Prognostic utility of BRAF mutation in papillary thyroid cancer

BRAF V600E mutation in thyroid carcinoma: a large-scale study in Han Chinese population

BACKGROUND

The prevalence of genetic mutations in thyroid cancer varies significantly among different ethnic backgrounds. The present study aimed to investigate the clinical potential of BRAF V600E in a large group of homogenous Han Chinese patients.

METHODS

From 2018 to 2021, 6232 thyroid disease patients who underwent thyroidectomy at our hospital were enrolled. We measured the diagnostic value of BRAF and plotted ROC curves. Patients with full clinical-pathological data were selected and divided into the BRAF mutation and wild type groups. We conducted univariate and multivariate analyses to quantify the differences in potential predictive factors of papillary thyroid carcinoma (PTC) patients between the groups. Kaplan-Meier survival analysis was used to estimate overall recurrence and recurrence rate.

RESULTS

The prevalence of BRAF V600E mutation was 86.0% in PTCs. The sensitivity and specificity of BRAF mutation for diagnosing PTC from suspicious lesions were 85.5% and 100%, respectively. The sensitivity and specificity of BRAF analysis in the indeterminate cytology group were 72.5% and 100%, respectively. BRAF mutation showed an independent association with older age, negative HT, larger tumor size, extrathyroidal extension, and multifocality in PTCs. In micro-PTCs (tumor size ≤ 1), the mutation was also positively correlated with progressive phenotypes of extrathyroidal extension and multifocality. BRAF mutation was associated with poorer recurrence-free probability in Kaplan-Meier survival analysis.

CONCLUSIONS

This large single-center study reveals that BRAF V600E is highly prevalent in the Han Chinese population and demonstrates BRAF V600E mutation testing has high diagnostic accuracy and its strong association with the progress of aggressiveness in PTCs and a higher probability of recurrence. BRAF mutation can serve as an accurate marker for diagnosis and decision-making with great value.

Molecular testing for thyroid nodules: Where are we now?

Approximately 25% of the fine needle aspiration samples (FNAB) of thyroid nodules are classified as "indeterminate samples", that means, Bethesda III and IV categories. Until the last decade, most of these cases underwent diagnostic surgery, although only a minority (13-34%) confirmed malignancy postoperatively. In view of this, with the objective of improving the preoperative diagnosis in these cases, the molecular tests emerged, which are validated from the diagnostic point of view, presenting good performance, with good diagnostic accuracy, being able to avoid diagnostic surgeries. With the advancement of knowledge of the role of each of the mutations and gene rearrangements in thyroid oncogenesis, molecular markers have left to play only a diagnostic role and have been gaining more and more space both in defining the prognostic role of the tumor, as well as in the indication of target therapy. Thus, the objective of this review is to show how to use the tool of molecular tests, now commercially available in the world, in the management of indeterminate cytological nodules, assessing the pre-test malignancy risk of the nodule, through clinical, ultrasonographic and cytological characteristics, and decide on the benefit of molecular testing for each patient. In addition, to discuss its new and promising prognostic and therapeutic role in thyroid cancer.

Relationship of Recurrence Rate with some Characteristics in Patients with Thyroid Carcinoma

Background

Determining the clinical and subclinical characteristics related to the recurrence status in patients with a thyroid carcinoma has great significance for prognosis, prediction of recurrence and monitoring of treatment outcomes. This study aimed to determine the association between recurrence rate and some characteristics in patients with thyroid carcinoma.

Patients and Methods

The study was conducted by descriptive method with longitudinal follow-up on 102 thyroid carcinoma patients at 103 Military Hospital, Hanoi, Vietnam, from July 2013 to December 2016.

Results

Univariate analysis showed that there was a relationship between the recurrence characteristics in the studied patients and the characteristics of lymph node metastasis (P = 0.026; OR = 15; 95% CI = 1.4-163.2) and BRAF V600E mutation status (P = 0.01; OR = 3.41; 95% CI = 1.31-8.88). When analysing the multivariable Logistic regression model, there was a positive correlation between the occurrence of BRAF V600E gene mutation (P = 0.032; OR = 17.649; 95% CI = 1.290-241.523) and male sex (P = 0.036; OR = 12.788; 95% CI = 1.185-137.961) and the occurrence of recurrence in study patients. The mean time to relapse was earlier in male patients than in female patients (P = 0.02). The mean time to relapse in patients with the BRAF V600E mutation (31.81 ± 1.14 months) was shorter than the mean time to relapse in the group without the mutation (57.82 ± 2.08 months) (P = 0.01). The group of patients with mutations in the BRAF V600E gene increased the risk of recurrence compared with the group without the mutation (HR = 9.14, P = 0.04).

Conclusion

There is a positive correlation between recurrence and masculinity, lymph node metastasis and the occurrence of BRAF V600E mutations in thyroid carcinoma patients.

Relationships of BRAF V600E Gene Mutation With Some Immunohistochemical Markers and Recurrence Rate in Patients With Thyroid Carcinoma

Background

The B-type rafkinase (BRAF) V600E gene mutation plays an important role in the pathogenesis, diagnosis, and prognosis of thyroid carcinoma. This study was conducted to investigate the rate of the BRAF V600E mutation, the relationships between the BRAF V600E gene mutation and some immunohistochemical markers, and recurrence rate in patients with differentiated thyroid cancer.

Method

The study was conducted by a descriptive and longitudinal follow-up method on 102 thyroid carcinoma patients at 103 Military Hospital, Hanoi, Vietnam. All patients were identified with the BRAF V600E gene mutation by real-time polymerase chain reaction.

Results

The rate of BRAF V600E gene mutation in patients with thyroid cancer was 60.8%. Patients with BRAF V600E gene mutation had a significantly higher rate of positive cyclooxygenase 2 (COX-2) and Ki67 markers than those without the mutation (COX-2: odds ratio [OR] = 2.93; 95% confidence interval [CI] = 1.27-6.74, P = .011; Ki67: OR = 3.41; 95% CI = 1.31-8.88, P = .01). A statistically significant relationship was identified between the rate of BRAF V600E mutation and the rate of positive Hector Battifora mesothelial 1 (HBME-1) (B = -1.040; P = .037) and COX-2 (B = -1.123; P = .023) markers. The recurrence rate in patients with BRAF V600E gene mutation was significantly higher than that in those without the mutation (P = .007). The mean of the recurrence time of patients with BRAF V600E mutation was significantly lower than that in those without the mutation (P = .011).

Conclusions

A high prevalence of BRAF V600E gene mutation was found in thyroid carcinoma patients. The rates of positive HBME-1, COX-2, and Ki67 markers were significantly correlated to BRAF V600E gene mutation. Patients with BRAF V600E gene mutation showed a significantly higher relapse rate and earlier relapse time than those without the mutation.

p53 expression in cytology samples may represent a marker of early-stage cancer

BACKGROUND

TP53 gene plays a major role in the negative control of cell proliferation and in the regulation of signaling cascades. TP53 mutation may have a relevant role in the malignant transformation of thyroid cells as well as thyroid tumor progression. TP53 mutation has been detected only in few well differentiated thyroid carcinomas and is absent in benign conditions.

METHODS

A total of 162 prospective thyroid cytology and corresponding histological samples diagnosed from atypia of indeterminate significance (AUS) to malignant, were studied via immunocytochemistry for p53. Hence, 50 benign lesions (B) were used as negative control. Molecular analysis for p53 only was performed.

RESULTS

The cytology resulted in 50 B, 48 AUS, 40 follicular neoplasms (FNs), 23 suspicious for malignancy (SFM), and 1 malignant (M) case. The authors reported 102 negative and 60 positive p53 cases. The 60 positive cases included 27 cases with weak and/or focal cytoplasmic positivity (+1) and 33 with cases moderate (2+) to strong (3+) cytoplasmic and/or nuclear expression. Overall, 71 cases had histology (2 B, 11 AUS, 37 FN, 20 SFM, and 1 M) including 61.7% benign and 38.2% malignant diagnoses. Only 16 of 71 (5 FN, 10 SFM, and 1 M) were p53-positive. Furthermore, 100% AUS and 86.5% FN cases were p53-negative, none of which had malignant histology. All p53-positive cases were associated with a larger nodule size, tall-cell variant subtype, multifocality, extra thyroidal infiltration, and nodal metastases. Noninvasive follicular thyroid neoplasm with papillary like nuclear features were negative for p53. Few discrepancies in p53 intensity were observed on histology; there were no differences with the molecular testing.

CONCLUSIONS

p53 might be useful in discriminating thyroid follicular lesions. p53 is likely to be a useful diagnostic marker in recognizing indeterminate lesions that are well-differentiated thyroid cancers.

Profile of BRAFV600E, BRAFK601E, NRAS, HRAS, and KRAS Mutational Status, and Clinicopathological Characteristics of Papillary Thyroid Carcinoma in Indonesian National Referral Hospital

INTRODUCTION

BRAFV600E and RAS mutations are the most common gene mutations in papillary thyroid carcinoma (PTC) that may be correlated with its biological behavior. There are still limited data about BRAFV600E and RAS mutations in Indonesia. This study aims to determine the prevalence of BRAFV600E and RAS mutations, and their association with clinicopathologic characteristics.

METHODS

Patients who had total thyroidectomy from 2019 to 2021 and those who met our study criteria underwent PCR and DNA sequencing analysis for BRAFV600E, BRAFK601E, exon 2 and 3 of NRAS, HRAS, and KRAS. Analyses were performed to determine the associations of BRAFV600E and RAS mutations with clinicopathologic characteristics.

RESULTS

Of 172 PTC patients, BRAFV600E mutation was observed in 37.8% of the patients and RAS mutations were found in 21.5%. One patient harbored BRAFK601E mutation. There was a significant association of BRAFV600E with a high-stage (p = 0.033, OR: 3.279; 95% CI: 1.048-10.259), tall-cell variants (p ≤0.001, OR: 41.143; 95% CI: 11.979-141.308), non-encapsulated (p = 0.001, OR: 4.176; 95% CI: 2.008-8.685), lymphovascular invasion (p = 0.043, OR: 1.912; 95% CI: 1.018-3.592), extrathyroidal extension (p = <0.001, OR: 3.983; 95% CI: 1.970-8.054), and lymph node metastasis (p = 0.009, OR: 2.301; 95% CI: 1.224-4.326). Follicular variant (p = 0.001, OR: 7.011; 95% CI: 2.690-18.268), encapsulated (p = 0.017, OR: 2.433; 95% CI: 1.161-5.100), and absent of extrathyroidal extension (p = 0.033, OR: 2.890; 95% CI: 1.052-7.940) were associated with RAS mutations.

CONCLUSION

A significant association between BRAFV600E mutation and high clinical stage, tall-cell variants, non-encapsulated morphology, lymphovascular invasion, extrathyroidal extension, and lymph node metastasis in PTC was observed. RAS mutations were associated with the follicular variant, encapsulated tumor, and no extrathyroidal extension. HRAS-mutated PTC frequently exhibited tumor multifocality.

Integrating BRAFV600E mutation, ultrasonic and clinicopathologic characteristics for predicting the risk of cervical central lymph node metastasis in papillary thyroid carcinoma

Background

The advantages of prophylactic central lymph node dissection (CLND) for clinically node-negative patients remained a great deal of controversies. Our research was aimed to analyze the relationship between cervical central lymph node metastasis (CLNM) and BRAF^V600E mutation, ultrasonic and clinicopathologic characterizes in papillary thyroid carcinoma (PTC).

Methods and materials

In current study, a total of 112 consecutive PTC patients who experienced thyroidectomy plus cervical central neck dissection were included in our research. All PTC were pre-operatively analyzed by ultrasonic features, including tumor size, multifocality or not, tumor location, internal components, echogenicity, microcalcification, margins, orientation, taller than wide shape, and internal vascularity. The presence of clinicopathologic factors, including age, sex, T stage, Hashimoto’s thyroiditis, and BRAF^V600E mutation was then investigated. Univariate and multivariate analysis were conducted to check into the relationship between predictive factors and cervical CLNM in PTC patients, and then a predictive model was also established.

Results

Pathologically, 58.0% (65/112) of the PTC patients harbored cervical CLNM. Univariate and multivariate analysis were conducted to identify age < 55 years, tumor size > 10 mm, microcalcification, non-concomitant Hashimoto’s thyroiditis and BRAF^V600E mutation were predictive factors for cervical CLNM in PTC. The risk score for cervical CLNM in PTC patients was calculated: risk score = 1.284 × (if age < 55 years) + 1.241 × (if tumor size > 10 mm) + 1.143 × (if microcalcification) – 2.097 × (if concomitant Hashimoto’s thyroiditis) + 1.628 × (if BRAF^V600E mutation).

Conclusion

Age < 55 years old, PTC > 10 mm, microcalcification, non-concomitant Hashimoto’s thyroiditis and BRAF^V600E mutation are predictive factors for cervical CLNM. BRAF^V600E mutation by pre-operative US-FNA technology synergized with clinicopathologic and ultrasonic features is expected to guide the appropriate surgical management for PTC patients.

Positive Correlation of Thyroid Nodule Cytology with Molecular Profiling-a Single-Center Experience

Despite several reports on the association between molecular profiling, aggressive histology, and clinical outcomes, the association between mutation expression and pre-operative cytology is yet to be demonstrated. Therefore, we performed a retrospective, single-center study, including all patients who underwent molecular profiling of thyroid nodules in Bethesda System for Reporting Thyroid Cytopathology (BSRTC) categories III to VI, between 2018 and 2019. Medical records were reviewed to collect demographics, cytology results according to BSRTC, final pathology (presence of malignancy and its type, as well as presence of aggressive features, including extrathyroidal extension, positive neck lymph nodes, and multifocality), and the identified genetic variants stratified by risk levels, according to the 2015 ATA guidelines. We supplemented this analysis with a systematic review to identify the variant distributions across the literature. We included data on 55 nodules from 48 patients for the final analysis. A significant positive correlation was found between BSRTC categories and the mutation risk level, shown by an increase in the intermediate to high-risk mutation rate in the higher BSRTC categories (Rs = 0.660, p ≤ 0.001). A significant positive correlation was also found between mutation risk levels and the presence of malignancy and aggressive tumor features (Rs = 0.637, p < 0.001 and Rs = 0.459, p = 0.006, respectively). This novel positive and significant correlation between BSRTC categories and the mutation risk level provides additional insight to aid clinicians in the interpretation of BSRTC results and may contribute to the discussion of appropriate management of thyroid nodule with patients.

Papillary Thyroid Carcinoma Landscape and Its Immunological Link With Hashimoto Thyroiditis at Single-Cell Resolution

The tumor microenvironment heterogeneity of papillary thyroid cancer (PTC) is poorly characterized. The relationship between PTC and Hashimoto thyroiditis (HT) is also in doubt. Here, we used single-cell RNA sequencing to map the transcriptome landscape of PTC from eight PTC patients, of which three were concurrent with HT. Predicted copy number variation in epithelial cells and mesenchymal cells revealed the distinct molecular signatures of carcinoma cells. Carcinoma cells demonstrated intertumoral heterogeneity based on BRAF V600E mutation or lymph node metastasis, and some altered genes were identified to be correlated with disease-free survival in The Cancer Genome Atlas datasets. In addition, transcription factor regulons of follicular epithelial cells unveil the different transcription activation state in PTC patients with or without concurrent HT. The immune cells in tumors exhibited distinct transcriptional states, and the presence of tumor-infiltrating B lymphocytes was predominantly linked to concurrent HT origin. Trajectory analysis of B cells and plasma cells suggested their migration potential from HT adjacent tissues to tumor tissues. Furthermore, we revealed diverse ligand–receptor pairs between non-immune cells, infiltrating myeloid cells, and lymphocytes. Our results provided a single-cell landscape of human PTC. These data would deepen the understanding of PTC, as well as the immunological link between PTC and HT.

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.

α-Enolase Lies Downstream of mTOR/HIF1α and Promotes Thyroid Carcinoma Progression by Regulating CST1

Novel therapy strategies are crucial for thyroid carcinoma treatment. It is increasingly important to clarify the mechanism of thyroid carcinoma progression. Several studies demonstrate that α-Enolase (ENO1) participates in cancer development; nevertheless, the role of ENO1 in thyroid carcinoma progression remains unclear. In the present study, we found that the expression of ENO1 was upregulated in thyroid carcinoma samples. Proliferation and migration of thyroid carcinoma cells were suppressed by depletion of ENO1; conversely, ENO1 overexpression promoted thyroid carcinoma cell growth and invasion. To elucidate the mechanisms, we found that the hypoxia-related mTOR/HIF1 pathway regulated ENO1 expression. ENO1 regulated the expression of CST1; knockdown of CST1 reversed the tumorigenicity enhanced by ENO1 overexpression. Taken together, our findings provide a theoretical foundation for thyroid carcinoma treatment.

Personalized treatment for differentiated thyroid cancer: current data and new perspectives

More conservative and personalized treatment options have been developed in recent years to face the rising diagnosis of low-risk differentiated thyroid carcinoma (DTC). The present review describes the change towards a more risk-adapted management either in the treatment or in the follow-up of DTC. Particular attention is given to the innovations introduced by the latest guidelines for low-risk tumors, starting from the most appropriate extension of surgery up to the postoperative management. The emerging role of active surveillance for low-risk microcarcinoma is discussed, as well as the development of percutaneous strategies in the setting of malignant thyroid disease. The recent use of approved new systemic target therapies for advanced radioiodine refractory thyroid cancer is reported, together with the description of new compounds in trial. Finally, we provide some considerations to improve the risk evaluation in a presurgical setting, especially related to the rising role of genetics, to enable better risk-based cancer management and personalized treatment choices.

KRAS G12V Mutation in Acquired Resistance to Combined BRAF and MEK Inhibition in Papillary Thyroid Cancer

BRAF V600E mutations occur in approximately 40% of all patients with papillary thyroid cancer (PTC) and are associated with a worse prognosis in population studies. Treatment with single-agent BRAF inhibitors can result in nondurable partial responses (PRs) in clinical trials, but resistance inevitably develops. The mechanisms of resistance are not completely understood, but in non-thyroid tumors harboring BRAF V600E mutations, resistance has been ascribed to concurrent or acquired mutations in MEK1/2, RAC1, KRAS, and NRAS. This case report describes a patient with radioactive iodine-refractory metastatic PTC treated in a clinical trial with combination BRAF and MEK inhibition who achieved a durable PR. At time of progression, biopsy revealed an acquired KRAS G12V-activating mutation. The patient subsequently went on to have a PR to cabozantinib therapy in the clinical trial. This is the first reported case of an acquired KRAS-activating mutation that developed during treatment with BRAF and MEK inhibition in a patient with BRAF-mutated PTC. The KRAS mutation was also detected in peripheral blood samples taken as part of the trial, indicating that resistant mutations may be identified through noninvasive means. The identification of resistant mutations in patients at time of progression is necessary to identify possible therapeutic options including potential clinical trials.ClinicalTrials.gov identifier: NCT01723202.

Prophylactic lymph node dissection in clinically N0 differentiated thyroid carcinoma: example of personalized treatment

Considering the 'differentiated thyroid carcinoma (DTC) epidemic', the indolent nature of DTC imposes a treatment paradigm shift toward elimination of recurrence. Lymph node metastases in cervical compartments, encountered in 20-90% of DTC, are the main culprit of recurrent disease, affecting 5-30% of patients. Personalized risk-stratified cervical prophylactic lymph node dissection (PLND) at initial thyroidectomy in DTC with no clinical, sonographic or intraoperative evidence of lymph node metastases (clinically N0) has been advocated, though not unanimously. The present review dissects the controversy over PLND. Weighing the benefit yielded from PLND up against the PLND-related morbidity is so far hampered by the inconsistent profit yielded by PLND and the challenging patient selection. Advances in tailoring PLND are anticipated to empower optimal patient care.

Sorafenib and radioiodine-refractory differentiated thyroid cancer (RR-DTC): a systematic review and meta-analysis

BACKGROUND

Except conventional treatments, research on medical approach for radioiodine-refractory differentiated thyroid cancer (RR-DTC) was considered particularly challenging. Sorafenib, a novel biological agent, has been widely studied in the treatment of RR-DTC for years. We performed a systematic review and meta-analysis to explore the efficiency and safety of treating RR-DTC patients with sorafenib.

METHODS

An electronic search on PubMed/Medline and Embase was carried out to search associated articles. Fixed-effects or random-effects models were chose according to the heterogeneity.

RESULTS

A total of 15 eligible studies (636 patients) were included. As shown by the only randomised clinical trial-DECISION, sorafenib significantly improved progression-free survival (PFS) compared with placebo in patients with progressive RR-DTC. The pooled analysis indicated that there were 26% patients (95% CI: 0.19-0.34) achieved partial response (PR), and 44% patients (98% CI: 0.39-0.48) achieved stable disease (SD). The most frequent adverse effects (AEs) observed included hand-foot syndrome (HFS), diarrhoea, fatigue, alopecia, weight loss (WS) and rash, the incidence of all grades AEs for which were 71%, 60%, 59%, 55%, 51% and 50%, respectively. There were 68% patients (252/368), who had a dose reduction because of the drug toxicities and AEs.

CONCLUSIONS

Sorafenib could improve PFS in patients with progressive RR-DTC, comparing with placebo. Due to the resistance to conventional treatments, sorafenib is considered as a promising treatment for RR-DTC by most physicians specialised in this field. However, the use of sorafenib should be cautious due to a high incidence of AEs caused by the agent. More effective agents with less toxicities are warranted.

VE1 Immunohistochemistry Improves the Limit of Genotyping for Detecting BRAFV600E Mutation in Papillary Thyroid Cancer

Detection of BRAF^V600E is useful for making diagnosis and risk stratification of papillary thyroid carcinoma (PTC). Molecular testing, however, is not always available for routine clinical use. To assess the clinical utility and reliability of VE1 immunohistochemistry (IHC) for detecting BRAF^V600E mutation in PTC, VE1 IHC was performed on the tissue microarrays of 514 patients with PTC and was compared with Sanger sequencing results. Of 514 PTC cases, 433 (84.2%) were positive for VE1 expression. Among 6 discordant cases between VE1 IHC and Sanger sequencing, 3 initial VE1-false negative cases turned out to be true false negative on repeat testing, and 3 VE1-false positive cases showed BRAF^V600E mutation using digital PCR analysis. PTCs with low variant allele fraction were positive for VE1 IHC but were not detected using sequencing. VE1 IHC showed 99.3% sensitivity, 100% specificity, 100% positive predictive value, and 96.4% negative predictive value. The BRAF^V600E mutation was significantly associated with older age, multifocality, extrathyroidal extension, lymph node metastasis, and advanced tumor stage. In conclusion, VE1 IHC is a reliable method for detecting BRAF^V600E mutation in PTC specimens.

Prognostic implications of the BRAF-V600E mutation in papillary thyroid carcinoma based on a new cut-off age stratification

The BRAF-V600^E mutation is the most common and specific oncogenic event known in papillary thyroid carcinoma (PTC). However, it remains controversial whether there is an association between the BRAF-V600^E mutation and clinicopathologically aggressive characteristics of PTC. The purpose of the present retrospective study was to investigate the significance of the BRAF-V600^E mutation in predicting prognostic and aggressive clinicopathological characteristics according to a new age-based stratification. Clinical data and the BRAF-V600^E mutation status of 475 patients with PTC were downloaded from The Cancer Genome Atlas database. The association between BRAF-V600^E status and clinicopathological characteristics was analyzed by χ² test or Fisher's exact test. Recurrence-free survival rate (RFS) was analyzed using the Kaplan-Meier method. Aggressive clinicopathological factors associated with recurrence were analyzed by Cox multivariate regression. This study was conducted on 219 cases of patients with PTC with a known BRAF-V600^E mutational status. In the ≥55 years age group, BRAF-V600^E was found to be significantly associated with aggressive PTC characteristics, including tumor size, PTC subtype, radioactive iodine (RAI) dose, follow-up time, recurrence, recurrence risk stage, advanced T stage, advanced N stage and American Joint Committee on Cancer (III/IV) stage (all P<0.05). RFS was analyzed by the log-rank test and exhibited statistically significant differences in the ≥55 years group (P=0.041), but there was no significant difference in the <55 group (P=0.757), according to the BRAF-V600^E mutation status. The BRAF-V600^E gene was excluded from the recurrence Cox multivariate regression model. The BRAF-V600^E mutation was found to better predict aggressive and recurrent PTC based on age stratification with the cut-off age of 55 years. The synergistic interaction between BRAF-V600^E mutation and the new age stratification may help clinicians reach the optimal decision in terms of surgical approach and the extent of surgery.

[Molecular markers as risk factors for thyroid cancer]

Thyroid cancer is the most common malignant tumor of the endocrine system. An increase in the incidence of thyroid cancer has been noted over the past decade, mainly due to papillary cancer. The influence of environmental factors, increased availability of medical care, including sensitive diagnostic tests, such as ultrasound and fine - needle aspiration (FNA), can affect the fact of the growth of this incidence. Palpation of thyroid gland has very low diagnostic value for detecting thyroid cancer, while thyroid ultrasound and FNA can detect malignant tumors in 20% of cases. Today, the FNA is the fastest, most accurate, economically accessible, and quite safe method for cytological diagnosis of the thyroid nodules. And molecular genetic testing of FNA samples could serve as an additional reliable diagnostic tool in the case of atypia of undetermined significance.

Risk Stratification in Differentiated Thyroid Cancer: From Detection to Final Follow-Up

CONTEXT

Modern management of differentiated thyroid cancer requires individualized care plans that tailor the intensity of therapy and follow-up to the estimated risks of recurrence and disease-specific mortality.

DESIGN

This summary is based on the authors' knowledge and extensive clinical experience, supplemented by review of published review articles, thyroid cancer management guidelines, published staging systems, and original articles identified through a PubMed search, which included terms such as risk stratification, staging, clinical outcomes, and differentiated thyroid cancer.

MAIN OUTCOME MEASURES

In the past, risk stratification in differentiated thyroid cancer usually referred to a static estimate of disease-specific mortality that was based on a small set of clinicopathological features available within a few weeks of completing initial therapy (thyroidectomy, with or without radioactive iodine). Today, risk stratification is a dynamic, active process used to predict the appropriateness for minimalistic initial therapy, disease-specific mortality, risk of recurrence, and the most likely response to initial therapy. Rather than being a static prediction available only after initial therapy, modern risk stratification is a dynamic, iterative process that begins as soon as a suspicious nodule is detected and continues through final follow-up.

CONCLUSIONS

Dynamic risk assessment should be used to guide all aspects of thyroid cancer management, beginning before a definitive diagnosis is made and continuing through the final follow-up visit.

Prognostic significance of TERT promoter and BRAF mutations in TIR-4 and TIR-5 thyroid cytology

OBJECTIVE

Follicular-derived thyroid cancers generally have a good prognosis, but in a minority of cases, they have an aggressive behavior and develop distant metastases, with an increase in the associated mortality. None of the prognostic markers currently available prior to surgery can identify such cases.

METHODS

TERT promoter and BRAF gene mutations were examined in a series of 436 consecutive TIR-4 and TIR-5 nodes referred for surgery. Follow-up (median: 59 months, range: 7-293 months) was available for 384/423 patients with malignant nodes.

RESULTS

TERT promoter and BRAF mutations were detected in 20/436 (4.6%) and 257/434 thyroid nodules (59.2%), respectively. At the end of the follow-up, 318/384 patients (82.8%) had an excellent outcome, 48/384 (12.5%) had indeterminate response or biochemical persistence, 18/384 (4.7%) had a structural persistence or died from thyroid cancer. TERT promoter mutations correlated with older age (P < 0.0001), larger tumor size (P = 0.0002), oxyntic and aggressive PTC variants (P = 0.01), higher tumor stages (P < 0.0001), distant metastases (<0.0001) and disease outcome (P < 0.0001). At multivariate analysis, TERT promoter mutation was not an independent predictor of disease outcome. TERT promoter mutation- (OR: 40.58; 95% CI: 3.06-539.04), and N1b lymph node metastases (OR: 40.16, 95% CI: 3.48-463.04) were independent predictors of distant metastases. BRAF mutation did not predict the outcome, and it correlated with a lower incidence of distant metastases (P = 0.0201).

CONCLUSIONS

TERT promoter mutation proved an independent predictor of distant metastases, giving clinicians the chance to identify many of the patients who warranted more aggressive initial treatment and closer follow-up.

Interaction of BRAF-induced ETS factors with mutant TERT promoter in papillary thyroid cancer

Synergistic effects of BRAFV600E and TERT promoter mutations on the poor clinical outcomes in papillary thyroid cancer (PTC) have been demonstrated. The potential mechanism of this phenomenon has been proposed: MAPK pathway activation by the BRAFV600E mutation may upregulate E-twenty six (ETS) transcription factors, increasing TERT expression by binding to the ETS-binding site generated by the TERT promoter mutation; however, it has not yet been fully proven. This article provides transcriptomic insights into the interaction between BRAFV600E and TERT promoter mutations mediated by ETS factors in PTC. RNA sequencing data on 266 PTCs from The Cancer Genome Atlas and 65 PTCs from our institute were analyzed for gene expression changes and related molecular pathways, and the results of transcriptomic analyses were validated by in vitro experiments. TERT mRNA expression was increased by the coexistence of BRAFV600E and TERT promoter mutations (fold change, 16.17; q-value = 7.35 × 10-12 vs no mutation). In the ETS family of transcription factors, ETV1, ETV4 and ETV5 were upregulated by the BRAFV600E/MAPK pathway activation. These BRAFV600E-induced ETS factors selectively bound to the mutant TERT promoter. The molecular pathways activated by BRAFV600E were further augmented by adding the TERT promoter mutation, and the pathways related to immune responses or adhesion molecules were upregulated by TERT expression. The mechanism of the synergistic effect between BRAFV600E and TERT promoter mutations on cancer invasiveness and progression in PTC may be explained by increased TERT expression, which may result from the BRAF-induced upregulation of several ETS transcription factors.

Impact of tumor-associated macrophages and BRAFV600E mutation on clinical outcomes in patients with various thyroid cancers

BACKGROUND

Tumor-associated macrophages (TAMs) play a role in thyroid cancer tumor progression and metastasis. This study aimed to investigate the association of TAM density and cluster of differentiation 68 (CD68) expression with thyroid tumors as a prognostic marker and the relationship of these factors with BRAF^V600E mutations.

METHODS

This study included 275 thyroid specimen tissues, including benign and malignant lesions. We compared the clinicopathological features according to thyroid tumor types and evaluated the presence of CD68 expression and BRAF^V600E mutations.

RESULTS

CD68 positive expression increased with aggressiveness of thyroid tumor histologic grades (P < 0.001). In patients with poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC), CD68 positivity was associated with aggressive adverse clinical outcomes such as extrathyroidal extension, cervical lymph node metastases, and distant metastases (P < 0.05).

CONCLUSIONS

CD68 positivity was more frequent in advanced and aggressive thyroid cancer types such as PDTC/ATC.

High-accuracy Detection of Preoperative Thyroid Nodules Using Combination of BRAFV600E Mutation and TMPRSS4 mRNA Level

BACKGROUND

Papillary thyroid cancer (PTC) is the most common epithelial thyroid tumor, accounting for more than 80% of all thyroid cancers. Though the fine needle aspiration biopsy (FNAB) represents as the golden standard for the diagnostics of thyroid nodules, there is a ∼25% risk of indeterminate cytological features. TMPRSS4 is a newly found transmembrane serine protease which was overexpressed in papillary thyroid cancer (PTC).

AIMS

The aim of this study was to determine its potential as a diagnostic marker to improve the diagnostic accuracy of thyroid cancer.

METHODS

We used pyrosequencing and quantitative real-time PCR (qRT-PCT) approaches to examine BRAF^V600E mutation and TMPRSS4 mRNA level in FNAB specimens of thyroid nodules. The detection and analysis were respectively applied to training group with 91, and test group with 88 samples.

RESULTS

We demonstrated that PTC patients had an increased TMPRSS4 mRNA level as compared with benign subjects. The diagnostic sensitivity, specificity, and accuracy of TMPRSS4 were 93.33, 100, and 96.70%, respectively. Notably, compared with BRAF^V600E mutation testing alone, combining with TMPRSS4 mRNA level significantly increased the diagnostic sensitivity and accuracy.

CONCLUSIONS

Our findings indicated BRAF^V600E mutation combination with TMPRSS4 mRNA analysis can dramatically improve the sensitivity and accuracy of preoperative diagnosis of thyroid nodules.

Copper Chelation as Targeted Therapy in a Mouse Model of Oncogenic BRAF-Driven Papillary Thyroid Cancer

Purpose: Sixty percent of papillary thyroid cancers (PTC) have an oncogenic (V600E) BRAF mutation. Inhibitors of BRAF and its substrates MEK1/2 are showing clinical promise in BRAFV600E PTC. PTC progression can be decades long, which is challenging in terms of toxicity and cost. We previously found that MEK1/2 require copper (Cu) for kinase activity and can be inhibited with the well-tolerated and economical Cu chelator tetrathiomolybdate (TM). We therefore tested TM for antineoplastic activity in BRAFV600E -positive PTC.Experimental Design: The efficacy of TM alone and in combination with current standard-of-care lenvatinib and sorafenib or BRAF and MEK1/2 inhibitors vemurafenib and trametinib was examined in BRAFV600E-positive human PTC cell lines and a genetically engineered mouse PTC model.Results: TM inhibited MEK1/2 kinase activity and transformed growth of PTC cells. TM was as or more potent than lenvatinib and sorafenib and enhanced the antineoplastic activity of sorafenib and vemurafenib. Activated ERK2, a substrate of MEK1/2, overcame this effect, consistent with TM deriving its antineoplastic activity by inhibiting MEK1/2. Oral TM reduced tumor burden and vemurafenib in a BrafV600E -positive mouse model of PTC. This effect was ascribed to a reduction of Cu in the tumors. TM reduced P-Erk1/2 in mouse PTC tumors, whereas genetic reduction of Cu in developing tumors trended towards a survival advantage. Finally, TM as a maintenance therapy after cessation of vemurafenib reduced tumor volume in the aforementioned PTC mouse model.Conclusions: TM inhibits BRAFV600E -driven PTC through inhibition of MEK1/2, supporting clinical evaluation of chronic TM therapy for this disease. Clin Cancer Res; 24(17); 4271-81. ©2018 AACR.

Conventional Ultrasound, Immunohistochemical Factors and BRAFV600E Mutation in Predicting Central Cervical Lymph Node Metastasis of Papillary Thyroid Carcinoma

The study was aimed at evaluating the correlation between central cervical lymph node metastasis (CLNM) in papillary thyroid carcinoma (PTC) patients and ultrasound (US) features, immunohistochemical factors and BRAF^V600E mutation. A total of 225 consecutive patients (225 PTCs) who had undergone surgery were included. All PTCs were pre-operatively analysed by US with respect to size, components, echogenicity, shape, margins, microcalcification, multiple cancers or not, internal vascularity and capsule contact or involvement. The presence of four immunohistochemical factors, including cytokeratin 19, human bone marrow endothelial cell 1, galectin-3 and thyroid peroxidase, and BRAF^V600E mutation was also evaluated. Univariate and multivariate analyses were performed to identify the risk factors for central CLNM, and a risk model was established. Pathologically, 44% (99/225) of the PTCs had central CLNMs. Multivariate analysis revealed that size ≤10mm, microcalcification, internal vascularity, capsule contact or involvement and BRAF^V600E mutation were independent risk factors for central CLNM. The risk score for central CLNM was calculated as follows: risk score = 1.5 × (if lesion size ≤10 mm) + 1.9 × (if microcalcification) + 0.8 × (if internal flow) + 3.0 × (if capsule contact or involvement) + 1.5 × (if BRAF^V600E mutation). The rating result was divided into six stages, and the relevant risk rates of central CLNM were 0% (0/1), 0% (0/22), 7.4% (4/54), 48.6% (34/70), 71.2% (42/59) and 100% (19/19), respectively. In conclusion, PTC ≤10mm, microcalcification, internal vascularity, capsule contact or involvement and BRAF^V600E mutation are risk factors for central CLNM. The risk model may be useful in treatment planning and management of patients with PTCs.

Prognosis of patients with TX stage differentiated thyroid cancer: propensity scored matching analysis of the SEER database 2004-2013

In differentiated thyroid cancer (DTC), TX stage is defined as 'primary tumour cannot be assessed'. The prognosis of patients with TX stage remains unclear. The aim of this study was to investigate the prognosis of TX stage and provide a perspective on treatment guidelines. We investigated a large cohort of DTC patients from the Surveillance, Epidemiology, and End Results database between 2004 and 2013. Patient mortality was examined by Kaplan-Meier analyses with log-rank tests and Cox proportional hazards regression analyses. The rate of cancer-specific mortality per 1000 person-years for patients with TX stage was higher than for patients with T1-T3 stage, but lower than for patients with T4 stage. The all-cause mortality per 1000 person-years for TX stage patients was also higher than for T1-T3 stage patients, but lower than for T4 stage patients. TX stage showed significant risk for cancer-specific mortality compared to T1 and T4 stages, but not T2 and T3 stages, after adjusting for influential risk factors. TX stage patients showed no significant risk for all-cause mortality compared to T2-T3 stage patients, but were different than T1 and T4 stage patients. These results provide new implications for the treatment of TX stage DTC patients.

Epigenetic modifications in poorly differentiated and anaplastic thyroid cancer

Well-differentiated thyroid cancer accounts for the majority of endocrine malignancies and, in general, has an excellent prognosis. In contrast, the less common poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) are two of the most aggressive human malignancies. Recently, there has been an increased focus on the epigenetic alterations underlying thyroid carcinogenesis, including those that drive PDTC and ATC. Dysregulated epigenetic candidates identified include the Aurora group, KMT2D, PTEN, RASSF1A, multiple non-coding RNAs (ncRNA), and the SWI/SNF chromatin-remodeling complex. A deeper understanding of the signaling pathways affected by epigenetic dysregulation may improve prognostic testing and support the advancement of thyroid-specific epigenetic therapies. This review outlines the current understanding of epigenetic alterations observed in PDTC and ATC and explores the potential for exploiting this understanding in developing novel therapeutic strategies.

Surgical approaches for papillary microcarcinomas: Turkey's perspective

Objectives

The incidence of papillary microcarcinomas, which are defined as thyroid cancers of <10mm in size, has been increasing in the last decade. Herein, we present internet-based questionnaire results performed by the Turkish Association of Endocrine Surgery with the aim to evaluate the perspective of the management of papillary microcarcinomas in Turkey.

Material and Methods

The user-friendly questionnaire consisted of 13 questions in total. These questions mainly addressed the surgical management of nodules and cancer of <1 cm in size. Patient management before, during, and after surgical intervention was also included; additionally, the "active surveillance approach" was questioned.

Results

There were 420 responders in total who were of multidisciplinary origin (endocrinologists, surgeons, nuclear medicine specialists, pathologists, and oncologists). Total thyroidectomy was the predominant treatment approach (65%) for the classical type of microcarcinoma limited in one lobe, whereas in cases of microcarcinomas incidentally diagnosed during hemithyroidectomy, complementary surgery approach was advised by 40% of the responders. The responders found capsule invasion (86%) and patient based management (94%) of high importance. The percentage of the responders who recommended radioactive iodine ablation in incidental cancers having no aggressive criteria was 51%. The survey participants that were against routine central dissection in these cases accounted for 73% of the responders. The recommendation of active surveillance (follow-up without any interventional therapy) was limited with 9% responders.

Conclusion

The results of the questionnaire demonstrated that there have been various choices in Turkey for the surgical treatment of the papillary microcarcinomas.

Mps1 is associated with the BRAFV600E mutation but does not rely on the classic RAS/RAF/MEK/ERK signaling pathway in thyroid carcinoma

In previous studies, the B-Raf proto-oncogene, serine/threonine kinase (BRAF)^V600E mutation has been identified in multiple malignant tumors. BRAF^V600E has been revealed to contribute to tumorigenesis by the activation of phospho-mitogen-activated protein kinases (MAPKs) and their downstream Monopolar spindle 1 (Mps1), leading to chromosome euploidy and tumor development. In the present study, the presence of phospho-MAPK and Mps1 in 161 thyroid carcinoma cases with complete clinical parameters was analyzed by immunohistochemistry, and the BRAF mutation was detected by polymerase chain reaction-direct sequencing. It was revealed that BRAF^V600E was present in ~34% of thyroid cancer cases and was associated with age, clinical tumor stage and lymph node stage. However, the association of BRAF^V600E with overall survival was not statistically significant. The expression of Mps1 was significantly increased in tumor tissues with BRAF^V600E, however, this did not affect the expression of phospho-MAPK in thyroid carcinomas. Collectively, the results of the present study suggested that BRAF^V600E may regulate the expression of Mps1 in MAP kinase independent ways in thyroid carcinoma. Therefore, Mps1 expression is associated with BRAF^V600E while the upstream signaling of phospho-MAPK has no relevance. The specific mechanisms of BRAF^V600E and the unknown pathway associated with Mps1 exhibit potential for further study, and provide a theoretical basis for the molecular treatment of thyroid carcinoma.

Targeted next generation sequencing identifies somatic mutations and gene fusions in papillary thyroid carcinoma

138 papillary thyroid carcinoma (PTC) samples were assessed for somatic mutation profile and fusion genes by targeted resequencing using a cancer panel (ThyGenCap^TM) targeting 244 cancer-related genes and 20 potential fusion genes. At least one genetic alteration (including mutations and fusion genes) was observed in 118/138 (85.5%) samples. The most frequently mutated gene was BRAF V600E (57.2%). Moreover, we identified 11 fusion genes including eight previously reported ones and three novel fusion genes, UEVLD-RET, OSBPL9-BRAF, and SQSTM1-NTRK3. Alterations affecting the mitogen-activated protein kinase (MAPK) signaling pathway components were seen in 69.6% of the PTC cases and all of these driver mutations were mutually exclusive. Univariate analysis ascertained that the fusion genes were strongly associated with distinct clinicopathological characteristics, such as young age, local invasion, extensive metastasis, and disease stage. In conclusion, our approach facilitated simultaneous high-throughput detection of gene fusions and somatic mutations in PTC samples.

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase-PTEN-AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.

Identification of somatic TERT promoter mutations in familial nonmedullary thyroid carcinomas

OBJECTIVE

The genes causing familial nonmedullary thyroid carcinoma (FNMTC) identified to date are only involved in a small fraction of the families. Recently, somatic mutations in TERT promoter region and in EIF1AX gene were reported in thyroid tumours of undefined familial status. The aim of this study was to investigate the role of TERT and EIF1AX mutations in familial thyroid tumours.

DESIGN

The promoter region of TERT was sequenced in leucocyte DNA of the probands from 75 FNMTC families. In thyroid tumours from 54 familial cases, we assessed somatic TERT promoter, RAS and BRAF hotspot mutations, and the whole EIF1AX gene.

RESULTS

No potentially pathogenic germline variants were identified in TERT in the 75 FNMTC families' probands. In the 54 carcinomas, we identified five cases (9%) with hotspot somatic TERT promoter mutations. BRAF mutations were found in 41% of the tumours. All TERT-positive samples were also positive for BRAF p.Val600Glu, and this co-occurrence was found to be statistically significant (P=.008). RAS mutations were detected in four tumours wild-type for TERT (7%). Evaluation of tumour mutation data together with the patients' clinicopathological features revealed a significant correlation between TERT plus BRAF mutations and advanced tumour stage (T4) (P=.020). No mutations were identified in EIF1AX.

CONCLUSIONS

The results of this study suggest that TERT promoter and EIF1AX mutations are not frequently involved in FNMTC aetiology. However, we show for the first time that TERT alterations are associated with familial thyroid tumour progression. Our data also suggest that TERT mutations are more often found in concomitance with BRAF mutations in advanced stages of FNMTC.

Management of the central compartment in differentiated thyroid carcinoma

Management of differentiated thyroid carcinoma (DTC) is gradually evolving with considerations of de-escalation of treatment and/or active surveillance in a significant proportion of patients on the basis of an improved understanding of the long-term disease and functional outcomes from both surgical and non-surgical approaches. This is fueled by improved risk stratification using clinicopathologic prognostic factors as determined through high resolution ultrasound and fine needle aspiration cytology. This paper discusses general recommendations for preoperative decision-making in the management of the central compartment in DTC with particular reference to micropapillary thyroid carcinoma and encapsulated follicular variant papillary thyroid carcinoma. Given the multitude of specific factors that must be considered for each patient, therapeutic decisions should occur in a multidisciplinary setting weighing the risks of treatment morbidity against the risks of disease progression or recurrence. Recurrent/persistent disease merits special attention with regard to pre-operative planning and surgical risk, and should be managed by high-volume thyroid surgeons.

Association between BRAF V600E Mutation and Ultrasound Features in Papillary Thyroid Carcinoma Patients with and without Hashimoto's Thyroiditis

To assess the association between BRAF V600E mutation and ultrasound (US) features in papillary thyroid carcinoma (PTC) patients with and without Hashimoto’s thyroiditis (HT). We retrospectively reviewed the US features and status of BRAF V600E mutation in 438 consecutive patients with surgically confirmed PTCs. The association between BRAF mutation and US features were analyzed. In addition, we conducted subgroup analyses in terms of coexistent HT. The BRAF mutation was found in 86.5% of patients (379 of 438). Patient age (OR: 1.028, P = 0.010), age ≥ 50 y (OR: 1.904, P = 0.030), and microcalcification (OR: 2.262, P = 0.015) on US were significantly associated with BRAF mutation in PTC patients. Solid component (OR: 5.739, P = 0.019) on US was the significant predictor for BRAF mutation in patients with HT, while age (OR: 1.036, P = 0.017) and microcalcification (OR: 3.093, P = 0.017) were significantly associated with BRAF mutation in patients without HT. In conclusion, older age and microcalcification are risk factors for BRAF mutation in PTC patients, especially in those without HT. For those with HT, however, PTCs with BRAF mutation tend to be solid on ultrasound. These factors might be considered when making treatment planning or prognosis evaluation.

Cytotoxic and genotoxic effects of 131 I and 60 Co in follicular thyroid cancer cell (WRO) with and without recombinant human thyroid-stimulating hormone treatment

Normally, differentiated thyroid cancer (DTC) tends to be biologically indolent, highly curable and has an excellent prognosis. However, the treatment may fail when the cancer has lost radioiodine avidity. The present study was carried out in order to evaluate the cytotoxic and genotoxic effects of ¹³¹ I and ⁶⁰ Co and radioiodine uptake in WRO cells, derived from DTC, harboring the BRAF^V600E mutation. WRO cells showed a relatively slow cell cycle of 96.3 h with an unstable karyotype containing various double minutes. The genotoxicity assay (micronucleus test) showed a relative high radioresistance to ¹³¹ I (0.07-3.70 MBq/mL), independent of treatment with recombinant human thyroid-stimulating hormone (rhTSH). For the cytotoxicity assay, WRO cells were also relatively resistant to ⁶⁰ Co (range: 0.2-8.3 Gy), but with a gradual decrease of viability as a function of time for higher doses (20 and 40 Gy, starting from the fifth to sixth day). For internal irradiation with ¹³¹ I, WRO cells showed a decline in viability at radioactive concentration higher than 1.85 MBq/mL; this was even more effective at 3.70 MBq/mL, but only when preceded by rhTSH, in coincidence with the highest level of ¹³¹ I uptake. These data show promising results, since the loss of the ability of thyroid cells to concentrate radioiodine is considered to be one of the main factors responsible for the failure of ¹³¹ I therapy in patients with DTC. The use of tumor-derived cell lines as a model for in vivo tumor requires, however, further investigations and deep evaluation of the corresponding in vivo effects. Environ. Mol. Mutagen. 58:451-461, 2017. © 2017 Wiley Periodicals, Inc.

Quantitative NMR analysis of intra- and extracellular metabolism of mammalian cells: A tutorial

Metabolomics analysis of body fluids as well as cells is depended on many factors. While several well-accepted standard operating procedures for the analysis of body fluids are available, the NMR based quantitative analysis of cellular metabolites is less well standardized. Experimental designs depend on the cell type, the quenching protocol and the applied post-acquisition workflow. Here, we provide a tutorial for the quantitative description of the metabolic phenotype of mammalian cells using NMR spectroscopy. We discuss all key steps of the process, starting from the selection of the appropriate culture medium, quenching techniques to arrest metabolism in a reproducible manner, the extraction of the intracellular components and the profiling of the culture medium. NMR data acquisition and methods for both qualitative and quantitative analysis are also provided. The suggested methods cover experiments for adherent cells and cells in suspension. We ultimately describe the application of the discussed workflow to a thyroid cancer cell line. Although this tutorial focuses on mammalian cells, the given guidelines and procedures may be adjusted for the analysis of other cell types.

Indications and extent of central neck dissection for papillary thyroid cancer: An American Head and Neck Society Consensus Statement

BACKGROUND

The primary purposes of this interdisciplinary consensus statement were to review the relevant indications for central neck dissection (CND) in patients with papillary thyroid cancer (PTC) and to outline the appropriate extent and relevant techniques required to accomplish a safe and effective CND.

METHODS

A writing group convened by the American Head and Neck Society (AHNS) Endocrine Committee was tasked with identifying the important clinical elements to consider when managing the central neck compartment in patients with PTC based on available evidence in the literature, and the group's collective experience. The position statement paper was then submitted to the full Endocrine Committee, Education Committee, and AHNS Council.

RESULTS

This consensus statement was developed to inform the clinical decision-making process when managing the central neck compartment in patients with PTC from the AHNS. This document is intended to provide clarity through definitions as well as a basic guideline from which to manage the central neck. It is our hope that this improves the quality and reduces variation in management of the central neck, facilitates communication, and furthers research for patients with thyroid cancer.

CONCLUSION

This represents, in our opinion, contemporary optimal surgical care for this patient population and is endorsed by the American Head and Neck Society. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1269-1279, 2017.

Tumour suppressive function of HUWE1 in thyroid cancer

HUWE1 (the HECT, UBA, and WWE domain-containing protein 1) is an ubiquitin E3 ligase which plays an important role in coordinating diverse cellular processes. It has been found to be dysregulated in various cancer type and its functions in tumorigenesis remain controversial. The potential tumour suppressive role of HUWE1 in thyroid cancer development was investigated by knocking down HUWE1 in three authentic thyroid cancer cell lines, WRO, FTC133 and BCPAP, followed by various functional assays, including cell proliferation, scratch wound healing and invasion assays. Xenograft experiment was performed to examine in vivo tumour suppressive properties of HUWE1. Small-interfering RNA mediated knockdown of HUWE1 promoted cell proliferation, cell migration and invasion in thyroid cancer cells. Overexpression of HUWE1 conferred partial sensitivity to chemo drugs interfering with DNA replication in these cells. Moreover, HUWE1 was found to be down-regulated in human thyroid cancer tissues compared with matched normal thyroid tissues. In addition, overexpression of HUWE1 significantly inhibited tumour growth in vivo using xenograft mouse models. Mechanistic investigation revealed that HUWE1 can regulate p53 protein level through its stabilization. HUWE1 functions as a tumour suppressor in thyroid cancer progression, which may represent a novel therapeutic target for prevention or intervention of thyroid cancer.

Identification of Specific Long Non-Coding RNA Expression: Profile and Analysis of Association with Clinicopathologic Characteristics and BRAF Mutation in Papillary Thyroid Cancer

BACKGROUND

In recent years, long non-coding RNAs (lncRNAs) have been shown to play a critical regulatory role in cancer biology. However, the contribution of lncRNAs to papillary thyroid cancer (PTC) remains largely unknown.

METHODS

RNA sequencing and quantitative reverse transcription polymerase chain reaction were used to detect and verify changes to the transcriptome profile in 12 PTC tissues compared to paired normal adjacent tissues. The statistical correlation between differentially expressed lncRNAs and clinicopathologic characteristics was analyzed, and potential lncRNA functions were predicted by examining annotations for the co-expressed mRNAs. Furthermore, the specific subgroup patterns of the PTC transcriptome remodeled by BRAF mutations were also analyzed.

RESULTS

A total of 188 lncRNAs and 505 mRNAs were differentially expressed in 50% or more of the PTC tissues (fold change >2; p < 0.05) as assessed by RNA-sequencing compared with paired normal adjacent tissues. Forty-seven lncRNAs and 39 mRNAs were verified in 31 pairs of PTC specimens using quantitative reverse transcription polymerase chain reaction, and the results were consistent with the RNA sequencing data. The lncRNAs NONHSAT076747 and NONHSAT122730 were associated with lymph node metastasis, and NONHSAG051968 expression was negatively correlated with tumor size. A co-expression network between differentially expressed lncRNAs and protein-coding RNAs was constructed and analyzed, and functional analysis suggested that the differentially expressed genes mainly participate in ECM-receptor interactions and the focal adhesion pathway. Furthermore, a specific PTC transcriptome subtype pattern stratified by BRAF mutation was also uncovered. The p53 signaling pathway was the most highly enriched pathway among the BRAF mutation-related genes.

CONCLUSIONS

This study reveals specific changes to the lncRNA profile associated with PTC, and provides new insight into its pathogenesis. The PTC-associated lncRNAs NONHSAG051968, NONHSAT076747, and NONHSAT122730 might be potential diagnostic and therapeutic targets for PTC patients, and lncRNAs with subtype-specific expression stratified by BRAF mutation might be significant in individual molecular subtypes.

BRAFV600E mutation as a predictor of thyroid malignancy in indeterminate nodules: A systematic review and meta-analysis

BACKGROUND

Thyroid nodules are usually diagnosed using fine-needle aspiration (FNA). The sensitivity limitations of FNA result in 10-30% of nodules being classified as "indeterminate". The BRAF^V600E mutation is associated with papillary thyroid carcinoma (PTC). We conducted a systemic review and meta-analysis to evaluate the diagnostic utility of the BRAF^V600E mutation in indeterminate nodules.

METHOD

PUBMED and EMBASE were searched for studies testing for the BRAF^V600E involving indeterminate nodules (Thy3a, Thy3f, Thy4) and containing information on final surgical histopathology. Thirty two studies involving 3150 indeterminate nodules were included in the analysis.

RESULTS

The overall sensitivity and specificity for BRAF^V600E for the diagnosis of thyroid malignancy was 0.40 (95% CI: 0.32-0.48) and 1.00 (95% CI: 0.98-1.00) respectively. The diagnostic odds ratio (DOR) was 205.4 (95% CI: 40.1-1052). With a Fagan plot, the post-test probability of thyroid cancer, given a negative mutation was 6%, but this rose to 92% with a positive result. On subgroup analysis, for Thy3a nodules, the pooled sensitivity and specificity for thyroid malignancy was 0.21 (95% CI: 0.13-0.34) and 1.00 (95% CI: 0.98-1.00). For Thy3f nodules, the pooled sensitivity and specificity was 0.09 (95% CI: 0.03-0.20) and 1.00 (95% CI: 0.05-1.00) respectively. For Thy4 nodules, the corresponding sensitivity and specificity was 0.58 (95% CI: 0.5-0.64) and 0.99 (95% CI: 0.95-1.00) respectively.

CONCLUSIONS

Despite a high specificity for thyroid cancer, BRAF^V600E mutation has a low overall sensitivity and therefore has a limited diagnostic value as a single screening test.

Long intergenic non-coding RNA 271 is predictive of a poorer prognosis of papillary thyroid cancer

A number of long non-coding RNAs (lncRNAs) have been found to play critical roles in oncogenesis and tumor progression. We aimed to investigate whether lncRNAs could act as prognostic biomarkers for papillary thyroid cancer (PTC) that may assist us in evaluating disease status and prognosis for patients. We found 220 lncRNAs with expression alteration from the annotated 2773 lncRNAs approved by the HUGO gene nomenclature committee in The Cancer Genome Atlas (TCGA) dataset, of which FAM41C, CTBP1-AS2, LINC00271, HAR1A, LINC00310 and HAS2-AS1 were associated with recurrence. After adjusting classical clinicopathogical factors and BRAF^V600E mutation, LINC00271 was found to be an independent risk factor for extrathyroidal extension, lymph node metastasis, advanced tumor stage III/IV and recurrence in multivariate analyses. Additionally, LINC00271 expression was significantly downregulated in PTCs versus adjacent normal tissues (P < 0.001). The Gene Set Enrichment Analysis (GSEA) revealed that genes associated with cell adhesion molecules, cell cycle, P53 signaling pathway and JAK/STAT signaling pathway were remarkably enriched in lower-LINC00271 versus higher-LINC00271 tumors. In conclusion, LINC00271 was identified as a possible suppressor gene in PTC in our study, and it may serve as a potential predictor of poor prognoses in PTC.

[Intracellular signaling mechanisms in thyroid cancer]

BACKGROUND

Thyroid cancer is the most common malignancy of the endocrine system, the papillary variant accounts for 80-90% of all diagnosed cases. In the development of papillary thyroid cancer, BRAF and RAS genes are mainly affected, resulting in a modification of the system of intracellular signaling proteins known as «protein kinase mitogen-activated» (MAPK) which consist of «modules» of internal signaling proteins (Receptor/Ras/Raf/MEK/ERK) from the cell membrane to the nucleus. In thyroid cancer, these signanling proteins regulate diverse cellular processes such as differentiation, growth, development and apoptosis. MAPK play an important role in the pathogenesis of thyroid cancer as they are used as molecular biomarkers for diagnostic, prognostic and as possible therapeutic molecular targets. Mutations in BRAF gene have been correlated with poor response to treatment with traditional chemotherapy and as an indicator of poor prognosis.

OBJECTIVE

To review the molecular mechanisms involved in intracellular signaling of BRAF and RAS genes in thyroid cancer.

CONCLUSIONS

Molecular therapy research is in progress for this type of cancer as new molecules have been developed in order to inhibit any of the components of the signaling pathway (RET/PTC)/Ras/Raf/MEK/ERK; with special emphasis on the (RET/PTC)/Ras/Raf section, which is a major effector of ERK pathway.

Significance of the BRAF mRNA Expression Level in Papillary Thyroid Carcinoma: An Analysis of The Cancer Genome Atlas Data

Background

BRAF^V600E is the most common mutation in papillary thyroid carcinoma (PTC), and it is associated with high-risk prognostic factors. However, the significance of the BRAF mRNA level in PTC remains unknown. We evaluated the significance of BRAF mRNA expression level by analyzing PTC data from The Cancer Genome Atlas (TCGA) database.

Methods

Data from 499 patients were downloaded from the TCGA database. After excluding other PTC variants, we selected 353 cases of classic PTC, including 193 cases with BRAF^V600E and 160 cases with the wild-type BRAF. mRNA abundances were measured using RNA-Seq with the Expectation Maximization algorithm.

Results

The mean BRAF mRNA level was significantly higher in BRAF^V600E patients than in patients with wild-type BRAF (197.6 vs. 179.3, p = 0.031). In wild-type BRAF patients, the mean BRAF mRNA level was higher in cases with a tumor > 2 cm than those with a tumor ≤ 2.0 cm (189.4 vs. 163.8, p = 0.046), and was also higher in cases with lymph node metastasis than in those without lymph node metastasis (188.5 vs. 157.9, p = 0.040). Within BRAF^V600E patients, higher BRAF mRNA expression was associated with extrathyroidal extension (186.4 vs. 216.4, p = 0.001) and higher T stage (188.1 vs. 210.2, p = 0.016).

Conclusions

A higher BRAF mRNA expression level was associated with tumor aggressiveness in classic PTC regardless of BRAF mutational status. Evaluation of BRAF mRNA level may be helpful in prognostic risk stratification of PTC.

Relevance of BRAF and NRAS mutations in the primary tumor and metastases of papillary thyroid carcinomas

BACKGROUND

Multifocality of papillary thyroid carcinoma (PTC) is common. BRAF and NRAS mutations are the most frequent genetic alterations in PTC. The purpose of this study was to determine the distribution and relevance of BRAF^T1799A and NRAS mutations in PTC.

METHODS

BRAF^T1799A and NRAS mutations were evaluated in 195 intrathyroid or metastatic foci from 29 patients with multifocal PTC.

RESULTS

BRAF^T1799A mutation was positive in 46.7% of the 59 intrathyroid and 136 metastatic foci (91/195 foci). Heterogeneous BRAF pattern was observed in 51.7% patients (15/29 patients). Irrespective of BRAF status at diagnosis (thyroid or nodes), all patients with recurrent PTC presented BRAF-mutated metastases during follow-up. All foci were negative for NRAS mutations.

CONCLUSION

BRAF but not NRAS mutations were heterogeneously distributed among primary tumor, nodal sites, and recurrent disease. The BRAF status of metastases generated during the follow-up can differ from the status of foci at diagnosis. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1772-1779, 2016.

Classic Architecture with Multicentricity and Local Recurrence, and Absence of TERT Promoter Mutations are Correlates of BRAF (V600E) Harboring Pediatric Papillary Thyroid Carcinomas

This study is aimed to investigate the BRAF (V600E) and TERT promoter mutation profile of 50 pediatric papillary thyroid carcinomas (PTCs) to refine their clinicopathological correlates. The median age at the time of surgery was 16 years (range, 6-18). No TERT promoter mutations were identified in this series. The BRAF (V600E) mutation was present in 15 (30 %) tumors. From genotype-histologic variant correlation perspective, 13 of 24 classic variant PTCs and 2 of 7 diffuse sclerosing variant PTCs were found to harbor BRAF (V600E) mutation. One cribriform-morular variant, 3 solid variant, and 15 follicular variant PTCs were BRAF wild type. While tumors with distant metastasis were BRAF wild type, two of five tumors with extrathyroidal extension (ETE) harbored BRAF (V600E) mutation. Nine of 15 BRAF (V600E) harboring tumors had central lymph node metastases. There was no significant correlation with BRAF (V600E) mutation and age, gender, tumor size, ETE, central lymph node metastasis, the status of pT, pN1a-b, and distant metastasis. An adverse correlation between BRAF (V600E) mutation and disease-free survival (DFS) was noted in the entire cohort; however, the predictive value of BRAF (V600E) mutation disappeared within the group of tumors displaying classic architecture as well as classic variant PTCs. The present cohort identifies that the classic architecture with multicentricity and local recurrence are correlates of BRAF (V600E) harboring pediatric PTCs. While the small size of this cohort is one of the limitations, neither the BRAF mutation status nor the classic tumor architecture does seem to be an independent prognosticator of DFS in this series. Evidence also suggests that TERT promoter mutations do not seem to play a major role in the pathogenesis of pediatric PTCs.