The Risk of Relapse in Papillary Thyroid Cancer (PTC) in the Context of BRAFV600E Mutation Status and Other Prognostic Factors

Prognostic Significance of BRAF V600E Mutation and CPSF2 Protein Expression in Papillary Thyroid Cancer

The early-stage diagnosis of papillary thyroid cancer (PTC) has significantly increased in incidence worldwide without any beneficial impact on survival. In order to improve the risk assessment in PTC, we have conducted a retrospective study in which we analyzed the BRAF V600E mutation and CPSF2 protein expression as prognostic markers on archival tissue samples of 49 patients without (control group) and 97 patients with (study group) PTC metastases in the cervical lymph nodes at the time of initial diagnosis. Our aim was to correlate the BRAF V600E mutation and the expression of CPSF2 protein with the clinical and pathological features of PTC. The expression of CPSF2 protein was evaluated via immunohistochemistry and graded semi-quantitatively. The presence of the BRAF V600E mutation was determined via real-time polymerase chain reac-tion (PCR). CPSF2 protein < 3+ intensity expression was correlated with more frequent recurrences (Fisher-Freeman-Halton exact test; p = 0.010; 95% CI: 1.26−22.03), and patients who presented with the BRAF V600E mutation and CPSF2 protein expression < 3+ intensity had shorter disease-free survival (log-rank test; 105.0 months vs. 146.6 months; p < 0.001; HR 8.32, 95% CI: 2.91−23.83), whereas patients with PTC who had CPSF2 expression 3+ had longer disease-free survival in correlation with other lower intensity expressions of CPSF2 protein (log-rank test; 139.7 months vs. 129.6 months; p = 0.008). The multivariate analysis showed that younger patients with CPSF2 protein expression <3+ and the BRAF V600E mutation are at an increased risk for recurrence and require more intensive monitoring (Cox proportional hazards regression model; X2 = 17.5, df = 10, p = 0.025). Our results correlate the BRAF V600E mutation and CPSF2 protein expression with recurrence and disease-free survival as relevant prognostic factors for PTC.

Combined expression of the BRAFV600E mutation and PD-L1 in early papillary thyroid carcinoma and its relationship with clinicopathological features and recurrence-a retrospective cohort study

Background

Identifying the high recurrence group of patients with early-stage papillary thyroid cancer (PTC) is the greatest challenge in the management of this disease. It has been noted that B-type Rafkinase (BRAF) V600E mutation and programmed death ligand 1 (PD-L1) are associated in PTC and highly expressed in PTC, correlating in PTC as potential prognostic biomarkers. However, whether they can be used to predict the aggressiveness and recurrence of early PTC remains unclear.

Methods

Clinicopathological data of 137 patients with early PTC [tumor-node-metastasis (TNM) stage I-II] who underwent surgery in Zhejiang Cancer Hospital between 2008 and 2010 were retrospectively analyzed. BRAF^V600E mutation and PD-L1 was detected by immunohistochemistry. The median follow-up time was 136 months (interquartile range 5.8). The presence of tumor confirmed by imaging or pathology or lymph node metastasis was considered as tumor recurrence. The association of both alone and in combination with clinicopathological features and recurrence was statistically analyzed respectively. The risk of recurrence was assessed using Cox regression models.

Results

Most of the 137 early PTC were female (78.1%). The mean age was 43.2±12.1 years. The median tumor size was 1.4 cm; 14 patients developed recurrence during follow-up period; 56 patients (40.9%) were detected positive for BRAF^V600E mutation; 76 patients (55.5%) were detected positive for PD-L1. Patients with both BRAF^V600E mutation and PD-L1 expression had larger tumors (P=0.038), were more likely to have extrathyroidal invasion (P=0.045), and had a lower rate of cervical lymph node metastasis (P=0.046). The recurrence rate was 17.5% (7/40) in patients with BRAF^V600E mutation and PD-L1 double expression compared to 8.9% (4/45) in patients with BRAF^V600E mutation and PD-L1 double negative [hazard ratio (HR) =1.267; 95% CI: 0.841-1.909; P=0.257]. Survival curves showed flatter recurrence-free survival (RFS) curves in positive BRAF^V600E mutation only and PD-L1 expression only, whereas decreased sharply in positive expression of both BRAF^V600E mutation and PD-L1; however, the differences were not significant (P>0.05).

Conclusions

The combination of BRAF^V600E mutation and PD-L1 to identify group at higher risk of recurrence in early PTC has insufficient clinical evidence and should be used with caution in the clinical management of PTC.

Construction and validation of BRAF mutation diagnostic model based on ultrasound examination and clinical features of patients with thyroid nodules

Introduction: Fine Needle Aspiration (FNA) is currently the most popular method for identifying benign and malignant thyroid nodules. However, its diagnostic sensitivity is sometimes limited, which makes it necessary to apply genetic testing and other modalities as a secondary diagnostic method. The diagnostic accuracy of thyroid nodule can be improved by combining mutations in the B-Raf proto-oncogene serine/threonine kinase (BRAF) with FNA. Thus, this study was conducted to create a nomogram diagnostic model based on the clinical and ultrasonic characteristics of patients with BRAF mutations to aid in the identification of benign and malignant thyroid nodules using FNA.

Methods: From April 2018 to December 2021, 275 patients with thyroid nodules who underwent ultrasonography and BRAF gene testing (137 positive and 138 negative) were included from Xianyang Central Hospital. The clinical and ultrasonic characteristics of the patients were used to develop a nomographic, diagnostic model of BRAF gene mutation, and to validate and evaluate the usefulness of the model.

Results: Independent risk factors for BRAF mutations included: focal strong echogenicity (microcalcifications, OR = 3.04, 95%CI = 1.41–6.58, p = 0.005), hypoechogenicity (OR = 3.8, 95%CI = 1.14–12.61, p = 0.029), lymph node metastases (OR = 3.54, 95%CI = 1.43–8.75, p = 0.006), margin (lobulated, OR = 3.7, 95%CI = 1.66–8.23, p = 0.001; extrathyroidal invasion, OR = 2.81, 95%CI = 1.11–7.06, p = 0.029), and shape (vertical position, OR = 2.7, 95%CI = 1.11–6.59, p = 0.029). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve of the BRAF mutation diagnostic model constructed on these factors was 0.806 (95% CI = 0.754–0.851), and 39.5% was set as the threshold probability of making a clinical decision. The results of the validation and clinical utility evaluation showed that our model had good predictive performance and clinical application value.

Conclusion: Our nomogram diagnostic model based on clinical and ultrasound features of patients accurately predicted the possibility of BRAF gene mutations in patients with thyroid nodules.

Risk and Prognostic Factors for BRAFV600E Mutations in Papillary Thyroid Carcinoma

Background

Over the past ten years, the incidence rate of papillary thyroid carcinoma (PTC) worldwide has been increasing rapidly year by year, with the incidence rate increasing 6% annually. PTC has become the malignant tumor with the highest growth rate in the world that fourteen PTC-related mutant genes have been identified. Whether the BRAF^V600E mutation related to more aggressive clinicopathologic features and worse outcome in PTC remains variable and controversial. We aim to investigate the risk factors that may predict the BRAF^V600E mutation potential of these lesions and new prevention strategies in PTC patients.

Methods

A total of 9,908 papillary thyroid carcinoma patients with average 74.6% BRAF^V600E mutations were analyzed (RevMan 5.3 software) in this study. The PubMed, Embase, and ISI Web of Science databases were systematically searched for works published through December 15, 2021.

Results

The following variables were associated with an increased risk of BRAF^V600E mutation in PTC patients: age ≥ 45 years (OR = 1.39, 95%CI = 1.21–1.60, p < 0.00001), male gender (OR = 1.13, 95%CI = 0.99–1.28, p = 0.06), multifocality (OR = 1.22, 95%CI = 1.07–1.40, p = 0.004), lymph node metastasis (OR = 1.33, 95%CI = 0.79–2.23, p = 0.28), extrathyroidal extension + (OR = 1.61, 95%CI = 1.06–2.44, p = 0.03), vascular invasion + (OR = 2.04, 95%CI = 1.32–3.15, p = 0.001), and tumor node metastasis stage (OR = 1.61, 95%CI = 1.38–1.88, p < 0.00001). In addition, tumor size (>1 cm) (OR = 0.51, 95%CI = 0.32–0.81, p = 0.005) and distant metastasis (OR = 0.69, 95%CI = 0.22–2.21, p = 0.54) had no association or risk with BRAF^V600E mutation in PTC patients.

Conclusion

Our systematic review identified the following significant risk factors of BRAF^V600E mutation in PTC patients: age (≥45 years), gender (male), multifocality, lymph node metastasis, vascular invasion, extrathyroidal extension, and advanced tumor node metastasis stage (stages III and IV). Tumor size (>1 cm) and distant metastasis do not appear to be correlated with BRAF^V600E mutation in PTC patients.

Construction of a Signature Model to Predict the Radioactive Iodine Response of Papillary Thyroid Cancer

Papillary thyroid cancer (PTC) accounts for about 90% of thyroid cancer. There are approximately 20%-30% of PTC patients showing disease persistence/recurrence and resistance to radioactive iodine (RAI) treatment. For these PTC patients with RAI refractoriness, the prognosis is poor. In this study, we aimed to establish a comprehensive prognostic model covering multiple signatures to increase the predictive accuracy for progression-free survival (PFS) of PTC patients with RAI treatment. The expression profiles of mRNAs and miRNAs as well as the clinical information of PTC patients were extracted from TCGA and GEO databases. A series of bioinformatics methods were successfully applied to filtrate a two-RNA model (IPCEF1 and hsa-mir-486-5p) associated with the prognosis of RAI-therapy. Finally, the RNA-based risk score was calculated based on the Cox coefficient of the individual RNA, which achieved good performances by the time-dependent receiver operating characteristic (tROC) curve and PFS analyses. Furthermore, the predictive power of the nomogram, integrated with the risk score and clinical parameters (age at diagnosis and tumor stage), was assessed by tROC curves. Collectively, our study demonstrated high precision in predicting the RAI response of 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-).

Therapeutic Strategy in Low-Risk Papillary Thyroid Carcinoma - Long-Term Results of the First Single-Center Prospective Non-Randomized Trial Between 2011 and 2015

Optimal therapeutic strategy in low advanced papillary thyroid carcinoma (PTC) is still a matter of debate. The management differs depending on the country. A prospective non-randomized study was performed to evaluate whether less extensive surgery could be a safe, acceptable, and sufficient therapeutic option in PTC cT1N0M0 patients. The present paper summarizes the results of over a 5-year follow-up.

MATERIAL

Our prospective group (PG) treated between 2011 and 2015 consisted of 139 patients with cT1aN0M0 PTC who underwent lobectomy (LT) as initial surgical treatment (PGcT1aN0M0 group) and 102 cT1bN0M0 patients in whom total thyroidectomy (TT) with unilateral central neck dissection (CND) was performed (PGcT1bN0M0). PG was compared with the retrospective group (RG) of patients who underwent TT with bilateral CND between 2004 and 2006: 103 cT1aN0M0 patients (RGcT1aN0M0) and 91cT1bN0M0 (RGcT1bN0M0). The risks of reoperation, cancer relapse and postoperative complications were analyzed.

RESULTS

Only 12 cT1aN0M0 patients (7.6%) withdrew from the trial and underwent TT with bilateral CND. Over 90% of patients accepted less extensive surgery. In 4 cT1aN0M0 cases, TT with CND was performed due to lymph node metastases found intraoperatively. The initial clinical stage according to the TNM/AJCC 7^th edition was confirmed histologically in 77% of cases in PGT1aN0M0 and in 72% in PGT1bN0M0, respectively. 24 PGcT1aN0M0 patients were reoperated on. In this group, cancer lesions in the postoperative histological specimens were found in 8 cases (32%). Five-year disease-free survival (DFS) was excellent. However, no statistically significant differences were found between PG and RG groups (99.3% in PGcT1aN0M0 and 99.0%, in RGcT1aN0M0; p = 0.41 and 98%, in PGcT1bN0M0 and 94.4% in RGcT1bN0M0; p=0.19). No significant differences were observed in the incidence of early paresis of the recurrent laryngeal nerves between PG and RG. However, as predicted, LT completely eliminated the risk of postoperative hypoparathyroidism.

SUMMARY

The results of the prospective clinical trial confirm that less extensive surgery in adequately selected low-advanced PTC patients is both safe and sufficient.

Differences in Gene Expression Profile of Primary Tumors in Metastatic and Non-Metastatic Papillary Thyroid Carcinoma-Do They Exist?

Molecular mechanisms of distant metastases (M1) in papillary thyroid cancer (PTC) are poorly understood. We attempted to analyze the gene expression profile in PTC primary tumors to seek the genes associated with M1 status and characterize their molecular function. One hundred and twenty-three patients, including 36 M1 cases, were subjected to transcriptome oligonucleotide microarray analyses: (set A-U133, set B-HG 1.0 ST) at transcript and gene group level (limma, gene set enrichment analysis (GSEA)). An additional independent set of 63 PTCs, including 9 M1 cases, was used to validate results by qPCR. The analysis on dataset A detected eleven transcripts showing significant differences in expression between metastatic and non-metastatic PTC. These genes were validated on microarray dataset B. The differential expression was positively confirmed for only two genes: IGFBP3, (most significant) and ECM1. However, when analyzed on an independent dataset by qPCR, the IGFBP3 gene showed no differences in expression. Gene group analysis showed differences mainly among immune-related transcripts, indicating the potential influence of tumor immune infiltration or signal within the primary tumor. The differences in gene expression profile between metastatic and non-metastatic PTC, if they exist, are subtle and potentially detectable only in large datasets.

Association of MicroRNA Expression and BRAFV600E Mutation with Recurrence of Thyroid Cancer

Many miRNAs and cancer-related mutations have been proposed as promising molecular markers of papillary thyroid carcinoma (PTC). However, there are limited data on the correlation between miRNA expression, BRAFV600E mutation, and PTC recurrence. Therefore, to evaluate the potential of BRAFV600E mutation and five selected miRNAs (-146b, -222, -21, -221, -181b) in predicting PTC recurrence, these molecular markers were analyzed in 400 formalin-fixed, paraffin-embedded PTC tissue specimens. The expression levels of miRNAs were measured using qRT-PCR. It was demonstrated that expression levels of all analyzed miRNAs are significantly higher in recurrent PTC than in non-recurrent PTC (p < 0.05). Moreover, higher expression levels of miR-146b, miR-222, miR-21, and miR-221 were associated with other clinicopathologic features of PTC, such as tumor size and lymph node metastases at initial surgery (p < 0.05). No significant differences in the frequency of BRAFV600E mutation in recurrent PTC and non-recurrent PTC were determined. Our results suggest that miRNA expression profile differs in PTC that is prone to recurrence when compared to PTC that does not reoccur after the initial surgery while BRAFV600E mutation frequency does not reflect the PTC recurrence status. However, the prognostic value of the analyzed miRNAs is rather limited in individual cases as the pattern of miRNA expression is highly overlapping between recurrent and non-recurrent PTC.

MicroRNA-384 Inhibits the Progression of Papillary Thyroid Cancer by Targeting PRKACB

Background

Growing evidence shows that dysregulation of miRNAs plays a significant role in papillary thyroid cancer (PTC) tumorigenesis and development. The abnormal expression of miR-384 has been acknowledged in the proliferation or metastasis of some cancers. However, the function and the underlying mechanism of miR-384 in PTC progression remain largely unknown.

Methods

Real-time PCR was conducted to detect miR-384 expression in 58 cases of PTC and their adjacent noncancerous tissues. MTT, soft agar assay Transwell assay, and wound-healing assay were carried out to explore the biological function of miR-384 in PTC cell lines of BCPAP and K1. Bioinformatics analysis, dual-luciferase reporter assay, western blot, and functional complementation analysis were conducted to explore the target gene of miR-384. Moreover, Spearman's correlation analysis was conducted to reveal the correlation between miR-384 and PRKACB mRNA in PTC.

Results

The expression of miR-384 decreased obviously in PTC, especially in the tumors with lymph node metastasis or larger tumor size. The ectopic upregulation of miR-384 significantly suppressed PTC progression, and the inhibition of miR-384 had the opposite effects. Moreover, PRKACB gene was confirmed as the target of miR-384.

Conclusion

The study suggests that miR-384 serves as a tumor suppressor in PTC progression by directly targeting the 3′-UTR of PRKACB gene.

Associations of the BRAF V600E Mutation and PAQR3 Protein Expression with Papillary Thyroid Carcinoma Clinicopathological Features

The BRAF^V600E mutation is the most prevalent genetic event in patients with papillary thyroid cancer (PTC). However, no study has investigated the expression of PAQR3 in papillary thyroid tissues in relation to the BRAF^V600E mutation and the clinicopathological features of PTC patients. Furthermore, the potential associations of the BRAF^V600E mutation, PAQR3 expression and clinicopathological parameters in the cancerous tissues of PTC patients have not been investigated. This study was conducted on 60 patients with PTC who were treated surgically at our institution from 2017 to 2018. PCR was used to amplify DNA by the amplification refractory mutation system (ARMS) method to detect BRAF^V600E gene mutations. In addition, immunohistochemical techniques were utilized to assess PAQR3 expression in tumor tissue sections. The BRAF^V600E mutation was associated with lymph node metastasis (LNM, p < 0.05) but not with other clinicopathological features. Low PAQR3 expression was associated with extrathyroidal extension and LNM (χ² = 7.143, p = 0.009; χ² = 6.459, p = 0.014, respectively). Furthermore, a statistically significant association was observed between chronic lymphocytic thyroiditis and LNM (χ² = 5.275, p = 0.0250). A linear relationship between the BRAF^V600E mutation and PAQR3 protein expression has not been identified. These factors may be independent risk factors of extrathyroidal extension and LNM in PTC and be used to indicate the invasiveness of PTC tumors. Higher quality, multivariate analyses based on larger samples from around the world are urgently needed to further validate and revise our findings in the future.

A novel gene panel for prediction of lymph-node metastasis and recurrence in patients with thyroid cancer

BACKGROUND

Although well-differentiated papillary thyroid cancer may remain indolent, lymph node metastases and the recurrence rates are approximately 50% and 20%, respectively. No current biomarkers are able to predict metastatic lymphadenopathy and recurrence in early stage papillary thyroid cancer. Hence, identifying prognostic biomarkers predicting cervical lymph-node metastases would prove very helpful in determining treatment.

METHODS

The database of the Cancer Genome Atlas included 495 papillary thyroid cancer samples. Using this database, we developed a machine learning model to define a gene signature that could predict lymph-node metastasis (N0 or N1). Kruskal-Wallis tests, univariate and multivariate logistic and Cox regression models, and Kaplan-Meier analyses were performed to correlate the gene signature with clinical outcomes.

RESULTS

We identified a panel of 25 genes and constructed a risk score that can differentiate N0 and N1 papillary thyroid cancer samples (P < .001) with a sensitivity of 86%, a specificity of 62%, a positive predictive value of 93%, and a negative predictive value of 42%. This panel represents an independent biomarker to predict metastatic lymphadenopathy (OR = 8.06, P < .001) specifically in patients with T1 lesions (OR = 7.65, P = .002) and disease-free survival (HR = 2.64, P = .043).

CONCLUSION

This novel 25-gene panel may be used as a potential prognostic marker for accurately predicting lymph-node metastasis and disease-free survival in patients with early-stage papillary thyroid cancer.

Evolution and Impact of Subclonal Mutations in Papillary Thyroid Cancer

Unlike many cancers, the pattern of tumor evolution in papillary thyroid cancer (PTC) and its potential role in relapse have not been elucidated. In this study, multi-region whole-exome sequencing (WES) was performed on early-stage PTC tumors (n = 257 tumor regions) from 79 individuals, including 17 who had developed relapse, to understand the temporal and spatial framework within which subclonal mutations catalyze tumor evolution and its potential clinical relevance. Paired primary-relapse tumor tissues were also available for a subset of individuals. The resulting catalog of variants was analyzed to explore evolutionary histories, define clonal and subclonal events, and assess the relationship between intra-tumor heterogeneity and relapse-free survival. The multi-region WES approach was key in correctly classifying subclonal mutations, 40% of which would have otherwise been erroneously considered clonal. We observed both linear and branching evolution patterns in our PTC cohort. A higher burden of subclonal mutations was significantly associated with increased risk of relapse. We conclude that relapse in PTC, while generally rare, does not follow a predictable evolutionary path and that subclonal mutation burden may serve as a prognostic factor. Larger studies utilizing multi-region sequencing in relapsed PTC case subjects with matching primary tissues are needed to confirm these observations.

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.

PFKFB2 Promoter Hypomethylation as Recurrence Predictive Marker in Well-Differentiated Thyroid Carcinomas

Despite the low mortality rates, well-differentiated thyroid carcinomas (WDTC) frequently relapse. BRAF and TERT mutations have been extensively related to prognosis in thyroid cancer. In this study, the methylation levels of selected CpGs (5-cytosine-phosphate-guanine-3) comprising a classifier, previously reported by our group, were assessed in combination with BRAF and TERT mutations. We evaluated 121 WDTC, three poorly-differentiated/anaplastic thyroid carcinomas (PDTC/ATC), 22 benign thyroid lesions (BTL), and 13 non-neoplastic thyroid (NT) tissues. BRAF (V600E) and TERT promoter (C228T and C250T) mutations were tested by pyrosequencing and Sanger sequencing, respectively. Three CpGs mapped in PFKFB2, ATP6V0C, and CXXC5 were evaluated by bisulfite pyrosequencing. ATP6V0C hypermethylation and PFKFB2 hypomethylation were detected in poor-prognosis (PDTC/ATC and relapsed WDTC) compared with good-prognosis (no relapsed WDTC) and non-malignant cases (NT/BTL). CXXC5 was hypomethylated in both poor and good-prognosis cases. Shorter disease-free survival was observed in WDTC patients presenting lower PFKFB2 methylation levels (p = 0.004). No association was observed on comparing BRAF (60.7%) and TERT (3.4%) mutations and prognosis. Lower PFKFB2 methylation levels was an independent factor of high relapse risk (Hazard Ratio = 3.2; CI_95% = 1.1–9.5). PFKFB2 promoter methylation analysis has potential applicability to better stratify WDTC patients according to the recurrence risk, independently of BRAF and TERT mutations.

Influence of Body Mass Index on the Clinicopathologic Features of Papillary Thyroid Carcinoma

BACKGROUND

Epidemiologic studies have demonstrated an increased risk for papillary thyroid carcinoma (PTC) with increasing body mass index (BMI). However, the relationships between excess weight and the behavior of PTC are inconsistent. The aim of this study was to evaluate the impact of excess weight on clinicopathologic features of PTC and on patient outcomes.

METHODS

Data from 417 patients with PTC who underwent total thyroidectomy with cervical lymph node dissection were retrospectively analyzed. On the basis of World Health Organization standardized categories of BMI, patients were divided into 4 groups: underweight, normal weight, overweight, and obese. Histopathologic tumor features, stage at diagnosis, and disease status were determined by chart review. Logistic regression models were used to define associations between BMI and clinicopathologic features of PTC. Cox proportional-hazards models were used to assess associations between BMI and locoregional recurrence.

RESULTS

Overweight (odds ratio [OR], 3.90; P = .040) and obesity (OR, 9.19; P = .012) were independent predictors of vascular invasion. Furthermore, obesity (OR, 6.14; P = .004) was an independent predictor of extrathyroidal invasion. During follow-up (median, 29 months; range, 5-87 months), 48 patients (11.5%) experienced locoregional recurrence. There were no significant differences in locoregional recurrence of PTC among BMI groups. When adjusted for other confounding factors, extrathyroidal invasion (OR, 8.35; P < .001), vascular invasion (OR, 3.57; P < .001), cervical lymph node metastasis (OR, 3.71; P = .009), and advanced tumor-node-metastasis stage (OR, 3.81; P < .001) were identified as independent factors for locoregional recurrence.

CONCLUSIONS

Higher BMI was associated with extrathyroidal invasion and vascular invasion in patients with PTC, which suggests that excess weight is associated with aggressive clinicopathologic features of PTC. But patients with higher BMI did not have an increased risk for developing postoperative complications and locoregional recurrence.

Predictive Value of BRAFV600E Mutation for Lymph Node Metastasis in Papillary Thyroid Cancer: A Meta-analysis

BRAF^V600E mutation has been thought to be a valuable molecular marker that may predict a worse prognosis for papillary thyroid cancer (PTC). But whether BRAF^V600E mutation is associated with lymph node metastasis (LNM) remains controversial. Different surgical strategies may bring a bias in demonsstrating the association between them. In order to delineate a risk stratification to guide a tailored initial approach to tumors that express BRAF^V600E mutation, we performed this meta-analysis by using the articles in which total or near-total thyroidectomy plus bilateral central lymph node dissection was routinely performed to avoid the bias from the surgical strategy. We searched the Medline, Embase and CNKI database for eligible studies from January 2003 to May 2018. Meta-analysis was performed using the STATA 12.0 software. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated under fixed-effects or randomeffects models. Fifteen clinical studies were included with a total of 4909 PTC patients. Our meta-analysis results reported that BRAFV600E mutation was associated with LNM (OR=1.34; 95% CI: 1.09-1.65; P=0.005), as well as central LNM (OR=1.59; 95% CI: 1.35-1.88; P<0.00001). Moreover, in patients with papillary thyroid microcarcinoma, we also confirmed the predictive value of BRAF^V600E mutation for LNM (OR=3.49; 95% CI: 2.02-6.02; P<0.00001). This meta-analysis demonstrates that BRAF^V600E mutation is closely related to LNM in PTC patients. The results suggest that BRAF^V600E mutation can be considered as a risk factor for LNM in PTC. Moreover, combining BRAF^V600E mutation with other risk factors to determine the initial surgical treatment may bring benefits for PTC patients.

Evaluation of the Role of BRAFV600E Somatic Mutation on Papillary Thyroid Cancer Disease Persistence: A Prospective Study

BACKGROUND

BRAFV600E (c.1799T>A) somatic mutation evaluation in fine needle aspiration biopsies (FNAB) is a powerful diagnostic tool in the settings of papillary thyroid cancer (PTC). However, its prognostic value is still a matter of great debate and has been addressed mostly in retrospective studies.

OBJECTIVES

To evaluate whether the somatic BRAFV600E mutation, assessed by direct sequencing in FNAB material of thyroid nodules, may correlate with disease persistence in PTC patients.

STUDY DESIGN

We conducted a prospective cohort study investigating 160 PTC patients previously assessed for the somatic BRAFV600E mutation, and submitted to total thyroidectomy, with a follow-up of 2-10 years. Patients were matched according to somatic BRAFV600E mutation (80 BRAF+ and 80 BRAF- patients) and to the presence (LN+, 40 patients each group) or absence (LN, 40 patients each group) of neck lymphnode metastases. Disease persistence was considered according to basal or TSH-stimulated Thyroglobulin (TG) levels, anti-TG antibodies, neck ultrasound, CT scan where applicable and whole body scan after radioiodine ablation treatment (RAI).

RESULTS

The presence of the somatic BRAFV600E mutation did not influence the indication for RAI. None of the enrolled patients showed disease recurrence or died due to disease-related causes. During follow-up, disease persistence did not correlate with the presence of somatic BRAFV600E mutation both in patients submitted to RAI nor in those treated more conservatively.

CONCLUSIONS

The somatic BRAFV600E mutation does not associate with a worse prognosis in low risk PTC and, in our settings, may not be considered an independent risk factor for disease persistence.

Integrated Characterization of MicroRNA and mRNA Transcriptome in Papillary Thyroid Carcinoma

The incidence rate of papillary thyroid carcinoma (PTC) has rapidly increased in the recent decades, and the microRNA (miRNA) is one of the potential biomarkers in this cancer. Despite good prognosis, certain features such as lymph node metastasis (LNM) and BRAF V600E mutation are associated with a poor outcome. More than 50% of PTC patients present with LNM and BRAF V600E is the most common mutation identified in this cancer. The molecular mechanisms underlying these features are yet to be elucidated. This study aims to elucidate miRNA-genes interaction networks in PTC with or without LNM and to determine the association of BRAF V600E mutation with miRNAs and genes expression profiles. Next generation sequencing was performed to characterize miRNA and gene expression profiles in 20 fresh frozen tumor and the normal adjacent tissues of PTC with LNM positive (PTC LNM-P) and PTC without LNM (PTC LNN). BRAF V600E was genotyped using Sanger sequencing. Bioinformatics integration and pathway analysis were performed to determine the regulatory networks involved. Based on network analysis, we then investigated the association between miRNA and gene biomarkers, and pathway enrichment analysis was performed to study the role of candidate biomarkers. We identified 138 and 43 significantly deregulated miRNAs (adjusted p value < 0.05; log2 fold change ≤ -1.0 or ≥1.0) in PTC LNM-P and PTC LNN compared to adjacent normal tissues, respectively. Ninety-six miRNAs had significant expression ratios of 3p-to-5p in PTC LNM-P as compared to PTC LNN. In addition, ribosomal RNA-reduced RNA sequencing analysis revealed 699 significantly deregulated genes in PTC LNM-P versus normal adjacent tissues, 1,362 genes in PTC LNN versus normal adjacent tissue, and 1,576 genes in PTC LNM-P versus PTC LNN. We provide the evidence of miRNA and gene interactions, which are involved in LNM of papillary thyroid cancer. These findings may lead to better understanding of carcinogenesis and metastasis processes. This study also complements the existing knowledge about deregulated miRNAs in papillary thyroid carcinoma development.

Response to therapy of papillary thyroid cancer of known BRAF status

OBJECTIVE

A dynamic risk stratification with modified initial estimated risk based on response to therapy and disease course is one of the crucial changes adopted recently by the American Thyroid Association (ATA). This approach focuses on an individualized risk-adapted approach to the management of differentiated thyroid cancer. The BRAF V600E mutation is the most common genetic alteration in papillary thyroid cancer (PTC). However, the prognostic value of this mutation remains unclear. The aim of this study was to examine the relation between the BRAF V600E status in PTC and all ATA response-to-therapy categories, as well as the recurrence and persistence of both biochemical disease and structural disease.

PATIENTS

Unselected PTC cases with known BRAF status diagnosed from 2000 to 2013 and actively monitored at one institution (n=723) were reviewed retrospectively. The association between the BRAF V600E mutation and clinicopathological characteristics, ATA 2015 response-to-therapy category, recurrence after a period of no evidence of disease (NED) and persistent biochemical or structural disease, was analysed.

RESULTS

BRAF V600E was found in 65.7% (475/723) of PTC cases. Although BRAF mutation status correlated significantly with certain clinicopathological prognostic factors, there was no correlation with any of the response-to-therapy categories. Recurrences and persistent biochemical or structural disease were not associated with BRAF status.

CONCLUSIONS

Our data are consistent with those of other studies reporting a positive relation between BRAF V600E mutation and poor prognostic factors in PTC; however, the BRAF status did not significantly correlate with a response to therapy.

Correlation between BRAF V600E mutation and clinicopathological features in pediatric papillary thyroid carcinoma

In adults, the presence of the BRAF ^V600E mutation in papillary thyroid cancer (PTC) has been demonstrated to be strongly associated with aggressive cancer-cell characteristics and poor patient prognosis. In contrast, the frequency of this mutation in pediatric PTC has undergone limited study, and the few available estimates range from 0 to 63%. Furthermore, the role of the BRAF ^V600E mutation in pediatric PTC is controversial; thus, the present study aimed to investigate the prevalence and role of the BRAF ^V600E mutation in 48 pediatric patients with PTC, aged 3-13 years. Of these patients, 41 were diagnosed with classic PTC, five were found to have a follicular variant of PTC, and two to exhibit a diffuse sclerosing PTC variant. The BRAF ^V600E mutation was identified to be present in 35.4% of the 48 analyzed patients, and in 41.5% of the patients diagnosed with classical PTC. Furthermore, the presence of the BRAF ^V600E mutation was found to be associated with a patient age at diagnosis of less than ten years (P=0.011), the performance of a thyroidectomy (P=0.03), exhibited tumor multifocality (P=0.02) and/or extra-thyroidal invasion (P=0.003), and both a low MACIS (Metastases, Age, Completeness of resection, Invasion, Size)(P=0.036) and AMES (Age, Metastasis, Extent of tumor, Size)(P=0.001) score. Together, these data suggest that the presence of the BRAF ^V600E mutation may be negatively correlated with partial aggressive clinicopathological features of pediatric PTC.

Integrated data analysis reveals potential drivers and pathways disrupted by DNA methylation in papillary thyroid carcinomas

BACKGROUND

Papillary thyroid carcinoma (PTC) is a common endocrine neoplasm with a recent increase in incidence in many countries. Although PTC has been explored by gene expression and DNA methylation studies, the regulatory mechanisms of the methylation on the gene expression was poorly clarified. In this study, DNA methylation profile (Illumina HumanMethylation 450K) of 41 PTC paired with non-neoplastic adjacent tissues (NT) was carried out to identify and contribute to the elucidation of the role of novel genic and intergenic regions beyond those described in the promoter and CpG islands (CGI). An integrative and cross-validation analysis were performed aiming to identify molecular drivers and pathways that are PTC-related.

RESULTS

The comparisons between PTC and NT revealed 4995 methylated probes (88% hypomethylated in PTC) and 1446 differentially expressed transcripts cross-validated by the The Cancer Genome Atlas data. The majority of these probes was found in non-promoters regions, distant from CGI and enriched by enhancers. The integrative analysis between gene expression and DNA methylation revealed 185 and 38 genes (mainly in the promoter and body regions, respectively) with negative and positive correlation, respectively. Genes showing negative correlation underlined FGF and retinoic acid signaling as critical canonical pathways disrupted by DNA methylation in PTC. BRAF mutation was detected in 68% (28 of 41) of the tumors, which presented a higher level of demethylation (95% hypomethylated probes) compared with BRAF wild-type tumors. A similar integrative analysis uncovered 40 of 254 differentially expressed genes, which are potentially regulated by DNA methylation in BRAFV600E-positive tumors. The methylation and expression pattern of six selected genes (ERBB3, FGF1, FGFR2, GABRB2, HMGA2, and RDH5) were confirmed as altered by pyrosequencing and RT-qPCR.

CONCLUSIONS

DNA methylation loss in non-promoter, poor CGI and enhancer-enriched regions was a significant event in PTC, especially in tumors harboring BRAFV600E. In addition to the promoter region, gene body and 3'UTR methylation have also the potential to influence the gene expression levels (both, repressing and inducing). The integrative analysis revealed genes potentially regulated by DNA methylation pointing out potential drivers and biomarkers related to PTC development.

A meta-analysis of prognostic roles of molecular markers in papillary thyroid carcinoma

The prognostic role of molecular markers in papillary thyroid carcinoma (PTC) is a matter of ongoing debate. The aim of our study is to investigate the impact of RAS, BRAF, TERT promoter mutations and RET/PTC rearrangements on the prognosis of PTC patients. We performed a search in four electronic databases: PubMed, Scopus, Web of Science and Virtual Health Library (VHL). Data of hazard ratio (HR) and its 95% confidence interval (CI) for disease-specific survival (DSS) and disease-free survival (DFS) were directly obtained from original papers or indirectly estimated from Kaplan-Meier curve (KMC). Pooled HRs were calculated using random-effect model weighted by inverse variance method. Publication bias was assessed by using Egger's regression test and visual inspection of funnel plots. From 2630 studies, we finally included 35 studies with 17,732 patients for meta-analyses. TERT promoter mutation was significantly associated with unfavorable DSS (HR = 7.64; 95% CI = 4.00-14.61) and DFS (HR = 2.98; 95% CI = 2.27-3.92). BRAF mutations significantly increased the risk for recurrence (HR = 1.63; 95% CI = 1.27-2.10) but not for cancer mortality (HR = 1.41; 95% CI = 0.90-2.23). In subgroup analyses, BRAF mutation only showed its prognostic value in short-/medium-term follow-up. Data regarding RAS mutations and RET/PTC fusions were insufficient for meta-analyses. TERT promoter mutation can be used as an independent and reliable marker for risk stratification and predicting patient's outcomes. The use of BRAF mutation to assess patient prognosis should be carefully considered.

PI3K/AKT Pathway and Its Mediators in Thyroid Carcinomas

Thyroid malignancies are the most common endocrine system carcinomas, with four histopathological forms. The phosphoinositide 3-kinase-protein kinase B/AKT (PI3K-PKB/AKT) pathway is one of the most critical molecular signaling pathways implicated in key cellular processes. Its continuous activation by several aberrant receptor tyrosine kinases (RTKs) and genetic mutations in its downstream effectors result in high cell proliferation in a broad number of cancers, including thyroid carcinomas. In this review article, the role of different signaling pathways of PI3K/AKT in thyroid cancers, with the emphasis on the PI3K/AKT/mammalian target of rapamycin (mTOR), PI3K/AKT/forkhead box O (FOXO) and PI3K/AKT/phosphatase and tensin homolog deleted on chromosome ten (PTEN) pathways, and various therapeutic strategies targeting these pathways have been summarized. In most of the in vitro studies, agents inhibiting mTOR in monotherapy or in combination with chemotherapy for thyroid malignancies have been introduced as promising anticancer therapies. FOXOs and PTEN are two outstanding downstream targets of the PI3K/AKT pathway. At the present time, no study has been undertaken to consider thyroid cancer treatment via FOXOs and PTEN targeting. According to the critical role of these proteins in cell cycle arrest, it seems that a treatment strategy based on the combination of FOXOs or PTEN activity induction with PI3K/AKT downstream mediators (e.g., mTOR) inhibition will be beneficial and promising in thyroid cancer treatment.

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

Papillary thyroid cancer (PTC) offers excellent prognosis, however relapse risk or persistent disease is related to ~30%. Currently, attention is paid to the possibility of patient group selection of different risk of unfavorable outcome to match a particular therapeutic approach. Therefore, interest in new prognostic and predictive markers known preoperatively is observed. BRAF V600E mutation is such a marker. Many studies analyzing the prevalence of the mutation and its relationship with other clinico-pathological risk factors were reported but with controversial conclusions. The prognostic significance of BRAF mutation was confirmed by some single centre studies, a few meta-analyses and a large multicenter retrospective international study. They confirmed a correlation between the mutation and the risk of recurrence. The strongest argument against using BRAF mutation as an independent prognostic and predictive factor in PTC is its high prevalence (30-80%). At present it seems that BRAF mutation is one of the factors influencing the prognosis and it should be analyzed in correlation with other prognostic factors. The most recent ATA recommendations do not indicate a routine application of BRAF status for initial risk stratification in differentiated thyroid cancer due to a lack of evident confirmation of a direct influence of mutation on the increase in relapse risk. However, ATA demonstrates the continuous risk scale for the relapse risk assessment, considering BRAF and/or TERT status. At present, researchers are working on determining the role of BRAF mutation in patients from a low-risk group and its correlations with others molecular events. Currently, BRAF mutation cannot be used as a single, independent predictive factor. However, its usefulness in the context of other molecular and clinico-pathological risk factors cannot be excluded. They may be used to make modern prognostic scales of relapse risk and be applied to individualized diagnostic and therapeutic strategy for PTC patients.

Increase in Papillary Thyroid Cancer Incidence Is Accompanied by Changes in the Frequency of the BRAF V600E Mutation: A Single-Institution Study

BACKGROUND

Thyroid cancer (TC) has one of the fastest increasing incidences worldwide and primarily involves papillary thyroid cancer (PTC). The BRAF(V600E) mutation is the most common genetic alteration identified in PTC. There are few data concerning an association between the rising incidence of PTC and the increasing prevalence of BRAF-positive cases. Environmental factors such as iodine intake may be responsible for the changing molecular features of PTC. The aim of this study was to evaluate probable variations in the frequency of the BRAF(V600E) mutation in PTC that were diagnosed at a single institution over 14 years in Poland, a country with a demonstrated improvement in iodine supplementation in the early 21st century.

METHODS

Time-dependent trends in the prevalence of the BRAF(V600E) mutation during three time periods (2000-2004, 2005-2009, and 2010-2013) were analyzed. The BRAF mutation was genotyped using direct sequencing, allele-specific polymerase chain reaction (PCR), and real-time PCR in 723 unselected cases of PTC that were diagnosed in 2000-2013. Trends in the clinicopathologic characteristics of all PTCs and BRAF(V600E)-positive PTCs were also analyzed.

RESULTS

The proportion of PTCs with mutations significantly increased over the study period (54.8% vs. 70.6%; p = 0.001). The median tumor size of all and BRAF-positive tumors decreased (p = 0.008 and p = 0.001, respectively) and correlated with an increase in the proportion of all and mutated microcarcinomas (p = 0.003 and p = 0.003, respectively). A decrease in all and mutated tumors between 2 and 4 cm was also observed (p = 0.002 and p = 0.006, respectively). A significant decrease in tumors ≥ 4 cm in size was only observed in BRAF-positive cases (p = 0.017). The proportion of classic PTC with BRAF(V600E) mutation was observed to increase (57.6% vs. 74.4%; p = 0.001) and was stable for the follicular variant of PTC (p = 0.336).

CONCLUSIONS

The prevalence of the BRAF(V600E)mutation increased significantly in PTCs diagnosed in the authors' institution. Improved detection and several causative factors, most likely environmental and changes in iodine intake, may contribute to the increasing occurrence of TC.

Specific immunohistochemical detection of the BRAF V600E mutation in primary and metastatic papillary thyroid carcinoma

PURPOSE

To evaluate the clinical value of immunohistochemistry (IHC) using anti-BRAF V600E antibody (clone VE1) for specific detection of the BRAF V600E mutant protein in formalin-fixed paraffin-embedded papillary thyroid carcinoma (PTC) specimens.

METHODS

A total of 118 PTC cases and 116 control cases processed between January 2008 and June 2010 were selected and created tissue microarrays (TMAs) for the study. BRAF V600E (VE1) IHC was performed on tissue sections from PTC cases to determine mutation status. Molecular tests (Sanger sequencing/ARMS) were used to confirm the BRAF V600E gene mutation in primary PTC.

RESULTS

A uniformly cytoplasmic staining throughout the tumors was observed in IHC-positive cases. BRAF V600E was detected in 68.6% (81/118) of PTC samples by IHC and in 61.9% (73/118) by Sanger sequencing/ARMS. The overall concordance between IHC and Sanger sequencing/ARMS was 93.2% (110/118). The sensitivity and specificity of the BRAF V600E IHC was 100% (73/73) and 82.2% (37/45), respectively. Positive and negative predictive values were 90.1% (73/81) and 100% (37/37), respectively. Expression of the BRAF V600E mutant protein was detected in all of 59 cases of primary carcinoma and corresponding metastatic carcinoma in lymph nodes. The concordance between IHC staining in primary and metastatic PTC was 100% (59/59).

CONCLUSION

IHC using VE1 antibody for detection of the BRAF V600E mutant protein expression in PTC showed high sensitivity and acceptable specificity, which are critical for diagnostic purposes. IHC staining for BRAF V600E showed uniformly cytoplasmic expression in both primary tumor and metastatic nodes. Therefore, IHC has high practical value for the detection of the BRAF V600E mutation in metastatic and primary PTC.