Reduction of false-negative papillary thyroid carcinomas by the routine analysis of BRAF(T1799A) mutation on fine-needle aspiration biopsy specimens: a prospective study of 814 thyroid FNAB patients

Construction of prediction models for determining the risk of lateral lymph node metastasis in patients with thyroid papillary carcinoma based on gender stratification

BACKGROUND

Lateral lymph node metastasis (LLNM) is associated with poor prognosis in patients with papillary thyroid cancer (PTC). The purpose of this study was to determine the risk factors for LLNM and establish prediction models that could individually assessed the risk of LLNM.

METHODS

A total of 619 PTC patients were retrospectively analyzed in our study. Univariate and multivariate analysis were performed for male and female patients, respectively, to assess relationships between clinicopathological features and LLNM. By integrating independent predictors selected by binary logistic regression modeling, preoperative and postoperative nomograms were developed to estimate the risk of LLNM.

RESULTS

LLNM was detected in 80 of 216 male patients. Of 403 female patients, 114 had LLNM. The preoperative nomogram of male patients included three clinical variables: the number of foci, tuner size, and echogenic foci. In addition to the above three variables, the postoperative nomogram of male patients included extrathyroidal extension (ETE) detected in surgery, central lymph node metastasis (CLNM) and high-volume CLNM. The preoperative nomogram of female patients included the following variables: age, chronic lymphocytic thyroiditis (CLT), BRAF V600E, the number of foci, tumor size and echogenic foci. Variables such as CLT, BRAF V600E, the number of foci, tumor size, ETE detected in surgery, CLNM, high-volume CLNM and central lymph node ratio were included in the postoperative nomogram. Above Nomograms show good discrimination.

CONCLUSIONS

Considering the difference in the incidence rate of LLNM between men and women, a separate prediction system should be established for patients of different genders. These nomograms are helpful in promoting the risk stratification of PTC treatment decision-making and postoperative management.

Opportunities and Challenges of Liquid Biopsy in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system, encompassing different entities with distinct histological features and clinical behavior. The diagnostic definition, therapeutic approach, and follow-up of thyroid cancers display some controversial aspects that represent unmet medical needs. Liquid biopsy is a non-invasive approach that detects and analyzes biological samples released from the tumor into the bloodstream. With the use of different technologies, tumor cells, free nucleic acids, and extracellular vesicles can be retrieved in the serum of cancer patients and valuable molecular information can be obtained. Recently, a growing body of evidence is accumulating concerning the use of liquid biopsy in thyroid cancer, as it can be exploited to define a patient's diagnosis, estimate their prognosis, and monitor tumor recurrence or treatment response. Indeed, liquid biopsy can be a valuable tool to overcome the limits of conventional management of thyroid malignancies. In this review, we summarize currently available data about liquid biopsy in differentiated, poorly differentiated/anaplastic, and medullary thyroid cancer, focusing on circulating tumor cells, circulating free nucleic acids, and extracellular vesicles.

Preoperative molecular testing in thyroid nodules with Bethesda VI cytology: Clinical experience and review of the literature

Risk assessment is critical to determine the timing of elective surgeries and preserve valuable resources in time of pandemic. This study was undertaken to better understand the potential value of molecular testing to risk‐stratify thyroid nodules with malignant cytology (Bethesda VI). Systematic review of the literature contributed 21 studies representing 2036 preoperative specimens. The BRAF p.V600E substitution was detected in 46% to 90% of cases with a pooled positivity rate of 70% (95% confidence intervals: 64%‐76%). None of the studies used comprehensive oncogene panels. Retrospective analysis of 531 clinical specimens evaluated with the next‐generation sequencing ThyGeNEXT Thyroid Oncogene Panel identified a total of 436 gene alterations. BRAF mutation rate was 64% in specimens tested as part of standard clinical care and 75% in specimens from cross‐sectional research studies (P = .022). Testing for additional actionable gene alterations such as TERT promoter mutations or RET and NTRK gene rearrangements further increased the diagnostic yield to 78%‐85% and up to 95% when including the ThyraMIR Thyroid miRNA Classifier. These data support the role of molecular cytopathology in surgical and therapeutic decision‐making and warrant additional studies.

Molecular markers for the classification of cytologically indeterminate thyroid nodules

BACKGROUND

The diagnosis of indeterminate lesions of the thyroid is a challenge in cytopathology practice. Indeed, up to 30% of cases lack the morphological features needed to provide definitive classification. Molecular tests have been developed to assist in the diagnosis of these indeterminate cases. The first studies dealing with the preoperative molecular evaluation of FNA samples focused on the analysis of BRAF^V600E or on the combined evaluation of two or three genetic alterations. The sensitivity of molecular testing was then improved through the introduction of gene panels, which became available for clinical use in the late 2000s. Two different categories of molecular tests have been developed, the 'rule-out' methods, which aim to reduce the avoidable treatment of benign nodules, and the 'rule-in' tests that have the purpose to optimize surgical management. The genetic evaluation of indeterminate thyroid nodules is predicted to improve patient care, particularly if molecular tests are used appropriately and with the awareness of their advantages and weaknesses. The main disadvantage of these tests is the cost, which makes them rarely used in Europe. To overcome this limitation, customized panels have been set up, which are able to detect the most frequent genetic alterations of thyroid cancer.

CONCLUSIONS

In the present review, the most recent available versions of commercial molecular tests and of custom, non-commercial panels are described. Their characteristics and accuracy in the differential diagnosis of indeterminate nodules, namely Bethesda classes III (Atypical follicular lesion of undetermined significance, AUS/FLUS) and IV (Suspicious for follicular neoplasm, FN/SFN) are fully analyzed and discussed.

Molecular Variants and Their Risks for Malignancy in Cytologically Indeterminate Thyroid Nodules

Background: Gene panels are routinely used to assess predisposition to hereditary cancers by simultaneously testing multiple susceptibility genes and/or variants. More recently, genetic panels have been implemented as part of solid tumor malignancy testing assessing somatic alterations. One example is targeted variant panels for thyroid nodules that are not conclusively malignant or benign upon fine-needle aspiration (FNA). We systematically reviewed published studies from 2009 to 2018 that contained genetic data from preoperative FNA specimens on cytologically indeterminate thyroid nodules (ITNs) that subsequently underwent surgical resection. Pooled prevalence estimates per gene and variant, along with their respective positive predictive values (PPVs) for malignancy, were calculated. Summary: Our systematic search identified 540 studies that were supplemented by 18 studies from bibliographies or personal files. Sixty-one studies met all inclusion criteria and included >4600 ITNs. Overall, 26% of nodules contained at least 1 variant or fusion. However, half of them did not include details on the specific gene, variant, and/or complete fusion pair reported for inclusion toward PPV calculations. The PPVs of genomic alterations reported at least 10 times were limited to BRAF^V600E (98%, 95% confidence interval [CI 96-99%]), PAX8/PPARG (55% [CI 34-78%]), HRAS^Q61R (45% [CI 22-72%]), BRAF^K601E (42% [CI 19-68%]), and NRAS^Q61R (38% [CI 23-55%]). Excluding BRAF^V600E, the pooled PPV for all other specified variants and fusions was 47%. Multiple variants within the same nodule were identified in ∼1% of ITN and carried a cumulative PPV of 77%. Conclusions: The chance that a genomic alteration predicts malignancy depends on the individual variant or fusion detected. Only five alterations were reported at least 10 times; BRAF^V600E had a PPV of 98%, while the remaining four had individual PPVs ranging from 38% to 55%. The small sample size of most variants and fusion pairs found among ITNs, however, limits confidence in their individual PPV point estimates. Better specific reporting of genomic alterations with cytological category, histological subtype, and cancer staging would facilitate better understanding of cancer prediction, and the independent contribution of the genomic profile to prognosis.

Individual prediction of lateral neck metastasis risk in patients with unifocal papillary thyroid carcinoma

INTRODUCTION

Much controversy exists over whether to perform lateral neck dissection (LND) on patients with papillary thyroid carcinoma (PTC). This study aimed to build predictive nomograms that could individually estimate lateral neck metastasis (LNM) risk and help determine follow up intensity.

PATIENTS AND METHODS

Unifocal PTC patients who underwent LND between April 2012 and August 2014 were identified. Clinical and pathological variables were retrospectively evaluated using univariate and stepwise multivariate logistic regression analysis. Variables that had statistical significance in final multivariate logistic models were chosen to build nomograms, which were further corrected using the bootstrap resampling method.

RESULTS

In all, 505 PTC patients were eligible for analysis. Among these, 178 patients (35.2%) had lateral neck metastasis. Two nomograms were generated: nomogram (c) and nomogram (c + p). Nomogram (c) incorporated four clinical variables: age, tumor size, tumor site, and extrathyroidal extension (ETE). It had a good discriminative ability, with a C-index of 0.79 (bootstrap-corrected, 0.78). Nomogram (c + p) incorporated two clinical variables and two pathological variables: tumor size, tumor site, extranodal extension (ENE), and number of positive nodes in the central compartment. Nomogram (c + p) showed an excellent discriminative ability, with a C-index of 0.86 (bootstrap-corrected, 0.85).

CONCLUSION

Two predictive nomograms were generated. Nomogram (c) is a clinical model, whereas nomogram (c + p) is a clinicopathological model. Each nomogram incorporates only four variables and can give an accurate estimate of LNM risk in unifocal PTC patients, which may assist clinicians in patient counseling and decision making regarding LND.

Diagnostic Utility of Molecular and Imaging Biomarkers in Cytological Indeterminate Thyroid Nodules

Indeterminate thyroid cytology (Bethesda III and IV) corresponds to follicular-patterned benign and malignant lesions, which are particularly difficult to differentiate on cytology alone. As ~25% of these nodules harbor malignancy, diagnostic hemithyroidectomy is still custom. However, advanced preoperative diagnostics are rapidly evolving.This review provides an overview of additional molecular and imaging diagnostics for indeterminate thyroid nodules in a preoperative clinical setting, including considerations regarding cost-effectiveness, availability, and feasibility of combining techniques. Addressed diagnostics include gene mutation analysis, microRNA, immunocytochemistry, ultrasonography, elastosonography, computed tomography, sestamibi scintigraphy, [18F]-2-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET), and diffusion-weighted magnetic resonance imaging.The best rule-out tests for malignancy were the Afirma® gene expression classifier and FDG-PET. The most accurate rule-in test was sole BRAF mutation analysis. No diagnostic had both near-perfect sensitivity and specificity, and estimated cost-effectiveness. Molecular techniques are rapidly advancing. However, given the currently available techniques, a multimodality stepwise approach likely offers the most accurate diagnosis, sequentially applying one sensitive rule-out test and one specific rule-in test. Geographical variations in cytology (e.g., Hürthle cell neoplasms) and tumor genetics strongly influence local test performance and clinical utility. Multidisciplinary collaboration and implementation studies can aid the local decision for one or more eligible diagnostics.

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

BACKGROUND

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Novel BRAFI599Ins Mutation Identified in a Follicular Variant of a Papillary Thyroid Carcinoma: A Molecular Modeling Approach

OBJECTIVE

BRAF mutations are the most common genetic alteration found in papillary thyroid carcinoma (PTC). Approximately, 90% correspond to BRAFV600E, although other less common BRAF mutations have been described. The aim of this study was to describe a new mutation on BRAF gene discovered on the previous thyroid cytology of a patient diagnosed with a follicular variant of PTC (FV-PTC).

METHODS

The mutation was identified by independent cloning of the 2 alleles and direct sequencing in the previous cytology and tumor tissue samples from a patient diagnosed with FV-PTC. To elucidate the effect of the mutation on the structure and hence on the activating mechanism of the protein, the structures of BRAFI599Ins, BRAFT599Ins, BRAFV599Ins and BRAFV600E were modeled by using the reconstructed wild-type BRAF (BRAFWT) crystal structure.

RESULTS

The novel mutation in BRAF consisted in the in-frame insertion of 3 nucleotides (TAA) after nucleotide 1795, resulting in the incorporation of an extra isoleucine residue at position 599 (BRAFI599Ins) of the protein. The structural comparison of BRAFI599Ins, BRAFT599Ins, BRAFV599Ins with BRAFWT, and BRAFV600E models revealed that the overall shape of the kinase was conserved in the protein produced by this novel mutation, except for the displacement of the activation loop (A-loop), as a direct consequence of the increase in loop size, and the exposition of 1 of the 2 residues involved in BRAF activation (T599), probably facilitating its phosphorylation.

CONCLUSION

BRAFI599Ins mutation constitutes a new BRAF mutation affecting the length of the A-loop, which most likely facilitates BRAF activation by altering the A-loop conformation.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Diagnostic value of BRAF (V600E)-mutation analysis in fine-needle aspiration of thyroid nodules: a meta-analysis

Fine-needle aspiration (FNA) is a reliable method for preoperative diagnosis of thyroid nodules; however, about 10%–40% nodules are classified as indeterminate. The BRAF^V600E mutation is the most promising marker for thyroid FNA. This meta-analysis was conducted to investigate the diagnostic value of BRAF^V600E analysis in thyroid FNA, especially the indeterminate cases. Systematic searches were performed in PubMed, Web of Science, Scopus, Ovid, Elsevier, and the Cochrane Library databases for relevant studies prior to June 2015, and a total of 88 studies were ultimately included in this meta-analysis. Compared with FNA cytology, the synergism of BRAF^V600E testing increased the diagnostic sensitivity from 81.4% to 87.4% and decreased the false-negative rate from 8% to 5.2%. In the indeterminate group, the mutation rate of BRAF^V600E was 23% and varied in different subcategories (43.2% in suspicious for malignant cells [SMC], 13.77% in atypia of undetermined significance/follicular lesion of undetermined significance [AUS/FLUS], and 4.43% in follicular neoplasm/suspicious for follicular neoplasm [FN/SFN]). The sensitivity of BRAF^V600E analysis was higher in SMC than that in AUS/FLUS and FN/SFN cases (59.4% vs 40.1% vs 19.5% respectively), while specificity was opposite (86.1% vs 99.5% vs 99.7% respectively). The areas under the summary receiver-operating characteristic curve also confirmed the diagnostic value of BRAF^V600E testing in SMC and AUS/FLUS rather than FN/SFN cases. Therefore, BRAF^V600E analysis can improve the diagnostic accuracy of thyroid FNA, especially indeterminate cases classified as SMC, and select malignancy to guide the extent of 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.

Role of gene expression profiling in defining indeterminate thyroid nodules in addition to BRAF analysis

Fine-needle aspiration (FNA) is routinely used in the preoperative evaluation of thyroid nodules. However, 15% to 30% of aspirations yield indeterminate cytologic findings. Because the assessment of BRAF mutations seems to improve the diagnostic accuracy, this study evaluated BRAF mutations with Sanger sequencing and real-time methods in 650 consecutive thyroid aspirates. In addition, the expression of a large number of genes involved in basement membrane remodeling, extracellular matrix proteolysis, and cell adhesion was studied in both benign and malignant nodules to identify new diagnostic tools. In this prospective series, despite the use of a very sensitive BRAF mutational testing method, the frequency of a BRAF alteration being identified in indeterminate FNA samples was 3 of 68. Expression analysis revealed several genes that were differentially expressed between benign and malignant nodules (transforming growth factor, cadherin 1, collagen α1, catenin α1, integrin α3, and fibronectin 1 [FN1]), between follicular adenomas and follicular variant of papillary thyroid carcinoma (FN1, laminin γ1, integrin β2, connective tissue growth factor, catenin δ1, and integrin αV), and between BRAF-wild-type and BRAF-mutated papillary thyroid carcinomas (TIMP metallopeptidase inhibitor 1; catenin α1; secreted phosphoprotein 1; FN1; ADAM metallopeptidase with thrombospondin type 1 motif, 1; and selectin L). These data were partially confirmed with real-time polymerase chain reaction analysis and immunohistochemistry. When the cost/benefit ratio of the procedures was taken into account, BRAF mutational testing failed to increase diagnostic accuracy in cytologically indeterminate nodules. However, the additional analysis of the expression of specific molecular markers could have possible utility as a diagnostic tool, although further evidence based on a large series of samples is needed before definitive conclusions can be drawn. Cancer Cytopathol 2016;124:340-9. © 2015 American Cancer Society.

Tumor genotype determines phenotype and disease-related outcomes in thyroid cancer: a study of 1510 patients

OBJECTIVES

To correlate thyroid cancer genotype with histology and outcomes.

BACKGROUND

The prognostic significance of molecular signature in thyroid cancer (TC) is undefined but can potentially change surgical management.

METHODS

We reviewed a consecutive series of 1510 patients who had initial thyroidectomy for TC with routine testing for BRAF, RAS, RET/PTC, and PAX8/PPARG alterations. Histologic metastatic or recurrent TC was tracked for 6 or more months after oncologic thyroidectomy.

RESULTS

Papillary thyroid cancer (PTC) was diagnosed in 97% of patients and poorly differentiated/anaplastic TC in 1.1%. Genetic alterations were detected in 1039 (70%); the most common mutations were BRAFV600E (644/1039, 62%), and RAS isoforms (323/1039, 31%). BRAFV600E-positive PTC was often conventional or tall cell variant (58%), with frequent extrathyroidal extension (51%) and lymph node metastasis (46%). Conversely, RAS-positive PTC was commonly follicular variant (87%), with infrequent extrathyroidal extension (4.6%) and lymph node metastasis (5.6%). BRAFV600E and RET/PTC-positive PTCs were histologically similar. Analogously, RAS and PAX8/PPARG-positive PTCs were histologically similar. Compared with RAS or PAX8/PPARG-positive TCs, BRAFV600E or RET/PTC-positive TCs were more often associated with stage III/IV disease (40% vs 15%, P < 0.001) and recurrence (10% vs 0.7%, P < 0.001; mean follow-up 33 ± 21 mo). Distant metastasis was highest in patients with RET/PTC-positive TC (10.8%, P = 0.02).

CONCLUSIONS

In this large study of prospective mutation testing in unselected patients with TC, molecular signature was associated with distinctive phenotypes including cancers, with higher risks of both distant metastasis and early recurrence. Preoperative genotype provides valuable prognostic data to appropriately inform surgery.

High-Resolution Melting Is a Sensitive, Cost-Effective, Time-Saving Technique for BRAF V600E Detection in Thyroid FNAB Washing Liquid: A Prospective Cohort Study

OBJECTIVE

The diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB) can be improved by the combination of cytological and molecular analysis. In this study, washing liquids of FNAB (wFNAB) were tested for the BRAF V600E mutation, using the sensitive and cost-effective technique called high-resolution melting (HRM). The aim was to demonstrate the feasibility of BRAF analysis in wFNAB and its diagnostic utility, combined with cytology.

DESIGN

Prospective cohort study.

METHODS

481 patients, corresponding to 648 FNAB samples, were subjected to both cytological (on cells smeared onto a glass slide) and molecular analysis (on fluids obtained washing the FNAB needle with 1 ml of saline) of the same aspiration. BRAF V600E analysis was performed by HRM after methodological validation for application to wFNAB (technique sensitivity: 5.4%).

RESULTS

The cytological results of the FNAB were: 136 (21%) nondiagnostic (THY1); 415 (64%) benign (THY2); 80 (12.4%) indeterminate (THY3); 9 (1.4%) suspicious for malignancy (THY4); 8 (1.2%) diagnostic of malignancy (THY5). The BRAF V600E mutation was found in 5 THY2, 2 THY3, 6 THY4 and 6 THY5 samples. Papillary carcinoma diagnosis was histologically confirmed in all BRAF+ thyroidectomized patients. BRAF combined with cytology improved the diagnostic value compared to cytology alone in a subgroup of 74 operated patients.

CONCLUSIONS

HRM was demonstrated to be a feasible method for BRAF analysis in wFNAB. Thanks to its sensitivity and cost-effectiveness, it might be routinely used on a large scale in clinical practice. In perspective, standby wFNAB samples could be analyzed a posteriori in case of indeterminate cytology and/or suspicious findings on ultrasound.

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.

How to use molecular testing results to guide surgery: a surgeon's perspective

PURPOSE OF REVIEW

Multiple genetic mutations have been found to be associated with thyroid cancer, and molecular testing of thyroid nodule fine-needle aspiration (FNA) specimens has been proposed as an adjunct to the cytologic diagnosis. The purpose of this review is to examine how molecular testing of FNAs could be used to guide surgical decision-making.

RECENT FINDINGS

B-type RAF kinase mutations in papillary thyroid cancer have been found to be associated with extrathyroidal extension, lymph node metastases, and advanced stage in two meta-analyses that are based largely on retrospective data. Testing for a panel of gene mutations has been found to have high specificity and positive predictive value, whereas microarray testing using a commercially available gene-expression classifier has been found to have high sensitivity and negative predictive value for the diagnosis of malignancy in cytologically indeterminate FNAs. Although there is no consensus regarding the use of such tests, they have already started to change clinical practice.

SUMMARY

Molecular testing of FNA specimens may help to avoid diagnostic thyroidectomy or may help in deciding the extent of surgery in a patient with an indeterminate FNA biopsy. The use of these tests is currently undergoing review by a task force within the American Thyroid Association.

Molecular characterization of 54 cases of false-negative fine-needle aspiration among 1347 papillary thyroid carcinomas

BACKGROUND

Fine-needle aspiration (FNA) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules, but the false-negative rates are generally reported to be between 3.6% and 10.2%. To lower the overall incidence of this false-negative testing, new reporting systems encourage the molecular testing of thyroid nodules. However, to the authors' knowledge, the role of molecular testing in false-negative FNA has not yet been evaluated.

METHODS

In total, 1347 consecutive papillary thyroid carcinomas (PTCs) with both cytological and histological diagnoses were collected from the same center. A blinded revision of the false-negative cases was performed. An analysis of the BRAF and Ras genes in the false-negative cases was then performed.

RESULTS

The false-negative rate at the time of primary FNA diagnosis was 4.8% (65 of 1347 cases). False-negative cases were 15 follicular variant PTCs, 2 classical variant, and 1 solid variant that lacked peculiar PTC cytomorphological features. Adequate cellular material for molecular analysis was available only in 54 of the 65 false-negative cases. Mutations were found in 6 cases (11%), and Ras alterations were present in 16 cases (29.6%). The addition of molecular analysis decreased the false-negative rate to 0.4% (5 of 1347 cases).

CONCLUSIONS

The results of the current study confirm the feasibility of BRAF and Ras analysis in routine FNA. However, when the false-negative FNA rate is low, the cost-benefit analysis of the detection of BRAF and Ras mutations should be carefully evaluated. Consequently, the authors suggest that preoperative molecular assessment could be helpful for benign nodules, but only in the presence of clinical suspicion of malignancy.

Circulating lymphocytes as predictors of sensitivity to preoperative chemoradiotherapy in rectal cancer cases

OBJECTIVE

The objective of this study was to identify clinical predictive factors for tumor response after neoadjuvant chemoradiotherapy (nCRT) in locally advanced rectal cancer (LARC).

METHODS

All factors were evaluated in 88 patients with LARC treated with nCRT. After a long period of 4-8 weeks of chemoradiotherapy, 3 patients achieved clinical complete response (cCR) and thus aggressive surgery was avoided, and the remaining 85 patients underwent a curative-intent operation. The response to nCRT was evaluated by tumor regression grade (TRG) system.

RESULTS

There were 32 patients (36.4%) with good tumor regression (TRG 3-4) and 56 (63.6%) with poor tumor regression (TRG 0-2). Lymphocyte counts and ratios were higher in good response cases (P=0.01, 0.03, respectively) while neutrophil ratios and N/L ratios were higher in poor response cases (P=0.04, 0.02, respectively). High lymphocyte ratios before nCRT and good tumor regression (TRG3-4) were significantly associated with improved 5-year disease-free survival (P<0.05). Pretreatment nodal status was also significantly associated with 5-year disease-free survival and 5-year overall survival (P<0.05). Multivariate analysis confirmed that the pretreatment lymphocyte ratio and lymph nodal status were independent prognostic factors.

CONCLUSION

Our study suggested that LARC patients with high lymphocyte ratios before nCRT would have good tumor response and high 5-year DFS and OS.

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.

Clinicopathological relevance of BRAF mutations in human cancer

BRAF represents one of the most frequently mutated protein kinase genes in human tumours. The mutation is commonly tested in pathology practice. BRAF mutation is seen in melanoma, papillary thyroid carcinoma (including papillary thyroid carcinoma arising from ovarian teratoma), ovarian serous tumours, colorectal carcinoma, gliomas, hepatobiliary carcinomas and hairy cell leukaemia. In these cancers, various genetic aberrations of the BRAF proto-oncogene, such as different point mutations and chromosomal rearrangements, have been reported. The most common mutation, BRAF V600E, can be detected by DNA sequencing and immunohistochemistry on formalin fixed, paraffin embedded tumour tissue. Detection of BRAF V600E mutation has the potential for clinical use as a diagnostic and prognostic marker. In addition, a great deal of research effort has been spent in strategies inhibiting its activity. Indeed, recent clinical trials involving BRAF selective inhibitors exhibited promising response rates in metastatic melanoma patients. Clinical trials are underway for other cancers. However, cutaneous side effects of treatment have been reported and therapeutic response to cancer is short-lived due to the emergence of several resistance mechanisms. In this review, we give an update on the clinical pathological relevance of BRAF mutation in cancer. It is hoped that the review will enhance the direction of future research and assist in more effective use of the knowledge of BRAF mutation in clinical practice.

Sonographically suspicious thyroid nodules with initially benign cytologic results: the role of a core needle biopsy

PURPOSE

To evaluate the diagnostic role of core needle biopsy (CNB) in sonographically suspicious thyroid nodules with initially benign cytologic results through a histologic analysis of CNB specimens.

METHODS

Between October 2008 and July 2011, 88 patients underwent ultrasound (US)-guided CNB for initially benign cytologic results with suspicious US features at our institution. In all, 85 patients with 85 focal thyroid nodules were included in the study after surgery or concordant benign readings following fine-needle aspiration biopsy (FNAB) and CNB. We evaluated the risk of malignancy, diagnostic performance of CNB, and histologic findings for these nodules.

RESULTS

Of the 85 nodules, 28 (32.9%) were histologically upgraded on CNB specimens including one case of atypia of undetermined significance (AUS), seven cases of follicular neoplasm, one case of suspicious for malignancy, and 19 cases of malignancy. Of these, 27 (31.8%) were finally confirmed as malignant, and one as follicular adenoma at surgery. The 27 malignant nodules included 21 papillary thyroid carcinomas (PTCs), five follicular thyroid carcinomas, and one Hürthle cell carcinoma. All PTCs were diagnosed from CNB readings of AUS suspicious for malignancy or malignancy. Follicular thyroid carcinomas and Hürthle cell carcinoma were diagnosed from CNB readings of follicular neoplasm. Histologic analysis of benign CNB specimens revealed severe fibrosis (96.4%), hemosiderin (21.4%), calcification (17.9%), granulation tissue (12.5%), and focal lymphocytic thyroiditis (12.5%).

CONCLUSIONS

The histologic information obtained by analysis of CNB specimens may enable more confident diagnosis for benign nodules with suspicious US features and reduce the need for repetitive FNABs or diagnostic surgery.

Preoperative BRAF(V600E) mutation screening is unlikely to alter initial surgical treatment of patients with indeterminate thyroid nodules: a prospective case series of 960 patients

BACKGROUND

Preoperative B-type Raf kinase Val600Glu mutation, or BRAF(V600E), analysis has been proposed as a tool to guide initial surgery for indeterminate thyroid nodules. This study sought to determine if cytologic markers of malignancy are associated with the BRAF(V600E) mutation and if preoperative BRAF(V600E) testing would alter the initial management of patients with indeterminate nodules.

METHODS

Patients who underwent surgery for a thyroid nodule between 2003 and 2012 at a tertiary care center were prospectively enrolled. Stored nodule samples were retrospectively genotyped for the BRAF(V600E) mutation. BRAF(V600E) status, demographics, cytologic and histopathologic findings, and choice of initial surgery were examined.

RESULTS

A total of 960 patients were enrolled, of which 310 (32%) had an indeterminate nodule. The BRAF(V600E) mutation was identified in 13 patients (4%), 12 of whom had either cytologic atypia or were Bethesda category V. Three percent of Bethesda category III or IV nodules that were malignant harbored the mutation compared with 42% of Bethesda category V malignancies. Nuclear grooves (P = .030), pseudoinclusions (P < .001), and oval nuclei (P = .022) were all more common among BRAF(V600E) mutants. The sensitivities of using BRAF testing alone, cytologic atypia/Bethesda category V classification, or both, were 15%, 73%, and 76%, respectively. Twelve of the 13 BRAF(V600E) mutants had total thyroidectomies initially due to worrisome cytologic features, and therefore the initial management of only one patient would have been altered if BRAF(V600E) testing had been performed preoperatively.

CONCLUSIONS

Preoperative mutation screening for BRAF(V600E) does not meaningfully improve risk stratification and is unlikely to alter the initial management of patients with indeterminate nodules.

Clinical predictive factors of pathologic tumor response after preoperative chemoradiotherapy in rectal cancer

Purpose

The aim of this study was to identify clinical predictive factors for tumor response after preoperative chemoradiotherapy (CRT) in rectal cancer.

Materials and Methods

The study involved 51 patients who underwent preoperative CRT followed by surgery between January 2005 and February 2012. Radiotherapy was delivered to the whole pelvis at a dose of 45 Gy in 25 fractions, followed by a boost of 5.4 Gy in 3 fractions to the primary tumor with 5 fractions per week. Three different chemotherapy regimens were used (5-fluorouracil and leucovorin, capecitabine, or tegafur/uracil). Tumor responses to preoperative CRT were assessed in terms of tumor downstaging and pathologic complete response (ypCR). Statistical analyses were performed to identify clinical factors associated with pathologic tumor response.

Results

Tumor downstaging was observed in 28 patients (54.9%), whereas ypCR was observed in 6 patients (11.8%). Multivariate analysis found that predictors of downstaging was pretreatment relative lymphocyte count (p = 0.023) and that none of clinical factors was significantly associated with ypCR.

Conclusion

Pretreatment relative lymphocyte count (%) has a significant impact on the pathologic tumor response (tumor downstaging) after preoperative CRT for locally advanced rectal cancer. Enhancement of lymphocyte-mediated immune reactions may improve the effect of preoperative CRT for rectal cancer.