of BRAF mutation. Due to the observed clinicopathological differences in those patients among different alterations, further prospective studies are needed to verify our results and to evaluate the most suitable treatment strategies.

A clinical and molecular pathology prediction model for central lymph node metastasis in cN0 papillary thyroid microcarcinoma

BACKGROUND

The frequency of thyroid cancer has rapidly increased in recent years globally. Thus, more papillary thyroid microcarcinoma (PTMC) patients are being diagnosed, including clinical lymph node-negative (cN0) patients. Our study attempted to develop a prediction model for assessing the probability of central lymph node metastasis (CLNM) in cN0 PTMC patients.

METHODS

A total of 595 patients from the Affiliated Hospital of Qingdao University (training cohort: 456 patients) and the Affiliated Hospital of Jining Medical University (verification cohort: 139 patients) who underwent thyroid surgery between January 2020 and May 2022 were enrolled in this study. Their clinical and molecular pathology data were analyzed with multivariate logistic regression to identify independent factors, and then we established a prediction model to assess the risk of CLNM in cN0 PTMC patients.

RESULTS

Multivariate logistic regression analysis revealed that sex, Hashimoto's thyroiditis (HT), tumor size, extrathyroidal extension, TERT promoter mutations and NRAS mutation were independent factors of CLNM. The prediction model demonstrated good discrimination ability (C-index: 0.757 and 0.753 in the derivation and validation cohorts, respectively). The calibration curve of the model was near the optimum diagonal line, and decision curve analysis (DCA) showed a noticeably better benefit.

CONCLUSION

CLNM in cN0 PTMC patients is associated with male sex, tumor size, extrathyroidal extension, HT, TERT promoter mutations and NRAS mutation. The prediction model exhibits good discrimination, calibration and clinical usefulness. This model will help to assess CLNM risk and make clinical decisions in cN0 PTMC patients.

Benign Neurofibroma/Schwannoma Hybrid Peripheral Nerve Sheath Tumor of the Ulnar Nerve Harboring a Metastatic Papillary Thyroid Carcinoma Deposit: A Case Report of Tumor-to-Tumor Metastasis

A 74-year-old man with a medical history significant for papillary thyroid cancer (PTC) presented with a rapidly enlarging grape-sized mass in his right medial arm with paresthesia in the ulnar nerve distribution. Imaging was suspicious for a peripheral nerve sheath tumor (PNST), but an ultrasound-guided biopsy was equivocal. The mass was excised with final histopathology demonstrating a benign neurofibroma/schwannoma hybrid nerve sheath tumor (N/S HNST) harboring a metastatic PTC deposit, ultimately mimicking the rare glandular schwannoma subtype. Next-generation sequencing (NGS) of the lesion demonstrated somatic variants in BRAF and TERT (common in PTC) and NF2 (common in PNSTs). After excision, the patient's nerve symptoms improved. A postsurgical PET/CT scan also showed progression in the lungs/mediastinum. Due to the metastatic nature of his PTC, he was treated with 14 mg of Lenvima (lenvatinib) daily, and his PET/CT surveillance was performed at more frequent intervals. Tumor-to-tumor metastasis (TTM) is a rare occurrence. To our knowledge, this is the first case reported on PTC metastasizing into a benign (hybrid) PNST, which mimicked glandular schwannoma. Symptomatology, imaging characteristics, NGS, and histopathological characteristics that can decipher between different benign PNST subtypes (schwannoma, neurofibroma, glandular, hybrid, etc.), malignant PNSTs (MPNSTs), and TTM are described.

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.

Enhancing Radioiodine Incorporation into Radioiodine-Refractory Thyroid Cancer with MAPK Inhibition (ERRITI): A Single-Center Prospective Two-Arm Study

PURPOSE

Restoration of iodine incorporation (redifferentiation) by MAPK inhibition was achieved in previously radioiodine-refractory, unresectable thyroid carcinoma (RR-TC). However, results were unsatisfactory in BRAFV600E-mutant (BRAF-MUT) RR-TC. Here we assess safety and efficacy of redifferentiation therapy through genotype-guided MAPK-modulation in patients with BRAF-MUT or wildtype (BRAF-WT) RR-TC.

PATIENTS AND METHODS

In this prospective single-center, two-arm phase II study, patients received trametinib (BRAF-WT) or trametinib + dabrafenib (BRAF-MUT) for 21 ± 3 days. Redifferentiation was assessed by 123I-scintigraphy. In case of restored radioiodine uptake, 124I-guided 131I therapy was performed. Primary endpoint was the redifferentiation rate. Secondary endpoints were treatment response (thyroglobulin, RECIST 1.1) and safety. Parameters predicting successful redifferentiation were assessed using a receiver operating characteristic analysis and Youden J statistic.

RESULTS

Redifferentiation was achieved in 7 of 20 (35%) patients, 2 of 6 (33%) in the BRAF-MUT and 5 of 14 (36%) in the BRAF-WT arm. Patients received a mean (range) activity of 300.0 (273.0-421.6) mCi for 131I therapy. Any thyroglobulin decline was seen in 57% (4/7) of the patients, RECIST 1.1 stable/partial response/progressive disease in 71% (5/7)/14% (1/7)/14% (1/7). Peak standardized uptake value (SUVpeak) < 10 on 2[18F]fluoro-2-deoxy-D-glucose (FDG)-PET was associated with successful redifferentiation (P = 0.01). Transient pyrexia (grade 3) and rash (grade 4) were noted in one patient each.

CONCLUSIONS

Genotype-guided MAPK inhibition was safe and resulted in successful redifferentiation in about one third of patients in each arm. Subsequent 131I therapy led to a thyroglobulin (Tg) decline in more than half of the treated patients. Low tumor glycolytic rate as assessed by FDG-PET is predictive of redifferentiation success. See related commentary by Cabanillas et al., p. 4164.

Bone metastases in newly diagnosed patients with thyroid cancer: A large population-based cohort study

Background

Population-based estimates of the incidence and prognosis of bone metastases (BM) stratified by histologic subtype at diagnosis of thyroid cancer are limited.

Methods

Using multivariable logistic and Cox regression analyses, we identified risk factors for BM and investigated the prognostic survival of BM patients between 2010 and 2015 via the Surveillance, Epidemiology, and End Results (SEER) database.

Results

Among 64,083 eligible patients, a total of 347 patients with BM at the time of diagnosis were identified, representing 0.5% of the entire cohort but 32.4% of the subset with metastases. BM incidence was highest (11.6%) in anaplastic thyroid cancer (ATC), which, nevertheless, was highest (61.5%) in follicular thyroid cancer (FTC) among the subset with metastases. The median overall survival among BM patients was 40.0 months, and 1-, 3-, and 5-year survival rates were 65.2%, 51.3%, and 38.7%, respectively. Compared with papillary thyroid cancer (PTC), FTC (aOR, 6.33; 95% CI, 4.72–8.48), medullary thyroid cancer (MTC) (aOR, 6.04, 95% CI, 4.09–8.92), and ATC (aOR, 6.21; 95% CI, 4.20–9.18) significantly increased the risk of developing BM. However, only ATC (aHR, 6.07; 95% CI, 3.83–9.60) was independently associated with worse survival in multivariable analysis. Additionally, patients with BM alone (56.5%) displayed the longest median survival (66.0 months), compared with those complicated with one extraskeletal metastatic site (lung, brain, or liver) (35.2%; 14.0 months) and two or three sites (8.3%; 6.0 months). The former 5-year overall survival rate was 52.6%, which, however, drastically declined to 23.0% in patients with one extraskeletal metastatic site and 9.1% with two or three sites.

Conclusion

Closer bone surveillance should be required for patients with FTC, MTC, and ATC, and extraskeletal metastases at initial diagnosis frequently predict a poorer prognosis.

Mitochondrial Respiration Inhibition Suppresses Papillary Thyroid Carcinoma Via PI3K/Akt/FoxO1/Cyclin D1 Pathway

Background

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, but little is known regarding PTC metabolic phenotypes and the effects of mitochondrial activity on PTC progression. The great potential of mitochondria-targeting therapy in cancer treatment promoted us to use tool compounds from a family of Mito-Fu derivatives to investigate how the regulation of mitochondrial respiration affected tumor progression characteristics and molecular changes in PTC.

Methods

Mito-Fu L20, a representative of 12 synthetic derivatives, was chosen for mitochondrial inhibition experiments. Sample sections from PTC patients were collected and processed to explore potential molecular alterations in tumor lymph node metastasis (LNM). In vitro analyses were performed using human PTC cell lines (K1 and TPC-1), with the human normal thyroid follicular cell line (Nthy) as a control. K1 cells were injected into nude mice to generate an animal model. The mice were injected with normal saline or Mito-Fu L20 at 20 or 50 mg/kg every other day; their body weights and tumor volumes were also measured over time. To elucidate the resulting metabolic phenotype, we measured oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), cellular adenosine triphosphate (ATP) levels and reactive oxygen species (ROS) production, and mitochondrial membrane potential. Wound healing and Transwell assays, cell cycle assays, real-time fluorescence quantitative PCR, Western blotting, and immunohistochemical staining were performed to explore glycolysis-dominant metabolism in PTC.

Results

Cyclin D1 and mitochondrial complex IV were detected in tumor samples from PTC patients with LNM. Mito-Fu L20 showed dose-independent and reversible modulation of mitochondrial respiration in PTC. In addition to mitochondrial dysfunction and early apoptosis, G1/S phase arrest. Notably, reversible mitochondrial inhibition yielded durable suppression of tumor proliferation, migration, and invasion via the PI3K/Akt/FoxO1/Cyclin D1 pathway. In vivo experiments demonstrated that Mito-Fu L20 has a good safety profile and specific restorative effect on mitochondrial activity in the liver. In addition, Mito-Fu L20 showed antitumor effects, alleviated tumor angiogenesis, and improved thyroid function.

Conclusion

Reversible inhibition of ATP production and durable suppression of PTC growth indicates that the downregulation of mitochondrial function has a negative impact on tumor progression and LNM via the PI3K/Akt/FoxO1/Cyclin D1 pathway. The results provide new insights into the antitumor potential and clinical translation of mitochondrial inhibitors.

Bioinformatic Analysis of the Effect of the Sirtuin Family on Differentiated Thyroid Carcinoma

A growing body of experimental evidence suggests that sirtuins (SIRTs) are associated with tumorigenesis in differentiated thyroid cancer (DTC). Nevertheless, the involvement of SIRTs in the pathogenesis of DTC and their clinical value remain ill-defined and should be thoroughly examined. We explored the transcription of SIRTs and survival data of patients with DTC by the systematic utilization of bioinformatics to analyze data of publicly accessible databases including Oncomine, cBioPortal, Kaplan-Meier Plotter, Gene Expression Profiling Interactive Analysis (GEPIA), Protein Atlas, LinkedOmics, and GSCALite. The examination of gene expression profiles showed that SIRT2, SIRT3, SIRT4, SIRT5, and SIRT6 were downregulated in DTC tissues compared with the normal thyroid tissues. The decreased expression levels of SIRT2, SIRT4, and SIRT5 were correlated with advanced tumor stages. The survival results showed that the increased SIRT4 mRNA expression level was associated with improved overall survival (OS) in the DTC patients. In addition, patients with DTC with high SIRT2, SIRT3, SIRT4, and SIRT5 mRNA levels had higher disease-free survival (DFS). These results showed that SIRT2, SIRT3, SIRT4, SIRT5, and SIRT6 are potential targets for precise treatment of DTC patients and that SIRT2, SIRT3, SIRT4, and SIRT5 are novel potential biomarkers for the prognosis of DTC.

The Multifaceted Profile of Thyroid Disease in the Background of DICER1 Germline and Somatic Mutations: Then, Now and Future Perspectives

DICER1 protein is a member of the ribonuclease (RNAse) III family with a key role in the biogenesis of microRNAs (miRNA) and in microRNA processing, potentially affecting gene regulation at the post-transcriptional level. The role of DICER1 and its relevance to thyroid cellular processes and tumorigenesis have only recently been explored, following the acknowledgement that DICER1 germline and somatic changes can contribute not only to non-toxic multinodule goiter (MNG) lesions detected in individuals of affected families but also to a series of childhood tumours, including thyroid neoplasms, which can be identified from early infancy up until the decade of 40s. In a context of DICER1 germline gene mutation, thyroid lesions have recently been given importance, and they may represent either an index event within a syndromic context or the isolated event that may trigger a deeper and broader genomic analysis screening of individuals and their relatives, thereby preventing the consequences of a late diagnosis of malignancy. Within the syndromic context MNG is typically the most observed lesion. On the other hand, in a DICER1 somatic mutation context, malignant tumours are more common. In this review we describe the role of DICER protein, the genomic events that affect the DICER1 gene and their link to tumorigenesis as well as the frequency and pattern of benign and malignant thyroid lesions and the regulation of DICER1 within the thyroidal environment.

A Clinical Predictive Model of Central Lymph Node Metastases in Papillary Thyroid Carcinoma

BACKGROUND

Thyroid carcinoma is one of the most common endocrine tumors, and papillary thyroid carcinoma (PTC) is the most common pathological type. Current studies have reported that PTC has a strong propensity for central lymph node metastases (CLNMs). Whether to prophylactically dissect the central lymph nodes in PTC remains controversial. This study aimed to explore the risk factors and develop a predictive model of CLNM in PTC.

METHODS

A total of 2,554 patients were enrolled in this study. The basic information, laboratory examination, characteristics of cervical ultrasound, genetic test, and pathological diagnosis were collected. The collected data were analyzed by univariate logistic analysis and multivariate logistic analysis. The risk factors were evaluated, and the predictive model was constructed of CLNM.

RESULTS

The multivariate logistic analysis showed that Age (p < 0.001), Gender (p < 0.001), Multifocality (p < 0.001), BRAF (p = 0.027), and Tumor size (p < 0.001) were associated with CLNM. The receiver operating characteristic curve (ROC curve) showed high efficiency with an area under the ROC (AUC) of 0.781 in the training group. The calibration curve and the calibration of the model were evaluated. The decision curve analysis (DCA) for the nomogram showed that the nomogram can provide benefits in this study.

CONCLUSION

The predictive model of CLNM constructed and visualized based on the evaluated risk factors was confirmed to be a practical and convenient tool for clinicians to predict the CLNM in PTC.

Positive BRAFV600E mutation of primary tumor influences radioiodine avidity but not prognosis of papillary thyroid cancer with lung metastases

PURPOSE

This study investigated the relationship between BRAFV600E mutation of the primary tumor and radioiodine avidity in lung metastases (LMs) and then further evaluated the impact of BRAFV600E mutation and radioiodine avidity status on the prognosis of papillary thyroid cancer (PTC) with LMs.

METHODS

Ninety-four PTC patients with LMs after total thyroidectomy and cervical lymph node dissection between January 2012 and September 2021 were retrospectively included. All patients received BRAFV600E mutation examination of primary tumors and radioactive iodine (RAI) therapy. The therapeutic response was evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) assessments (version 1.1). For patients with target lesions, the response was divided into complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD); for patients without target lesions, the response was divided into CR, non-CR/non-PD, and PD. In therapeutic response, PR and SD were classified as non-CR/non-PD for analysis. The chi-square test and logistic regression were used to analyze the impact factor on PD and mortality. Progression-free survival (PFS) and overall survival (OS) curves were constructed by the Kaplan-Meier method.

RESULTS

It was found that 21.2% (7/33) of patients with positive BRAFV600E mutation and 62.3% (38/61) of patients with negative BRAFV600E mutation had radioiodine-avid LMs (χ² = 14.484, p = 0.000). Patients with positive BRAFV600E mutation are more likely to lose radioiodine avidity; the odds ratios (ORs) were 5.323 (95% CI: 1.953-14.514, p = 0.001). Finally, 25 patients had PD, and six patients died; loss of radioiodine avidity was the independent predictor for PD, and the ORs were 10.207 (95% CI: 2.629-39.643, p = 0.001); BRAFV600E mutation status was not correlated with PD (p = 0.602), whether in the radioiodine avidity group (p = 1.000) or the non-radioiodine avidity group (p = 0.867). Similarly, BRAFV600E mutation status was not correlated with mortality; only loss of radioiodine avidity was the unfavorable factor associated with mortality in univariate analyses (p = 0.030).

CONCLUSION

Patients with LMs of PTC were more likely to lose radioiodine avidity when their primary tumor had positive BRAFV600E mutation; however, only radioiodine avidity and not BRAFV600E mutation status affected the clinical outcome of patients with lung metastatic PTC.

TERT Promoter Mutations Are an Independent Predictor of Distant Metastasis in Middle Eastern Papillary Thyroid Microcarcinoma

BACKGROUND

Papillary thyroid microcarcinomas (PTMCs) have been attributed to the recent increased incidence of thyroid cancer. Although indolent, a subset of PTMC could potentially develop distant metastasis (DM). This study aimed to evaluate the clinico-pathological features and molecular characteristics of PTMC and identify the risk factors for DM in PTMC patients from Middle Eastern ethnicity.

METHODS

We retrospectively analyzed 210 patients with histologically confirmed PTMC. Clinico-pathological associations for DM, BRAF mutation and TERT mutation were analyzed successfully in 184 patients. Multivariate analysis was performed using Cox proportional hazards model and logistic regression analysis.

RESULTS

Among the PTMC patients included in this cohort, DM was noted in 6.0% (11/184), whereas tumor relapse occurred in 29/184 (15.8%). Of the 11 cases with DM, lung metastasis occurred in 8 cases, bone metastasis in 2 cases and brain metastasis in 1 case. Presence of extrathyroidal extension and male sex were significantly associated with DM. Molecular analysis showed BRAF V600E mutations to be the most frequent, being detected in 45.7% (84/184). TERT promoter mutations were detected in 16 (8.7%) cases and were significantly associated with DM and shorter metastasis-free survival in multivariate analysis.

CONCLUSIONS

Our study indicates a surprisingly high frequency of TERT promoter mutation in Saudi patients with PTMC. Identifying TERT promoter mutations as an independent predictor of DM in patients with microcarcinoma could explain the inherent aggressive nature of PTMC from Middle Eastern ethnicity and magnify its role in patient risk stratification, which might help in improving therapeutic strategy for these patients.

Metabolic Reprogramming of Thyroid Cancer Cells and Crosstalk in Their Microenvironment

Metabolism differs significantly between tumor and normal cells. Metabolic reprogramming in cancer cells and metabolic interplay in the tumor microenvironment (TME) are important for tumor formation and progression. Tumor cells show changes in both catabolism and anabolism. Altered aerobic glycolysis, known as the Warburg effect, is a well-recognized characteristic of tumor cell energy metabolism. Compared with normal cells, tumor cells consume more glucose and glutamine. The enhanced anabolism in tumor cells includes de novo lipid synthesis as well as protein and nucleic acid synthesis. Although these forms of energy supply are uneconomical, they are required for the functioning of cancer cells, including those in thyroid cancer (TC). Increasing attention has recently focused on alterations of the TME. Understanding the metabolic changes governing the intricate relationship between TC cells and the TME may provide novel ideas for the treatment of TC.

BRAFV600E mutation test on fine-needle aspiration specimens of thyroid nodules: Clinical correlations for 4600 patients

Background

The BRAF^V600E mutation is valuable for the diagnosis, prognosis, and therapy of papillary thyroid cancer (PTC). However, studies related to this mutation have involved only a small number of patients. Therefore, we performed a large‐scale analysis from a single institute to evaluate the accuracy of combined fine‐needle aspiration (FNA) and BRAF^V600E mutation tests for PTC diagnosis.

Methods

A total of 4600 patients with thyroid nodules who underwent both FNA cytology and BRAF^V600E mutation analysis on FNA specimens were enrolled. The association between the BRAF^V600E mutation and clinicopathological features was analyzed. A separate analysis was performed for the 311 patients who underwent repeated FNA for comparison of cytological evaluation and BRAF^V600E mutation results. The diagnostic efficacy of the BRAF^V600E mutation test and cytologic diagnoses was evaluated for 516 patients who underwent preoperative FNA tests in comparison with conclusive postoperative histopathologic results.

Results

The cytology results of all 4600 FNA samples were categorized according to The Bethesda System for Reporting Thyroid Cytology (TBSRTC) stages I–VI, which accounted for 11.76%, 60.02%, 6.46%, 3.61%, 6.71%, and 11.43% of the samples, respectively. The BRAF^V600E mutation was detected in 762 (16.57%) FNA samples, with rates of 1.48%, 0.87%, 20.20%, 3.01%, 66.02%, and 87.81% for TBSRTC I–VI lesions, respectively. Among the 311 repeat FNA cases, 81.0% of the BRAF^V600E‐positive and 4.3% of the BRAF^V600E‐negative specimens with an initial indication of cytological non‐malignancy were ultimately diagnosed as malignant by repeat FNA (p < 0.001). Among the 516 patients who underwent thyroidectomy, the sensitivity and specificity of the BRAF^V600E mutation test alone for PTC diagnosis were 76.71% and 100.0%, respectively, which increased to 96.62% and 88.03%, respectively, when combining the BRAF^V600E mutation test with cytology. BRAF^V600E mutation was significantly associated with lymph node metastasis (p < 0.001), but not with age, gender, or tumor size.

Conclusions

The BRAF^V600E mutation test in FNA samples has potential to reduce false negatives in PTC diagnosis, and therefore plays an important role in the diagnosis of thyroid nodules, especially those with an indeterminate or nondiagnostic cytology, which should be considered for repeat FNA.

Targeted Therapy of Papillary Thyroid Cancer: A Comprehensive Genomic Analysis

Background

A limited number of targeted therapy options exist for papillary thyroid cancer (PTC) to date. Based on genetic alterations reported by the "The Cancer Genome Atlas (TCGA)", we explored whether PTC shows alterations that may be targetable by drugs approved by the FDA for other solid cancers.

Methods

Databases of the National Cancer Institute and MyCancerGenome were screened to identify FDA-approved drugs for targeted therapy. Target genes were identified using Drugbank. Genetic alterations were classified into conferring drug sensitivity or resistance using MyCancerGenome, CiViC, TARGET, and OncoKB. Genomic data for PTC were extracted from TCGA and mined for alterations predicting drug response.

Results

A total of 129 FDA-approved drugs with 128 targetable genes were identified. One hundred ninety-six (70%) of 282 classic, 21 (25%) of 84 follicular, and all 30 tall-cell variant PTCs harbored druggable alterations: 259 occurred in 29, 39 in 19, and 31 in 2 targetable genes, respectively. The BRAF V600 mutation was seen in 68% of classic, 16% of follicular variant, and 93% of tall-cell variant PTCs. The RET gene fusion was seen in 8% of classic PTCs, NTRK1 and 3 gene fusions in 3%, and other alterations in <2% of classic variant PTCs. Ninety-nine of 128 (77%) FDA-approved targetable genes did not show any genetic alteration in PTC. Beside selective and non-selective BRAF-inhibitors, no other FDA-approved drug showed any frequent predicted drug sensitivity (<10%).

Conclusion

Treatment strategies need to focus on resistance mechanisms to BRAF inhibition and on genetic alteration-independent alternatives rather than on current targeted drugs.

TERT Promoter Mutational Status in the Management of Cutaneous Melanoma: Comparison with Sentinel Lymph Node Biopsy

BACKGROUND

While BRAF mutations seem important for early melanomagenesis, mutations in the TERT promoter (TERTp) are related to metastasis. Yet, in conventional melanoma management, risk stratification does not depend on molecular biomarkers that can indicate the stage of progression, but rather on clinical, pathological, sentinel lymph node (SLN), and radiologic evaluation. The aim of this work was to evaluate the frequency and prognostic impact of TERTp mutations, comparing their predictive value to those of conventional procedures in melanoma management.

METHODS

Mutational analysis of a series of 91 cases was performed. The correlations between TERTp and BRAF mutational status and clinicopathological features were assessed.

RESULTS

The mutation rate was 33% for TERTp and 30% for BRAF. There was 68% concordance between primary and metastatic samples for TERTp mutations and 92% for BRAF mutations. TERTp mutations are significantly associated with the presence of BRAF mutations, features of worse prognosis, and a reduced disease-free survival. Also, TERTp mutational status was similar to SLN biopsy as a predictive factor of cutaneous melanoma recurrence and metastasis.

CONCLUSIONS

The predictive value of TERTp mutations may be similar to that of SLN biopsy and its integration in the management algorithm of melanoma patients should be considered.

S616-p-DRP1 associates with locally invasive behavior of follicular cell-derived thyroid carcinoma

PURPOSE

Dynamin-related protein 1 (DRP1), a mitochondrial fission protein, and its active form phosphorylated at Serine 616 (S616-p-DRP1) have been increasingly associated with tumorigenesis and invasion in various tumor models, including oncocytic thyroid cancer (TC). In this study, the expression of DRP1 and S616-p-DRP1 and its relationship with patients' clinicopathological characteristics, tumor genetic profiles, and clinical outcomes were assessed in a large series of follicular cell-derived TC (FCDTC).

METHODS

Retrospective biomarker study characterizing the clinicopathological and immunochemistry DRP1 and S616-p-DRP1 expression of a series of 259 patients with FCDTC followed in two University Hospitals.

RESULTS

DRP1 expression was positive in 65.3% (169/259) of the cases, while the expression of the S616-p-DRP1 was positive in only 17.3% (17/98). DRP1-positive expression was significantly associated with differentiated tumors (67.7 vs. 48.0%; P = 0.049), non-encapsulated tumors (73.8 vs. 57.4%; P = 0.011) and thyroid capsule invasion (73.4 vs. 57.5%; P = 0.013). S616-p-DRP1-positive expression was significantly associated with tumor infiltrative margins (88.9 vs. 11.1%; P = 0.033), thyroid capsule invasion (29.8 vs. 3.1%; P = 0.043), lymph node metastases (23.3 vs. 8.1%; P = 0.012), and higher mean cumulative radioiodine dosage (317.4 ± 265.0 mCi vs. 202.5 ± 217.7 mCi; P = 0.038). S616-p-DRP1 expression was negatively associated with oncocytic phenotype (0.0 vs. 26.2%; P = 0.028).

CONCLUSIONS

S616-p-DRP1 is a better candidate than DRP1 to identify tumors with locally invasive behavior. Prospective studies should be pursued to assess S616-p-DRP1 role as a molecular marker of malignancy in TC and in patients' risk assessment.

Large contribution of copy number alterations in early stage of Papillary Thyroid Carcinoma

Papillary Thyroid Carcinoma (PTC) accounts for approximately 85% of patients with thyroid cancer. Despite its indolent nature, progression to higher stages is expected in a subgroup of patients. Hence, genomic characterization of the early stages of PTC may help to identify this subgroup, leading to better clinical management. Here, we conducted a comprehensive mutational and somatic copy number alteration (SCNA) investigation on 277 stage one PTC from TCGA. SCNA analysis revealed amplification and deletion of several cancer related genes. We found amplification of 60 oncogenes (Oncs), from which 15 were recurrently observed. Deletion of 58 tumor suppressors (TSs) was also detected. MAPK, PI3K-Akt, Rap1 and Ras were the signaling pathways with large numbers of amplified Oncs. On the other hand, deleted TSs belonged mostly to cell cycle, PI3K-Akt, mTOR and cellular senescence pathways. This suggests that despite heterogeneity in SCNA events, the final results would be the activation/deactivation of a few cancer signaling pathways. Of note, despite large amounts of heterogeneity in stage one PTC, recurrent broad deletion on Chr22 was detected in 21 individuals, leading to deletion of several tumor suppressors. In parallel, the oncogenic/pathogenic mutations in the RTK-RAS and PI3k-Akt pathways were detected. However, no pathogenic mutation was identified in known tumor suppressor genes. In order to identify a potential subgroup of BRAF (V600E) positive patients, who might progress to higher stages, low frequency mutations accompanying BRAF (V600E) were also identified. In conclusion, our findings imply that SCNA have a substantial contribution to early stages of PTC. Experimental validation of the observed genomic alterations could help to stratify patients at the time of diagnosis, and to move toward precision medicine in PTC.

How limited molecular testing can also offer diagnostic and prognostic evaluation of thyroid nodules processed with liquid-based cytology: Role of TERT promoter and BRAF V600E mutation analysis

BACKGROUND

Mutational analysis contributes to the diagnosis and prognosis of thyroid nodules analyzed with fine-needle aspiration cytology (FNAC). Although several advanced molecular tests based on multiple molecular markers are available for clinical use and have increased their impact on clinical management of patients, they are not widely available. Among them is BRAF V600E, one of the most studied mutations. Other genetic alterations, such as TERT promoter mutations, may coexist in thyroid carcinomas. Previous studies have demonstrated that this duet might be involved in the aggressiveness of thyroid cancer, although its prognostic value related to mortality remains undefined. The detection of such genetic alterations in thyroid liquid-based cytology (LBC) thus may assist with patient management.

METHODS

From January 2013 to June 2014, 356 thyroid FNAC samples were processed by LBC, including 174 surgical follow-up samples. BRAF V600E and TERT mutation analyses were performed on both LBC and histopathology.

RESULTS

The study included 119 samples categorized as atypia of undetermined significance, 42 categorized as follicular neoplasms, 61 categorized as suspicious for malignancy, and 34 categorized as positive for malignancy. BRAF V600E mutation was detected in 10.4% of all cases, whereas TERT promoter mutations were identified in 1.1%. TERT-mutated cases belonged to the positive for malignancy category, with a histologic diagnosis of tall cell variant of papillary thyroid carcinoma. These genetic alterations correlated with lymph node metastases (P = .0349) and higher disease stage.

CONCLUSIONS

BRAF V600E and TERT analysis can be performed on LBC. TERT mutations are rarely identified in well differentiated thyroid carcinoma but are associated with higher stage. Although a larger molecular panel may offer more information, analyzing these few point mutations is still likely to be useful for managing potentially more aggressive thyroid carcinomas.

High expression of spermatogenesis associated serine rich 2 promotes tumorigenicity in esophageal squamous cell carcinoma cells and is associated with poor patient prognosis

Spermatogenesis associated serine rich 2 (SPATS2), recognized as a cytoplasmic RNA-binding protein, is implicated in the tumorgenicity of several cancers. However, the potential role of SPATS2 in esophageal squamous cell carcinoma (ESCC) is yet to be elucidated. The present study aimed to explore the functional implication of SPATS2 in ESCC. The ESCC cell lines Eca109 and KYSE-150 were used to conduct loss-of-function experiments. The expression patterns of SPATS2 in patients with ESCC were obtained from Oncomine, The Cancer Genome Atlas and Genotype-Tissue Expression databases. Reverse transcription-quantitative PCR and western blot analysis were applied to determine the expression levels of SPATS2 in ESCC cells. The proliferation of ESCC cells was measured via cell proliferation and colony-formation assays. Subsequently, the migration and invasion capacities of ESCC cells were observed using Transwell assays. Finally, the expression levels of P53, cyclin E, matrix metalloproteinase (MMP)-9 and neuronal-cadherin were determined via western blot analysis. SPATS2 was expressed at higher levels in ESCC tissues compared with the controls, and high expression of SPATS2 was associated with poor prognosis. ESCC cell line proliferation, migration and invasion abilities were suppressed after silencing SPATS2. Moreover, following knockdown of SPATS2, the proteins cyclin E, MMP-9 and N-cadherin were expressed at markedly decreased levels, while P53 expression was increased. In summary, the results of the present study suggest that SPATS2 promotes ESCC development and progression, providing potential insights into future ESCC targeted treatment.

The Genomic Landscape of Thyroid Cancer Tumourigenesis and Implications for Immunotherapy

Thyroid cancer is the most prevalent endocrine malignancy that comprises mostly indolent differentiated cancers (DTCs) and less frequently aggressive poorly differentiated (PDTC) or anaplastic cancers (ATCs) with high mortality. Utilisation of next-generation sequencing (NGS) and advanced sequencing data analysis can aid in understanding the multi-step progression model in the development of thyroid cancers and their metastatic potential at a molecular level, promoting a targeted approach to further research and development of targeted treatment options including immunotherapy, especially for the aggressive variants. Tumour initiation and progression in thyroid cancer occurs through constitutional activation of the mitogen-activated protein kinase (MAPK) pathway through mutations in BRAF, RAS, mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway and/or receptor tyrosine kinase fusions/translocations, and other genetic aberrations acquired in a stepwise manner. This review provides a summary of the recent genetic aberrations implicated in the development and progression of thyroid cancer and implications for immunotherapy.

Genetic Determinants for Prediction of Outcome of Patients with Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) usually presents an excellent prognosis, but some patients present with aggressive metastatic disease. BRAF, RAS, and TERT promoter (TERTp) genes are altered in PTC, and their impact on patient outcomes remains controversial. We aimed to determine the role of genetic alterations in PTC patient outcomes (recurrent/persistent disease, structural disease, and disease-specific mortality (DSM)). The series included 241 PTC patients submitted to surgery, between 2002-2015, in a single hospital. DNA was extracted from tissue samples of 287 lesions (primary tumors and metastases). Molecular alterations were detected by Sanger sequencing. Primary tumors presented 143 BRAF, 16 TERTp, and 13 RAS mutations. Isolated TERTpmut showed increased risk of structural disease (HR = 7.0, p < 0.001) and DSM (HR = 10.1, p = 0.001). Combined genotypes, BRAFwt/TERTpmut (HR = 6.8, p = 0.003), BRAFmut/TERTpmut (HR = 3.2, p = 0.056) and BRAFmut/TERTpwt (HR = 2.2, p = 0.023) showed increased risk of recurrent/persistent disease. Patients with tumors BRAFwt/TERTpmut (HR = 24.2, p < 0.001) and BRAFmut/TERTpmut (HR = 11.5, p = 0.002) showed increased risk of structural disease. DSM was significantly increased in patients with TERTpmut regardless of BRAF status (BRAFmut/TERTpmut, log-rank p < 0.001; BRAFwt/TERTpmut, log-rank p < 0.001). Our results indicate that molecular markers may have a role in predicting PTC patients' outcome. BRAFmut/TERTpwt tumors were prone to associate with local aggressiveness (recurrent/persistent disease), whereas TERTpmut tumors were predisposed to recurrent structural disease and DSM.

Blood prognostic predictors of treatment response for patients with papillary thyroid cancer

Background: Papillary thyroid cancer (PTC) is a very common malignant disease with high morbidity. We needed some pretreatment indicators to help us predict prognosis and guide treatment. We conducted a study about some pretreatment prognostic indicators.

Methods: This clinical study recruited 705 postoperative PTC patients (211 males, 494 females). Clinical data before radioactive iodine (RAI) treatment were collected. Patients’ response to therapy were classified into two categories: ‘Good Prognosis Group’ (GPG) and ‘Poor Prognosis Group’ (PPG), according to ‘2015 American Thyroid Association Guidelines’. Differences of indicators between different prognosis groups were compared. Odds ratios (ORs) were calculated by univariate/multiple binary logistic regression models. Difference of body mass index (BMI) changes before and after RAI treatment between different prognosis groups was also compared.

Results: A total of 546 (77.45%) belonged to GPG, and 159 (22.55%) belonged to PPG. Platelet (PLT), neutrophil (NEUT), PLT subgroups, and combination of red blood cell distribution width (RDW) and BMI (COR-BMI) were different between two prognosis groups. The significance of the difference between the two groups of BMI disappeared after the Bonferroni correction. PLT and PLT subgroups had detrimental effects on the risk of PPG; T stage had a positive effect on the risk of PPG. PLT subgroup showed a detrimental effect on the risk of PPG when we included additional covariates.

Conclusions: We found that lower pretreatment PLT levels may indicate a poor prognosis for PTC. The relationship between platelet-derived growth factor (PDGF) and radiation sensitivity may be the key to this association.

The role of the size in thyroid cancer risk stratification

Only a minority of cases of differentiated thyroid carcinoma (DTC) have a poor clinical outcome. Clinical outcomes and molecular aspects were assessed in: 144 DTC ≤ 40 mm without distant metastases (group 1); 50 DTC > 40 mm without distant metastases (group 2); and 46 DTC with distant metastases (group 3). Group 3 had a worse outcome than the other two groups: during the follow-up, patients more frequently had persistent disease, died, or underwent further treatment. The outcomes did not differ between groups 1 and 2. Group 3 had a higher prevalence of TERT promoter mutations than group 2 (32.6% vs 14%). Group 1 had a higher frequency of BRAF mutations than groups 2 or 3 (61.1% vs 16.0% and 26.1%, respectively), while RAS mutations were more common in group 2 than in groups 1 and 3 (16.0% vs 2.1% and 6.5%, respectively). Groups 1 and 2 shared the same outcome, but were genetically distinct. Only lymph node involvement, distant metastases, older age and (among the molecular markers) TERT promoter mutations were independent predictors of a worse outcome. Metastatic DTC had the worst outcome, while the outcome was identical for large and small non-metastatic DTC, although they showed different molecular patterns. TERT promoter mutations emerged as an independent factor pointing to a poor prognosis.

Molecular Genetics of Follicular-Derived Thyroid Cancer

Simple Summary

Thyroid tumors that derive from follicular cells are not a homogeneous entity, showing variable morphological appearance and different degrees of differentiation. Molecular markers are useful for both diagnostic purposes and prognostic stratification of patients. In presurgical setting, molecular testing of indeterminate thyroid nodules on aspirates provides useful diagnostic information; the molecular analysis on tumor tissues can also reveal the presence of genetic alterations related to patients’ prognosis. In recent years, the molecular characterization of these tumors has acquired even more importance thanks to the introduction of targeted drugs. This review summarizes the current literature on the molecular landscape of follicular-derived thyroid tumors.

Abstract

Thyroid cancer is the most common type of endocrine-related malignancy, whose incidence rates have increased dramatically in the last few decades. Neoplasms of follicular origin generally have excellent prognosis, with the exception of less differentiated tumors. Follicular-derived thyroid cancer can manifest as a variety of morphologically distinct entities, characterized by various degrees of differentiation and invasiveness. Histological evaluation is thus crucial for the definition of patients’ prognosis. However, within each histological subtype, tumor behavior can be highly variable, and, in this respect, molecular characterization can provide insightful information to refine the risk stratification of tumors. In addition to the importance of its prognostic role, molecular testing can be used to support the differential diagnosis of thyroid nodules in the absence of marked cyto-morphological aberrations. Finally, with the advent of targeted drugs, the presence of molecular alterations will guide the therapeutic strategies for patients with advanced tumors who do not respond to standard treatment. This review aims to describe the genetic landscape of follicular-derived thyroid tumors also highlighting differences across histological subtypes.

Molecular Pathology of Non-familial Follicular Epithelial-Derived Thyroid Cancer in Adults: From RAS/BRAF-like Tumor Designations to Molecular Risk Stratification

This review addresses the impact of molecular alterations on the diagnosis and prognosis of differentiated thyroid carcinoma (DTC), including papillary, follicular, and well-differentiated carcinoma NOS, as well as oncocytic neoplasms. The molecular characterization of DTC is based upon the well-established dichotomy of BRAF-like and RAS-like designations, together with a remaining third group, less homogeneous, composed of non-BRAF-/non-RAS-like tumors. The role of BRAF V600E mutation in risk stratification is discussed in the clinico-pathological context, namely, staging and invasive features of classic papillary thyroid carcinoma (PTC) and histopathological variants carrying an excellent prognosis (microPTC) or a guarded prognosis, including the aggressive variants tall cell and hobnail cell PTCs. In follicular patterned tumors, namely, follicular thyroid carcinoma (FTC), with or without oncocytic features, the most prevalent molecular alteration are RAS mutations that do not carry prognostic significance. The only genetic alteration that has been proven to play a role in risk stratification of PTC and FTC is TERT promoter (TERTp) mutation.

Do Molecular Profiles of Primary Versus Metastatic Radioiodine Refractory Differentiated Thyroid Cancer Differ?

Management of metastatic radioiodine refractory differentiated thyroid cancer (DTC) can be a therapeutic challenge. Generally, little is known about the paired molecular profile of the primary tumor and the metastases and whether they harbor the same genetic abnormalities. The present study compared the molecular profile of paired tumor specimens (primary tumor/metastatic sites) from patients with radioiodine refractory DTC in order to gain insight into a possible basis for resistance to radioiodine. Twelve patients with radioiodine refractory metastases were studied; median age at diagnosis of 61 years (range, 25-82). Nine patients had papillary TC (PTC), one had follicular TC (FTC), and two had Hürthle cell TC (HTC). Distant metastases were present in the lungs (n = 10), bones (n = 4), and liver (n = 1). The molecular profiling of paired tumors was performed with a panel of 592 genes for Next Generation Sequencing, RNA-sequencing, and immunohistochemistry. Digital microfluidic PCR was used to investigate TERT promoter mutations. The genetic landscape of all paired sites comprised BRAF, NRAS, HRAS, TP53, ATM, MUTYH, POLE, and NTRK genes, including BRAF and NTRK fusions. BRAF V600E was the most common point mutation in the paired specimens (5/12). TERT promoter mutation C228T was detected in one case. PD-L1 expression at metastatic sites was highly positive (95%) for one patient with HTC. All specimens were stable for microsatellite instability testing, and the tumor mutation burden was low to intermediate. Therefore, the molecular profile of DTC primary and metastatic lesions can show heterogeneity, which may help explain some altered responses to therapeutic intervention.

Thyroid Carcinoma: Phenotypic Features, Underlying Biology and Potential Relevance for Targeting Therapy

Thyroid carcinoma consists a group of phenotypically heterogeneous cancers. Recent advances in biological technologies have been advancing the delineation of genetic, epigenetic, and non-genetic factors that contribute to the heterogeneities of these cancers. In this review article, we discuss new findings that are greatly improving the understanding of thyroid cancer biology and facilitating the identification of novel targets for therapeutic intervention. We review the phenotypic features of different subtypes of thyroid cancers and their underlying biology. We discuss recent discoveries in thyroid cancer heterogeneities and the critical mechanisms contributing to the heterogeneity with emphases on genetic and epigenetic factors, cancer stemness traits, and tumor microenvironments. We also discuss the potential relevance of the intratumor heterogeneity in understanding therapeutic resistance and how new findings in tumor biology can facilitate designing novel targeting therapies for thyroid cancer.

Arms-qPCR Improves Detection Sensitivity of Earlier Diagnosis of Papillary Thyroid Cancers With Worse Prognosis Determined by Coexisting BRAF V600E and Tert Promoter Mutations

OBJECTIVE

The coexistence of BRAF V600E and the telomerase reverse transcriptase (TERT) promoter mutation C228T/C250T is extensively associated with thyroid cancer prognosis. Our study aimed to establish a sensitive method for mutation detection and explore the correlation in detail.

METHODS

The BRAF and TERT promoter mutation status of 250 papillary thyroid cancers was determined using amplification-refractory mutation system quantitative polymerase chain reaction (ARMS-qPCR) and Sanger sequencing to compare the sensitivity of the 2 methods. Associations between the mutation status and clinicopathological features were then analyzed.

RESULTS

ARMS-qPCR was more sensitive than Sanger sequencing (BRAF V600E: 75.2% [188 of 250] vs 52.4% [131 of 250], P < .001; TERT promoter C228T/C250T mutation: 12.0% [30 of 250] vs 3.6% [9 of 250], P = .001; comutation: 9.6% [24 of 250] vs 3.2% [8 of 250], P = .005). Both ARMS-qPCR and Sanger sequencing indicated that patients with coexisting BRAF V600E and TERT promoter mutations had an older diagnosis age, higher recurrence rate, and were associated with a more advanced TNM stage and higher metastasis, age, completeness of resection, invasion, and size score. Moreover, ARMS-qPCR helped identify an earlier group stage, which was younger and had smaller tumors and a lower recurrence rate, compared with the group with coexisting BRAF V600E and TERT promoter mutations identified by Sanger sequencing. The newly identified group had a lower metastasis, age, completeness of resection, invasion, and size score and TNM stage.

CONCLUSION

Patients with coexisting BRAF V600E and TERT promoter mutations had a worse prognosis. ARMS-qPCR, the more sensitive method, can be used to identify patients who have a potentially worse prognosis earlier.

Impact of Lin28 on lymph node metastasis in papillary thyroid carcinoma

Lin28 is involved in the progression of several types of tumors. Data collected from clinical trials have suggested that Lin28 expression is correlated with poor prognosis in thyroid carcinoma. The present study was conducted to investigate the association between Lin28 expression and the clinicopathological parameters of papillary thyroid carcinoma (PTC). Accordingly, the clinical data and diagnostic results from 237 patients with PTC were collected. Immunohistochemical staining was performed to evaluate the Lin28 expression levels in thyroid tissue samples. Associations between the expression levels and clinicopathological parameters were evaluated. Lin28 was expressed in 96/237 (40.5%) of PTC specimens. Compared with patients with no Lin28 expression, patients with expression had higher rates of lymph node metastasis (P<0.001) and larger tumors (P=0.011). Multivariate analysis revealed that Lin28 was associated with lymph node metastasis. Next, bioinformatics analysis was performed based using the Gene Expression Omnibus database and The Cancer Genome Atlas database. Lin28 expression was associated with aggressive tumor characteristics, such as lymph node metastasis and larger tumors. In conclusion, the present study revealed that Lin28 expression served as a risk factor for lymph node metastasis. Accordingly, Lin28 expression may be used as a prognostic marker to predict lymph node metastasis in patients with PTC. In addition, Lin28 may serve as a therapeutic target in the management of this tumor type, which may help improve patient outcomes.

BRAF V600E and TERT promoter mutations in paediatric and young adult papillary thyroid cancer and clinicopathological correlation

Objectives The primary objective of this study was to determine the prevalence of BRAF V600E and TERTpromoter mutations in paediatric and young adult patients with papillary thyroid carcinoma (PTC) and the secondary objective, to assess their association with clinicopathological features. Methods Patients ≤20 years who underwent surgery for differentiated thyroid cancer (DTC) from 2005 to 2018 were consecutively enrolled for BRAF V600E and TERTpromoter mutations analysis and records analysed for the association of aggressive features. Univariate analysis and multivariate logistic regression were used to identify the independent predictors of BRAF V600E mutations. Results Among 100 patients with DTC, 68 patients were ≤18 years and the remaining 30 patients were >18 years of age with a median age of 17 years (IQR 14-19 years) 98 patients had PTC and 2 had FTC. BRAF V600E mutation was present in 14/98 (14.3%) PTC and TERTpromoter mutation noted in none. Multivariate analysis identified RAI refractoriness (OR:10.57, 95% CI: 2.6 to 41.6, P-0.0008) as an independent factor associated with BRAF V600E mutation. 17 patients with distant metastases were negative for both BRAF V600E or TERTpromoter mutation. No significant association was observed between age, gender, PTC variants, extra-thyroidal extension, lymphovascular invasion, multifocality, RAI administration and event rate with BRAF V600E mutation. Irrespective of BRAF V600E mutation, radioiodine refractory status (p-0.0001) had a reduced EFS probability. Conclusion In paediatric & young adult PTC, TERTpromoter mutation is absent and BRAFV600E mutation is not associated with distant metastasis. The prevalence rate of the BRAF V600E mutation is much lower compared to adult PTC patients.

The molecular and gene/miRNA expression profiles of radioiodine resistant papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most frequent endocrine tumor. Radioiodine (RAI) treatment is highly effective in these tumors, but up to 60% of metastatic cases become RAI-refractory. Scanty data are available on either the molecular pattern of radioiodine refractory papillary thyroid cancers (PTC) or the mechanisms responsible for RAI resistance.

Methods

We analyzed the molecular profile and gene/miRNA expression in primary PTCs, synchronous and RAI-refractory lymph node metastases (LNMs) in correlation to RAI avidity or refractoriness.

We classified patients as RAI+/D+ (RAI uptake/disease persistence), RAI−/D+ (absent RAI uptake/disease persistence), and RAI+/D- (RAI uptake/disease remission), and analyzed the molecular and gene/miRNA profiles, and the expression of thyroid differentiation (TD) related genes.

Results

A different molecular profile according to the RAI class was observed: BRAF^V600E cases were more frequent in RAI−/D+ (P = 0.032), and fusion genes in RAI+/D+ cases. RAI+/D- patients were less frequently pTERT mutations positive, and more frequently wild type for the tested mutations/fusions. Expression profiles clearly distinguished PTC from normal thyroid. On the other hand, in refractory cases (RAI+/D+ and RAI−/D+) no distinctive PTC expression patterns were associated with either tissue type, or RAI uptake, but with the driving lesion and BRAF−/RAS-like subtype. Primary tumors and RAI-refractory LNMs with BRAF^V600E mutation display transcriptome similarity suggesting that RAI minimally affects the expression profiles of RAI-refractory metastases. Molecular profiles associated with the expression of TPO, SLC26A4 and TD genes, that were found more downregulated in BRAF^V600E than in gene fusions tumors.

Conclusions

The present data indicate a different molecular profile in RAI-avid and RAI-refractory metastatic PTCs. Moreover, BRAF^V600E tumors displayed reduced differentiation and intrinsic RAI refractoriness, while PTCs with fusion oncogenes are RAI-avid but persistent, suggesting different oncogene-driven mechanisms leading to RAI refractoriness.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01757-x.

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.

Genetic Landscape of Papillary Thyroid Carcinoma and Nuclear Architecture: An Overview Comparing Pediatric and Adult Populations

Thyroid cancer is a rare malignancy in the pediatric population that is highly associated with disease aggressiveness and advanced disease stages when compared to adult population. The biological and molecular features underlying pediatric and adult thyroid cancer pathogenesis could be responsible for differences in the clinical presentation and prognosis. Despite this, the clinical assessment and treatments used in pediatric thyroid cancer are the same as those implemented for adults and specific personalized target treatments are not used in clinical practice. In this review, we focus on papillary thyroid carcinoma (PTC), which represents 80-90% of all differentiated thyroid carcinomas. PTC has a high rate of gene fusions and mutations, which can influence the histologic subtypes in both children and adults. This review also highlights telomere-related genomic instability and changes in nuclear organization as novel biomarkers for thyroid cancers.

The clonal origin of multifocal papillary thyroid cancer: intrathyroidal spread or independent tumors?

Multifocality is a common finding in papillary thyroid cancer but the molecular pathogenesis, prognosis and management of multifocal papillary thyroid cancer are debated. The clonal origin of multifocal papillary thyroid cancer represents a controversial aspect, as two opposite viewpoints have been proposed: independent origin or intraglandular spread. Different approaches have been used for inferring the clonality of multifocal papillary thyroid cancer, including X-chromosome inactivation, mutational analysis, determination of loss of heterozygosity and, more recently, next-generation sequencing. Next-generation sequencing, able to provide information on genetic heterogeneity and phylogenetic evolution in multifocal tumors, represents the most reliable approach. While most evidences indicated an independent origin of multifocal papillary thyroid cancer, a minority of studies suggested that multifocal papillary thyroid tumors might be monoclonally derived. This discrepancy may reflect technical limitations; nevertheless, studies based on next-generation sequencing indicated that both independent and clonal origins are possible. The co-existence of multiple tumors implies a high degree of genetic heterogeneity, which may influence the best and targeted therapeutic strategy. On the other hand, intrathyroidal dissemination may indicate metastatic potential of the dominant tumor, thereby prompting more aggressive treatments. In conclusion, data available in the literature indicated that multifocal papillary thyroid cancer may derived from both intraglandular spread and independent tumor foci. The understanding of the clonal origin of multifocal papillary thyroid tumors might represent an important issue in patient treatment.

Telomerase reverse transcriptase promoter mutations in thyroid carcinomas: implications in precision oncology-a narrative review

Telomerase is a ribonucleoprotein enzyme with telomerase reverse transcriptase (TERT) as a catalytic component. In normal human follicular thyroid cells or thyrocytes, telomerase is silent due to the TERT gene being tightly repressed. However, during the formation of thyroid carcinoma (TC), telomerase becomes activated via TERT induction. The TERT promoter’s gain-of-function mutation has recently been identified in TCs and many other malignancies. The mutation creates a de novo ETS-binding motif through which TERT transcription is de-repressed and telomerase is activated; through this, the mutant TERT promoter promotes the development of TC, contributes to disease aggressiveness and treatment resistance, and thereby leads to poor patient outcomes. From a clinical point of view, the strong association between the TERT promoter mutation and disease malignancy and aggressiveness holds great promise for its value in TC diagnostics, risk stratification, prognostication, treatment decision, and follow-up design. In the present review article, we summarize the recent findings of studies of TERT promoter mutations in TC and underscore the implications of TERT hyperactivity driven by genetic events in the pathogenesis and management of TC. Finally, the targeting of TERT promoter mutations and the disruption of telomere maintenance are considered as potential therapeutic strategies against TC.

BRAF V600E and lymph node metastases in papillary thyroid cancer

OBJECTIVE

To evaluate the relationship between the BRAF V600E mutation in lymph node metastasis (LNM) and its invasive characteristics in papillary thyroid cancer (PTC).

MATERIAL AND METHODS

A total of 373 PTC patients were enrolled in this study conducted at Zhujiang Hospital of Southern Medical University between January 2017 and December 2018. PTCs with cervical lymph node metastases were verified pathohistologically, and primary tumors and LNM were examined for the BRAF V600E mutation. Patients were excluded from the study if the BRAF V600E mutation was examined only in primary tumors or only in LNM.

RESULTS

Of the 373 patients examined, BRAF V600E mutation frequency in primary tumors was slightly higher than in LNM (81.5% vs 78.0%, P = 0.000), the intra-class correlation coefficient (ICC) was 0.865 (95% CI 0.835-0.890). The BRAF V600E mutation in both primary tumor and LNM negatively correlated with the size of the largest metastatic focus of LNM (Odds ratio, OR = 0.297, 95% CI 0.143-0.616, P = 0.001; OR = 0.242, 95% CI 0.119-0.492, P = 0.000, respectively). There was no relationship between BRAF V600E mutation in LNM and the number, extranodal extension or stage of LNM (P > 0.05).

CONCLUSION

The BRAF V600E mutation in LNM may not be related to the invasive characteristics of LNM in PTC.

Prevalence of BRAFV600E mutation in Asian series of papillary thyroid carcinoma-a contemporary systematic review

Papillary thyroid carcinoma (PTC), the most common malignancy of the endocrine system, is frequently driven by BRAFV600E mutation, which was reported in 35-60% cases in Western series. Numerous studies have recently emerged from Asian countries and regions; however sufficient summary is lacking to date. BRAF mutation serves as a diagnostic and prognostic tool in thyroid cancer, therefore establishing a rate of BRAF on the national scale could be of practical significance. We performed systematic reviews of available literature to investigate the prevalence of BRAF mutation in series of PTC from various Asian countries and regions. Out of the total 3,966 reports identified via initial screening, 138 studies encompassing over 40,000 PTCs were included for the final analysis. A vast majority (90.2%) of PTCs with known BRAF status were from East Asia, including China, South Korea, and Japan, with BRAF mutation rates of 71.2%, 75.5%, and 70.6%, respectively. Less abundant Indian and Saudi Arabian series found 45.6% and 46.3% prevalence of BRAFV600E in PTC, respectively. Much limited evidence was available from Thailand, Iran, Kazakhstan, Taiwan, Singapore, Indonesia, Hong Kong, Philippines, Vietnam, Iraq, and Myanmar. No relevant publications were found from other highly populated countries, such as Pakistan, Bangladesh, and Malaysia. After grouping by geographic region, we found that the highest rate of BRAFV600E was reported in the PTC series from East Asia (76.4%). Much lower rate (45-48%) was seen in PTC cohorts from South Asia, Central Asia, and the Middle East while the Southeast Asian series were in between (57%). Further subgroup analysis revealed that studies employing fresh frozen tissue and fine-needle aspirates showed higher rates of BRAF compared to those used formalin-fixed paraffin-embedded tissues. We found that the PTC series enrolled patients' cohorts after 2010 demonstrated a higher rate of BRAF compared to the earlier series. Finally, pediatric PTCs had lower BRAF prevalence compared to the baseline rate for the country. In conclusion, despite considerable among and within countries heterogeneity, the Asian PTC series showed a higher prevalence of BRAFV600E mutation than that in Western series. Causes of geographic heterogeneity, whether genuine (etiology, genetics) or methodology-related should be further investigated.

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.