Age and BRAFV600E Mutation Stratified Patients with Cytologically Benign Thyroid Nodules

Purpose

Our objective was to evaluate the diagnostic performance of BRAFV600E mutation for malignant, and to identify clinical characteristics associated with positive BRAFV600E mutation in low-risk cytological and ultrasound diagnostic thyroid nodules. This aims to identify patients who may benefit from BRAFV600E mutation testing and subsequent surgical intervention.

Patients and Methods

We analysis the clinical characteristics correlated with BRAFV600E mutation in our detection cohort, including 204 patients with 217 thyroid nodules, and separate analyses were performed in 103 thyroid nodules with benign cytological result. Signaling pathway and immune response associated with age and BRAFV600E mutation status were also evaluated in Asian patients with thyroid cancer from the Cancer Genome Atlas (TCGA) dataset.

Results

The positive BRAFV600E mutation was significantly associated with higher Ultrasound (US) classification (p<0.001) and fine-needle aspiration (FNA) categories (p<0.001). BRAFV600E mutation as a risk factor for malignancy, showing the optimal diagnostic efficacy for malignancy combined with FNA categories, with the AUC was 0.923. Otherwise, BRAFV600E mutation is a risk factor in screening malignancy in low-risk FNA and US classification, which is significant correlation with patients age. Patients over 50 years old exhibiting a higher percentage of positive BRAFV600E mutation when both ultrasound and FNA results indicate benign conditions, with higher risk of malignancy.

Conclusion

BRAFV600E mutation is an accurate adjunctive diagnostic marker on FNA to screen malignancy. In low risk of both ultrasound and FNA results, the positive BRAFV600E was significant increased in patients over 50 years old, which have higher risk of malignancy. Thus, the BRAFV600E mutation detection and further surgery should be strengthened in older patients with benign cytological and US results thyroid nodules.

Diagnostic Efficacy of Ultrasound, Cytology, and BRAFV600E Mutation Analysis and Their Combined Use in Thyroid Nodule Screening for Papillary Thyroid Microcarcinoma

Background

Ultrasound, cytology, and BRAF^V600E mutation analysis were applied as valuable tools in the differential diagnosis of thyroid nodules. The aim of the present study was to evaluate the diagnostic efficiency of the three methods and their combined use in screening for papillary thyroid microcarcinoma (PTMC).

Methods

A total of 1,081 patients with 1,157 thyroid nodules (0.5–1 cm in maximum diameter) classified as thyroid imaging reporting and data system (TIRADS) 4–5 were recruited. All patients underwent ultrasound, fine-needle aspiration (FNA) examination, and an additional BRAF^V600E mutation test. TIRADS and Bethesda System for Reporting Thyroid Cytopathology (BSRTC) were adopted to judge the ultrasound and cytological results. The receiver operating characteristic (ROC) curve was established to assess the diagnostic values of different methods.

Results

Of the 1,157 nodules, 587 were benign and 570 were PTMCs. BRAF^V600E mutation test had highest sensitivity (85.4%), specificity (97.1%), accuracy (91.4%), and area under the ROC curve (Az) value (0.913) among the three methods. The combination of BSRTC and BRAF^V600E mutation analysis yielded a considerably high sensitivity (96.0%), accuracy (94.3%), and negative predictive value (95.9%) than either BSRTC or BRAF^V600E mutation alone (P < 0.0001 for all comparisons). Of all the methods, the combined use of the three methods produced the best diagnostic performance (Az = 0.967), which was significantly higher than that (Az = 0.943) for the combination of BSRTC and BRAF^V600E mutation (P < 0.0001). The diagnostic accuracy of the molecular method in the 121 nodules with indeterminate cytology was 90.1% (109/121), which was significantly higher than that of TIRADS classification, 74.4% (90/121) (P = 0.002).

Conclusion

The combined use of ultrasound, cytology, and BRAF^V600E mutation analysis is the most efficient and objective method for diagnosing PTMC. Both BRAF^V600E mutation and TIRADS classification are potentially useful adjuncts to differentiate thyroid nodules, especially indeterminate samples classified as BSRTC III.

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

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

Diagnostic Value of Molecular Testing in Sonographically Suspicious Thyroid Nodules

Objective

Molecular testing can refine the diagnosis for the 20% of thyroid fine-needle aspiration biopsies that have indeterminate cytology. We assessed the diagnostic accuracy of molecular testing based on ultrasound risk classification.

Methods

This retrospective cohort study analyzed all thyroid nodules with indeterminate cytology at an academic US medical center (2012-2016). All indeterminate nodules underwent reflexive molecular testing with the Afirma Gene Expression Classifier (GEC). Radiologists performed blinded reviews to categorize each nodule according to the American Thyroid Association (ATA) ultrasound classification and the American College of Radiology Thyroid Imaging, Reporting and Data System. GEC results and diagnostic performance were compared across ultrasound risk categories.

Results

Of 297 nodules, histopathology confirmed malignancy in 65 (22%). Nodules by ATA classification were 8% high suspicion, 44% intermediate, and 48% low/very low suspicion. A suspicious GEC result was more likely in ATA high-suspicion nodules (81%) than in nodules of all other ATA categories (57%; P = .04). The positive predictive value (PPV) of GEC remained consistent across ultrasound categories (ATA high suspicion, 64% vs all other ATA categories, 48%; P = .39). The ATA high-suspicion category had higher specificity than a suspicious GEC result (93% vs 51%; P < .01). A suspicious GEC result did not increase specificity for the ATA high-suspicion category.

Conclusion

The PPV of molecular testing remained consistent across ultrasound risk categories. However, a suspicious GEC result was very likely in ATA high-suspicion nodules and did not improve specificity in this sonographic category.

Association Between BRAFV600E Mutation and the American College of Radiology Thyroid Imaging, Reporting and Data System in Solitary Papillary Thyroid Carcinoma

RATIONALE AND OBJECTIVES

The purpose of this study was to evaluate the associations between BRAF^V600E mutation, the American College of Radiology (ACR) thyroid imaging, reporting and data system (TI-RADS) on ultrasound and clinicopathological characteristics in patients with a solitary papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

This retrospective study included 397 patients with a solitary PTC, proved pathologically. BRAF^V600E mutation status was detected in postoperative samples by real-time fluorescent polymerase chain reaction. Associations of BRAF^V600E mutation with the ACR TI-RADS and clinicopathological characteristics were analyzed.

RESULTS

In this study, the incidence of BRAF^V600E mutation was 81.4% (323/397) in patients with a solitary PTC. Univariate analyses showed that BRAF^V600E mutation was significantly associated with margin, higher ACR TI-RADS point scores, and Hashimoto's thyroiditis. In multivariate analyses, lobulated or irregular margin was independently associated with BRAF^V600E mutation in total solitary PTC. Furthermore, both in total solitary PTC and papillary thyroid microcarcinoma, BRAF^V600E mutation was associated with ACR TI-RADS point scores, which was positively correlated with the risk of BRAF^V600E mutation. There was no significant relationship between BRAF^V600E mutation and ACR TI-RADS point scores in PTC >10 mm. In addition, Hashimoto's thyroiditis had a significant negative association with BRAF^V600E mutation.

CONCLUSION

A lobulated or irregular margin of the thyroid nodule is independently associated with BRAF^V600E mutation in patients with PTC. In addition, higher ACR TI-RADS point scores is an independent risk factor for BRAF^V600E mutation, and ACR TI-RADS point scores is positively associated with the risk of BRAF^V600E mutation in solitary PTC, especially in papillary thyroid microcarcinoma. Our findings may be helpful for preoperative identification and medical management of PTC patients with BRAF^V600E mutation.

Utility of including BRAF mutation analysis with ultrasonographic and cytological diagnoses in ultrasonography-guided fine-needle aspiration of thyroid nodules

This study investigated the role of BRAF mutation analysis in thyroid fine-needle aspiration (FNA) samples compared to ultrasonographic and cytological diagnoses. A total 316 patients underwent ultrasonography (US)-guided FNA with BRAFV600E mutation analysis to diagnose thyroid nodules. One hundred sixteen patients with insufficient US images (n = 6), follow-up loss (n = 43), or unknown final diagnosis (n = 67) were excluded from the study. Comparisons between US diagnoses, cytological diagnoses, and BRAF mutation analysis were performed. Of 200 thyroid nodules, there was US diagnosis with 1 false negative and 11 false positive cases, cytological diagnosis with 10 false negative and 2 false positive cases, and BRAFV600E mutation analysis with 19 false negative and 2 false positive cases. The sensitivity, specificity, positive and negative predictive values, and accuracy of BRAFV600E mutation analysis were 83.2%, 98.1%, 97.5%, 86.6%, and 91%, respectively. Of the 18 nodules with Bethesda category III, 9 were true positive, 6 were true negative, 3 was a false negative, and none were false positive on BRAF mutation analysis. In conclusion, we recommend that BRAFV600E mutation analysis only be performed for evaluating thyroid nodules with Bethesda category III, regardless of US diagnosis.

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

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

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

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

Initial clinical experience with BRAF(V600E) mutation analysis of core-needle biopsy specimens from thyroid nodules

OBJECTIVE

The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study was to evaluate the feasibility of core-needle biopsy with BRAF(V600E) mutation analysis (CNB + BRAF(V600E) ) and to compare the clinical usefulness of CNB + BRAF(V600E) and fine-needle aspiration with BRAF(V600E) mutation analysis (FNA + BRAF(V600E) ) in the diagnosis of thyroid malignancy.

DESIGN, PATIENTS AND MEASUREMENTS

The results of BRAF(V600E) mutation analyses of 820 nodules from 820 patients (153 men, 667 women; mean age, 51·1 years), who underwent CNB + BRAF(V600E) (n = 256) or FNA + BRAF(V600E) (n = 564) between January 2011 and March 2012 were retrospectively evaluated. The feasibility of CNB + BRAF(V600E) was assessed by comparing its rate of detection of BRAF(V600E) mutations and positive predictive value with those of FNA + BRAF(V600E) . The clinical usefulness of CNB + BRAF(V600E) was determined by comparing rates of inconclusive results, the additional value of BRAF(V600E) mutation analysis, diagnostic surgery and diagnostic performance with those of FNA + BRAF(V600E) .

RESULTS

CNB + BRAF(V600E) and FNA + BRAF(V600E) had similar rates of BRAF(V600E) mutation detection (66·3% vs 64·4%, P = 0·883) and positive predictive value (100·0% vs 96·6%, P = 0·135). CNB + BRAF(V600E) had a significantly higher diagnostic accuracy rate (95·7% vs 85·9%, P < 0·001), and significantly lower rates of inconclusive results (8·2% vs 51·8%, P < 0·001), and diagnostic surgery (8·9% vs 22·3%, P = 0·006), than FNA + BRAF(V600E) .

CONCLUSIONS

The greater diagnostic performance of CNB + BRAF(V600E) and its lower rate of inconclusive results than FNA + BRAF(V600E) suggest that CNB + BRAF(V600E) can reduce rates of preventable diagnostic surgery.

Clinical impact of BRAF mutation on the diagnosis and prognosis of papillary thyroid carcinoma: a systematic review and meta-analysis

BACKGROUND

The possible role of BRAF(V) (600E) mutation in the diagnosis and prognosis of papillary thyroid carcinoma (PTC) remains controversial. A systematic review to investigate the diagnostic and prognostic role of BRAF(V) (600E) mutation in patients with PTC is urgently needed.

METHODS

A systematic review of relevant literatures was performed in PubMed, EMBASE and CENTRAL. The incremental accuracy (IA) of fine needle aspiration biopsy plus BRAF(V) (600E) mutation analysis over fine needle aspiration biopsy alone, and the statistical data about the association of BRAF(V) (600E) mutation and the prognosis of PTC (risk ratios (RR) for dichotomous data, standard mean differences for continuous data and hazard ratios (HRs) for disease-free survival (DFS) were pooled. Subgroup analysis was performed to explain the heterogeneities.

RESULTS

A total of 67 studies were included. The pooled IA was 2% (95% confidence interval (CI): 0·5-4%). The pooled RR for gender, multifocality, lymph node metastasis, extrathyroidal invasion and pathological stage was 1·11 (95% CI: 0·98-1·25), 1·17 (95% CI: 1·09-1·24), 1·36 (95% CI: 1·20-1·53), 1·60 (95% CI: 1·41-1·82), and 1·49 (95% CI: 1·33-1·68), respectively. The pooled standard mean differences for age and tumour size were 0·14 (95% CI: 0·04-0·23) and 0·21 (95% CI: 0·1-0·32), respectively. The pooled HR for DFS was 1·96 (95% CI: 1·62-2·37). Subgroup analysis showed that these statistical results were affected by the geographical background of patients, study design and detection methods.

CONCLUSIONS

BRAF(V) (600E) mutation analysis can not only be used in the diagnosis of PTC, but can also predict its prognosis.

Evaluation of the Clinical Usefulness of BRAFV600E Mutation Analysis of Core-Needle Biopsy Specimens in Thyroid Nodules with Previous Atypia of Undetermined Significance or Follicular Lesions of Undetermined Significance Results

BACKGROUND

The accurate diagnosis of thyroid nodules is important for making management decisions. The purpose of this study is to evaluate the clinical usefulness of BRAF(V600E) mutation analysis with core-needle biopsy (CNB+BRAF(V600E)) in thyroid nodules with previous atypia of undetermined significance (AUS) or follicular lesions of undetermined significance (FLUS) results.

MATERIALS AND METHODS

From January 2011 to December 2012, 590 CNB+BRAF(V600E) mutation analyses were performed. We analyzed 200 nodules from 200 patients with previous AUS/FLUS results (22 men, 178 women; mean age, 48.6 years). The clinical usefulness of CNB+BRAF(V600E) was assessed by comparing the rates of conclusive results, the additional value of BRAF(V600E) mutation analysis, diagnostic performances, and therapeutic/diagnostic surgery results with those of CNB alone. For the subgroup analysis, the study patients were divided into those with nodules with previous AUS results and those with previous FLUS results.

RESULTS

All CNB+BRAF(V600E) procedures were well-tolerated. CNB+BRAF(V600E) did not show significantly better diagnostic performance than CNB alone in thyroid nodules with previous AUS/FLUS results. However, the conclusive result rate of CNB+BRAF(V600E) was improved in thyroid nodules with previous AUS/FLUS results (76.5% vs. 73.0%, p=0.016), especially with previous AUS results (81.1% vs. 76.4%, p=0.031). Of the 56 previous AUS result thyroid nodules with surgical management, BRAF(V600E) mutation analysis led to therapeutic surgery in 5.4% by decreasing unnecessary diagnostic surgery.

CONCLUSIONS

In general, CNB+BRAF(V600E) did not show significantly higher diagnostic accuracy than CNB alone. Although CNB+BRAF(V600E) may add additional value in nodules with previous AUS results, routinely adding BRAF(V600E) mutation analysis to CNB is not recommended.

Prediction Table and Nomogram as Tools for Diagnosis of Papillary Thyroid Carcinoma: Combined Analysis of Ultrasonography, Fine-Needle Aspiration Biopsy, and BRAF V600E Mutation

Although ultrasonography (US)-guided fine-needle aspiration biopsy (FNAB) is the most reliable diagnostic modality for evaluating thyroid nodules, 10% to 40% of FNAB samples yield indeterminate findings. The BRAF V600E mutation, a highly specific molecular marker for papillary thyroid carcinoma (PTC), well known for its prognostic value, has dubious diagnostic value because of its low sensitivity. Novel strategies are clearly needed to distinguish PTC, which represents the majority of thyroid malignancies, from other thyroid nodules. The records of 3297 patients with surgically proven PTC were retrospectively reviewed. A prediction table and nomogram were designed using a combination of diagnostic parameters for US, FNAB, and the BRAF V600E mutation. For the nomogram, parameters were proportionally assigned 0 to 100 points according to their regression coefficient for PTC. The probability of PTC for thyroid nodules with intermediate-risk (IR) US and atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) FNAB was significantly dependent on BRAF V600E mutation status based on our prediction table (negative, 29.2% vs positive, 87.5%; P < 0.001). By our nomogram, the probability of PTC for thyroid nodules with IR US, AUS/FLUS FNAB, and positive BRAF V600E mutation was approximately 85% to 90%. We strongly recommend preoperative evaluation of the BRAF V600E mutation in indeterminate thyroid nodules. The prediction table and nomogram developed in this study could help clinicians and patients easily assess the probability of PTC in the preoperative period.

Clinical Implication of Highly Sensitive Detection of the BRAFV600E Mutation in Fine-Needle Aspirations According to the Thyroid Bethesda System in Patients With Conventional Papillary Thyroid Carcinoma

BACKGROUND

We investigated the additional diagnostic yield of the mutation test and evaluated the frequency of the BRAF mutation in conventional PTC (cPTC) according to ultrasound (US) features and the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) based on the BRAFV600E mutation status.

MATERIALS AND METHODS

During the study period, 279 patients who underwent FNA with an additional BRAFV600E mutation test were diagnosed as cPTC after surgery. We analyzed the association between the mutation and several clinical factors.

RESULTS

Of the 279 cPTCs, 250 (89.6%) had the BRAFV600E mutation. The BRAF mutation test was helpful in diagnosing an additional 19% (53/279) of cPTCs. The frequency of the BRAF mutation in cPTCs with suspicious US features was higher than that of cPTCs with negative US features regardless of the BSRTC.

CONCLUSIONS

Suspicious US features may be helpful in deciding whether an additional BRAFV600E mutation test should be done in thyroid nodules with indeterminate cytology.

Associations of the BRAF(V600E) mutation with sonographic features and clinicopathologic characteristics in a large population with conventional papillary thyroid carcinoma

OBJECTIVE

To evaluate the association of the BRAF(V600E) mutation with sonographic features and clinicopathologic characteristics in a large population with conventional papillary thyroid carcinoma (PTC).

METHODS

We retrospectively reviewed the sonographic features, clinicopathologic characteristics, and presence of the BRAF(V600E) mutation in 688 patients who underwent thyroidectomy for conventional PTC between January and July 2010 at a single institution. The incidence of the BRAF(V600E) mutation was calculated. The sonographic features and clinicopathologic characteristics were compared between BRAF-positive and BRAF-negative patients. BRAF-positive patients were subdivided into those with papillary thyroid microcarcinoma (the PTMC group) and those with PTC larger than 10 mm (the PTC>10 mm group), and their sonographic features were compared.

RESULTS

The BRAF(V600E) mutation was detected in 69.2% of patients (476 of 688). Sonographic features were not significantly different between BRAF-positive and BRAF-negative PTC, nor between PTMC and PTC>10 mm groups. The BRAF(V600E) mutation was associated with male sex (P = 0.028), large tumor size, extrathyroidal extension, central and lateral lymph node metastasis, and advanced tumor stage (P<0.0001).

CONCLUSION

The BRAF(V600E)mutation was significantly associated with several poor clinicopathologic characteristics, but was not associated with sonographic features, regardless of tumor size. We recommend that patients with a thyroid nodule with any suspicious sonographic feature undergo preoperative BRAF(V600E) testing for risk stratification and to guide the initial surgical approach in PTC.

Can ultrasound be as a surrogate marker for diagnosing a papillary thyroid cancer? Comparison with BRAF mutation analysis

PURPOSE

We investigated the merit of ultrasound (US) features and BRAF(V600E) mutation as an additional study of cytology and compared the diagnostic performances of cytology alone, cytology with US correlation, cytology with BRAFV600E mutation, and a combination of cytology, US, and BRAFV600E mutation all together.

MATERIALS AND METHODS

This study included 185 patients (mean age, 48.4 years; range 20-77 years) with 191 thyroid nodules who underwent US-guided fine-needle aspiration (FNA) with an additional BRAFV600E mutation test. Three radiologists highly experienced in thyroid imaging retrospectively reviewed US images and classified each nodule into two categories (positive for malignancy or negative for malignancy). Interobserver variability (IOV) of US assessment between the three readers was estimated using the generalized kappa statistic of Landis and Koch. We also calculated the diagnostic performances of these studies.

RESULTS

There were 131 cases of malignancy (131/191, 68.6%) and 60 cases of benign nodules (60/191, 31.4%). In terms of IOV of US assessment, the generalized kappa value was 0.242, indicating fair agreement was reached. The combination of cytology with BRAFV600E showed higher specificity (100%) and positive predictive value (PPV) (100%) compared to the combination of cytology, BRAFV600E, and US (specificity 28.3%, 66.7%, 68.3%; PPV 74.6%, 86.6%, 86.8%, respectively; p<0.001). However, cytology with BRAFV600E showed lower sensitivity (84.7%) than cytology with BRAFV600E and US (96.2%, 98.5%, 95.4%, respectively; p<0.001).

CONCLUSION

Considering the diagnostic performance and low reproducibility of US, the combination of FNA with BRAFV600E is the most reliable and objective method for diagnosing thyroid malignancy.

Outcome of thyroid nodules characterized as atypia of undetermined significance or follicular lesion of undetermined significance and correlation with Ultrasound features and BRAF(V600E) mutation analysis

OBJECTIVE

We aimed to establish the malignancy rate of thyroid nodules initially characterized as atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS) and whether they differ according to histologic subcategory. We also investigated the value of ultrasound features that predict malignancy and BRAF(V600E) mutation analysis and suggest strategies for the management of AUS/FLUS nodules.

MATERIALS AND METHODS

A total of 165 AUS/FLUS nodules were investigated. There are nine histologic subcategories of AUS/FLUS nodules. We compared the risk of malignancy in thyroid nodules according to the histologic subcategory using ultrasound findings and of those exhibiting the BRAF(V600E) mutation.

RESULTS

The malignancy rate of nodules with an initial diagnosis of AUS/FLUS was 55.2% (91/165). The malignancy rates by histologic subcategory were 0% in groups 1 (0/2), 2 (0/3), 4 (0/3), 7 (0/3), and 8 (0/1); 76.5% (13/17) in group 3; 83.1% (59/71) in group 5; and 29.2% (19/65) in group 9. The malignancy rate of nodules with suspicious ultrasound features was 79.3% (73/92), and the malignancy rate of nodules with indeterminate ultrasound features was 24.7% (18/73). AUS/FLUS nodules exhibiting taller-than-wide shape, illdefined margins, and microcalcifications or macrocalcifications showed significantly higher odds ratios. The likelihood of BRAF(V600E) mutation-positive nodules showing malignancy was 97.5% (39/40), whereas 39.7% (25/63) of BRAF(V600E) mutation-negative nodules were malignant (p < 0.05).

CONCLUSION

The malignancy rate of AUS/FLUS nodules in our study cohort was higher than previously reported. Nodules with suspicious features on ultrasound had a higher malignancy rate than did those with indeterminate features on ultrasound. The malignancy rate differed according to histologic subcategory; therefore, management of AUS/FLUS nodules should be tailored according to histologic subcategory.

Pilot of BRAF mutation analysis in indeterminate, suspicious and malignant thyroid FNA cytology

BACKGROUND

BRAF V600E mutation has been reported to show a high specificity for papillary thyroid carcinoma (PTC). Using this marker to upgrade 'indeterminate' or 'suspicious' thyroid fine needle aspiration (FNA) cytology to 'malignant' could potentially allow one-stage therapeutic total thyroidectomy.

METHODS

For a 14-month period, FNA cytology specimens in the Thy3-5 categories, which are the UK equivalents of indeterminate (Thy3a, atypical; Thy3f, follicular), suspicious for malignancy (Thy4) and malignant (Thy5) in the Bethesda System, underwent BRAF mutation testing by melt curve analysis. The results were correlated with histology.

RESULTS

We tested 123 cytology specimens of which 12 (9.8%) failed. The BRAF mutation rate in the remainder was 16.2% (18/111), with 93 showing the wild-type. Seventeen mutations were V600E and one was non-V600E. The rate of mutation increased significantly (P < 0.0001 if Thy3a and Thy3f were combined) with the cytology category: 1/42 Thy3a (2.4%), 1/36 Thy3f (2.8%), 4/15 Thy4 (26.7%), 12/18 Thy5 (66.7%). All BRAF mutations correlated with PTC on histology, except for one recurrent PTC without histology. One mutation-positive case with Thy3a cytology showed the target lesion to be a 10-mm follicular adenoma on histology with an immediately adjacent 4-mm micro-PTC, in a patient who did not require total thyroidectomy.

CONCLUSION

BRAF mutational analysis by melt curve analysis is feasible in routine thyroid cytology, and in our series had a 100% specificity for PTC in subsequent histology. The application of BRAF analysis could be useful for indeterminate cytology, but we suggest that it would be most appropriate and cost-effective for Thy4/suspicious cases, for which it could enable one-stage therapeutic surgery in the context of multidisciplinary discussion. In contrast, the sensitivity is low and there is no role for avoiding diagnostic thyroid surgery if wild-type BRAF is found.