BRAF V600E mutation in prognostication of papillary thyroid cancer (PTC) recurrence

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.

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.

Molecular Markers Are Associated with Onset of Radioiodine Refractoriness in Patients with Papillary Thyroid Carcinoma

The onset of radioiodine-refractory thyroid carcinoma (RR-TC) is a negative predictor of survival and has been linked to the presence of BRAFV600E mutations in papillary thyroid cancer. We aimed to identify further genetic alterations associated with RR-TC. Methods: We included 38 patients with papillary thyroid cancer who underwent radioiodine imaging and 18F-FDG PET/CT after total thyroidectomy. The molecular profile was assessed by next-generation sequencing. The time to the onset of RR-TC for different genetic alterations was compared using the log-rank test. Results: The median onset to RR-TC was 0.7 and 19.8 mo in patients with and without, respectively, telomerase reverse transcriptase promoter mutations (P = 0.02) and 1.7 and 19.8 mo in patients with and without, respectively, a tumor protein 53 mutation (P < 0.01). This association was not observed for BRAFV600E mutations (P = 0.49). Conclusion: Our data show a significant association between the onset of RR-TC and mutations in telomerase reverse transcriptase promoter and tumor protein 53, indicating the need for a more extensive diagnostic workup in these patients. Certain genetic changes put patients with thyroid cancer at risk of developing cancer spread that does not respond to radioiodine therapy.

BRAFV600E Positivity-Dependent Effect of Age on Papillary Thyroid Cancer Recurrence Risk

BRAFV600E positivity is associated with increased aggressiveness of papillary thyroid cancer (PTC), and age is an important prognostic factor. However, the association between age and BRAFV600E positivity and the recurrence risk has not been investigated. This study aimed to investigate the impact of age on recurrence between patients with BRAFV600E-positive and -negative PTC. Patients with PTC who underwent initial thyroid surgery between January 2010 and December 2018 at Seoul St. Mary's Hospital (Seoul, Republic of Korea) were retrospectively reviewed. The BRAFV600E-positive (n = 1768) and BRAFV600E-negative groups (n = 428) were divided into two subgroups: younger (<35 years) and older groups (≥55 years). In the BRAFV600E-positive group, the younger group exhibited higher lymphatic and vascular invasion rates, more positive lymph nodes, higher lymph node ratios, and higher recurrence rates than the older group (5.9% vs. 2.1%). Multivariate analysis revealed that age, lymphatic invasion, and N category were significant risk factors in the BRAFV600E-positive group. In the BRAFV600E-positive group, the younger group had a higher recurrence risk than the older group (OR, 2.528; 95% confidence interval, 1.443-4.430; p = 0.001). In the BRAFV600E-negative group, age had no impact on recurrence risk. These results contribute to tailored treatment strategies and informed patient management.

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.

BRAF, TERT and HLA-G Status in the Papillary Thyroid Carcinoma: A Clinicopathological Association Study

As BRAF, TERT, HLA-G, and microRNAs have been individually associated with papillary thyroid carcinoma (PTC), we aimed to evaluate the individual and collaborative role of these markers in PTC in the same patient cohort. HLA-G and BRAF tumor expression was evaluated by immunohistochemistry. Using molecular methods, BRAFV600E and TERT promoter mutations were evaluated in thyroid fine needle aspirates. MicroRNA tumor profiling was investigated using massively parallel sequencing. We observed strong HLA-G (67.96%) while BRAF (62.43%) staining was observed in PTC specimens. BRAF overexpression was associated with poor response to therapy. The BRAFV600E (52.9%) and TERTC228T (13%) mutations were associated with extrathyroidal extension, advanced-age, and advanced-stage cancer. The TERT rs2853669 CC+TC genotypes (38%) were overrepresented in metastatic tumors. Nine modulated microRNAs targeting the BRAF, TERT, and/or HLA-G genes were observed in PTC and involved with cancer-related signaling pathways. The markers were individually associated with PTC features, emphasizing the synergistic effect of BRAFV600E and TERTC228T; however, their collaborative role on PTC outcome was not fully demonstrated. The differentially expressed miRNAs targeting the BRAF and/or HLA-G genes may explain their increased expression in the tumor milieu.

Predicting BRAFV600E mutations in papillary thyroid carcinoma using six machine learning algorithms based on ultrasound elastography

The most common BRAF mutation is thymine (T) to adenine (A) missense mutation in nucleotide 1796 (T1796A, V600E). The BRAFV600E gene encodes a protein-dependent kinase (PDK), which is a key component of the mitogen-activated protein kinase pathway and essential for controlling cell proliferation, differentiation, and death. The BRAFV600E mutation causes PDK to be activated improperly and continuously, resulting in abnormal proliferation and differentiation in PTC. Based on elastography ultrasound (US) radiomic features, this study seeks to create and validate six distinct machine learning algorithms to predict BRAFV6OOE mutation in PTC patients prior to surgery. This study employed routine US strain elastography image data from 138 PTC patients. The patients were separated into two groups: those who did not have the BRAFV600E mutation (n = 75) and those who did have the mutation (n = 63). The patients were randomly assigned to one of two data sets: training (70%), or validation (30%). From strain elastography US images, a total of 479 radiomic features were retrieved. Pearson's Correlation Coefficient (PCC) and Recursive Feature Elimination (RFE) with stratified tenfold cross-validation were used to decrease the features. Based on selected radiomic features, six machine learning algorithms including support vector machine with the linear kernel (SVM_L), support vector machine with radial basis function kernel (SVM_RBF), logistic regression (LR), Naïve Bayes (NB), K-nearest neighbors (KNN), and linear discriminant analysis (LDA) were compared to predict the possibility of BRAFV600E. The accuracy (ACC), the area under the curve (AUC), sensitivity (SEN), specificity (SPEC), positive predictive value (PPV), negative predictive value (NPV), decision curve analysis (DCA), and calibration curves of the machine learning algorithms were used to evaluate their performance. ① The machine learning algorithms' diagnostic performance depended on 27 radiomic features. ② AUCs for NB, KNN, LDA, LR, SVM_L, and SVM_RBF were 0.80 (95% confidence interval [CI]: 0.65-0.91), 0.87 (95% CI 0.73-0.95), 0.91(95% CI 0.79-0.98), 0.92 (95% CI 0.80-0.98), 0.93 (95% CI 0.80-0.98), and 0.98 (95% CI 0.88-1.00), respectively. ③ There was a significant difference in echogenicity,vertical and horizontal diameter ratios, and elasticity between PTC patients with BRAFV600E and PTC patients without BRAFV600E. Machine learning algorithms based on US elastography radiomic features are capable of predicting the likelihood of BRAFV600E in PTC patients, which can assist physicians in identifying the risk of BRAFV600E in PTC patients. Among the six machine learning algorithms, the support vector machine with radial basis function (SVM_RBF) achieved the best ACC (0.93), AUC (0.98), SEN (0.95), SPEC (0.90), PPV (0.91), and NPV (0.95).

Hashimoto's Thyroiditis: A Protective Factor against Recurrence in BRAF-Wild Type Differentiated Thyroid Carcinoma

A recent work analyzing the concomitant factors BRAF mutation (risk factor) and Hashimoto's thyroiditis (HT) (protective factor) found that the presence of HT reduced lymph node metastasis in BRAF-mutated papillary thyroid carcinoma. Whether this notion is upheld with respect to disease recurrence and differentiated thyroid carcinoma (DTC), however, is unknown. We aimed to investigate the effect of underlying HT in DTC patients and its influence on recurrence with a specific emphasis in BRAF-mutated tumors. A total of 469 patients were included. Patients were stratified according to BRAF and HT status. Multivariate regression analysis was conducted to determine protective and risk factors of disease recurrence in patients with DTC. HT was associated with less-aggressive carcinomas including more frequent microcarcinomas (HT: 45.0% vs. no-HT: 34.0%, p = 0.02), less lymph node involvement (HT: 16.4% vs. no-HT: 26.1%, p = 0.02), and less disease recurrence (HT: 2.9% vs. no-HT: 11.9%, p = 0.002). BRAF mutation was also significantly associated with higher rates of lymph node involvement (BRAF-mutant: 41.9% vs. BRAF-wild type: 14.6%, p < 0.001) and almost two times the rate of recurrence (BRAF-mutant: 14.9% vs. BRAF-wild type: 6.5%, p = 0.004). Underlying HT was the only protective factor determined, reducing the odds of developing recurrence by 70% (HR: 0.30, 95%CI: 0.11-0.88). In the BRAF-wild type cohort, regression analysis continued to determine HT as a protective factor (p = 0.03). However, in the BRAF-mutant cohort, HT was no longer an independent protective factor (p = 0.20) against recurrence. Sub-group regression analysis, including PTC patients, similarly found HT as a protective factor only in BRAF-wild type patients (p = 0.039) and not BRAF-mutant (p = 0.627). The presence of underlying HT is associated with less aggressive tumors and is an independent protective factor against DTC recurrence, reducing the risk by 70%. HT remains a protective factor in BRAF-wild type carcinoma, but not in patients with BRAF-mutant carcinoma. HT may potentially be considered as a parameter which enhances American Thyroid Association patient risk stratification.

The Emerging Roles of circRNAs in Papillary Thyroid Carcinoma: Molecular Mechanisms and Biomarker Potential

Papillary thyroid carcinoma (PTC) is a common endocrine malignant tumor. The incidence of PTC has increased in the past decades and presents a younger trend. Accumulating evidence indicates that circular RNAs (circRNAs), featured with non-linear, closed-loop structures, play pivotal roles in tumorigenesis and regulate cell biological processes, such as proliferation, migration, and invasion, by acting as microRNA (miRNA) sponges. Additionally, due to their unique stability, circRNAs hold promising potential as diagnostic biomarkers and effective therapeutic targets for PTC treatment. In this review, we systematically arrange the expression level of circRNAs, related clinical characteristics, circRNA-miRNA-mRNA regulatory network, and molecular mechanisms. Furthermore, related signaling pathways and their potential ability of diagnostic biomarkers and therapeutic targets are discussed, which might provide a new strategy for PTC diagnosis, monitoring, and prognosis.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic and prognostic value of Stanniocalcin 1 expression in papillary thyroid cancer

PURPOSE

To evaluate the potential role of immunohistochemical changes in stanniocalcin 1 (STC1) and stanniocalcin 2 (STC2) expressions in papillary thyroid cancer (PTC) tissues in the disease's diagnosis and to investigate their relationship with classical clinicopathological prognostic factors.

METHODS

The study included 100 patients with PTC. Normal thyroid tissue adjacent to the tumor was taken as the control group. Clinicopathological prognostic features at the time of diagnosis of patients were recorded. STC1 and STC2 expressions of tumor tissue and adjacent normal tissue were determined immunohistochemically.

RESULTS

The sensitivity of STC1 in the diagnosis of PTC was 93%, the specificity was 94%, positive predictive value (PPV) 93.9%, and negative predictive value (NPV) 93.1%. It was determined that the STC1 staining score in tumor tissue was positively correlated with the disease TNM stage score (r = 0.259, p = 0.009) and the increase in STC1 staining score were independent risk factors that increased the risk of lymph node metastasis (R² = 0.398, p < 0.001). While 21% of the tumor tissues were stained with STC2, none of the normal thyroid tissues adjacent to the tumor tissue showed any staining with STC2. No correlation was found between STC2 immunohistochemical staining of tumor tissue and clinicopathological risk factors for the disease.

CONCLUSION

Increased STC1 expression in thyroid lesions may be helpful in diagnosing PTC. In addition, since increased STC1 expression in PTC tissues is associated with the risk of lymph node metastasis, it may be an efficient marker for predicting the prognosis of the disease.

A Potential Four-Gene Signature and Nomogram for Predicting the Overall Survival of Papillary Thyroid Cancer

Background. Although the prognosis of papillary thyroid cancer (PTC) is relatively good, some patients experience recurrence or distant metastasis after thyroidectomy and progress to radioactive iodine refractory stage. Therefore, accurate prediction of clinical outlook can aid to screen out the minority of patients with poorer prognosis and avoid excessive treatment in low-risk patients. Methods. The RNA-seq and clinical data of PTC patients was downloaded from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) databases. Multivariate and Lasso Cox regression analyses were used to construct a prognostic nomogram to predict overall survival (OS). Thereafter, quantitative RT-PCR and Human Protein Atlas (HPA) database were employed to verify the expression of key genes. Results. A four-gene risk score comprising ABI3BP, DPT, MRO, and TENM1 was exhibited strong prognostic value. Moreover, an integrated nomogram was established based on the risk score, age, AJCC (American Joint Commission on Cancer) stage, tumor size, extrathyroidal extension, and history of neoadjuvant treatment, which exhibited significantly better predictive performance than TNM stage system ( $P<0.05$ ). GSEA (Gene Set Enrichment Analysis) and GSVA (Gene Set Variation Analysis) revealed that the different tumor-associated hallmarks, biological processes, and pathways were substantially enriched in the poor-prognosis group. In addition, a ceRNA network was constructed by including the four genes (ABI3BP, DPT, MRO, and TENM1), 54 lncRNAs, and 10 miRNAs. Finally, both the relative mRNA and protein expression of ABI3BP, DPT, MRO, and TENM1 were validated. Conclusion. The present study identified a four-gene risk signature and developed a novel nomogram, which could be regarded as a reliable prognostic model for PTC patients. The findings also revealed preliminary potential mechanisms that may influence the prognosis outcome. These results can be conducive to design personalized treatment and prognosis management in affected patients.

Relationship Between The BRAF V600E And Tumor Size, Lymph Node, And Distant Metastasis In Papillary Thyroid Carcinoma

Aim – This study aimed to analyze the association between B-Raf proto-oncogene, serine/threonine kinase (BRAF) V600E and tumor size, lymph node, and distant metastasis (TNM) status on patients with papillary thyroid carcinoma. Material and Methods – This research is a cross-sectional study. A total of 40 samples were papillary thyroid carcinoma tissue paraffin blocks from thyroidectomy surgery at State General Hospital (RSUP) Dr. Kariadi Semarang. Assessment of BRAF V600E mutation protein expression through immunohistochemical methods using antibody BRAF V600E was conducted. Results – The mean age of patients with papillary thyroid carcinoma with a positive BRAF V600E mutation was 49 years. The highest incidence was 71.4% in women. A significant difference between BRAF V600E and tumor size (p=0.03) was observed with as many as 53.2% more cases at size > 4 cm. A significant difference in the expression of BRAF V600E with enlargement of the lymph node (p=0.011) by 60.7% was observed compared to those without enlarged lymph nodes. On the other hand, no significant relationship between BRAF V600E expression and distant metastasis (p=0.652) was observed. The prevalence ratio in the positive BRAF V600E case at tumor size is more than 4 cm, and enlargement of lymph is 9.533 and 7.727. Conclusion – There is a significant relationship between BRAF V600E expression and tumor size and enlarged lymph nodes, while there is no significant relationship between BRAF V600E expression and distant metastases.

Is Gross Extrathyroidal Extension to Strap Muscles (T3b) Only a Risk Factor for Recurrence in Papillary Thyroid Carcinoma? A Propensity Score Matching Study

Simple Summary

In papillary thyroid carcinoma (PTC), staging classification of gross and minimal extrathyroidal extension (ETE) has been recently modified in the eighth edition of the American Joint Commission on Cancer/Union for International Cancer Control (AJCC/UICC) TNM staging system. In this study, we compared the clinicopathological characteristics and recurrence rates between minimal and gross ETE. No significant differences in the recurrence and disease-free survival rates were found between the two groups. Whether gross ETE invading strap muscles (T3b) only could be a risk factor for recurrence in PTC remains questionable.

Abstract

The presence of extrathyroidal extension (ETE) is associated with locoregional recurrence and distant metastases in papillary thyroid carcinoma (PTC). This study was designed to compare the recurrence risk between minimal ETE (mETE) and gross ETE (gETE) in patients with PTC using propensity score matching. In this study, 4452 patients with PTC who underwent thyroid surgery in a single center were retrospectively analyzed, and clinicopathological characteristics were compared according to the ETE status. Disease-free survival (DFS) and recurrence risk were compared between mETE and gETE after propensity score matching. The mean follow-up duration was 122.7 ± 22.5 months. In multivariate analysis, both mETE and gETE were not associated with recurrence risk before propensity score matching (p = 0.154 and p = 0.072, respectively). After propensity score matching, no significant difference in recurrence rates was observed between the two groups (p = 0.668). DFS of the gETE group did not significantly differ from that of the mETE group (log-rank p = 0.531). This study revealed that both mETE and gETE are not independent risk factors for the risk of recurrence in PTC. Our findings suggest that gETE invading strap muscles only might not be associated with worse oncological outcomes in PTC.

Radiomic Model for Determining the Value of Elasticity and Grayscale Ultrasound Diagnoses for Predicting BRAFV600E Mutations in Papillary Thyroid Carcinoma

BRAF^V600E is the most common mutated gene in thyroid cancer and is most closely related to papillary thyroid carcinoma(PTC). We investigated the value of elasticity and grayscale ultrasonography for predicting BRAF^V600E mutations in PTC.

METHODS

138 patients with PTC who underwent preoperative ultrasound between January 2014 and 2021 were retrospectively examined. Patients were divided into BRAF^V600E mutation-free group (n=75) and BRAF^V600E mutation group (n=63). Patients were randomly divided into training (n=96) and test (n=42) groups. A total of 479 radiomic features were extracted from the grayscale and elasticity ultra-sonograms. Regression analysis was done to select the features that provided the most information. Then, 10-fold cross-validation was used to compare the performance of different classification algorithms. Logistic regression was used to predict BRAF^V600E mutations.

RESULTS

Eight radiomics features were extracted from the grayscale ultrasonogram, and five radiomics features were extracted from the elasticity ultrasonogram. Three models were developed using these radiomic features. The models were derived from elasticity ultrasound, grayscale ultrasound, and a combination of grayscale and elasticity ultrasound, with areas under the curve (AUC) 0.952 [95% confidence interval (CI), 0.914-0.990], AUC 0.792 [95% CI, 0.703-0.882], and AUC 0.985 [95% CI, 0.965-1.000] in the training dataset, AUC 0.931 [95% CI, 0.841-1.000], AUC 0. 725 [95% CI, 0.569-0.880], and AUC 0.938 [95% CI, 0.851-1.000] in the test dataset, respectively.

CONCLUSION

The radiomic model based on grayscale and elasticity ultrasound had a good predictive value for BRAF^V600E gene mutations in patients with PTC.

Predicting malignancy in thyroid nodules with benign cytology results: The role of Conventional Ultrasound, Shear Wave Elastography and BRAF V600E

BACKGROUND: Ultrasound-guided fine-needle aspiration (US-FNA) is the most accurate method for preoperative diagnosis of thyroid nodules, but how to deal with false negative results. OBJECTIVE: This study aimed to find preoperative diagnosis methods including Conventional Ultrasound (CUS), Shear Wave Elastography (SWE) and BRAF V600E testing to differentiate false negative nodules. METHODS: Forty-nine nodules in 49 patients with benign FNA results and pathological diagnoses were included. CUS and SWE features were evaluated. BRAF V600E analysis was performed after FNA. Diagnostic performances of three methods were analyzed in predicting malignancy in benign FNA results. RESULTS: Twenty-seven of 49 nodules were malignant, and 22 nodules were benign. Hypoechogenicity, taller-than-wider, irregular boundary, microcalcification, SWE max, SWE mean and BRAF V600E mutation were risk factors for malignancy. All 7 malignant nodules with BRAF V600E mutations and 18 of 20 malignant nodules without BRAF V600E mutations have two or more suspicious CUS features. Six of 7 malignant nodules with BRAF V600E mutations and 16 of 20 malignant nodules without BRAF V600E mutations had SWE mean value greater than the cut-off value. CONCLUSIONS: CUS, SWE and BRAF V600E were diagnostic tools for malignancy in FNA benign nodules. Further clinical decisions should be considered for nodules with 2 or more suspicious CUS features and SWE parameters greater than cut-off values whether BRAF V600E is mutational or not.

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.

Papillary Thyroid Cancer Prognosis: An Evolving Field

Simple Summary

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

Abstract

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

Novel Inhibitor-Based Therapies for Thyroid Cancer-An Update

Thyroid cancers (TCs) are the most common tumors of the endocrine system and a constant rise in the number of TC cases has been observed for the past few decades. TCs are one of the most frequent tumors in younger adults, especially in women, therefore early diagnosis and effective therapy are especially important. Ultrasonography examination followed by fine needle biopsy have become the gold standard for diagnosis of TCs, as these strategies allow for early-stage detection and aid accurate qualification for further procedures, including surgical treatment. Despite all the advancements in detection and treatment of TCs, constant mortality levels are still observed. Therefore, a novel generation line of targeted treatment strategies is being developed, including personalized therapies with kinase inhibitors. Recent molecular studies on TCs demonstrate that kinase inhibitor-based therapies might be considered as the most promising. In the past decade, new kinase inhibitors with different mechanisms of action have been reported and approved for clinical trials. This review presents an up-to-date picture of new approaches and challenges of inhibitor-based therapies in treatment of TCs, focusing on the latest findings reported over the past two years.

Osteopontin Expression in Thyroid Cancer: Deciphering EMT-Related Molecular Mechanisms

Thyroid cancer is the most common tumor arising from the endocrine system and generally presents good prognosis. However, its aggressive subtypes are related to therapeutic resistance and early metastasis. Epithelial–mesenchymal transition (EMT) and its reverse process, the mesenchymal–epithelial transition (MET), are key events mediating cancer progression, including in thyroid cancer. The matricellular protein osteopontin (OPN) has been reported as a master regulator of EMT in many tumor types. Although high OPN expression has been described and associated with important aspects of thyroid cancer progression, there is no clear evidence regarding OPN as a regulator of EMT in thyroid cancer. Thus, taking together the known roles of OPN in the modulation of EMT in cancer and the information reporting the expression of OPN in thyroid tumor progression, this review aims at summarizing and discussing data related to EMT in thyroid cancer and its putative relation to the roles of OPN in the development of thyroid cancer. These data provide new insights into the molecular mechanisms by which OPN could potentially modulate EMT in thyroid tumors, generating evidence for future studies that may contribute to new therapeutic, prognostic and/or diagnostic tools.

Development of a Molecular Assay for Detection and Quantification of the BRAF Variation in Residual Tissue From Thyroid Nodule Fine-Needle Aspiration Biopsy Specimens

Importance

Thyroid cancer, predominantly papillary thyroid carcinoma (PTC), is common, but an estimated 30% of ultrasonography-guided fine-needle aspiration (FNA) biopsies of thyroid nodules are indeterminate. BRAF variation, associated with poor clinicopathological characteristics, is a useful molecular marker for diagnostics.

Objective

To develop a sensitive molecular assay for BRAF V600E detection in remaining tissue of thyroid FNA biopsies to identify patients with cancer carrying a BRAF variation.

Design, Setting, and Participants

This diagnostic study used tumor tissue from surgical formalin-fixed, paraffin-embedded (FFPE) specimens and residual tissue from thyroid FNA biopsies for genomic DNA extraction. FFPE specimens served as the validation set, and residual tissue from FNA biopsies served as the test set. A molecular assay was developed for accurate detection of BRAF V600E variation using locked nucleic acid (LNA) probe-based droplet digital polymerase chain reaction (dPCR), and the assay was validated by BRAF V600E immunohistochemical staining (IHC). The study was conducted between February 2019 and May 2021.

Results

A total of 271 specimens, including 77 FFPE specimens (with a follow-up of 48 matched surgical specimens) and 146 residual FNA samples, were collected from 223 patients (mean [SD] age, 53.8 [15.3] years; 174 [78.0%] women; 49 [22.0%] men). The molecular assay by dPCR was first established to specifically and accurately detect and quantify wild-type BRAF and variant BRAF in DNA from human follicular thyroid carcinoma-derived FTC-133 and papillary thyroid carcinoma-derived BCPAP cells. The linearity of quantification of BRAF V600E was calculated (y = 0.7339x; R2 = 0.9996) with sensitivity at 0.02 copies/μL and reproducibility in detecting variant DNA at various dilutions(coefficient of variance in 0.3% DNA, 9.63%; coefficient of variance in 1.0% DNA, 7.41%). In validation testing, the dPCR assay and IHC staining exhibited 100% specificity in concordantly identifying BRAF V600E in PTCs (κ = 0.873; P < .001) and sensitivity of 32.0% (95% CI, 19.1% to 44.9%) in dPCR and 26.0% (95% CI, 13.1% to 38.9%) in IHC staining, with an improvement by 23.08% in dPCR compared with the IHC staining. The dPCR assay further detected BRAF V600E in 39 of 146 residual FNA specimens (26.7%). At short-term follow-up, 48 patients, including 14 of 39 patients with BRAF variation and 34 of 107 patients without BRAF variation on residual FNA specimens, underwent resection. The dPCR assay of BRAF status in the matched surgical specimens showed BRAF V600E variations in 12 patients and wild-type BRAF in 36 patients, with a high agreement to that in residual tissue of FNA specimens (κ = 0.789; P < .001). Among 14 patients with BRAF variations on residual FNA, 13 were diagnosed with PTC and 1 was diagnosed with anaplastic thyroid cancer at the thyroidectomy.

Conclusions and Relevance

This diagnostic study developed a sensitive molecular assay for detection and quantification of BRAF V600E variation in residual tissue from thyroid FNA biopsies to identify patients with cancer harboring BRAF V600E in a cost-effective manner, highlighting the clinical value of molecular assay of the remaining FNA tissue in the management of thyroid nodules.

Polymorphisms at the IL17A and IL17RA genes are associated with prognosis of papillary thyroid carcinoma

BACKGROUND

Interleukin (IL)-17A has a dual role in tumor immunity, promotes anti-tumor responses and facilitates angiogenesis by interacting with IL-17 receptor A (IL-17RA). Although IL-17A has been associated with the pathogenesis of papillary thyroid carcinoma (PTC), the nucleotide variability at the IL17A and IL17RA genes is still poorly characterized.

AIM

To assess the contribution of the IL17A (-197 G >A, rs2275913) and IL17RA (-947 A >G, rs4819554) single nucleotide polymorphisms (SNP) on the development and progression of PTC and on IL-17 plasma levels.

METHODS

We studied 188 PTC patients and 170 healthy controls. SNPs were identified using PCR-amplified DNA and restriction fragment length polymorphism (RFLP) techniques. Plasma levels of IL-17A was evaluated in 83 PTC patients using ELISA. Statistical analyses were performed to evaluate the associations between SNPs and clinicohistopathological features of PTC and IL-17A levels.

RESULTS

No significant difference was observed regarding the allele and genotype distributions of both SNPs between PTC patients and controls. The IL17A GA was associated with poor biochemical and structural incomplete response to therapy, whereas no influence over the IL-17A expression was observed. The IL17RA AG was significantly associated with small-sized tumors, initial tumor stage at diagnosis and better response to therapy.

CONCLUSIONS

The IL17A SNP may predict an aggressive manifestation of PTC, whereas the IL17RA SNP was associated with a more favorable clinical outcome.

Concomitant Langerhans cell histiocytosis of cervical lymph nodes in adult patients with papillary thyroid carcinoma: A report of two cases and review of the literature

Objective

: Langerhans cell histiocytosis (LCH) is an uncommon entity of unknown etiology. It contains a wide range of clinical presentations. The discovery of oncogenic BRAF V600E mutation in LCH has provided additional evidence that LCH is a neoplasm. Papillary thyroid carcinoma is the most common cancer of the thyroid characterized by a high incidence of BRAF V600E mutations. LCH with concomitant PTC is rare, with few cases reported in the literature.

Cases summary

We identified two cases of LCH with concomitant papillary thyroid carcinoma in adult patients. The first was a 49-year-old female with a thyroid nodule diagnosed with papillary thyroid carcinoma. Later, the patient had a left neck mass; Ultrasound-guided lymph node FNA was diagnosed with Langerhans histiocytosis. Subsequently, a chest CT scan revealed signs of Langerhans cell histiocytosis in the lung. The second case refers to a 69-year-old male who presented with a left thyroid nodule diagnosed on FNA cytology as papillary thyroid carcinoma. The patient was found to have multiple bone lytic lesions. Biopsies revealed Langerhans cell histiocytosis. Later, the patient experienced LCH involvement of the bone marrow with associated secondary myelofibrosis.

Conclusions

LCH is rare in adults; the association with papillary thyroid carcinoma is reported and should be considered in the presence of Langerhans cell groups along with PTC, whether in the thyroid gland or cervical lymph nodes. Once LCH has been diagnosed, pulmonary involvement should also be investigated. This will direct treatment plans for patients with pulmonary or systemic disease involvement.

BRAFV600E mutation is associated with increased prevalence of contralateral lymph-node metastases in low and low-to-intermediate risk papillary thyroid cancer

OBJECTIVE

Papillary thyroid cancer (PTC) is the most common endocrine malignancy. Despite good prognosis being generally associated with PTC, persistent/recurrent disease can be observed in a not negligible number of patients. Accurate postoperative management can lead to a significant improvement of risk stratification/staging of PTC patients identifying those at higher risk of a more aggressive clinical course. Molecular tests were introduced at the beginning of the 2000s to improve PTC risk stratification.

METHODS

We reviewed the records of 354/1185 patients affected by low or low-to-intermediate risk unilateral-PTC. In these patients, BRAFV600E mutation was looked for and 131-radioiodine therapy was performed 3 months after thyroid surgery. A radioiodine post-therapeutic imaging was obtained in all patients.

RESULTS

BRAFV600E mutation was found in 170/354 PTC patients (female = 126). Forty-two out of 170 BRAFV600E mutation +ve patients (female = 27) had ipsilateral (n = 24) or contralateral (n = 18) loco-regional metastases at post-therapeutic imaging. Significant differences in terms of 2015 American Thyroid Association risk stratification, Hashimoto thyroiditis prevalence, tumor size, multifocality, disease staging and aggressive variant were observed between BRAFV600E mutation +ve and BRAFV600E mutation -ve patients (P ≤ 0.001;P = 0.001; P ≤ 0.001; P = 0.026; P ≤ 0.001; P ≤ 0.001). Interestingly, the prevalence of contralateral lymph-node metastases was significantly higher in BRAFV600E mutation +ve than BRAFV600E mutation -ve patients (18/42 vs. 2/22, respectively; P = 0.013).

CONCLUSION

This study suggests that BRAFV600E mutation represents a significant risk factor for developing contralateral lymph-node metastases and confirms that BRAFV600E mutation is associated with more aggressive PTC features and a higher prevalence of metastatic disease also in low or low-to-intermediate-risk PTC patients.

The BRAFV600E mutation analysis and risk stratification in papillary thyroid carcinoma

OBJECTIVE

Although the prognostic role of BRAFV600E mutation in papillary thyroid carcinoma (PTC) is controversial, the American Thyroid Association (ATA) includes the mutational status in their risk stratification system. To evaluate the impact of the BRAFV600E mutation status on PTC risk stratification.

METHODS

PTC patients attending a university-based hospital who had the analysis of the BRAFV600E mutation were included. Persistent disease was defined as the presence of biochemical or structural disease. The performance of the ATA risk stratification system on predicting persistent disease with or without the BRAFV600E mutation status information was evaluated.

RESULTS

Of the 134 patients evaluated, 44 (32.8%) carried BRAFV600E mutation. The median tumor size was 1.7 cm (P25-75 1.0-3.0), 64 (47.8%) patients had lymph node, and 11 (8.2%) distant metastases. According to the ATA risk stratification system, patients were classified as low, intermediate, and high risk in 55 (41%), 59 (44%), and 20 (14%) patients, respectively. The data on BRAFV600E mutation reclassified 12 (8.9%) patients from low to intermediate risk. After a median follow-up of 8.5 years, the prevalence of persistent disease was similar in patients with and without BRAFV600E mutation (P = 0.42). Multivariate analysis failed to demonstrate an association between the BRAFV600E mutation and persistent disease status (RR 0.96; 95%CI 0.47-1.94). Notably, none of the patients reclassified from low to intermediate risk showed persistent disease on follow-up.

CONCLUSION

Inclusion of BRAFV600E mutational status has a limited impact on risk stratification and does not add to the prediction of outcomes in PTC patients.

The predictive value of coexisting BRAFV600E and TERT promoter mutations on poor outcomes and high tumour aggressiveness in papillary thyroid carcinoma: A systematic review and meta-analysis

BRAFV600E mutation is highly prevalent in patients with papillary thyroid carcinoma (PTC), and TERT promoter (TERTp) mutation is strongly associated with cancer-related mortality. However, predictive power of the two mutations remains inconclusive. We aimed to verify the prognostic effects of both mutations to assess the value of mutation detection for risk stratification in terms of PTC prognosis and tumour invasion, to guide PTC diagnosis and treatment. We conducted a literature search in the MEDLINE (PubMed), EMBASE, Web of Science and CENTRAL (Cochrane library) databases, from inception to February 2020. Basic characteristics, prognoses and clinicopathological features were collected from the included studies for further analysis. Twelve studies involving 4184 PTC patients were enrolled in our analysis. In total, 2412 (57.6%) of the patients carried either BRAFV600E or TERTp mutation, and 290 (6.9%) patients had both mutations. TERTp mutation was more common in patients with BRAFV600E mutation (RR = 1.75 [95% CI 1.44-2.13]). Patients with both mutations had a worse prognosis compared with those with a single mutation (vs BRAFV600E only: RR = 5.34 [4.20-6.78] vs TERTp only: RR = 2.12 [1.41-3.19]). TERTp mutation alone independently increased the risk of a poor prognosis (RR = 2.90 [1.93-4.35]) in terms of mortality (RR = 15.09 [7.75-29.37]), disease persistence (RR = 4.00 [2.03-7.90]), recurrence (RR = 4.34 [4.20-6.78]), lymph node metastasis (RR = 1.57 [1.24-1.99]) and distant metastasis (RR = 2.94 [1.13-7.65]). We found that PTC patients with BRAFV600E mutation were more likely to have TERTp mutation. TERTp mutation was an independent predictive factor for poor prognosis of PTC patients, but the predictive value of BRAFV600E mutation remains inconclusive. Patients with both mutations have remarkably higher risks of adverse outcomes compared with those with a single mutation. PTC patients could benefit from mutation detection for aiding risk stratification (BRAF + TERT+ > BRAF - TERT+ > BRAF + TERT-).

Hobnail variant of papillary thyroid carcinoma: a systematic review and meta-analysis

OBJECTIVE

The hobnail variant of papillary thyroid carcinoma (HVPTC) has emerged as a rare and aggressive variant of papillary thyroid carcinoma (PTC). We aim to determine the prevalence and clinicopathologic factors of HVPTC.

METHODS

A systematic review of the literature for studies examining HVPTC was performed. Four databases (PubMed, Scopus, OVID, Cochrane library) were queried from inception of databases through March 20th, 2020.

RESULTS

Sixteen studies with 124 cases of HVPTC were included. The mean age for all patients was 52.3 years. HVPTC had a prevalence of 1.08% out of all PTC cases, with a mean tumor size of 3.1 cm. In 62% and 50% of cases, lymphovascular invasion and extrathyroidal extension were present, respectively. Follow-up data, with a mean of 49.9 months, revealed a 66% rate of lymph node metastasis and 23% rate of distant metastasis. Tumors with ≥30% hobnail morphology had a 2.6-fold increased odds of developing lymph node metastasis compared with <30% hobnail morphology, however did not differ in rates of distant metastasis. Patients ≥55 years old had a 4.5-fold increased odds of distant metastasis and a 4.7-fold increased odds of lymphovascular invasion over patients <55.

CONCLUSIONS

High rates of locoregional and distant disease as well as high-risk pathological factors reveal the aggressive nature of HVPTC. Diagnostic criteria regarding percentage of hobnail morphology requires further refinement. Further studies are warranted in order to better understand how recognition of this high-risk variant impacts clinical treatment.

HYOU1 facilitates proliferation, invasion and glycolysis of papillary thyroid cancer via stabilizing LDHB mRNA

HYOU1 is upregulated in many kinds of cancer cells, and its high expression is associated with tumour invasiveness and poor prognosis. However, the role of HYOU1 in papillary thyroid cancer (PTC) development and progression remains to be elucidated. Here, we reported that HYOU1 was highly expressed in human PTC and associated with poor prognosis. HYOU1 silencing suppressed the proliferation, migration and invasion of PTC cells. Mechanistic analyses showed that HYOU1 silencing promoted oxidative phosphorylation while inhibited aerobic glycolysis via downregulating LDHB at the posttranscriptional level. We further confirmed that the 3'UTR of LDHB mRNA is the indirect target of HYOU1 silencing and HYOU1 silencing increased miR‐375‐3p levels. While LDHB overexpression significantly suppressed the inhibitory effects of HYOU1 silencing on aerobic glycolysis, proliferation, migration and invasion in PTC cells. Taken together, our findings suggest that HYOU1 promotes glycolysis and malignant progression in PTC cells via upregulating LDHB expression, providing a potential target for developing novel anticancer agents.

Highly Sensitive Detection of Low-Abundance BRAF V600E Mutation in Fine-Needle Aspiration Samples by Zip Recombinase Polymerase Amplification

Papillary thyroid carcinoma (PTC) is the most common thyroid cancer with high incidence in endocrine tumors, which emphasizes the significance of accurate diagnostics. Still, the commonly used cytological method (fine-needle aspiration (FNA) cytology) and molecular diagnostic methods (such as PCR and sequencing) are limited in terms of diagnostic time, sensitivity, and user-friendliness. In this study, we introduce a novel Zip recombinase polymerase amplification (Z-RPA) strategy to efficiently detect rare mutant alleles in PTC fine-needle aspiration samples, which is sensitive, fast, and simple to manipulate. Using Zip nucleic acid (ZNA) probes to clamp the mutation region, the phi 29 polymerase could selectively displace mismatched ZNA probes and start amplification, while leaving complementary ZNA probes untouched and blocking amplification according to genotype. We demonstrated the good sensitivity and specificity of this strategy with optimized conditions and design, which enabled detection of BRAF V600E mutation in a total 4 ng of genomic DNA within 40 min (≈1 copy). Robust behavior in clinical specimen analysis was also demonstrated. The Z-RPA strategy provides a pragmatic approach to rapidly, sensitively, and easily detect BRAF V600E mutation in clinical fine-needle aspiration samples, which is a promising method for early cancer diagnosis and treatment guideline.

Concomitant Langerhans cell histiocytosis of cervical lymph nodes in adult patients with papillary thyroid carcinoma: A report of two cases and review of the literature

Objective

: Langerhans cell histiocytosis (LCH) is an uncommon entity of unknown etiology. It contains a wide range of clinical presentations. The discovery of oncogenic BRAF V600E mutation in LCH has provided additional evidence that LCH is a neoplasm. Papillary thyroid carcinoma is the most common cancer of the thyroid characterized by a high incidence of BRAF V600E mutations. LCH with concomitant PTC is rare, with few cases reported in the literature.

Cases summary

We identified two cases of LCH with concomitant papillary thyroid carcinoma in adult patients. The first was a 49-year-old female with a thyroid nodule diagnosed with papillary thyroid carcinoma. Later, the patient had a left neck mass; Ultrasound-guided lymph node FNA was diagnosed with Langerhans histiocytosis. Subsequently, a chest CT scan revealed signs of Langerhans cell histiocytosis in the lung. The second case refers to a 69-year-old male who presented with a left thyroid nodule diagnosed on FNA cytology as papillary thyroid carcinoma. The patient was found to have multiple bone lytic lesions. Biopsies revealed Langerhans cell histiocytosis. Later, the patient experienced LCH involvement of the bone marrow with associated secondary myelofibrosis.

Conclusions

LCH is rare in adults; the association with papillary thyroid carcinoma is reported and should be considered in the presence of Langerhans cell groups along with PTC, whether in the thyroid gland or cervical lymph nodes. Once LCH has been diagnosed, pulmonary involvement should also be investigated. This will direct treatment plans for patients with pulmonary or systemic disease involvement.

DNA repair pathway activation features in follicular and papillary thyroid tumors, interrogated using 95 experimental RNA sequencing profiles

DNA repair can prevent mutations and cancer development, but it can also restore damaged tumor cells after chemo and radiation therapy. We performed RNA sequencing on 95 human pathological thyroid biosamples including 17 follicular adenomas, 23 follicular cancers, 3 medullar cancers, 51 papillary cancers and 1 poorly differentiated cancer. The gene expression profiles are annotated here with the clinical and histological diagnoses and, for papillary cancers, with BRAF gene V600E mutation status. DNA repair molecular pathway analysis showed strongly upregulated pathway activation levels for most of the differential pathways in the papillary cancer and moderately upregulated pattern in the follicular cancer, when compared to the follicular adenomas. This was observed for the BRCA1, ATM, p53, excision repair, and mismatch repair pathways. This finding was validated using independent thyroid tumor expression dataset PRJEB11591. We also analyzed gene expression patterns linked with the radioiodine resistant thyroid tumors (n = 13) and identified 871 differential genes that according to Gene Ontology analysis formed two functional groups: (i) response to topologically incorrect protein and (ii) aldo-keto reductase (NADP) activity. We also found RNA sequencing reads for two hybrid transcripts: one in-frame fusion for well-known NCOA4-RET translocation, and another frameshift fusion of ALK oncogene with a new partner ARHGAP12. The latter could probably support increased expression of truncated ALK downstream from 4th exon out of 28. Both fusions were found in papillary thyroid cancers of follicular histologic subtype with node metastases, one of them (NCOA4-RET) for the radioactive iodine resistant tumor. The differences in DNA repair activation patterns may help to improve therapy of different thyroid cancer types under investigation and the data communicated may serve for finding additional markers of radioiodine resistance.

Somatic Mutation Profiling of Papillary Thyroid Carcinomas by Whole-exome Sequencing and Its Relationship with Clinical Characteristics

The incidence of papillary thyroid carcinomas (PTCs) has increased rapidly during the past several decades. Until now, the mechanisms underlying the tumorigenesis of PTCs have remained largely unknown. Next-generation-sequencing (NGS) provides new ways to investigate the molecular pathogenesis of PTCs. To characterize the somatic alterations associated with PTCs, we performed whole-exome sequencing (WES) of PTCs from 23 Chinese patients. This study revealed somatic mutations in genes with relevant functions for tumorigenesis, such as BRAF, BCR, CREB3L2, DNMT1, IRS2, MSH6, and TP53. We also identified novel somatic gene alterations which may be potentially involved in PTC progression. Gene set enrichment analysis revealed that the cellular response to hormone stimulus, epigenetic modifications, such as protein/histone methylation and protein alkylation, as well as MAPK, PI3K-AKT, and FoxO/mTOR signaling pathways, were significantly altered in the PTCs studied here. Moreover, Protein-Protein Interaction (PPI) network analysis of our mutated gene selection highlighted EP300, KRAS, PTEN, and TP53 as major core genes. The correlation between gene mutations and clinicopathologic features of the PTCs defined by conventional ultrasonography (US) and contrast-enhanced ultrasonography (CEUS) were assessed. These analyses established significant associations between subgroups of mutations and respectively taller-than-wide, calcified, and peak time iso- or hypo-enhanced and metastatic PTCs. In conclusion, our study supplements the genomic landscape of PTCs and identifies new actionable target candidates and clinicopathology-associated mutations. Extension of this study to larger cohorts will help define comprehensive genomic aberrations in PTCs and validate target candidates. These new targets may open methods of individualized treatments adapted to the clinicopathologic specifics of the patients.

Tall Cell Carcinoma with Reverse Polarity of Breast: Report of a Case with Unique Morphologic and Molecular Features

Breast carcinomas are a heterogeneous group of malignancy, having variable clinical outcomes depending on their cellular and molecular properties. Tall cell carcinoma with reverse polarity (TCCRP) is a recently described rare entity, which shares morphological features with tall cell variant of papillary thyroid carcinoma but has a distinct morphological, immunohistochemical, and molecular profile. We describe a case of a 40-year-old female patient, who presented with lump in the breast. The patient underwent lumpectomy and was diagnosed as tall cell carcinoma with reverse polarity. Immunohistochemistry and bi-directional Sanger sequencing for IDH2 mutation were used for diagnosis. Tall cell carcinoma with reverse polarity is a rare and newly described entity with characteristic morphological and molecular findings, which carries an excellent prognosis.

BRAF V600E mutation correlates with aggressive clinico-pathological features but does not influence tumor recurrence in papillary thyroid carcinoma-10-year single-center results

Background

BRAF V600E mutation is common in papillary thyroid carcinoma (PTC) but its prognostic value and influence on tumor recurrence is controversial. We investigated if BRAF V600E mutation influences tumor behavior and recurrence, and if it can be used as surrogate parameter in PTC.

Methods

In a single center retrospective study with a median follow-up of 5 years, incidence of BRAF V600E mutation in 186 PTC specimens from 2007-2016 was investigated. Tumor outcome parameters including TNM status, multifocal and invasive growth and tumor recurrence rate were examined.

Results

In 98 specimens (52.7%) a BRAF V600E mutation (BRAF+), and in 88 specimens (47.3%) no mutation (BRAF-) was detected. There was no gender specific difference. BRAF+ patients were significantly older (mean 5.6 years; P=0.011). BRAF+ tumors were significantly smaller (14.4 vs. 18.3 mm; P=0.018), and more often showed a multifocal (30.6% vs. 17%; P=0.031) and extracapsular tumor growth pattern (pT3b and pT4a; BRAF+ 22.4% vs. BRAF- 10.2%; P=0.026). Although lymph node-status did not differ in both groups, BRAF+ showed a higher infiltration rate of the lateral lymph node compartment (12.2% vs. 5.7%; P=n.s.). Distant metastases occurred only in BRAF+ (3.1% vs. 0%). There was no significant difference in terms of tumor recurrence rate.

Conclusions

Results regarding the incidence of malignant lymph nodes, tumor growth pattern and tumor multifocality suggest a more aggressive tumor behavior in BRAF+ PTC but this fact does not affect tumor recurrence rate in a five year follow up period. Therefore, the postoperative role of BRAF V600E mutation remains unclear, and a general change of operative procedure and radicality cannot be recommended based on BRAF status alone.

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.

Detection of BRAF V600E Mutation in Ganglioglioma and Pilocytic Astrocytoma by Immunohistochemistry and Real-Time PCR-Based Idylla Test

The BRAF V600E mutation is an important oncological target in certain central nervous system (CNS) tumors, for which a possible application of BRAF-targeted therapy grows continuously. In the present study, we aim to determine the prevalence of BRAF V600E mutations in a series of ganglioglioma (GG) and pilocytic astrocytoma (PA) cases. Simultaneously, we decided to verify whether the combination of fully automated tests—BRAF-VE1 immunohistochemistry (IHC) and Idylla BRAF mutation assay—may be useful to accurately predict it in the case of specified CNS tumors. The study included 49 formalin-fixed, paraffin-embedded tissues, of which 15 were GG and 34 PA. Immunohistochemistry with anti-BRAF V600E (VE1) antibody was performed on tissue sections using the VentanaBenchMark ULTRA platform. All positive or equivocal cases on IHC and selected negative ones were further assessed using the Idylla BRAF mutation assay coupled with the Idylla platform. The BRAF-VE1 IHC was positive in 6 (6/49; 12.3%) and negative in 39 samples (39/49; 79.6%). The interpretation of immunostaining results was complicated in 4 cases, of which 1 tested positive for the Idylla BRAF mutation assay. Therefore, the overall positivity rate was 14.3%. This included 2 cases of GG and 5 cases of PA. Our study found that BRAF V600E mutations are moderately frequent in PA and GG and that for these tumor entities, IHC VE1 is suitable for screening purposes, but all negative, equivocal, and weak positive cases should be further tested with molecular biology techniques, of which the Idylla system seems to be a promising tool.

BRAF mutations in KIT/PDGFRA positive gastrointestinal stromal tumours (GISTs): Is their frequency underestimated?

BRAF V600E mutations in GISTs are considered to be one of the mutational events in KIT/PDGFRA negative or positive GISTs, respectively. BRAF mutated GISTs usually do not respond to imatinib treatment, even more GISTs with imatinib sensitive KIT mutation. However, they are almost phenotypically and morphologically identical with KIT/PDGFRA positive GISTs. In general, due to the small number of BRAF mutations in GIST and because of the rarity of concomitant BRAF/KIT or BRAF/PDGFRA mutations, their frequency may be depreciated. The aim of this study was BRAF mutation detection in KIT/PDGFRA positive GISTs and their verification by other molecular methods. We applied the sensitive droplet digital PCR on 35 randomly selected KIT/PDGFRA positive GISTs to detect V600E mutations. We have established two criteria for the evaluation of samples: false positive rate (FPR) based on the negative controls; Limit of Detection (LoD) based on the serial dilution of positive control from RKO cell line harboring heterozygous V600E mutation in constant wild-type DNA background. Results from ddPCR were verified by other molecular methods: allele-specific PCR, dideoxysequencing, competitive allele-specific TaqMan PCR (castPCR). FPR was determined as 5 (∼4.4) positive droplets, and LoD was assessed to 3.4293 copies/μL what is the method sensitivity of 0.0162 %. We identified eight KIT/PDGFRA positive patients with concomitant V600E mutation. The five of them were in coexistence with KIT mutation and three with PDGFRA mutation. We also included the liver metastasis, but data from primary tumour were not available. We achieved the very high sensitivity of the ddPCR method for detecting BRAF mutation in GISTs to have importance from the point of view of therapy.

Risk Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

Purpose: To explore the risk factors that may predict the lymph node metastasis potential of these lesions and new prevention strategies in papillary thyroid carcinoma patients. Materials and Methods: In total, 9,369 papillary thyroid carcinoma patients with 37.17% lymph node metastasis were analyzed (Revman 5.3 software) in this study. The PubMed and Embase databases were used for searching works systematically that were published through to January 22, 2020. Results: Several factors were related to the increased risk of lymph node metastasis in patients with papillary thyroid carcinoma: age <45 years (pooled OR = 1.52, 95% CI = 1.14-2.01, p <0.00001); gender = male (pooled OR = 1.68, 95% CI = 1.51-1.87, p <0.00001); multifocality (pooled OR = 2.05, 95% CI = 1.45-2.89, p <0.0001); tumor size ≥1.0 cm (pooled OR = 3.53, 95% CI = 2.62-4.76, p <0.00001); tumor location at the upper pole 1/3 (pooled OR =1.46, 95% CI = 1.04-2.04, p = 0.03); capsular invasion + (pooled OR = 3.48, 95% CI = 1.69-7.54, p = 0.002); and extrathyroidal extension + (pooled OR = 2.03, 95% CI= 1.78-2.31, p <0.00001). However, tumor bilaterality (pooled OR = 0.85, 95% CI = 0.54-1.34, p = 0.49) and Hashimoto's thyroditis (pooled OR = 1.08, 95% CI = 0.79-1.49, p = 0.62) showed no correlation with lymph node metastasis in papillary thyroid carcinoma patients. Conclusion: The systematic review and meta-analysis defined several significant risk factors of lymph node metastasis in papillary thyroid cancer patients: age (<45 years), gender (male), multifocality, tumor size (>1 cm), tumor location (1/3 upper), capsular invasion, and extra thyroidal extension. Bilateral tumors and Hashimoto's thyroiditis were unrelated to lymph node metastasis in patients with papillary thyroid cancer.

Evaluation of the expression levels of BRAFV600E mRNA in primary tumors of thyroid cancer using an ultrasensitive mutation assay

Background

The BRAF^V600E gene encodes for the mutant BRAF^V600E protein, which triggers downstream oncogenic signaling in thyroid cancer. Since most currently available methods have focused on detecting BRAF^V600E mutations in tumor DNA, there is limited information about the level of BRAF^V600E mRNA in primary tumors of thyroid cancer, and the diagnostic relevance of these RNA mutations is not known.

Methods

Sixty-two patients with thyroid cancer and non-malignant thyroid disease were included in the study. Armed with an ultrasensitive technique for mRNA-based mutation analysis based on a two step RT-qPCR method, we analysed the expression levels of the mutated BRAF^V600E mRNA in formalin-fixed paraffin-embedded samples of thyroid tissues. Sanger sequencing for detection of BRAF^V600E DNA was performed in parallel for comparison and normalization of BRAF^V600E mRNA expression levels.

Results

The mRNA-based mutation detection assay enables detection of the BRAF^V600E mRNA transcripts in a 10,000-fold excess of wildtype BRAF counterparts. While BRAF^V600E mutations could be detected by Sanger sequencing in 13 out of 32 malignant thyroid cancer FFPE tissue samples, the mRNA-based assay detected mutations in additionally 5 cases, improving the detection rate from 40.6 to 56.3%. Furthermore, we observed a surprisingly large, 3-log variability, in the expression level of the BRAF^V600E mRNA in FFPE samples of thyroid cancer tissue.

Conclusions

The expression levels of BRAF^V600E mRNA was characterized in the primary tumors of thyroid cancer using an ultrasensitive mRNA-based mutation assay. Our data inspires further studies on the prognostic and diagnostic relevance of the BRAF^V600E mRNA levels as a molecular biomarker for the diagnosis and monitoring of various genetic and malignant diseases.

Clinicopathological Significance of Overall Frequency of Allelic Loss (OFAL) in Lesions Derived from Thyroid Follicular Cell

Background

Loss of heterozygosity (LOH) and microsatellite instability (MSI) are frequent molecular events in thyroid tumor etiopathogenesis occurring in several chromosomal critical areas, including 3p12–25.3, 7q21–31, 10q22–24, and 15q11–13, with loci of tumor suppressor genes.

Objective

We evaluated the usefulness of LOH/MSI as a diagnostic/prognostic biomarker in lesions derived from thyroid follicular cells: follicular thyroid carcinoma (FTC); follicular adenoma (FA), papillary thyroid carcinoma (PTC), and nodular goiter (NG).

Methods

We performed allelotyping (GeneMapper Software v. 4.0.) of ten microsatellite markers linked to the 1p31.2, 3p21.3, 3p24.2, 9p21.3, 11p15.5, and 16q22.1 region on DNA from 93 primary thyroid lesions then evaluated the LOH/MSI frequency and overall frequency of allelic loss (OFAL).

Results

We found regions with significantly increased frequency of LOH/MSI for specific histotypes: the 3p24.2 region for FA and 1p31.2 for FTC. LOH/MSI in 3p21.3 was significantly elevated in PTC and FTC. LOH/MSI in 3p21.3 was increased for small size tumors (T1a + T1b), tumors with no regional lymph node involvement (N0 + Nx), American Joint Committee on Cancer (AJCC) stage I tumors, and tumor diameter (Td) < 10 mm; in 1p31.2 for T2–3, N1, stage II–IV, and Td 10–30 mm; in 11p15.5 for T2–3, N1, stage II–IV, and Td > 30 mm. OFAL values were significantly higher in younger patients (< 40 years), in men, in those with T2–3 stage tumors, in those with increased Td, and in FA and FTC compared with NG and PTC.

Conclusions

We confirmed the occurrence of LOH/MSI in 3p21.3 at an early stage of tumorigenesis and mapped 1p31.2 and 11p15.5 as characteristic for advanced-stage tumors. The results of our study may enable consideration of OFAL, defined as LOH/MSI coincidence in various chromosomal regions, as a tumor progression marker. OFAL values were significantly higher in follicular neoplasms (FA and FTC) than in PTC or NG; hence, increased OFAL values can be regarded as a characteristic feature of the follicular phenotype.

BRAF mutation and age in differentiated thyroid cancer risk stratification: Two sides of the same coin

BRAF V600E mutation is seen in about 45% of patients with Papillary Thyroid Carcinoma (PTC). Thyroid cancers are among the unique cancers where the age influences the prognosis. Current evidence suggests BRAF mutation in the presence of other risk factors in DTC is associated with poor prognosis. Considering the high prevalence of the BRAF mutation in differentiated thyroid cancer, there has been an inclination to include molecular testing as a rule-in test. However, studies have shown a reciprocal relationship between BRAF mutations and advancing age. One needs to rethink if both are two independent poor prognostic indicators. The future risk stratification systems should use technological advances to create a truly dynamic system that incorporates molecular markers in cohesion with age.

Cutaneous Adverse Events of Anti-PD-1 Therapy and BRAF Inhibitors

OPINION STATEMENT

The treatment of advanced melanoma has undergone a dramatic transformation over the last decade with the advent of targeted and immunomodulatory therapies. This transition from cytotoxic chemotherapy has yielded improvements in both survival and quality of life; yet despite their therapeutic advantages, these treatments have been associated with a diverse range of cutaneous adverse events (AEs). These range from relatively benign eczematous conditions to more severe inflammatory and bullous disorders, and can include induction of second malignancies. AEs can result in serious morbidity and risk of mortality if not recognised and managed early. As a consequence of their novelty, and rapid uptake, these agents have been subject to intense scrutiny and there is a general understanding that cutaneous AEs should be anticipated in treatment plans. Dermatologists should be integrated into management teams to assist in the development of treatment protocols for anticipated common AEs and to provide expert management of more severe, rare or unusual AEs. Our experience has shown a reduction in treatment interruptions, more rapid recognition of unusual AEs and improved management pathways for patients suffering cutaneous AEs.

Hypermethylated RASSF1 and SLC5A8 promoters alongside BRAFV600E mutation as biomarkers for papillary thyroid carcinoma

Circulating cell-free DNA (cfDNA) has been considered as a diagnostic source to track genetic and epigenetic alterations in cancer. We aimed to study mutation in addition to the methylation status in the promoter regions of RASSF1 and SLC5A8 genes in tissues and circulating free DNA samples of patients affected with papillary thyroid carcinoma (PTC) and thyroid nodules as controls. BRAF^V600E mutation was studied by ARMS-scorpion real-time polymerase chain reaction method in 57 PTC and 45 thyroid nodule cases. Methylation status of RASSF1 and SLC5A8 promoter regions was analyzed by methylation-specific high-resolution melting curve analysis. BRAF^V600E mutation was found in 39 (68.4%) out of 57 PTC tissue samples, while in 33 (49.1%) cases of cfDNA, this mutation was detected. The frequency of BRAF^V600E mutation in cfDNA was significantly different between metastatic and nonmetastatic PTC cases (22 of 33 PTC cases vs. 5 of 34 thyroid nodule samples). Methylation levels of three promoter regions of SLC5A8 and proximal promoter region of RASSF1 was significantly different between PTC and thyroid nodule cases in both cfDNA and tissue DNA. In addition, the methylation status of these two genes in tissue DNA was reflected in methylation status observed in cfDNA. This study confirmed that BRAF^V600E mutation is better for discrimination between papillary thyroid carcinoma and thyroid nodules. On the other hand, hypermethylation in the more proximal promoter regions to RASSF1 and SLC5A8 genes showed higher sensitivity and more acceptable specificity for this discrimination.

BRAF Inhibitors in Thyroid Cancer: Clinical Impact, Mechanisms of Resistance and Future Perspectives

The Kirsten rat sarcoma viral oncogene homolog (RAS)/v-raf-1 murine leukemia viral oncogene homolog 1 (RAF)/mitogen-activated protein kinase 1 (MAPK) signaling cascade is the most important oncogenic pathway in human cancers. Tumors leading mutations in the gene encoding for v-raf murine sarcoma viral oncogene homolog B (BRAF) serine-threonine kinase are reliant on the MAPK signaling pathway for their growth and survival. Indeed, the constitutive activation of MAPK pathway results in continuous stimulation of cell proliferation, enhancement of the apoptotic threshold and induction of a migratory and metastatic phenotype. In a clinical perspective, this scenario opens to the possibility of targeting BRAF pathway for therapy. Thyroid carcinomas (TCs) bearing BRAF mutations represent approximately 29–83% of human thyroid malignancies and, differently from melanomas, are less sensitive to BRAF inhibitors and develop primary or acquired resistance due to mutational events or activation of alternative signaling pathways able to reactivate ERK signaling. In this review, we provide an overview on the current knowledge concerning the mechanisms leading to resistance to BRAF inhibitors in human thyroid carcinomas and discuss the potential therapeutic strategies, including combinations of BRAF inhibitors with other targeted agents, which might be employed to overcome drug resistance and potentiate the activity of single agent BRAF inhibitors.

Association analysis and the clinical significance of BRAF gene mutations and ultrasound features in papillary thyroid carcinoma

The aim of the present study was to evaluate the associations between the B-Raf proto-oncogene serine/threonine kinase (BRAF)V600E mutation and conventional and contrast-enhanced ultrasonographic features in patients with papillary thyroid carcinoma (PTC), and to subsequently investigate the clinical value of these associations. In total, 207 thyroid nodules (diameter ≤2 cm) were selected. Conventional ultrasound, contrast-enhanced ultrasound, BRAFV600E mutational analysis and ultrasound-guided fine-needle aspiration biopsy were preoperatively performed, and histopathological assessment of PTC was postoperatively confirmed. The nodules were divided into 2 groups based on the BRAFV600E mutational analysis, namely the mutant or the wild-type variant groups, and the association analyses of the ultrasonographic features between these 2 groups were performed. Overall, 74.9% (155/207) of the PTC nodules had the BRAFV600E mutation, while 25.1% (52/207) had the wild-type BRAF allele. The 2 groups were analyzed using univariate logistic regression analysis, which demonstrated no significant differences regarding morphology, boundary, hypoechogenicity of the nodules, blood flow signal, enhancement uniformity, enhancement degree and clearance time (P>0.05). Moreover, the 2 groups demonstrated significant differences regarding the aspect ratio, microcalcification, nodule size following enhancement, enhancement mode and enhancement time (P<0.05). A multivariate logistic regression analysis was performed to further validate the association of these features with the BRAFV600E mutation; however, only microcalcification [odds ratio (OR), 2.256; 95% confidence interval (CI), 1.160–5.500; P=0.020] and nodule size following enhancement (OR, 2.119; 95% CI, 1.039–4.321; P=0.039) were associated with the BRAF mutational status. The associations found between the two ultrasonographic features and BRAFV600E mutation indicate that they can predict the BRAF mutational status to provide a reliable basis for clinical diagnosis and treatment.

MiR-4500 Regulates PLXNC1 and Inhibits Papillary Thyroid Cancer Progression

Although most patients with papillary thyroid cancer (PTC) are curable, there are still a few patients showing poor outcomes and increased risk of secondary cancers after therapies. In this study, we aimed to investigate the correlation between miR-4500 and PTC and to explore its molecular functions. A total of 50 patients were included, and sonography and histological examinations were used for diagnosis. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for detection of mRNA levels while Western blotting was used for measuring protein expression. Cell proliferation was tested using CCK-8 and colony formation assays. Caspase-3 activity and nucleosomal fragmentation assays were employed to test cell apoptosis. Cell invasive ability was measured using transwell assay. MiR-4500 target was identified using luciferase assay and RNA pull-down assay. MiR-4500 expression was significantly decreased in five PTC cell lines compared with Nthy-ori 3-1 cells and in PTC tissues compared with adjacent normal thyroid tissues, respectively. Decreased expression of miR-4500 showed lower survival rate, higher cancer stage, and lymphatic metastasis. Therefore, our results implied that miR-4500 could serve as a potential biomarker for PTC prognosis. Overexpression of miR-4500 repressed colony formation, proliferation, and invasiveness of PTC cells whereas increased cell apoptosis. We identified that PLXNC1 was a direct target of miR-4500. PLXNC1 knockdown showed similar effects on cell viability, colony formation, and cell apoptosis as overexpression of miR-4500 in PTC cells. In conclusion, miR-4500 inhibits the malignant transformation of PTC cells by directly targeting and repressing PLXNC1.