Clinicopathologic implications of the BRAF(V600E) mutation in papillary thyroid cancer: a subgroup analysis of 3130 cases in a single center

The Association between Lymphocytic Thyroiditis and Papillary Thyroid Cancer Harboring Mutant BRAF: A Systematic Review and Meta-Analysis

Background: Papillary thyroid cancer (PTC) and lymphocytic thyroiditis (LT) co-occur with a prevalence of about 30%. PTC harboring BRAFV600E (PTC-BRAF) confers a worse prognosis, but it is unclear if LT alters prognostic features and recurrence of PTC. Objective: We compared the prevalence of PTC-BRAF with and without LT. The risk of adverse pathological features in (i) PTC in the presence and absence of BRAF mutation, irrespective of LT status, was compared to (ii) PTC in the presence and absence of LT, irrespective of BRAF status. Methods: We searched PubMed, Embase, and Web of Science Core Collection for observational studies published from 2010 to June 2023 on adult patients with PTC. The search strategy yielded 47 studies with relevant data. Data of baseline characteristics, clinicopathological features, and the quality assessment tool were extracted by two reviewers. The study was registered with PROSPERO (CRD42023437492). Results: Of the 47 studies, 39 studies with a total cohort of 28 143, demonstrated that the odds of PTC-BRAF were significantly lower in the presence of LT compared to its absence (odds ratio [OR] 0.53, 95% confidence interval [CI]: 0.48-0.58, p < 0.00001). In PTC-BRAF patients, there was a positive association of central neck nodal disease (CNND), PTC > 1 cm, extra-thyroidal extension, American Joint Committee on Cancer (AJCC) Stage 3-4, and multifocality with pooled ORs of 1.54 (95% CI: 1.16-2.04), 1.14 (95% CI: 0.82-1.58), 1.66 (95% CI: 1.40-1.97), 1.53 (95% CI: 1.35-1.75), and 1.24 (95% CI: 1.11-1.40) respectively, compared to wild-type PTC, irrespective of LT status. In the same studies, PTC with LT patients had lower pooled ORs of 0.64 (95% CI: 0.51-0.81) for CNND, 0.83 (95% CI: 0.73-0.95) for PTC > 1 cm, 0.71 (95% CI: 0.58-0.86) for ETE, 0.84 (95% CI: 0.75-0.94) for AJCC Stage 3-4 compared to PTC without LT, irrespective of BRAF status. PTC recurrence was not affected by BRAF or LT, with pooled ORs of 1.12 (95% CI: 0.66-1.90, p = 0.67) and 0.60 (95% CI: 0.28-1.30, p = 0.20) respectively. Similar results were seen with recurrence expressed as hazard ratio in this limited data-set. Conclusion: The odds of PTC-BRAF are significantly lower in the presence of LT than without. PTC with LT, irrespective of BRAF status, was significantly associated with better prognostic factors. Further studies are required to evaluate if LT inhibits PTC-BRAF, and whether this is relevant to the role of immunotherapy in advanced thyroid cancer.

Management of aggressive variants of papillary thyroid cancer

PURPOSE OF REVIEW

The aim of this study was to provide a timely and relevant review of the latest findings and explore appropriate management of aggressive variants of papillary thyroid cancer (AVPTC).

RECENT FINDINGS

In general, AVPTCs tend to exhibit more invasive characteristics, a lack of responsiveness to radioiodine, increased occurrences of regional spreading, distant metastases and higher mortality rates. Meanwhile, each variant showcases unique clinical and molecular profiles.

SUMMARY

Given the elevated risk of recurrence postsurgery, a more aggressive strategy may be necessary when suspected preoperatively, particularly for those presenting with invasive features. Decision on the extent of surgical treatment and adjuvant therapy is individualized and made by experienced clinicians and multidisciplinary teams based on the clinical presentation, presence of aggressive features and molecular profile. Future studies on development of personalized medicine and molecular target therapy may offer tailored treatment options.

Integrating US-guided FNAB, BRAFV600E mutation, and clinicopathologic characteristics to predict cervical central lymph-node metastasis in preoperative patients with cN0 papillary thyroid carcinoma

BACKGROUND

The prevalence of cervical central lymph-node metastasis (CLNM) is high in patients with papillary thyroid carcinoma (PTC). There is considerable controversy surrounding the benefits of prophylactic central lymph-node dissection (pCLND) in patients with clinically negative central compartment lymph nodes (cN0). Therefore, it is crucial to accurately predict the likelihood of cervical CLNM before surgery to make informed surgical decisions.

METHODS

Date from 214 PTC patients (cN0) who underwent partial or total thyroidectomy and pCLND at the Guizhou Provincial People's Hospital were collected and retrospectively analyzed. They were divided into two groups in accordance with cervical CLNM or not. Their information, including clinical characteristics, ultrasound (US) features, pathological results of fine-needle aspirations biopsy (FNAB), and other characteristics of the groups, was analyzed and compared using univariate and multivariate logistic regression analyses.

RESULTS

A total of 214 patients were eligible in this study. Among them, 43.5% (93/214) of PTC patients had cervical CLNM, and 56.5% (121/214) did not. The two groups were compared using a univariate analyses, and there were no significant differences between the two groups in aspect ratio, boundary, morphology, component, and BRAFV600E (P > 0.05), and there were significant differences between gender, age, maximum tumor size, tumor location, capsule contact, microcalcifications, color Doppler flow imaging (CDFI), and Hashimoto's thyroiditis (HT) (P < 0.05). A multivariate logistic regression analysis was performed to further clarify the correlation of these indices. However, only age (OR = 2.455, P = 0.009), maximum tumor size (OR = 2.586, P = 0.010), capsule contact (OR = 3.208, P = 0.001), and CDFI (OR = 2.225, P = 0.022) were independent predictors of cervical CLNM. Combining these four factors, the area under the receiver-operating characteristic (ROC) curve for the joint diagnosis is 0.8160 (95% 0.7596-0.8725). Univariate analysis indicated that capsule contact (P = 0.001) was a possible predictive factor of BRAFV600E mutation.

CONCLUSIONS

In conclusion, four independent predictors of cervical CLNM, including age < 45 years, tumor size > 1.0 cm, capsule contact, and rich blood flow, were screened out. Therefore, a comprehensive assessment of these risk factors should be conducted when designing individualized treatment regimens for PTC patients.

Molecular Genetics of Diffuse Sclerosing Papillary Thyroid Cancer

CONTEXT

Diffuse sclerosing papillary thyroid cancer (DSPTC) is rare, with limited data on its molecular genetics.

OBJECTIVE

We studied the molecular genetics of a cohort of DSPTC.

METHODS

DNA was isolated from paraffin blocks of 22 patients with DSPTC (15 females, 7 males, median age 18 years, range 8-81). We performed polymerase chain reaction-based Sanger sequencing and a next-generation sequencing (NGS) gene panel to characterize the genomic landscape of these tumors. We classified genetic alterations to definitely or probably pathogenic. Definitely pathogenic are genetic alterations that are well known to be associated with PTC (e.g., BRAFV600E). Probably pathogenic are other alterations in genes that were reported in The Cancer Genome Atlas or the poorly differentiated and anaplastic thyroid cancer datasets.

RESULTS

Three tumors were tested only by Sanger sequencing and were negative for BRAFV600E, HRAS, KRAS, NRAS, TERT promoter, PTEN, and PIK3CA mutations. The other 19 tumors tested by NGS showed definitely pathogenic alterations in 10 patients (52.6%): 2/19 (10.5%) BRAFV600E, 5/19 (26.3%) CCDC6-RET (RET/PTC1), 1/19 (5.3%) NCOA4-RET (RET/PTC3), 1/19 (5.3%) STRN-ALK fusion, and 2/19 (10.6%) TP53 mutations. Probably pathogenic alterations occurred in 13/19 tumors (68.4%) and included variants in POLE (31.6%), CDKN2A (26%), NF1 (21%), BRCA2 (15.8%), SETD2 (5.3%), ATM (5.3%), FLT3 (5.3%), and ROS1 (5.3%). In 1 patient, the gene panel showed no alterations. No mutations were found in the RAS, PTEN, PIK3CA, or TERT promoter in all patients. There was no clear genotype/phenotype correlation.

CONCLUSION

In DSPTC, fusion genes are common, BRAFV600E is rare, and other usual point mutations are absent. Pathogenic and likely pathogenic variants in POLE, NF1, CDKN2A, BRCA2, TP53, SETD2, ATM, FLT3, and ROS1 occur in about two-thirds of DTPTC.

Clinicopathological and Genetic Characteristics of Patients of Different Ages with Diffuse Sclerosing Variant Papillary Thyroid Carcinoma

Diffuse sclerosing variant papillary thyroid carcinoma (DSVPTC) is commonly observed in young patients, with a median age at diagnosis in the third decade of life. Further, the risk of recurrence is higher for DSVPTC than for classical PTC. Therefore, this study aimed to describe the clinicopathological and genetic characteristics of patients of different ages with DSVPTC. We retrospectively reviewed 397 patients who underwent thyroidectomy for DSVPTC at Gangnam Severance Hospital, Yonsei University, from January 2005 to December 2017. The mean age at diagnosis was 36.7 ± 11.6 years, with most patients (163, 41.1%) aged 31-40 years. DSVPTC was predominant in women (276, 69.5%). We observed recurrence in 46 (11.6%) patients, with regional nodal recurrence being the most common type of recurrence (32 patients, 69.6%). The mean tumour size was larger in younger patients than in older patients. DSVPTC was more aggressive in paediatric patients with a larger-sized tumour, more common multiplicity, and lateral neck metastasis. Through random sampling, we selected 41 patients by age group and examined the mutations in 119 genes using next-generation sequencing. BRAF, KRAS, and TERT displayed relatively higher mutation rates than other genes. DSVPTC displays different clinical, pathological, and molecular profiles than classical PTC. The BRAF, KRAS, and TERT mutations are the most important, with age-specific differences.

Characterization of mortality and high-risk characteristics of thyroid cancer in Filipinos using the California Cancer Registry

Introduction

Filipinos are the third largest Asian American subgroup and have the highest incidence of thyroid cancer among all races. To better understand this racial/ethnic disparity in thyroid cancer affecting Filipinos we analyzed the California Cancer Registry (CCR) data in Filipino thyroid cancer cases from 1988 to 2018.

Methods

97,948 thyroid cancer cases in California from 1988 to 2018 (until 2015 for Asian subgroups) were evaluated. We examined the case distribution by sex, age at diagnosis, race/ethnicity including Asian ethnic subgroups, histology, TNM stage, tumor size, lymph node involvement, lymphovascular invasion, and multifocality. We also looked at treatment data including surgery and radiation including radioactive iodine therapy. We calculated age-adjusted mortality rates (AAMR) for each major racial group and each Asian ethnic subgroup. Binary logistic regression was used to determine the likelihood of high-risk characteristics and treatment when comparing Filipinos to other racial/ethnic groups. Kaplan-Meier Estimate was performed to evaluate thyroid cancer survival across all race/ethnicities. Multivariate Cox proportion hazards regression was performed to evaluate mortality risk from all causes of death by race.

Results

There were 5,243 (5.35%) Filipino thyroid cancer cases in California from 1988 to 2018. Filipinos had the highest AAMR (1.22 deaths per 100,000) in 2015. Filipinos had a higher likelihood of Stage IV thyroid cancer compared with Non-Hispanic Whites, Non-Hispanic Blacks, Hispanics and nearly all Asian subgroups. Filipinos had a worse 5-year and 10-year overall survival (OS) than the combination of all other Asian/Pacific Islanders. Filipinos compared to Non-Hispanic Whites had significant mortality risk in overall and papillary thyroid cancer cases (Overall HR: 1.10, 95% CI 1.07-1.13, p < 0.0001, Papillary HR: 1.11, 95% CI 1.07-1.14, p < 0.0001) when adjusted for race/ethnicity, age, gender, socioeconomic status, and stage. When stratified by Charlson comorbidity score, Filipinos compared to Non-Hispanic Whites still had significant mortality risk (Charlson 0 HR: 1.07, 95% CI 1.02-1.11, p = 0.0017, Charlson 1+ HR: 1.07 95% CI 1.002-1.14, p = 0.0434).

Conclusions

Filipino thyroid cancer patients have higher incidences of high-risk pathological features and greater AAMR and mortality risk. These findings warrant further investigation into better understanding the connection between the greater incidence of high-risk characteristics and increased mortality in Filipinos.

The Immune Landscape of Papillary Thyroid Cancer in the Context of Autoimmune Thyroiditis

Simple Summary

The association between papillary thyroid cancer and Hashimoto’s thyroiditis went through a long-standing human debate recently elucidated by the establishment of a novel mouse model. Papillary thyroid carcinoma is an excellent model for studying the tumor immune microenvironment because it is naturally accompanied by immune cells, making it a good candidate for the treatment with immune checkpoint inhibitors.

Abstract

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto’s thyroiditis, an association that has long been reported in clinical studies, remaining controversial. Experimental evidence has recently shown that pre-existing thyroiditis has a beneficial effect on PTC growth and progression by a distinctive expansion of effector memory CD8 T cells. Although the link between inflammation and PTC might involve different components of the immune system, a deep characterization of them which includes T cells, B cells and tertiary lymphoid structures, Mye-loid cells, Neutrophils, NK cells and dendritic cells will be desirable. The present review article considers the role of the adaptive and innate immune response surrounding PTC in the context of Hashimoto’s thyroiditis. This review will focus on the current knowledge by in vivo and in vitro studies specifically performed on animals’ models; thyroid cancer cells and human samples including (i) the dual role of tumor-infiltrating lymphocytes; (ii) the emerging role of B cells and tertiary lymphoid structures; (iii) the role of myeloid cells, dendritic cells, and natural killer cells; (iv) the current knowledge of the molecular biomarkers implicated in the complex link between thyroiditis and PTC and the potential implication of cancer immunotherapy in PTC patients in the context of thyroiditis.

Association between Hashimoto thyroiditis and clinical outcomes of papillary thyroid carcinoma: A meta-analysis

Objective

To assess association between Hashimoto thyroiditis (HT) and clinical outcomes of papillary thyroid carcinoma (PTC).

Methods

Databases including Pubmed, Embase, Cochrane Library, and Web of Science were searched. Weighed mean differences (WMDs) and odds ratios (ORs) were used to evaluate association between HT and clinical outcomes of PTC, and the effect size was represented by 95% confidence intervals (CIs). Heterogeneity test was performed for each indicator. If the heterogeneity statistic I²≥50%, random-effects model analysis was carried out, otherwise, fixed-effect model analysis was performed. Sensitivity analysis was performed for all outcomes, and publication bias was tested by Begg’s test.

Results

Totally 47,237 patients in 65 articles were enrolled in this study, of which 12909 patients with HT and 34328 patients without HT. Our result indicated that PTC patients with HT tended to have lower risks of lymph node metastasis (OR: 0.787, 95%CI: 0.686–0.903, P = 0.001), distant metastasis (OR: 0.435, 95%CI: 0.279–0.676, P<0.001), extrathyroidal extension (OR: 0.745, 95%CI: 0.657–0.845, P<0.001), recurrence (OR: 0.627, 95%CI: 0.483–0.813, P<0.001), vascular invasion (OR: 0.718, 95%CI: 0.572–0.901, P = 0.004), and a better 20-year survival rate (OR: 1.396, 95%CI: 1.109–1.758, P = 0.005) while had higher risks of multifocality (OR: 1.245, 95%CI: 1.132–1.368, P<0.001), perineural infiltration (OR: 1.922, 95%CI: 1.195–3.093, P = 0.007), and bilaterality (OR: 1.394, 95%CI: 1.118–1.739, P = 0.003).

Conclusions

PTC patients with HT may have favorable clinicopathologic characteristics, compared to PTCs without HT. More prospective studies are needed to further elucidate this relationship.

Clinicopathological Implications of the BRAF V600E Mutation in Papillary Thyroid Carcinoma of Ukrainian Patients Exposed to the Chernobyl Radiation in Childhood: A Study for 30 Years After the Accident

With time after the Chernobyl accident, the number of papillary thyroid carcinomas (PTCs) driven by the BRAF^V600E oncoprotein is growing in patients exposed to radiation at a young age. Clinicopathological associations of BRAF^V600E in PTCs from patients with internal radiation history have not been sufficiently studied so far. This work analyzes the structural characteristics, proliferative activity, invasive features, clinical information, and dosimetric data in the BRAF^V600E-positive and BRAF^V600E-negative PTCs from the Ukrainian patients exposed to Chernobyl radiation and treated over 30 years after the accident. The study included 428 PTCs from patients aged 4-49 years at surgery who lived in the six northern regions of Ukraine most contaminated by ¹³¹I, were ≤18 years of age at the time of exposure, and were operated on from 1990 to 2017. Immunohistochemical staining for BRAF^V600E was performed with the VE1 antibody. The probability of causation (POC) of a tumor due to radiation was determined using an interactive online NIH/NCI software. BRAF^V600E was detected in 136/428 (31.8%) PTCs. In comparison with the BRAF^V600E-negative PTCs, the BRAF^V600E-positivity was associated with older patient age at the accident and at surgery, a longer period of latency, and lower POC. The BRAF^V600E-positive PTCs were characterized by smaller tumor size, higher Ki67 labeling index, more frequent oncocytic changes, multifocality, and dominant papillary growth pattern. Tumor invasive features were less frequent in the BRAF^V600E-positive PTCs and did not change with POC level. Despite a less aggressive tumor phenotype, BRAF^V600E was a risk factor for recurrence, namely radioiodine-refractory (RAI-R) recurrent metastases. Multivariate models of RAI-R included BRAF^V600E and/or histopathological parameters closely correlating with BRAF^V600E such as tumor size, multifocality, dominant papillary growth pattern, or oncocytic changes. Thus, the BRAF^V600E-positive PTCs from patients from a high-risk group for radiogenic thyroid cancer diagnosed in the 30 years after the Chernobyl accident did not display higher invasiveness regardless of POC level, but in view of the prognostic impact of this genetic alteration, knowledge of the BRAF status may be beneficial for middle-aged patients with radiogenic PTC considered for RAI therapy, and suggests more careful follow-up of patients with the BRAF^V600E-positive tumors.

Hashimoto's Thyroiditis: A "Double-Edged Sword" in Thyroid Carcinoma

BACKGROUND

The prevalence of thyroid carcinoma (TC) and Hashimoto's thyroiditis (HT) has been increasing dramatically over the past decades. We investigated the relationship between HT and TC.

METHODS

We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines for carrying out and reporting this meta-analysis. The literature from January 1, 2010 to December 31, 2020, regardless of region and publication type, was searched comprehensively in PubMed, Embase, Web of Science, and Cochrane Library databases. After careful selection and data extraction, the pooled odds ratio of various clinical characteristics in 39 studies were calculated. Publication bias was analyzed using funnel plots.

RESULTS

Meta-analysis of 39 original research articles showed HT to be a risk factor of TC (pooled odds ratio = 1.71; 95% confidence interval, 1.57-1.80; p < 0.00001) and papillary thyroid carcinoma (1.67, 1.51-1.85, <0.00001). Patients with papillary thyroid carcinoma (PTC) combined with HT were more likely to have multifocal carcinomas. The prevalence of an extrathyroidal extension, metastasis, BRAF^V600E mutation, and recurrence was significantly lower in patients with PTC combined with HT.

CONCLUSIONS

HT is a "double-edged sword" in TC patients. HT increases the risk of TC and PTC but is a protective factor against PTC progression.

Increased diagnostic sensitivity of palpation-guided thyroid nodule fine-needle aspiration cytology by BRAF V600E-mutation analysis

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer and its incidence is increasing. Preoperative diagnosis is warranted in order to avoid 'two-stage' procedures that are associated with additional costs and higher radioactive iodine remnant uptake. In the setting of thyroid cancer, somatic BRAF V600E-mutations are highly specific for PTC and can be analyzed in aspirates from fine-needle aspiration cytology (FNAC). The 'gold standard' to perform FNAC is ultrasound guidance. Here, we analyze whether adding BRAF V600E-mutation analysis could be of value in palpation-guided FNACs. A total of 430 consecutive patients were included. Ultrasound-guided FNACs were performed in 251 patients and 179 patients underwent palpation-guided FNACs. BRAF V600E-mutation analysis was performed using two methods, an allele-specific polymerase chain reaction (PCR) analyzed by capillary gel electrophoresis (PCR/Qiaxcel), and a droplet digital PCR (ddPCR) assay. A total of 80 patients underwent surgery, and histology revealed 25 patients to have PTC. Of the 25 PTCs, 23 (92%) showed a BRAF V600E-mutation. Both mutation analysis methods (PCR/Qiaxcel and ddPCR) produced concordant results. In the ultrasound-guided group, the preoperative diagnostic sensitivity of FNAC using the Bethesda classification alone was very high and additional BRAF V600E-mutation analysis added little to the preoperative diagnostic sensitivity. By contrast, in the palpation-guided group, by adding BRAF V600E-mutation analysis, eight instead of four patients were diagnosed of having PTC. This increase in the diagnostic sensitivity was statistically significant (p < 0.05). The costs per sample were as low as 62 USD (PCR/Qiaxcel and ddPCR) and 35 USD (PCR/Qiaxcel only). Ultrasound-guided FNAC should be aimed for when dealing with thyroid nodules. However, if palpation-guided FNAC cannot be avoided or may be required due to resource utilization, adding BRAF V600E-mutation analysis using the methods described in this study might significantly increase the proportion of preoperatively diagnosed PTCs. The additional costs can be considered very reasonable.

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.

The clinical usefulness of chemokine C-X-C Motif Ligand 12 as a diagnostic marker for Papillary Thyroid Carcinoma

Background

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer worldwide. It is essential to develop methods for the accurate diagnosis of PTC to avoid unnecessary surgery. The chemokine C-X-C motif ligand 12 (CXCL12) is associated with various cancers. We aimed to investigate the efficacy of CXCL12 in the diagnosis of PTC in fine-needle aspiration (FNA) specimens.

Methods

We prospectively collected samples from 58 patients who were scheduled for surgical treatment of PTC from 2013 to 2015. Tissue samples of 31 people with benign thyroid conditions were used as controls. Immunocytochemical and immunohistochemical staining for CXCL12 was performed on FNAs and corresponding tissue specimens. B-type Raf kinase (BRAF) V600E mutant protein expression and gene mutation were also analyzed to compare the clinical usefulness.

Results

: The mean age of the patients was 49.1 ± 1.4 years and 88.1% were women. Positive CXCL12 staining was observed in 6.5% of benign and in 98.3% of PTC samples; positive BRAF V600E mutant protein expression was found in 19.4% of benign and 93.1% of PTC samples. For the diagnosis of PTC for CXCL12 staining of FNA specimens, the calculated values were 93.1% sensitivity, 90.3% specificity, 94.7% positive predictive value, 87.5% negative predictive value, and 89.1% accuracy. CXCL12 had 100% sensitivity and specificity for the 12 cases of atypia of undetermined significance (AUS) diagnosed in FNA specimens.

Conclusions

CXCL12 may be a useful diagnostic tool for PTC, especially when the FNA specimen is classified as AUS.

Diffuse intrathyroidal dissemination of papillary thyroid carcinoma with no stromal fibrosis at presentation: A pattern of aggressive differentiated thyroid carcinoma

BACKGROUND

Multifocal Papillary thyroid carcinoma (PTC) is a very common condition. In certain cases, it is possible to find tens to hundreds of foci with a diffuse intrathyroidal spread in the whole thyroid with no stromal fibrosis. Herein, PTC with such features was nominated as diffuse disseminate variant (DDV) PTC. The aim of the present study was to investigate the histopathological characteristics, molecular features, and biological behavior of DDV and compare the characteristics of DDV to diffuse sclerosing variant (DSV) PTC.

MATERIALS AND METHODS

Thirty-four DDV and 23 DSV cases were identified from consecutive surgical specimens diagnosed with PTC between 2014 and 2019. Targeted next-generation sequencing (NGS) was applied to investigate the mutation spectrum of DDV and DSV.

RESULTS

DDV was commonly diagnosed in young patients and exhibited high rates of LNM (100 %), ETE (61.8 %), and LVI (44.1 %); however, they did not differ from DSV (P >  0.05). Male patients were more frequently diagnosed with DDV than with DSV (P <  0.001). The size of the largest tumor was significantly greater in DDV than in DSV patients (P =  0.008). In addition, BRAF^V600E mutation was significantly higher in the DDV than in the DSV group (P <  0.001). The RET/PTC rearrangement was more frequent in DSV than in DDV patients; however, the difference was not statistically significant (P =  0.106). Moreover, DDV had a higher rate of recurrence compared to DSV treated with the same protocol (total thyroidectomy followed by radioactive iodine (RAI) treatment) (47.1 % and 8.7 %, P =  0.002).

CONCLUSIONS

DDV should be regarded as a novel aggressive variant of PTC with distinct clinicopathological characteristics, aggressive biological behaviors, and a high recurrence.

Preoperative Typing of Thyroid and Parathyroid Tumors with a Combined Molecular Classifier

In previous studies, we described a method for detecting and typing malignant tumors of the thyroid gland in fine-needle aspiration biopsy samples via analysis of a molecular marker panel (normalized HMGA2 mRNA level; normalized microRNA-146b, -221, and -375 levels; mitochondrial-to-nuclear DNA ratio; and BRAF^V600E mutation) in cytological preparations by quantitative PCR. In the present study, we aimed to estimate the specificity of the typing of different thyroid tumors by the proposed method. Fine-needle aspiration cytological preparations from 278 patients were used. The histological diagnosis was known for each sample. The positive and negative predictive values of the method assessed in this study were, respectively, 100% and 98% for papillary thyroid carcinoma (n = 63), 100% and 100% for medullary thyroid carcinoma (n = 19), 43.5% and 98% for follicular carcinoma (n = 15), and 86% and 100% for Hürthle cell carcinoma (n = 6). Thus, we demonstrate that the diagnostic panel, including the analysis of microRNA expression, mRNA expression, the BRAF^V600E mutation, and the mitochondrial-to-nuclear DNA ratio, allows the highly accurate identification of papillary thyroid carcinoma, medullary thyroid carcinoma, and Hürthle cell carcinoma but not malignant follicular tumors (positive predictive value was below 50%).

Molecular characterisation and clinical correlation of papillary thyroid microcarcinoma

PURPOSE

Papillary thyroid microcarcinoma (mPTC) is defined as a papillary thyroid cancer sized 10 mm or less. Despite their generally indolent clinical course and good prognosis, a subset of mPTCs shows potentially aggressive behaviour.

METHODS

To search for predictors of clinical outcome of mPTCs, we retrospectively evaluated the genetic tumour profile of 100 patients (23 M/77 F, mean age ± SD 53.8 ± 13.4 years) with histologically confirmed mPTCs through analysis of BRAF, NRAS and TERT promoter mutations as well as RET/PTC translocations.

RESULTS

Mean follow-up period was 8.4 ± 3.6 years. In 55 cases, mPTC were detected incidentally after surgery. Capsular invasion, bilateralism and multifocality were found in 11/100, 17/100 and 24/100 cases, respectively, while lymph-nodes metastases were present at diagnosis in 9/100 cases. After 3.5 ± 2.0 years, tumour relapse occurred in 6/100 cases and was locoregional in five (two in the thyroid bed, three in laterocervical lymph-nodes), while lung metastasis occurred in one case. Biochemical persistence of disease was seen in 1/100 case. Mutations occurred in 55/100 cases; BRAF^V600E was the most frequently detected (49/100) and was associated with higher tumour size, bilateralism and follicular variant but not with capsular invasion. RET/PTC rearrangements were found in 2/100 cases, NRAS^Q61R in 4/100, while no mutations of TERT promoter gene were detected. Despite the observed association between BRAF^V600E mutation and unfavourable histopathological features, we found no direct association with tumour recurrence, distant metastases and mortality.

CONCLUSION

In our study, the search for the most frequent genetic alterations as prognostic markers in mPTCs would not have changed the therapeutic strategy.

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

Background

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

Methods

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

Results

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

Conclusions

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

BRAF V600E and lymph node metastases in papillary thyroid cancer

OBJECTIVE

To evaluate the relationship between the BRAF V600E mutation in lymph node metastasis (LNM) and its invasive characteristics in papillary thyroid cancer (PTC).

MATERIAL AND METHODS

A total of 373 PTC patients were enrolled in this study conducted at Zhujiang Hospital of Southern Medical University between January 2017 and December 2018. PTCs with cervical lymph node metastases were verified pathohistologically, and primary tumors and LNM were examined for the BRAF V600E mutation. Patients were excluded from the study if the BRAF V600E mutation was examined only in primary tumors or only in LNM.

RESULTS

Of the 373 patients examined, BRAF V600E mutation frequency in primary tumors was slightly higher than in LNM (81.5% vs 78.0%, P = 0.000), the intra-class correlation coefficient (ICC) was 0.865 (95% CI 0.835-0.890). The BRAF V600E mutation in both primary tumor and LNM negatively correlated with the size of the largest metastatic focus of LNM (Odds ratio, OR = 0.297, 95% CI 0.143-0.616, P = 0.001; OR = 0.242, 95% CI 0.119-0.492, P = 0.000, respectively). There was no relationship between BRAF V600E mutation in LNM and the number, extranodal extension or stage of LNM (P > 0.05).

CONCLUSION

The BRAF V600E mutation in LNM may not be related to the invasive characteristics of LNM in PTC.

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.

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.

Clinical Analysis of BRAFV600E Mutation and Its Correlation With Sonographic Image Characteristics in Papillary Thyroid Carcinoma in Chinese Coastal Areas

This study analyzed the characteristics of BRAF^V600E mutation in papillary thyroid carcinoma (PTC) in Chinese coastal areas. We intended to identify noninvasive methods to determine BRAF^V600E status in thyroid nodules prior to surgery. BRAF^V600E mutation and the sonographic characteristics of thyroid nodules were investigated in 670 PTC patients in our hospital. We aimed to determine the relationship between BRAF^V600E mutation and the clinicopathological and sonographic imaging characteristics of PTC. The mutation rate of the BRAF^V600E was 78.2%. BRAF^V600E mutation was significantly associated with central node (univariate analyses, P = .005; multivariate analyses, P < .001, odds ratio [OR] = 10.255) and lateral node metastases (univariate analyses, P = .001; multivariate analyses, P < .001, OR = 22). It was less frequent in PTC coexisting with Hashimoto's thyroiditis (univariate analyses, P = .016; multivariate analyses, P < .001, OR = .034). Nodules without blood flow had a significantly higher mutation rate of BRAF^V600E in PTC patients (univariate analyses, P = .026). BRAF^V600E mutation was significantly associated with high suspicion in the Thyroid Imaging Reporting and Data System 5 (univariate analyses, P = .004; multivariate analyses, P = .014, OR = 6.456). Our results strongly suggest that BRAF^V600E mutation plays a potential role in lymph node metastasis (central node metastasis, OR = 10.225; lateral node metastasis, OR = 22). Some sonographic imaging features might be helpful in estimating the status of BRAF^V600E preoperatively.

Papillary Thyroid Cancer-Aggressive Variants and Impact on Management: A Narrative Review

Introduction

Aggressive variants of papillary thyroid cancer (PTC) have been described with increasing frequency. These variants include diffuse sclerosing variant, tall cell variant, columnar cell variant, solid variant, and hobnail variant.

Methods

We have performed a review of the more aggressive variants of PTC with respect to main characteristics, histological and molecular features, and the consequences that the knowledge of these variants should have in the treatment of the patients.

Results

At the present time, we do not know the prognostic value of these aggressive PTC variants. The extent of the surgical treatment and adjuvant therapy necessary should be decided on the basis of the extent of the tumor at presentation and the opinion of experienced clinicians.

Conclusion

These aggressive variants should be known by clinicians, to avoid underdiagnosis, and treated according to the latest recommendations in the literature.

A meta-analysis evaluating the relationship between B-type Raf kinase mutation and cervical lymphatic metastasis in papillary thyroid cancer

BACKGROUND

B-type Raf kinase (BRAF) mutation is proved to be a critical predictive factor in papillary thyroid cancer (PTC) with aggressive characteristics. However, the association between BRAF mutation and cervical lymphatic metastasis in PTC is controversial.

METHODS

We searched papers on the study of BRAF mutation and cervical lymphatic metastasis in PTC patients through PubMed, Web of Science, Embase, and Cochranelibrary. The BRAF (+) cases, BRAF (-) cases, and cervical lymphphatic metastatic cases in both BRAF (+) and BRAF (-) groups were collected. After Quality assessment, statistical Analysis (funnel plot and Harbord evaluation, Random-effect model, heterogeneity, subgroup analysis, sensitivity analysis, and metacum analysis) were done by the Review Manager (RevMan) 5.3 and stata14 statistical software.

RESULTS

There were 78 cross-section studies which met our inclusion criteria. And all of them had no selection bias, publication bias, or any other bias. A significant association existed between BRAF mutation and cervical lymph node metastasis (LNM) (odds ratio [OR] = 1.63; 95% confidence interval [CI]: 1.44-1.84; P < .05). Overall, 46 studies were conducted among East Asians. Twenty four articles had provided the data of central lymph node metastasis (CLNM), 11 articles with the data of lateral lymph node metastasis (LLNM), and classic/conventional PTC (CPTC) was analyzed in 10 studies. Subgroup analyses were performed based on ethnicity, metastatic site, and subtype of PTC. Significant association between BRAF (+) mutation and cervical LNM were indicated in East Asians (OR = 1.73; 95% CI: 1.49-2.02; P < .05), in non-East Asians (OR = 1.57; 95% CI: 1.26-1.96; P < .05), and in CLNM (OR = 1.80; 95% CI: 1.56-2.07; P < .05). While no significant association was found in LLNM (OR = 1.37; 95% CI: 0.76-2.48; P = .29 > .05) and in CPTC (OR = 1.32; 95% CI: 0.97-1.80; P = .08 > .05). We did not find any other major changes when sensitivity analysis was performed. The metacum analysis showed no significant association existed before 2012. While a significant association began to exist between BRAF mutation and LNM from 2012, and this association became stable from 2017.

CONCLUSIONS

We consider that a significant association exists between BRAF mutation and cervical LNM. Further meta-analysis on subgroup may reveal some valuable factors between BRAF gene mutation and LNM. And we do not recommend that BRAF (+) as the biomarker for LNM in PTC.

New insights into intranuclear inclusions in thyroid carcinoma: Association with autophagy and with BRAFV600E mutation

Background

Intranuclear inclusions (NI) in normal and neoplastic tissues have been known for years, representing one of the diagnostic criteria for papillary thyroid carcinoma (PTC). BRAF activation is involved among others in autophagy. NI in hepatocellular carcinoma contain autophagy-associated proteins. Our aim was to clarify if NI in thyroid carcinoma (TC) have a biological function.

Methods

NI in 107 paraffin-embedded specimens of TC including all major subtypes were analyzed. We considered an inclusion as positive if it was delimited by a lamin AC (nuclear membrane marker) stained intact membrane and completely closed. Transmission electron microscopy (TEM), immunohistochemistry (IHC), immunofluorescence (IF) and 3D reconstruction were performed to investigate content and shape of NI; BRAF^V600E mutation was analyzed by next generation sequencing.

Results

In 29% of the TCs at least one lamin AC positive intranuclear inclusion was detected; most frequently (76%) in PTCs. TEM analyses revealed degenerated organelles and heterolysosomes within such NI; 3D reconstruction of IF stained nuclei confirmed complete closure by the nuclear membrane without any contact to the cytoplasm. NI were positively stained for the autophagy-associated proteins LC3B, ubiquitin, cathepsin D, p62/sequestosome1 and cathepsin B in 14–29% of the cases. Double-IF revealed co-localization of LC3B & ubiquitin, p62 & ubiquitin and LC3B & p62 in the same NI. BRAF^V600E mutation, exclusively detected in PTCs, was significantly associated with the number of NI/PTC (p = 0.042) and with immunoreactivity for autophagy-associated proteins in the NI (p≤0.035). BRAF-IHC revealed that some of these BRAF-positive thyrocytes contained mutant BRAF in their NI co-localized with autophagy-associated proteins.

Conclusions

NI are completely delimited by nuclear membrane in TC. The presence of autophagy-associated proteins within the NI together with degenerated organelles and lysosomal proteases suggests their involvement in autophagy and proteolysis. Whether and how BRAF^V600E protein is degraded in NI needs further investigation.

The Role of BRAF V600E in Reducing AUS/FLUS Diagnosis in Thyroid Fine Needle Aspiration

BRAF V600E mutations are common in papillary thyroid carcinoma (PTC) and some de-differentiated thyroid cancers. In this study, we summarize AUS/FLUS diagnosed cases from thyroid fine needle aspirations in our center from 2015 to 2017 to explore the impact of BRAF V600E detection on the cytopathological diagnosis of PTC. BRAF V600E detection could significantly reduce the AUS/FLUS diagnosis rates from 11.59 to 8.42% when all BRAF V600E-mutated AUS/FLUS cases were diagnosed as conforming to PTC (20.01 to 19.13% in 2016 and 10.92 to 7.93% in 2017, respectively). The AUS/M rates decreased from 0.67 to 0.64 in 2016 and from 0.33 to 0.23 in 2017. We further discuss a case with a single BRAF V600E cytological mutant lacking a postoperative PTC diagnosis and discuss the limitations of BRAF V600E detection using puncture elution fluid. Our findings support the notion that BRAF V600E detection can effectively reduce the diagnostic rates of AUS/FLUS and help clinicians decide both treatment strategies and patient prognosis.

Coexisting Germline CHEK2 and Somatic BRAFV600E Mutations in Papillary Thyroid Cancer and Their Association with Clinicopathological Features and Disease Course

BRAF^V600E is the most common somatic mutation in papillary thyroid carcinoma (PTC) and the majority of evidence indicates that it is associated with an aggressive clinical course. Germline mutations of the CHEK2 gene impair the DNA damage repair process and increase the risk of PTC. Coexistence of both mutations is expected to be associated with poorer clinical course. We evaluated the prevalence of concomitant CHEK2 and BRAF^V600E mutations and their associations with clinicopathological features, treatment response, and disease course in PTC patients. The study included 427 unselected PTC patients (377 women and 50 men) from one center. Relationships among clinicopathological features, mutation status, treatment response, and disease outcomes were assessed. Mean follow-up was 10 years. CHEK2 mutations were detected in 15.2% and BRAF^V600E mutations in 64.2% patients. Neither mutation was present in 31.4% cases and both BRAF^V600E and CHEK2 mutations coexisted in 10.8% patients. No significant differences in clinicopathological features, initial risk, treatment response, or disease outcome were detected among these patient groups. CHEK2 mutations were significantly associated with older age, while BRAF^V600E was significantly associated with older age and extrathyroidal extension. The coexistence of both mutations was not associated with more aggressive clinicopathological features of PTC, poorer treatment response, or disease outcome.

Clinical significance of the BRAFV600E mutation in PTC and its effect on radioiodine therapy

The goal of this study was to explore the relationship of the BRAFV600E mutation with clinicopathologic factors and evaluate the effect of radioactive iodine (RAI) therapy in a large group of intermediate- and high-risk papillary thyroid cancer (PTC) patients with the BRAFV600E mutation and without distant metastases. We collected data for PTC patients who underwent total or near-total thyroidectomy and RAI treatment in our hospital from January 2014-December 2017. There were 1220 PTC patients who met the criteria, and the BRAFV600E mutation was observed in 979 of them (80.2%). Multivariate analysis identified that the BRAFV600E mutation remained independently associated with age at diagnosis, and bilaterality (OR = 1.023, 95% CI = 1.012-1.039, P < 0.001; OR = 1.685, 95% CI = 1.213-2.341, P = 0.002, respectively). In addition, the patients with bilateral PTCs had a higher prevalence of extrathyroid invasion, capsular invasion and fusion of metastatic lymph nodes than the unilateral PTC patients. The response to RAI therapy was evaluated in both the entire series and the patients with a high recurrence risk; no significant difference was discerned between the BRAFV600E mutation and the wild-type groups (P = 0.237 and P = 0.498, respectively). To summarize, our results confirmed that PTC patients with the BRAFV600E mutation exhibit more aggressive characteristics. In addition, the patients with bilateral PTC have a higher incidence of extrathyroid invasion. Moreover, BRAFV600E mutation PTC patients did not show a poorer clinical response after postsurgical RAI therapy, suggesting that RAI therapy may improve the general clinical outcome of these patients.

BRAF V600E Status and Stimulated Thyroglobulin at Ablation Time Increase Prognostic Value of American Thyroid Association Classification Systems for Persistent Disease in Differentiated Thyroid Carcinoma

BACKGROUND

Stimulated thyroglobulin levels measured at the time of remnant ablation (A-hTg) and BRAFV600E mutation had shown prognostic value in predicting persistent disease in differentiated thyroid cancer (DTC). The aim of this study was to evaluate the prognostic role of A-hTg combined with the BRAFV600E status in association with the revised American Thyroid Association (ATA) risk stratification.

MATERIAL AND METHODS

620 patients treated for a DTC were included in this study with a median follow-up duration of 6.1 years. All patients underwent total thyroidectomy followed by radioiodine ablation. Patients with positive anti-thyroglobulin antibodies were excluded. The predictive value of A-hTg was calculated by receiver operating characteristic curve (ROC curve) analysis. The Cox proportional hazard regression model, including the BRAF status, A-hTg, and ATA classification system, was assessed to evaluate the existing persistent disease risk.

RESULTS

Taken together, the BRAF status and A-hTg levels improve the ATA risk classification in all categories. In particular, in the low-risk ATA classification, only the combination of BRAFV600E+A-hTg > 8.9ng/ml was associated with persistent disease (P = 0.001, HR 60.2, CI 95% 5.28-687). In the intermediate-risk ATA classification, BRAFWT+A-hTg > 8.9ng/ml was associated with persistent disease (P = 0.029, HR 2.71, CI 95% 1.106-6.670) and BRAFV600E+A-hTg > 8.9ng/ml was also associated with persistent disease (P < 0.001, HR 5.001, CI 95% 2.318-10.790). In the high-risk ATA classification, both BRAFV600E+A-hTg < 8.9ng/ml and BRAFV600E+A-hTg > 8.9 ng/ml were associated with persistent disease (P = 0.042, HR 5.963, CI 95% 1.069-33.255 and P = 0.002, HR 11.564, CI 95% 2.543-52.576, respectively).

CONCLUSIONS

The BRAF status and stimulated thyroglobulin levels at ablation time improve the ATA risk stratification of differentiated thyroid cancer; therefore, even A-hTg could be included in risk classification factors.

Are BRAF V600E and K-Ras Mutations Associated With Tumor Aggressiveness in Well-Differentiated Thyroid Cancer?

Aim:

Many clinical studies have shown an association between B-type rapidly growing fibrosarcoma kinase [BRAF(V600E)] mutation and aggressive clinicopathologic features, although some results from others are controversial. Besides, Kirsten rat sarcoma (K-Ras) mutations are more common in endemic iodine deficiency regions, as our country is. However, use of the biologic markers are questioned in clinical practice; they are beginning to be used for the management of patients with thyroid nodules and cancers. The aim of the present study was to evaluate the prevalence of the BRAF(V600E) mutation in tumor samples and its relationship to high-risk clinicopathologic features.

Methods:

From 2000 to 2007, 82 patients with well-differentiated thyroid cancer (WDTC) who underwent surgery in Ege University were enrolled retrospectively in the study. Univariate and multivariate analyses were performed to analyze associations between BRAF(V600E) and K-Ras mutations and clinicopathologic features. We identified 82 patients with WDTC (male:female = 1:3.2).

Results:

The median follow-up was 96 months. The mean age was 46.4 (16–80). None of the all analyzed prognostic factors—age; sex; lymph node metastasis; multifocality; multicentricity; invasion; tumor diameter; and tumor, node, metastasis staging—were correlated with BRAF(V600E) mutation status in the univariate analysis. Meanwhile, none of the analyzed prognostic factors were correlated with K-Ras mutation status.

Discussion:

Although many studies suggest BRAF(V600E) and K-Ras mutations as prognostic factors in WDTC, our results are controversial. BRAF(V600E) and K-Ras mutations have no significant effects on tumor aggressiveness in Turkish patients with WDTC. Our results underline that it is too early to reach a conclusion that BRAF(V600E) and K-Ras mutations are involved with poor clinical outcomes.

Risk factors for cervical lymph node metastasis in papillary thyroid microcarcinoma: a study of 1,587 patients

Objective

The purposes of this study were to identify risk factors for cervical lymph node metastasis and to examine the association between BRAF^V600E status and clinical features in papillary thyroid microcarcinoma (PTMC).

Methods

A total of 1,587 patients with PTMC, treated in Tianjin Medical University Cancer Institute and Hospital from January 2011 to March 2013, underwent retrospective analysis. We reviewed and analyzed factors including clinical results, pathology records, ultrasound results, and BRAF^V600E status.

Results

Multivariate logistic regression analyses demonstrated that gender (male) [odds ratio (OR) = 1.845, P = 0.000], age (< 45 years)(OR = 1.606,P = 0.000), tumor size (> 6 mm) (OR = 2.137,P = 0.000), bilateralism (OR = 2.011, P = 0.000) and extrathyroidal extension (OR = 1.555, P = 0.001) served as independent predictors of central lymph node metastasis (CLNM). Moreover, CLNM (OR = 29.354, P = 0.000) served as an independent predictor of lateral lymph node metastasis (LLNM). Among patients with a solitary primary tumor, those with tumor location in the lower third of the thyroid lobe or the isthmus were more likely to experience CLNM (P < 0.05). Univariate analyses indicated that CLNM, LLNM, extrathyroidal extension, and multifocality were not significantly associated with BRAF^V600E mutation.

Conclusions

The present study suggested that prophylactic neck dissection of the central compartment should be considered in patients with PTMC, particularly in men with tumor size greater than 6 mm, age less than 45 years, extrathyroidal extension, and tumor bilaterality. Among patients with PTMC, BRAF^V600E mutation is not significantly associated with prognostic factors. For a better understanding of surgical management of PTMC and the risk factors, we recommend multicenter research and long-term follow-up.

Lysyl Oxidase Is a Key Player in BRAF/MAPK Pathway-Driven Thyroid Cancer Aggressiveness

BACKGROUND

The BRAF^V600E mutation is the most common somatic mutation in thyroid cancer. The mechanism associated with BRAF-mutant tumor aggressiveness remains unclear. Lysyl oxidase (LOX) is highly expressed in aggressive thyroid cancers, and involved in cancer metastasis. The objective was to determine whether LOX mediates the effect of the activated MAPK pathway in thyroid cancer.

METHODS

The prognostic value of LOX and its association with mutated BRAF was analyzed in The Cancer Genome Atlas and an independent cohort. Inhibition of mutant BRAF and the MAPK pathway, and overexpression of mutant BRAF and mouse models of BRAF^V600E were used to test the effect on LOX expression.

RESULTS

In The Cancer Genome Atlas cohort, LOX expression was higher in BRAF-mutant tumors compared to wild-type tumors (p < 0.0001). Patients with BRAF-mutant tumors with high LOX expression had a shorter disease-free survival (p = 0.03) compared to patients with a BRAF mutation and the low LOX group. In the independent cohort, a significant positive correlation between LOX and percentage of BRAF mutated cells was found. The independent cohort confirmed high LOX expression to be associated with a shorter disease-free survival (p = 0.01). Inhibition of BRAF^V600E and MEK decreased LOX expression. Conversely, overexpression of mutant BRAF increased LOX expression. The mice with thyroid-specific expression of BRAF^V600E showed strong LOX and p-ERK expression in tumor tissue. Inhibition of BRAF^V600E in transgenic and orthotopic mouse models significantly reduced the tumor burden as well as LOX and p-ERK expression.

CONCLUSIONS

The data suggest that BRAF^V600E tumors with high LOX expression are associated with more aggressive disease. The biological underpinnings of the clinical findings were confirmed by showing that BRAF and the MAPK pathway regulate LOX expression.

Associations between Hashimoto Thyroiditis and Clinical Outcomes of Papillary Thyroid Cancer: A Meta-Analysis of Observational Studies

BACKGROUND

Epidemiological studies have suggested an association between Hashimoto thyroiditis (HT) and papillary thyroid cancer (PTC) development. Other studies, however, have reported a protective role of HT against PTC progression. Through this updated meta-analysis, we aimed to clarify the effects of HT on the progression of PTC.

METHODS

We searched citation databases, including PubMed and Embase, for relevant studies from inception to September 2017. From these studies, we calculated the pooled odds ratios (ORs) of clinicopathologic features and the relative risk (RR) of PTC recurrence with 95% confidence intervals (CIs) using the Mantel-Haenszel method. Additionally, the Higgins I² statistic was used to test for heterogeneity.

RESULTS

The meta-analysis included 71 published studies with 44,034 participants, among whom 11,132 had HT. We observed negative associations between PTC with comorbid HT and extrathyroidal extension (OR, 0.74; 95% CI, 0.68 to 0.81), lymph node metastasis (OR, 0.82; 95% CI, 0.72 to 0.94), distant metastasis (OR, 0.49; 95% CI, 0.32 to 0.76), and recurrence (RR, 0.50; 95% CI, 0.41 to 0.61).

CONCLUSION

In this meta-analysis, PTC patients with HT appeared to exhibit more favorable clinicopathologic characteristics and a better prognosis than those without HT.

The increasing prevalence of chronic lymphocytic thyroiditis in papillary microcarcinoma

Although the incidence of some malignancy has decreased over the recent years, this is not the case of papillary thyroid microcarcinoma (PTMC), whose incidence has increased worldwide. Most PTMC are found incidentally after histological examination of specimens from surgery for benign thyroid disease. Hashimoto's thyroiditis, whose incidence has also increased, coexists in about one in three PTMC patients. Three different mechanisms have been proposed to clarify the association between chronic lymphocytic thyroiditis and PTMC, namely tumor development/growth by: (i) TSH stimulation, (ii) expression of certain proto-oncogenes, (iii) chemokines and other molecules produced by the lymphocytic infiltrate. Whether Hashimoto's thyroiditis protects against lymph node metastasis is debated. Overall, autommune thyroiditis seems to contribute to the favorable prognosis of PTMC. Major limitations of the studies so far performed include: (i) retrospective design, (ii) limited statistical power, (iii) high risk of selection bias, (iv) and predominant Asian ethnicity of patients. Full genetic profiling of both diseases and identification of environmental factors capable to trigger them, as well as well-powered prospective studies on different ethnical groups, may help understand their causal association and why their frequencies are continuing raising.

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

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

Integrated analysis of long noncoding RNA interactions reveals the potential role in progression of human papillary thyroid cancer

Recent scientific evidence has suggested that long noncoding RNAs (lncRNAs) play an important part in tumorigenesis as an important member of competing endogenous RNAs (ceRNAs). Hundreds of RNA sequence data and relevant clinic information are freely accessible in The Cancer Genome Atlas (TCGA) datasets. However, the role of cancer‐related lncRNAs in papillary thyroid cancer (PTC) is not fully understood yet. In this study, we identified 461 RNA sequencing data from TCGA. Subsequently, 45 lncRNAs, 21 miRNAs, and 78 mRNAs were chosen to construct a ceRNA network of PTC. Then, we analyzed the correlation between these 45 PTC‐specific lncRNAs and clinic features and patient outcome. Thirty‐seven of these lncRNAs were found to be closely related to age, race, gender, lymph node metastasis, TNM staging system, and patient outcome. Additionally, three of them were linked to PTC patient overall survival. Eventually, we selected eight lncRNAs randomly and performed quantificational real‐time polymerase chain reaction (qRT‐PCR) in 28 newly diagnosed patients with PTC to verify the reliability of the above results. The results of qRT‐PCR are totally in agreement with the bioinformatics analysis. Additionally, it was found that HAND2‐AS1 was negatively related to tumor size (P < 0.05). The results were consistent with the bioinformatics analysis in TCGA. Taken together, we identified the differentially expressed lncRNAs and constructed a PTC ceRNA network. The study provides a new perspective and supplement for our understanding of lncRNAs in PTC development and reveals potential diagnostic and prognostic markers in PTC.

Targeted next-generation sequencing of cancer-related genes in thyroid carcinoma: A single institution's experience

Thyroid carcinoma (TC) has characteristic genetic alterations, including point mutations in proto-oncogenes and chromosomal rearrangements that vary by histologic subtype. Recent developments in next-generation sequencing (NGS) technology enable simultaneous analysis of cancer-associated genes of interest, thus improving diagnostic accuracy and allowing precise personalized treatment for human cancer. A total of 50 patients who underwent thyroidectomy between 2014 and 2016 at Hokuto Hospital were enrolled. Total DNA was extracted from formalin-fixed, paraffin-embedded tissue sections and quantified. Targeted regions of 24 cancer-associated genes were amplified by PCR, barcoded and sequenced using an Illumina MiSeq platform. Subjects included 30 patients with papillary carcinoma (PC), two with PC tall cell variant (TVPC), two with PC follicular variant (FVPC), eight with follicular carcinoma, seven with poorly differentiated carcinoma (PDC), and one with anaplastic carcinoma (AC). The BRAF V600E mutation was present in 25 of 30 (83%) patients with PC, 2 of 2 (100%) patients with TVPC, 6 of 7 (86%) patients of PDC, and one patient with AC. PIK3CA mutations were present in 3 of 30 (delPV104P, A1046T and C420R; 10%) patients with PC and 1 of 7 (H1047R; 14%) patients with PDC. The TP53 mutation was present in 1 of 30 (R306*; 3.3%) patients with PC and 1 of 7 (Q152*; 14%) patients with PDC. The NRAS mutation was present in 1 of 2 (Q61K, 50%) patients with FVPC. Statistical analysis showed that patients without the BRAF V600E mutation had advanced pathologic T and N stages compared with those with the mutation (P=0.047 and P=0.019, respectively). The BRAF V600E mutation was not correlated with overall and disease-free survival in patients with PC. A patient with PC with a mutation in EGFR (K852Q) and the PIK3CA mutation had an aggressive course with multiple bone and lung metastases. Detection of mutations in cancer-associated genes using NGS could enhance the understanding of the clinical behavior of TC.

Clinicopathological characteristics and prognosis of thyroid cancer in northwest China: A population-based retrospective study of 2490 patients

Background

The specific clinical features of thyroid cancer patients in northwest China are unclear; therefore, we analyzed the clinicopathological characteristics and prognosis of this population.

Methods

Clinical characteristics including age, gender, blood type, histological type, and BRAF^V600E gene mutation; and incidence; risk factors; surgical treatment; and prognosis were recorded.

Results

A total of 2490 thyroid cancer patients were included; 98% were diagnosed with papillary thyroid cancer (PTC). Weight, blood type, histological type, and BRAF^V600E gene mutation rates were significantly different. Pediatric thyroid cancer patients had higher lymph node metastasis, lower BRAF^V600E mutation, and 6.2–9.2% greater recurrence rates than adult patients. PTC and papillary thyroid microcarcinoma displayed similar features, while in other types, such as follicular and medullary thyroid cancer, there were variations. Multiple logistic analyses showed that age (odds ratio [OR] 0.957, 95% confidence interval [CI] 0.944–0.970; P < 0.001), focal status (OR 16.174, 95% CI 9.257–28.262; P < 0.001), pathology (OR 0.642, 95% CI 0.473–0.871; P = 0.004) and lymph node metastasis (OR 0.059, 95% CI 0.033–0.107; P < 0.001) were independent factors for BRAF^V600E mutation.

Conclusion

Most real world clinicopathological features, treatment, and prognosis of thyroid cancer are similar to reported data, such as the higher incidence of disease in women and the larger proportion of PTC. However, the results in pediatric patients and those with BRAF gene mutations are controversial and require more clinical incidence.

Prevalence of BRAFV600E Mutation in Follicular Variant of Papillary Thyroid Carcinoma and Non-Invasive Follicular Tumor with Papillary-Like Nuclear Features (NIFTP) in a BRAFV600E Prevalent Area

BACKGROUND

BRAF^V600E mutation status and prevalence of non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) has not yet been reported in Korea. The aim of this study was to investigate the significance of the BRAF^V600E mutation in the follicular variant of papillary thyroid carcinoma (FVPTC) and to determine the prevalence of NIFTP in BRAF^V600E mutation-prevalent Korean patients.

METHODS

This study retrospectively analyzed 1,417 consecutive patients who underwent total thyroidectomy with routine prophylactic central lymph node dissection for papillary thyroid carcinoma (PTC). BRAF^V600E mutation analysis was performed routinely using multiplex polymerase chain reaction by applying dual priming oligonucleotide. Clinicopathological characteristics and ultrasonographic findings were compared between BRAF^V600E mutation-positive and -negative groups for FVPTC. Pathologists reviewed the pathology slides according to consensus diagnostic criteria for the encapsulated FVPTC and NIFTP.

RESULTS

The prevalence of the BRAF^V600E mutation in all subtypes of PTC was 61.0% (861/1,411). FVPTC presented a BRAF^V600E mutation rate of 27.3%. The FVPTC patients with BRAF^V600E mutation were older than those with no BRAF^V600E mutation (P = 0.021). The prevalence of NIFTP was 0.18% among all PTC patients (2/1,411) and the proportion of NIFTP among FVPTC was 9.1% (2/22).

CONCLUSION

The BRAF^V600E mutation is prevalent in Korean patients with FVPTC in a region with high frequency of the BRAF^V600E mutation and very low prevalence of NIFTP compared with that reported in western studies.

Association between diffuse lymphocytic infiltration and papillary thyroid cancer aggressiveness according to the presence of thyroid peroxidase antibody and BRAFV600E mutation

BACKGROUND

Diffuse lymphocytic infiltration (DLI) is frequently found with papillary thyroid cancer (PTC), so there has been long interest in how it affects the characteristics of PTC. This purpose of this study was to define the association between DLI and PTC aggressiveness according to thyroperoxidase antibody (TPOAb) and B-type Raf (BRAF)^V600E mutation positivity.

METHODS

There were 1879 patients with PTC who underwent surgery and were enrolled in this study. Clinicopathologic characteristics were compared between groups according to the presence of DLI and TPOAb. Multiple logistic regression analysis was conducted to assess odds ratio (OR) for each dependent variable (BRAF^V600E mutation, tumor size >1.0 cm, multifocality, extrathyroidal extension, and lymph node metastasis) of each group according to the presence of DLI and TPOAb, with the group with neither DLI or TPOAb (DLI-negative TPOAb-negative PTC) as the reference.

RESULTS

The DLI-positive PTC showed more frequent multifocality and less frequent BRAF^V600E mutation than DLI-negative PTC. Among patients with DLI-positive PTC, extrathyroidal extension and BRAF^V600E mutation was less frequent when serum TPOAb was positive. In multiple logistic regressions, DLI-positive TPOAb-positive PTC showed a high OR for multifocality (1.410; P = .017), but low ORs for BRAF^V600E mutation (0.521; P < .001) and extrathyroidal extension (0.691; P = .008). The patients with DLI-positive TPOAb-positive PTCs showed a high OR for multifocality (1.588; P = .002), and high ORs for tumor size >1.0 cm (2.205; P = .019) and lymph node metastasis (2.005; P = .032) in subgroup analyses of PTC with wild-type BRAF. The DLI-negative TPOAb-positive group was not associated with any tumor aggressiveness-related variables.

CONCLUSION

Although DLI was associated with multifocality regardless of TPOAb positivity, it was associated with an indolent feature when TPOAb was positive but with aggressive features in PTC with wild-type BRAF when TPOAb was negative. The TPOAb and BRAF status may help to define the clinical implication of lymphocytic infiltration found with PTC.

Clinical implications of the BRAF mutation in papillary thyroid carcinoma and chronic lymphocytic thyroiditis

Background

The purpose of this study was to examine the possible prognostics and clinicopathologic characteristics underlying the BRAFV600E mutation and papillary thyroid carcinoma (PTC) coexisting or in absence of chronic lymphocytic thyroiditis (CLT).

Methods

This study was conducted on 172 patients who had undergone total thyroidectomy or unilateral total thyroidectomy for PTC; the patients were then examined for the BRAFV600E mutation using specimens obtained after their surgery from January 2013 to August 2015.

Results

BRAF mutations were found in 130 of 172 patients (75.6%). CLT was present in 27.9% of patients (48/172). The incidence of the BRAFV600E mutation was significantly increased in the group with no CLT (P = 0.001). The findings of the multivariate analysis pertaining to the coexistence of CLT and PTC showed no significant correlation other than the BRAFV600E mutation. No significant difference was noted in the clinicopathologic factors between the two groups based on the coexistence of CLT in univariate and multivariate analyses.

Conclusions

The BRAFV600E mutation is less frequent in PTC coexisting with CLT presumably because CLT and the BRAFV600E mutation operate independently in the formation and progression of thyroid cancer.

Molecular alterations of coexisting thyroid papillary carcinoma and anaplastic carcinoma: identification of TERT mutation as an independent risk factor for transformation

Thyroid papillary carcinoma is the most common endocrine neoplasm and generally carries a favorable prognosis. However, a small subset of papillary carcinomas transforms into anaplastic carcinoma, an undifferentiated cancer with a dismal prognosis. Recent studies using next-generation sequencing revealed the genomic landscape of papillary carcinoma and anaplastic carcinoma. However, risk factors for anaplastic transformation in papillary carcinoma remain obscure. In the present study, we investigated molecular alterations of papillary carcinoma and anaplastic carcinoma components in 27 tumors in which anaplastic carcinoma coexisted with antecedent papillary carcinoma. We conducted direct sequencing for BRAF, TERT promoter and PIK3CA, and immunohistochemistry for p53, TTF-1 and subunits of the SWI/SNF complex (ARID1A, ARID1B, ATRX, SMARCA2, SMARCA4, SMARCB1, and PBRM1). BRAF^V600E and TERT promoter mutated at the rate of 90% and 95%, respectively, and these mutational statuses were almost identical between the papillary carcinoma and anaplastic carcinoma components. PIK3CA mutation was positive in 33% of our samples with a heterogeneous mutation pattern of the papillary carcinoma and anaplastic carcinoma components. Aberrant expression of p53 and loss of TTF-1 were present in 63 and 59%, respectively, and these two alterations were confined to the anaplastic carcinoma components. There was a loss of the SWI/SNF complex in a subset of the tumors with a heterogeneous pattern of the papillary carcinoma and anaplastic carcinoma components: SMARCA4 in 4% and PBRM1 in 4%. In a multivariate comparison between the antecedent papillary carcinoma components and control papillary carcinomas without anaplastic transformation, TERT promoter mutation was independently associated with anaplastic transformation. Collectively, papillary carcinoma-derived anaplastic carcinomas are characterized by BRAF and TERT promoter mutations, and these mutations occur prior to anaplastic transformation. Alterations of PIK3CA and the SWI/SNF complex are relatively rare and temporally heterogeneous. Of note, a papillary carcinoma harboring TERT promoter mutation is at higher risk for anaplastic transformation.

Signaling Pathways in Thyroid Cancer

The morbidity of thyroid cancer is increasing gradually year by year, showing an increasing tendency in nationality, sex, age, tumor size, and tumor staging. The changes of thyroid cell genes, signaling pathways, and related molecular dysfunction promote the occurrence, development, invasion, and metastasis of thyroid cancer. Surgical operation, radioiodine, and endocrinotherapy models can achieve a better prognosis for most patients with thyroid cancer. Although targeted therapeutic drugs bring possible therapeutic opportunities for refractory thyroid cancer, there is a great gap between their predictive value and their actual efficacy. Currently, there is still no completely effective drug for the treatment. Based on the signaling pathways, the "reclaim therapy" for residual tumor and systemic intervention aims to increase anticancer ability and to encourage new directions and thoughts in the treatment of refractory thyroid cancer.

The Flip Side of NIFTP: an Increase in Rates of Unfavorable Histologic Parameters in the Remainder of Papillary Thyroid Carcinomas

The term noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was recently proposed to replace noninvasive follicular variant of papillary thyroid carcinoma (FVPTC) both to promote more conservative management of these tumors and spare patients the psychological burden of a cancer diagnosis. This reclassification will lower the incidence of papillary thyroid carcinoma (PTC). In addition, it could result in an increase in the rates of unfavorable histologic prognosticators for PTC overall because NIFTPs had previously accounted for many of the PTCs without these features. Our aim was to evaluate the potential impact of the reclassification of NIFTP on the rates of extrathyroidal extension, lymphovascular invasion, and lymph node metastases in PTC. We identified all PTCs clinically over 1 cm diagnosed on surgical resection between August 2010 and August 2012. The histopathologic characteristics, including PTC subtype, tumor size, presence of extrathyroidal extension and lymphovascular invasion, and surgical margin and lymph node status were all recorded. Based on these parameters, cases were classified according to the American Thyroid Association (ATA) risk stratification system for structural disease recurrence. Tumor slides for cases initially diagnosed as FVPTC were reviewed to identify tumors that would now be classified as NIFTPs. Our cohort included 348 cases of PTC, of which 94 (27%) would now be classified as NIFTPs. After excluding NIFTPs from the PTC category, there were increased rates of extrathyroidal extension (26% up from 19%, p = 0.046), lymphovascular invasion (37% up from 27%, p = 0.0099), and lymph node metastases (26% up from 19%, p = 0.045) among the remaining PTCs. Based on these changes in histologic features, 10% fewer cases were defined as ATA low risk (62% down from 72%, p = 0.0081). Our results indicate that the downgrading of some carcinomas to NIFTP will increase the rates of higher risk histologic parameters in the remaining PTCs by statistically significant margins. Although the overall survival for PTC is very high and would likely not be changed significantly by the introduction of NIFTP, additional studies evaluating the impact of the NIFTP shift are warranted.

Frequent BRAF V600E and Absence of TERT Promoter Mutations Characterize Sporadic Pediatric Papillary Thyroid Carcinomas in Japan

Pediatric papillary thyroid carcinoma (PTC) has unique features but requires further genetic investigation. Moreover, there has been increasing concern about the risk for pediatric PTC in Japan after the Fukushima accident. This study aims to evaluate the frequencies of BRAF and TERT promoter mutations and to examine their significance in non-radiation-associated pediatric PTCs in Japan. We enrolled 81 pediatric PTC patients aged ≤20 years. The control group included 91 adult PTCs from patients >20 years old. BRAF and TERT mutations were analyzed by allele-specific-PCR and/or Sanger sequencing. Compared with adult PTCs, pediatric PTCs exhibited larger tumor size, more frequent lymph node metastasis, and less classical histology. The prevalence of BRAF ^V600E in pediatric PTCs was 54% and significantly lower than that in adults of 85%. In the pediatric PTCs, BRAF ^V600E was positively associated with older age, classical histology, and the lymph node metastasis but independent from other clinicopathological factors. TERT mutations were identified in 13% of adults and in none of the pediatric PTCs. In conclusion, pediatric PTCs are characterized by more advanced clinicopathological features, lower BRAF ^V600E frequency, and absence of TERT mutation. The BRAF ^V600E frequency in this study is similar to the reported BRAF ^V600E frequency in the ultrasonographically screened pediatric PTCs in Fukushima.

The Genetics of Papillary Microcarcinomas of the Thyroid: Diagnostic and Prognostic Implications

Papillary microcarcinoma of the thyroid (mPTC) is defined by the WHO as a papillary thy-roid cancer measuring 10mm or less in diameter and it is nowadays a topic of intense debate among the members of the medical community due to its apparent “epidemic” rise. Although these tumors follow almost always an indolent clinical course and carry an excellent prognosis, it is known that a small sub-set may display a potentially aggressive behavior. Nevertheless, we still lack an accurate way of predict-ing those which will cause significant disease. In an attempt to address this problem, a number of clini-co-pathologic features have been studied as poor prognostic markers in mPTC, and their association with known genetic alterations in thyroid cancer has been evaluated. Herein we review the present knowledge concerning mPTC’s genetic profile, namely the prevalence of BRAF (V600E), RAS and TERT promoter mutations and RET/PTC and PAX8-PPARG rearrangements and report the results of the evaluation in the putative prognostic value of these genetic alterations in mPTC.

Prognostic significance of diffuse sclerosing variant papillary thyroid carcinoma: a systematic review and meta-analysis

OBJECTIVE

Diffuse sclerosing variant papillary thyroid carcinoma (DSVPTC) is an uncommon variant of papillary thyroid carcinoma (PTC). The biological behaviors and prognostic outcomes of this variant, however, are still controversial. The aim of this systematic review and meta-analysis is to investigate the prognostic significance and outcomes of DSVPTCs in comparison with classical PTCs (cPTCs).

METHODS

An electronic search was performed in five libraries: PubMed, Scopus, ISI, World Health Organization Global Health Library (WHO GHL) and Virtual Health Library (VHL) in June 2016. Published data were extracted and were pooled into odds ratios (OR), mean differences and corresponding 95% confidence intervals (CI) using random-effect model. Publication bias was analyzed using Egger's regression test and funnel plot observation.

RESULTS

From 315 articles, we included 16 articles comprising 732 DSVPTCs for meta-analysis. Overall, DSVPTC manifested more aggressive clinicopathological behaviors than cPTC such as higher rate of vascular invasion (OR: 5.33; 95% CI: 3.08-9.23), extrathyroidal extension (OR: 2.96; 95% CI: 2.04-4.30), lymph node metastasis (OR: 5.40; 95% CI: 2.82-10.35), distant metastasis (OR: 3.61; 95% CI: 1.89-6.88) and were more likely to relapse (OR: 2.83; 95% CI: 1.59-5.05). DSVPTC patients were associated with a worsened overall survival (HR: 1.89; 95% CI: 1.36-2.62).

CONCLUSION

DSVPTCs should be considered high-risk PTCs because of high propensity for tumor invasion, metastasis, relapse and mortality. Aggressiveness of DSVPTCs might be related to a different molecular pathway than that in cPTCs.