BRAF Immunohistochemistry Using Clone VE1 is Strongly Concordant with BRAF(V600E) Mutation Test in Papillary Thyroid Carcinoma

A diagnostic model based on DNA methylation haplotype block characteristics for identifying papillary thyroid carcinoma from thyroid adenoma

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer. Methylation of some genes plays a crucial role in the tendency to malignancy as well as poor prognosis of thyroid cancer, suggesting that methylation features can serve as complementary markers for molecular diagnosis. In this study, we aimed to develop and validate a diagnostic model for PTC based on DNA methylation markers. A total of 142 thyroid nodule tissue samples containing 84 cases of PTC and 58 cases of thyroid adenoma (TA) were collected for reduced representation bisulfite sequencing (RRBS) and subsequent analysis. The diagnostic model was constructed by the logistic regression (LR) method followed by 5-cross validation and based on 94 tissue methylation haplotype block (MHB) markers. The model achieved an area under the receiver operating characteristic curve (AUROC) of 0.974 (95% CI, 0.964-0.981) on 108 training samples and 0.917 (95% CI, 0.864-0.973) on 27 independent testing samples. The diagnostic model scores showed significantly high in males (P = 0.0016), age ≤ 45 years (P = 0.026), high body mass index (BMI) (P = 0.040), lymph node metastasis (P = 0.00052) and larger nodules (P = 0.0017) in the PTC group, and the risk score of this diagnostic model showed significantly high in recurrent PTC group (P = 0.0005). These results suggest that the diagnostic model can be expected to be a powerful tool for PTC diagnosis and there are more potential clinical applications of methylation markers to be excavated.

Clinicopathological features of incidentally detected metastatic thyroid papillary carcinoma in cervical lymph nodes of non-thyroid cancer patients: a retrospective analysis of 31cases

BACKGROUND

The incidental finding of thyroid inclusions in lymph nodes of neck dissections of non-thyroid cancer patients is an unusual event. It is still controversial for pathologists about whether this represents benign inclusions or metastatic papillary thyroid carcinoma (PTC). This study is to analyze clinicopathological features of such cases in an attempt to explore their clinical implications.

METHODS

Pathological data were searched for incidentally detected PTC of cervical lymph nodes in non-thyroid cancer cases. Clinicopathological characteristics were reevaluated and recorded. BRAF V600E protein expression and sequencing analysis was then performed in cases with sufficient tissues.

RESULTS

31 patients had an incidental finding of PTC in lymph nodes of patients with non-thyroid cancer. BRAF immunohistochemical staining were performed in 17 metastatic lymph nodes with sufficient tumor tissues, and 6 were positive. BRAF V600E point mutation was detected in 5 of 6 BRAF V600E positive cases. Subsequent imaging examinations of the thyroid showed no nodules or calcifications/benign nodules in 20 patients, and suspected malignant nodules in 5 patients. 12 patients underwent total thyroidectomy or ipsilateral lobectomy, and 6 showed PTC in postoperative pathological examinations. The remaining 19 patients without surgery were kept under active surveillance, and no one had recurrence of PTC.

CONCLUSION

Incidentally discovered PTC in lymph nodes has usually interpreted as metastasis from a clinical occult thyroid primary cancer, but primary PTC was not always detected. This suggests it could be double occult lesions. With regards to concurrence with highly malignant tumor, most patients could keep regular surveillance.

High-Grade Non-Anaplastic Thyroid Carcinomas of Follicular Cell Origin: A Review of Poorly Differentiated and High-Grade Differentiated Carcinomas

Poorly differentiated thyroid carcinoma (PDTC) and high-grade differentiated thyroid carcinoma (HGDTC) are considered high-grade follicular-derived thyroid carcinomas, with prognoses intermediate between well-differentiated and anaplastic thyroid carcinoma. Both share the presence of invasion, thyroid follicular-cell origin, and tumor necrosis or increased mitoses (≥ 3 mitoses per 2 mm² in PDTC and ≥ 5 mitoses per 2 mm² in HGDTC), without anaplastic dedifferentiation. PDTC must possess solid, trabecular, or insular growth and lack classic papillary-like nuclei; HGDTC can be of any architectural or nuclear morphology (follicular-like, papillary-like, oncocytic). Transformation may be accompanied by acquisition of high-risk mutations (such as TP53 or TERT promoter) on top of RAS-like or BRAF p.V600E-like (including NTRK-fusion) initial driver mutations. These carcinomas most frequently affect adults and often present with metastases (20-50%) or wide local invasion. As PDTC and HGDTC may be radioactive iodine resistant, post-surgical therapy may consist of external beam radiotherapy or targeted, mutation-dependent chemotherapy, such as tyrosine kinase inhibitors. Ten-year disease specific survival is as low as 50%. Awareness of high-grade features in the diagnostic setting is important for patient prognosis and triage of tissue for molecular analysis in order to guide relevant clinical management and therapy.

Preoperative BRAFV600E mutation detection in thyroid carcinoma by immunocytochemistry

The BRAF^V600E (BRAF) mutation is present in 40-50% of papillary thyroid carcinomas (PTC) and has been associated with more aggressive clinicopathological characteristics of PTC. The aim of this study was to evaluate different methods for preoperative identification of the BRAF mutation in PTC using cytological and histological specimens. Prospectively collected preoperative cytological clots from patients with suspected PTC were tested with BRAF immunocytochemistry (ICC) and the Cobas Test (PCR). In addition, histological specimens were tested with BRAF immunohistochemistry (IHC) and the Cobas Test. All nodules were histologically examined. Fifty-three patients were included in the study. Complete mutation testing was available in 32 patients. The main reason for exclusion was insufficient cell content in the cytological specimen. Twenty-seven nodules were histologically diagnosed as PTC, and 41% (n = 11) of PTCs were BRAF ICC positive. All non-PTC nodules were negative by BRAF ICC. In 26 nodules, all four BRAF tests were concordant, while discordant test results were found in six nodules. ICC was in accordance with the consensus BRAF status in five of these nodules, while BRAF status was undetermined in one nodule. BRAF ICC showed high concordance with the Cobas Test and a low rate of false negative stain. These results indicate that BRAF ICC may be a feasible method for preoperative detection of the BRAF^V600E mutation in patients with PTC.

The Value of BRAF VE1 Immunoexpression in Pediatric Langerhans Cell Histiocytosis

IntroductionVE1 is a monoclonal antibody detecting mutant BRAF V600E protein by immunohistochemistry (IHC) with a high concordance rate with molecular analysis in many cancers. Materials and methods: BRAF V600E mutation was assessed on 94 pediatric LCH patients using sequencing analysis and VE1 immunohistochemistry with stringent and lenient-scoring criteria. Results: BRAF V600E mutation exon 15 was detected by sequencing in 47.9% of LCH cases. BRAF V600E mutation rate in multiple-system LCH was 65.2%, significantly higher than in single-system LCH (p = .001). VE1 assays showed 35.6% sensitivity, 75.5% specificity (Stringent criteria), and 91.1% sensitivity, 35.7% specificity (Lenient criteria). Conclusions: The proportion of BRAF V600E mutational status was relatively high and related to high-risk LCH. Molecular assays for BRAF mutation detection are preferred in LCH lesions. VE1 is not ready as an alternative option for LCH BRAF testing.

Conventional papillary thyroid carcinoma with intraglandular lymphatic dissemination shows more aggressive features

OBJECTIVE

To investigate the invasive capability and other clinicopathological features of conventional papillary thyroid carcinoma (CVPTC) with intraglandular lymphatic dissemination.

METHODS

Seventy-three conventional papillary thyroid carcinoma patients receiving total thyroidectomy were analyzed in this study. The expression of BRAF-V600E, D2-40 and CD31 in all thyroid samples was detected by immunohistochemical staining. The results were evaluated by two pathologists and were statistically analyzed. The rate of positive BRAF-V600E expression and the clinical invasiveness of CVPTC with intraglandular dissemination, multifocal non-intraglandular dissemination-CVPTC and single focus-CVPTC were evaluated. The correlation between BRAF-V600E expression, lymphatic vessel density, microvessel density and the clinicopathological characteristics of conventional papillary thyroid carcinoma were assessed.

RESULTS

Twenty-five intraglandular dissemination-CVPTC, 17 multifocal non-intraglandular dissemination-CVPTC and 31 single focus-CVPTC cases were included in this study. The results showed that BRAF-V600E expression was independently correlated with intraglandular dissemination, age and pN staging (P < 0.05). The lymphatic vessel density in the intraglandular dissemination-CVPTC group was higher than that in the non-intraglandular dissemination-CVPTC group (P < 0.05). Compared with cases without intraglandular dissemination, intraglandular dissemination-CVPTC was associated with a younger age, higher lymph node metastasis rate, pN staging, the expression of BRAF-V600E and increased Capsule invasion and lymphovascular tumor thrombus (P < 0.05). During the follow-up of 30 months (median 15 months), two patients in the intraglandular dissemination-CVPTC group had cervical lymph node metastasis after the first operation.

CONCLUSIONS

Intraglandular dissemination-CVPTC shows more aggressive features, and intraglandular lymphatic dissemination may be a potential biological indicator of poor prognosis.

Clinical Application of Next-Generation Sequencing in Advanced Thyroid Cancers

Background: With the emergence of mutation-based systemic therapies for patients with advanced thyroid cancer, molecular profiling has become an important component of care. Although next-generation sequencing (NGS) gene panels are accessible to clinicians, there is no consensus on the optimal approach to testing. This study investigates the clinical application of NGS results in the management of advanced thyroid cancer. Methods: Patients with advanced thyroid cancer with NGS completed as part of the Integrated Molecular Profiling in Advanced Cancers Trial (IMPACT; NCT01505400) or Ontario-wide Cancer TArgeted Nucleic Acid Evaluation (OCTANE; NCT02906943) clinical trials at the Princess Margaret Cancer Centre were included. Electronic medical records were reviewed to collect clinicopathologic and treatment data. The OncoKB framework was used to categorize molecular alterations based on levels of actionability. Patients with an actionable alteration by OncoKB framework who had treatment with a drug targeting the alteration were categorized as receiving "matched" therapy. Time-to-event data were analyzed using the Kaplan-Meier method. This study was approved by the University Health Network Research Ethics Board (ID# 19-5888). Results: NGS was performed on 118 patients with advanced thyroid cancer between 2013 and 2020. The most common molecular alterations included BRAF V600E (62%) and NRAS (15%) mutations in papillary thyroid cancer, RET alterations (78%) in medullary thyroid cancer, and BRAF V600E (38%) and TP53 (62%) mutations in anaplastic thyroid cancer. Actionable alterations were found in 87% of patients, and 57% of patients had at least one Level 1 or 2 alteration for which Food and Drug Administration (FDA)-approved drug is available. BRAF and RET alterations made up 86% of Level 1 and 2 alterations. A matched therapeutic approach was undertaken in 13% of patients. Conclusion: This study uses a structured framework to analyze the actionability and clinical use of NGS results in advanced thyroid cancer. Most patients had at least one potentially actionable mutation and 57% of patients had at least one Level 1 or 2 alteration, predominantly driven by BRAF V600E and RET alterations. This study rationalizes the need for routine multigene NGS testing or reflex BRAF and RET testing in the management of patients with advanced thyroid cancer.

Prophylactic vaccines against cancers of non-infectious origin: a dream or a real possibility?

The dramatic progress in tumour biology and immunology in the past several years has opened new avenues for the treatment and prevention of cancer. One of the great contributions of the immunotherapeutic approaches is an increasing understanding of the immunology of cancer, which is, gradually creating conditions for the development of prophylactic anti-cancer vaccines. Efficient vaccines have been developed and employed for the prophylaxis of two frequent cancers of viral origin, namely cervical cancer and liver cancer. The new knowledge on the interactions between the immune system and the malignant tumors seems to provide means for the development of prophylactic vaccines against cancers developing due to the mutations in the proto-oncogenes converting their products into oncoproteins. According to the present estimates, these cancers form a great majority of human malignancies. Recent evidence has indicated that the immune system recognizes such mutated proteins, and that the development of cancer is due to the failure of the immune system to eliminate neoplastic cells. Followingly, it can be expected that inducing immunity against the mutated epitopes will increase the capacity of the body to deal with the initiated precancerous cells. In the present paper this hypothesis is primarily discussed in the relationship with colorectal cancer (CRC), which seems to be a well-fitting candidate for prophylactic vaccination. CRC is the third most frequent malignancy and the fourth most common cause of cancer mortality. Mutations of two proto-oncogenes, namely RAS and RAF, are involved in the majority of CRC cases and, in addition, they are shared with other human malignancies. Therefore, the strategy to be used for prophylaxis of CRC is discussed together with several other frequent human cancers, namely lung cancer, pancreatic duct cancer and melanoma. The prophylactic vaccines proposed are aimed at the reduction of the incidence of these and, to a lesser extent, some other cancers.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Results

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

Conclusions and Relevance

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

Cartilage oligomeric matrix protein affects the biological behavior of papillary thyroid carcinoma cells by activating the PI3K/AKT/Bcl-2 pathway

Objective: To explore the effect of cartilage oligomeric matrix protein (COMP) on papillary thyroid carcinoma (PTC).

Methods: COMP expression levels in PTC tissues and matched adjacent normal tissues were measured using tissue microarrays. Human PTC cells were cultured and transduced with lentiviral short hairpin RNA against COMP (COMP-shRNA), a negative control (NC) shRNA, or mock transfected (Control). We used the Cell Counting Kit-8, performed colony formation assays, wound healing assays, Transwell invasion assays, flow cytometry, and measured the expression of apoptosis-related proteins at the mRNA and protein levels to explore the effects of COMP on the biological behavior of PTC cells and to discover the specific signaling pathway involved in these processes.

Results: COMP expression was significantly higher in PTC tissues than in adjacent normal tissues. At the cellular level, COMP promoted cell migration, increased the invasiveness of PTC cells, and inhibited apoptosis. However, differences in cell proliferation were only observed within 72 hours. At the same time, colony formation assays showed that silencing COMP inhibited the proliferation of PTC cells. We also found that COMP regulated the behavior of PTC cells by activating the PI3K/AKT/Bcl-2 pathway.

Conclusions: COMP is upregulated in PTC, which enhances cancer cell invasion and inhibits apoptosis, contributing to the development and progression of PTC. Thus, COMP may serve as a new biomarker for PTC.

Comparison of Molecular Methods and BRAF Immunohistochemistry (VE1 Clone) for the Detection of BRAF V600E Mutation in Papillary Thyroid Carcinoma: A Meta-Analysis

The evaluation of surgically resected papillary thyroid carcinomas (PTC) by immunohistochemistry (IHC) for BRAF mutation has diagnostic, prognostic and therapeutic implications. The goal of this meta-analysis was to perform a systematic review of studies using the VE1 clone (specific for detection of the BRAF V600E mutation) on formalin-fixed paraffin embedded (FFPE) thyroid surgical resection specimens for primary papillary thyroid carcinoma. The authors' molecular techniques, immunohistochemistry protocols, and scoring methods for VE1 immunostaining were also evaluated. This study included 4079 PTCs representing data from 23 studies. The results extracted from each study were split into two different groups, direct sequencing group or PCR group, based on the molecular "gold standard" method used to compare VE1 IHC staining. In the direct sequencing group, the IHC sensitivity was 100% (95% CI 0.97-1.00) and specificity 84% (95% 0.72-0.91). In the PCR group the sensitivity was 98% (95% CI 0.96-0.99) and specificity 89% (95% CI 0.82-0.94). Although immunohistochemical procedures varied by author, the overall performance of the VE1 clone shows that it is highly sensitive and relatively specific for detecting the BRAF V600E mutation in surgical resection specimens. However, standardization of immunohistochemical procedural method and scoring/interpretation criteria may improve the reliability and reproducibility for the use of VE1 clone for future practice.

An affordable immunohistochemical approach to estimate the prevalence of BRAFV600E in large cohort studies-establishing the baseline rate of BRAF mutation in an institutional series of papillary thyroid carcinoma from Thailand

Background

Papillary thyroid carcinoma (PTC) accounts for the majority of diagnoses of thyroid carcinoma. BRAF^V600E mutation is the most common genetic alteration in PTC, which has diagnostic and prognostic significance. The rate of BRAF^V600E mutation in PTC from Thailand has not been reported. Our purpose was to estimate the prevalence of BRAF mutation in a large institutional series using an affordable approach, which combined mutation-specific immunohistochemistry (IHC) with VE1 antibody and tissue microarray (TMA).

Methods

A total of 476 PTC cases plotted on TMA were employed for determining the mutation status in this study. The cancer tissue of initial 100 cases (pilot study) were analyzed for BRAF^V600E mutation by using both direct sequencing and VE1 immunostaining. For the subsequent PTC cases, VE1 IHC was used as an alternative to direct sequencing for the detection of mutation. Univariate and multivariate analyses were done to determine the association of clinicopathological variables with BRAF^V600E mutation.

Results

In the pilot study, VE1 IHC showed excellent analytical performance (κ=0.884) for detecting BRAF^V600E mutation in PTC TMA as compared to direct sequencing. The prevalence of BRAF^V600E in the whole cohort was 60.9% by using VE1 IHC. The mutation was commonly seen in tall cell (92.9%) and classic (70.2%) variants of PTC. Multivariate analysis (P<0.05) showed association of BRAF^V600E with histological type of tumor, extrathyroidal extension, and absence of Hashimoto's thyroiditis.

Conclusions

In conclusion, BRAF^V600E mutation was detected in 60.9% of Thai PTC and it was associated with several aggressive clinicopathological variables of thyroid cancer. VE1 IHC proved as a reliable method able to replace direct sequencing for detection of the mutation. A combination of mutation-specific IHC and TMA allows conducting large cohort studies more labor-saving and cost-efficiently.

BRAF Status in Papillary Microcarcinomas of the Thyroid Gland: a Brief Review

Papillary thyroid microcarcinoma (PTMC) is defined by the World Health Organization as papillary cancer measuring 10 mm or less in diameter. Generally, PTMC shows an indolent clinical behavior with a good prognosis, although a minority of PTMC is characterized by an aggressive course. However, efforts to identify this aggressive subset of PTMC after surgery remain inconclusive. Several oncogenic pathways have been identified in thyroid cancer and have been applied translationally to improve prognosis and clinical management. In particular, the BRAFV600E mutation was found more frequently in large, aggressive, recurrent and advanced tumors. We aimed at reviewing studies on BRAFV600E mutation as a prognostic factor in PTMC.

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

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

Prognostic Parameters in Differentiated Thyroid Carcinomas

Differentiated thyroid carcinomas make up most thyroid malignancies. The AJCC staging system and the ATA risk prediction system are the best predictors of mortality and recurrence, respectively. Key factors to be identified and reported by pathologists are reviewed in this article and include: (1) aggressive histologic variants of papillary thyroid carcinoma (including tall cell, columnar cell, and hobnail variants); (2) presence of gross extrathyroidal extension (into skeletal muscle or adjacent organs); (3) angioinvasion (including number of foci); (4) number, anatomic level, and size of lymph node metastases; (4) extranodal extension; (5) genetics (especially BRAF V600E or TERT promoter mutation).

A Systematic Review and Meta-Analysis of the Diagnostic Performance of BRAF V600E Immunohistochemistry in Thyroid Histopathology

Immunohistochemistry (IHC) in evaluating thyroid surgical specimens may facilitate diagnostic and prognostic evaluation, with potential therapeutic implications. We performed a systematic review and meta-analysis examining the analytic validity of IHC in detecting BRAFV600E mutations in thyroid cancer (primary or metastatic). We screened citations from three electronic databases (until December 20, 2018), supplemented by a hand search of authors' files and cross-references of reviews. Citations and full-text papers were independently reviewed in duplicate, and consensus was achieved on inclusion of papers. Two reviewers independently critically appraised and abstracted data from included papers. Random-effect meta-analyses were conducted for sensitivity and specificity estimates. We reviewed 1499 unique citations and 93 full-text articles. We included 1 systematic review and 30 original articles. The published review (from 2015) needed to be updated as there were multiple subsequent original studies. The pooled sensitivity of IHC in detecting a BRAFV600E mutation was 96.8% (95% confidence interval [CI] at 94.1%, 98.3%) (29 studies, including 2659 BRAFV600E mutant tumors). The IHC pooled specificity was 86.3% (95% CI 80.7%, 90.4%) (28 studies, including 1107 BRAFV600E wild-type specimens). These meta-analyses were subject to statistically significant heterogeneity, partly explained by antibody type (sensitivity and specificity) and tissue/tumor type (specificity). In conclusion, BRAF IHC is highly sensitive and reasonably specific in detecting the BRAFV600E mutation; however, there is some variability in analytic performance.

In papillary thyroid carcinoma, expression by immunohistochemistry of BRAF V600E, PD-L1, and PD-1 is closely related

Immune checkpoint inhibitor therapies targeting PD-L1/PD-1 have been shown to be effective in treating several types of human cancer. In papillary thyroid carcinoma (PTC), little is known about the expression of PD-L1/PD-1 in the tumor microenvironment or its potential correlation with BRAF V600E mutation status. In this study, we examined the expression of PD-L1, PD-1, and BRAF V600E in PTC by immunohistochemistry and investigated the clinical significance of expression status. We studied the expression of PD-L1, PD-1, and BRAF V600E by immunohistochemical staining in 110 cases of PTC with a diameter > 1 cm. Cases with a background of chronic lymphocytic thyroiditis (CLT) were excluded, as differentiating lymphocytes in the context of CLT from tumor-infiltrating lymphocytes (TILs) is difficult. We classified PD-L1+/PD-1+ expression as type 1 (41%), PD-L1-/PD-1- as type 2 (17%), PD-L1+/PD-1- as type 3 (5%), and PD-L1-/PD-1+ as type 4 (37%). Significant correlations were found between expression of BRAF V600E and that of PD-L1 and PD-1. The positive correlation observed between expression of BRAF V600E and PD-L1/PD-1 suggests that immunotherapies targeting PD-L1/PD-1 might be effective for PTC patients with the BRAF V600E mutation, which are refractory to radioiodine therapy.

Utility of the BRAF p.V600E immunoperoxidase stain in FNA direct smears and cell block preparations from patients with thyroid carcinoma

BACKGROUND

The identification of BRAF mutations in thyroid cancer has prognostic and therapeutic implications. Although the gold standard for identifying BRAF mutations is molecular testing, the ability to perform BRAF p.V600E immunostaining on fine-needle aspiration (FNA) samples can facilitate the rapid triaging of patients to treatment options.

METHODS

A total of 50 thyroid carcinoma FNA samples, including papillary (29 samples), poorly differentiated (10 samples), anaplastic (9 samples), and Hurthle cell (2 samples) carcinomas, with a known BRAF p.V600E mutation status were selected for the current study. Immunostaining was performed on smears and cell block sections using an anti-BRAF p.V600E antibody (clone VE1). The results were compared with the known mutation status obtained by molecular testing and/or immunostaining of surgical pathology material from the same patient.

RESULTS

Of the total of 50 cases, 26 cases had smears available for the evaluation of BRAF p.V600E immunostaining; positive immunostaining was noted in 16 samples and negative immunostaining was noted in 4 samples, whereas 6 cases were equivocal. Of the 34 cases for which cell blocks were available for evaluation, BRAF p.V600E immunostaining was positive in 17 cases, negative in 16 cases, and equivocal in 1 case. The overall sensitivity and specificity of BRAF p.V600E immunostaining on the cell block preparation was 94.4% and 100%, respectively, whereas for the smears it was 80% and 63.6%, respectively.

CONCLUSIONS

BRAF p.V600E immunostaining can be performed reliably on thyroid FNA cell block preparations. However, false-positive results on direct smears limit their utility and therefore need to be interpreted with caution. Cancer Cytopathol 2018;126:406-13. © 2018 American Cancer Society.

PD-L1 and PD-1 expression are correlated with distinctive clinicopathological features in papillary thyroid carcinoma

BACKGROUND

Immune checkpoint blockade targeting PD-1/PD-L1 has shown efficacy in several types of cancers. However, the correlation between PD-L1/PD-1 expression and the specific clinicopathological features in papillary thyroid carcinoma (PTC) has not been investigated.

METHODS

We examined the immunohistochemical expression of PD-L1, PD-1, and BRAF V600E on whole-tissue sections from 126 cases of primary PTC more than 1 cm in size. The correlation between the PD-L1/PD-1 expression and the clinicopathological features was evaluated.

RESULTS

PD-L1 was positively expressed in 53.2% PTCs, and its expression was positively correlated with rich tumor-infiltrating lymphocytes (TILs), background chronic lymphocytic thyroiditis (CLT), female gender, absence of psammoma bodies, and PD-1 expression. Among these parameters, rich TILs, female gender, and absence of psammoma bodies were independent factors affecting PD-L1 expression on the multivariate logistic regression analysis. PD-1 expression was detected in the TILs and was positively correlated with rich TILs, background CLT, and absence of stromal calcification. Lack of stromal calcification was an independent factor affecting PD-1 expression. Neither PD-L1 nor PD-1 expression showed significant correlation with BRAF V600E expression.

CONCLUSIONS

Our results show that the distinctive pathological features of PTCs, including TILs, background CLT, female gender, psammoma bodies, and stromal calcification, are useful parameters for predicting PD-L1 or PD-1 expression.

BRAFV600E mutation contributes papillary thyroid carcinoma and Hashimoto thyroiditis with resistance to thyroid hormone: A case report and literature review

Resistance to thyroid hormone (RTH) is a rare autosomal hereditary disorder characterized by increased serum thyroid hormone (TH) levels with unsuppressed or increased thyrotropin concentration. It remains unknown whether the coexistence of RTH with papillary thyroid carcinoma (PTC) and Hashimoto thyroiditis (HT) is incidental or whether it possesses a genetic or pathophysiological association. In the present study, a case of RTH with PTC and HT in an 11-year-old Chinese patient was examined and the clinical presentation of RTH with PTC was discussed. In addition, the possible associations between RTH, PTC and HT were determined. HT was confirmed in the patient using an autoimmune assay and thyroid ultrasound. RTH was diagnosed on the basis of clinical manifestations, laboratory information and gene analysis, and PTC was diagnosed according to histological results. Results of BRAF^V600E mutation analysis were positive. A literature review of 14 cases of RTH with PTC was included for comparison. The present case report indicates an association of RTH with PTC and HT coexistence in the patient. Close follow-up, histological evaluation and BRAF^V600E mutation detection should be performed in each RTH case with HT, since a persistent increase in TSH may be a risk factor for the development of thyroid neoplasm.

Systematic reviews of diagnostic tests in endocrinology: an audit of methods, reporting, and performance

BACKGROUND

Systematic reviews provide clinicians and policymakers estimates of diagnostic test accuracy and their usefulness in clinical practice. We identified all available systematic reviews of diagnosis in endocrinology, summarized the diagnostic accuracy of the tests included, and assessed the credibility and clinical usefulness of the methods and reporting.

METHODS

We searched Ovid MEDLINE, EMBASE, and Cochrane CENTRAL from inception to December 2015 for systematic reviews and meta-analyses reporting accuracy measures of diagnostic tests in endocrinology. Experienced reviewers independently screened for eligible studies and collected data. We summarized the results, methods, and reporting of the reviews. We performed subgroup analyses to categorize diagnostic tests as most useful based on their accuracy.

RESULTS

We identified 84 systematic reviews; half of the tests included were classified as helpful when positive, one-fourth as helpful when negative. Most authors adequately reported how studies were identified and selected and how their trustworthiness (risk of bias) was judged. Only one in three reviews, however, reported an overall judgment about trustworthiness and one in five reported using adequate meta-analytic methods. One in four reported contacting authors for further information and about half included only patients with diagnostic uncertainty.

CONCLUSION

Up to half of the diagnostic endocrine tests in which the likelihood ratio was calculated or provided are likely to be helpful in practice when positive as are one-quarter when negative. Most diagnostic systematic reviews in endocrine lack methodological rigor, protection against bias, and offer limited credibility. Substantial efforts, therefore, seem necessary to improve the quality of diagnostic systematic reviews in endocrinology.

Core Needle Biopsy Is a More Conclusive Follow-up Method Than Repeat Fine Needle Aspiration for Thyroid Nodules with Initially Inconclusive Results: A Systematic Review and Meta-Analysis

Background:

This study investigated the appropriate management of thyroid nodules with prior non-diagnostic or atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) through a systematic review and meta-analysis.

Methods:

This study included 4,235 thyroid nodules from 26 eligible studies. We investigated the conclusive rate of follow-up core needle biopsy (CNB) or repeat fine needle aspiration (rFNA) after initial fine needle aspiration (FNA) with non-diagnostic or AUS/FLUS results. A diagnostic test accuracy (DTA) review was performed to determine the diagnostic role of the follow-up CNB and to calculate the area under the curve (AUC) on the summary receiver operating characteristic (SROC) curve.

Results:

The conclusive rates of follow-up CNB and rFNA after initial FNA were 0.879 (95% confidence interval [CI], 0.801 to 0.929) and 0.684 (95% CI, 0.627 to 0.736), respectively. In comparison of the odds ratios of CNB and rFNA, CNB had more frequent conclusive results than rFNA (odds ratio, 5.707; 95% CI, 2.530 to 12.875). Upon subgroup analysis, follow-up CNB showed a higher conclusive rate than rFNA in both initial non-diagnostic and AUS/FLUS subgroups. In DTA review of followup CNB, the pooled sensitivity and specificity were 0.94 (95% CI, 0.88 to 0.97) and 0.88 (95% CI, 0.84 to 0.91), respectively. The AUC for the SROC curve was 0.981, nearing 1.

Conclusions:

Our results show that CNB has a higher conclusive rate than rFNA when the initial FNA produced inconclusive results. Further prospective studies with more detailed criteria are necessary before follow-up CNB can be applied in daily practice.