Differential Clinicopathological Risk and Prognosis of Major Papillary Thyroid Cancer Variants

Revolutionary multi-omics analysis revealing prognostic signature of thyroid cancer and subsequent in vitro validation of SNAI1 in mediating thyroid cancer progression through EMT

Thyroid carcinoma (TC), the most commonly diagnosed malignancy of the endocrine system, has witnessed a significant rise in incidence over the past few decades. The integration of scRNA-seq with other sequencing approaches offers researchers a distinct perspective to explore mechanisms underlying TC progression. Therefore, it is crucial to develop a prognostic model for TC patients by utilizing a multi-omics approach. We acquired and processed transcriptomic data from the TCGA-THCA dataset, including mRNA expression profiles, lncRNA expression profiles, miRNA expression profiles, methylation chip data, gene mutation data, and clinical data. We constructed a tumor-related risk model using machine learning methods and developed a consensus machine learning-driven signature (CMLS) for accurate and stable prediction of TC patient outcomes. 2 strains of undifferentiated TC cell lines and 1 strain of PTC cell line were utilized for in vitro validation. mRNA, protein levels of hub genes, epithelial-mesenchymal transition (EMT)-associated phenotypes were detected by a series of in vitro experiments. We identified 3 molecular subtypes of TC based on integrated multi-omics clustering algorithms, which were associated with overall survival and displayed distinct molecular features. We developed a CMLS based on 28 hub genes to predict patient outcomes, and demonstrated that CMLS outperformed other prognostic models. TC patients of relatively lower CMLS score had significantly higher levels of T cells, B cells, and macrophages, indicating an immune-activated state. Fibroblasts were predominantly enriched in the high CMLS group, along with markers associated with immune suppression and evasion. We identified several drugs that could be suitable for patients with high CMLS, including Staurosporine_1034, Rapamycin_1084, gemcitabine, and topotecan. SNAI1 was elevated in both undifferentiated TC cell lines, comparing to PTC cells. Knockdown of SNAI1 reduced the cell proliferation and EMT phenotypes of undifferentiated TC cells. Our findings highlight the importance of multi-omics analysis in understanding the molecular subtypes and immune characteristics of TC, and provide a novel prognostic model and potential therapeutic targets for this disease. Moreover, we identified SNAI1 in mediating TC progression through EMT in vitro.

Prediction of classical versus non classical papillary thyroid carcinoma subtypes from cytology of nodules classified according to TIRADS

PURPOSE

Our purposes were: 1) to estimate the prediction performance (PP) of cytology in identifying papillary thyroid carcinoma (PTC) subtypes; 2) to explore how the PTC subtypes distribute among the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) categories.

METHODS

Nodules were included if both the histology with the PTC subtype report and the cytology report with the possible PTC subtype were available. The PP was calculated by making the proportion of True positives/False positives+false negatives.

RESULTS

309 cytologically "suspicious for malignancy" and "malignant" thyroid nodules with PTC histology were evaluated. ACR TI-RADS categorization for classical PTC was significantly different from non-classical PTC (p-value 0.02). For the whole cohort the PP of cytologically classical cases was 0.74, while that of cytologically non classical cases was 0.41. ACR TI-RADS categorization was not significantly different for aggressive vs non-aggressive PTC subtypes (p-value 0.1). When considering only aggressive or non-aggressive PTC subtypes, the PP of cytologically classical cases was respectively 0.86 and 0.87, while that of cytologically non classical cases was respectively 0.27 and 0.22. The PP of cytologically classical cases was 0.73 and 0.79, respectively for macroPTCs and microPTCs, while that of cytologically non classical cases was 0.55 and 0.33, respectively for macroPTCs and microPTCs.

CONCLUSION

Cytology examination reliably performed in predicting classical PTC versus non classical PTC subtypes. ACR TI-RADS categorization was significantly different among classical PTC versus non classical PTC subtypes.

Recurrent Middle Eastern Differentiated Thyroid Carcinoma Has Worse Outcomes Than Persistent Disease

Background: Despite the excellent prognosis of differentiated thyroid carcinoma (DTC), recurrent and persistent disease remain major challenges. Emerging studies to differentiate between recurrent and persistent disease are controversial, with studies from the Middle East lacking. Methods: We retrospectively analyzed 1691 patients who underwent surgery ± I131 treatment for DTC, with a median age of 38.7 years and median follow-up of 95.3 months. Results: We found a similar prevalence rate for persistent and recurrent disease (17.7% vs. 17.9%) in Middle Eastern DTC patients. Relative to patients with persistent disease, patients with recurrent disease were significantly older (median age: 36.1 vs. 45.8 years; p < 0.0001) and were more likely to have ATA high-risk tumors (61.5% vs. 75.2%; p = 0.0003). On multivariate logistic regression analysis, both T and N status were independent predictors for recurrent as well as structural persistent disease. However, older age, bilaterality and extrathyroidal extension were independent predictors of recurrent disease alone. In addition, patients with recurrent disease had significantly worse cancer-specific survival (p < 0.0001), which remained significant in multivariate analysis. Conclusions: Although persistent and recurrent disease in Middle Eastern DTC have similar frequencies, recurrent disease has worse outcomes compared to persistent disease. Hence, differentiating recurrence from persistence has great potential clinical relevance for therapeutic and follow-up approaches, contributing to improving the outcomes of DTC patients of Middle Eastern ethnicity.

Expression and prognosis analysis of integrin subunit α3 (ITGA3) in papillary thyroid cancer

Integrin subunit α3 (ITGA3) is a member of the integrin family and interacts with extracellular matrix proteins. However, there have been few reports regarding the role of ITGA3 in papillary thyroid cancer. The expression levels of ITGA3 were firstly analyzed by bioinformatics tools and in vitro experiments, followed by evaluating its prognostic significance in papillary thyroid cancer patients using Kaplan-Meier, receiver operating characteristic, and Cox regression analyses. Then, cBioportal and GSCA databases were applied to evaluate genetic alterations of ITGA3. Functional enrichment analysis was conducted and the upstream miRNAs of ITGA3 were determined. The results showed that the ITGA3 mRNA and protein levels were higher in the papillary thyroid cancer group than those in the normal group (all P < 0.05). Moreover, ITGA3 performed well in distinguishing the recurrence-free survival (RFS) status and served as an independent prognostic factor of papillary thyroid cancer patients (P < 0.01). Besides, significant relations between ITGA3 and genetic alterations were observed (FDR <0.01). Functional enrichment analysis indicated ECM-receptor interaction and cell adhesion molecules were the shared regulatory pathways. Moreover, ITGA3 might be the target gene of hsa-miR-3129, hsa-miR-181d, hsa-miR-181b, hsa-miR-199a, and hsa-miR-199b. Of note, the ITGA3 mRNA level was reduced after has-miR-199b-3p/5p was overexpressed. In conclusion, ITGA3 could be a reliable biomarker and have potential value in predicting the RFS status of papillary thyroid cancer patients.

The U-Shaped association between age and distant metastasis in patients with papillary thyroid carcinoma

PURPOSE

To investigate the association between age distribution and synchronous distant metastasis of papillary thyroid carcinoma.

METHOD

Patients with PTC who were treated from January 2013 to December 2018 at a single institute in a cancer referral center in China were retrospectively reviewed. A logistic regression model with restricted cubic splines (RCS) was used to examine the association between age at diagnosis and synchronous distant metastasis.

RESULTS

A total of 111 patients (0.7%) were diagnosed with distant metastasis. The logistic regression model with RCS revealed a "U-shape" association between age and distant metastasis. The RCS curve suggested a U-shaped pattern. The multivariable regression analysis showed that patients in the age groups ≤21 years (OR 2.33, 95% CI 1.09-4.68, P = 0.022) and >55 years (OR 3.32, 95% CI 1.99-5.46, P < 0.001) had a significantly higher incidence of distant metastasis than patients in the age group of 22 to 55 years.

CONCLUSIONS

A U-shaped association was observed between age at diagnosis and synchronous distant metastasis in papillary thyroid carcinoma patients.

MicroRNA Expression Profiling-Potential Molecular Discrimination of Papillary Thyroid Carcinoma Subtypes

Recent research has revealed the importance of miRNAs in the diagnosis and clinical evolution of papillary thyroid cancer (PTC). We aim to identify a specific miRNA profile that could differentiate between specific subtypes of PTC.

METHODS

In this cross-sectional study, total RNA was extracted from paraffin-embedded tissues of 43 patients, 17 with an infiltrative follicular variant of PTC (iFVPTC) and 26 with a conventional variant of PTC (cPTC). Nine miRNAs were evaluated using qRT-PCR technology and specific miRNA assays.

RESULTS

We found specific patterns for cPTC and iFVPTC, such as miRNA altered in both types of tumours (miR-146b-5p, miR-181a-5p, miR-221-3p, miR-21-5p and miR-222-3p) and two miRNAs significantly expressed only in cPTC (miR-20b-5p, miR-21-5p). The iFVPTC group presented strong and moderate correlations between miRNA expression and clinical data. miR-221-3p, miR-195-5p, miR-181-5p, miR-146b-5p and miR-222 were correlated with age, tumour size (TS) or lymph node metastases (N), while only miR-20b-5p, miR-195-5p and miR-181-5p were correlated with TS, N and age in the cPTC group.

CONCLUSIONS

The present study allowed the identification of a signature of two miRNAs to confirm miRNA differences between the two histological subtypes of TC. Our results provide advances in the molecular diagnosis of TC and could help to improve the diagnostic performance of already existing molecular classifiers.

Cytological and Ultrasound Features of Thyroid Nodules Correlate With Histotypes and Variants of Thyroid Carcinoma

CONTEXT

Prognosis is excellent for papillary thyroid carcinoma (PTC), noninvasive follicular thyroid neoplasia with papillary-like nuclear features (NIFT-P), and follicular thyroid carcinoma (FTC) but is poor for poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC). Among PTCs, the prognosis is more favorable for follicular (FV-PTC) and classic (CV-PTC) than for tall cell (TCV-PTC), and solid (SV-PTC) variants.

OBJECTIVE

To associate histotypes and variants of thyroid carcinoma with ultrasound and cytological features.

METHODS

Histology of 1018 benign tumors and 514 PTC (249 CV, 167 FV, 49 TC, 34 SV, and 15 other variants), 52 NIFT-P, 50 FTC, 11 PDTC, and 3 ATC was correlated with fine-needle aspiration biopsy categories (Italian classification: TIR1, TIR2, TIR3A, TIR3B, TIR4, and TIR5) and ultrasound features at the Endocrinology Unit, University Hospital of Pisa. In total, 1117 patients with thyroid nodule(s) who underwent thyroidectomy were included.

RESULTS

Of PTC, 36.3% had indeterminate cytology (TIR3A or TIR3B), 56.6% were suspicious for malignancy or malignant (TIR4 or TIR5); 84.0% FTC and 69.3% NIFT-P were TIR3A or TIR3B; 72.5% FV-PTC and 73.6% SV-PTC were TIR3A or TIR3B; 79.9% CV-PTC and 95.9% TCV-PTC were TIR4 or TIR5. The association of a hypoechoic pattern, irregular margins, and no microcalcifications was more frequent in TCV-PTC than in CV-PTC (P = .02, positive predictive value = 38.9%; negative predictive value = 85.5%).

CONCLUSION

At cytology, most FTC, NIFT-P, FV-PTC, and SV-PTC were indeterminate, most CV-PTC and TCV-PTC were suspicious for malignancy or malignant. Ultrasound can be helpful in ruling out TCV-PTC.

New biomarkers: prospect for diagnosis and monitoring of thyroid disease

After the metabolic syndrome and its components, thyroid disorders represent the most common endocrine disorders, with increasing prevalence in the last two decades. Thyroid dysfunctions are distinguished by hyperthyroidism, hypothyroidism, or inflammation (thyroiditis) of the thyroid gland, in addition to the presence of thyroid nodules that can be benign or malignant. Thyroid cancer is typically detected via an ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) and cytological examination of the specimen. This approach has significant limitations due to the small sample size and inability to characterize follicular lesions adequately. Due to the rapid advancement of high-throughput molecular biology techniques, it is now possible to identify new biomarkers for thyroid neoplasms that can supplement traditional imaging modalities in postoperative surveillance and aid in the preoperative cytology examination of indeterminate or follicular lesions. Here, we review current knowledge regarding biomarkers that have been reliable in detecting thyroid neoplasms, making them valuable tools for assessing the efficacy of surgical procedures or adjunctive treatment after surgery. We are particularly interested in providing an up-to-date and systematic review of emerging biomarkers, such as mRNA and non-coding RNAs, that can potentially detect thyroid neoplasms in clinical settings. We discuss evidence for miRNA, lncRNA and circRNA dysregulation in several thyroid neoplasms and assess their potential for use as diagnostic and prognostic biomarkers.

Parotid Metastasis in a Case of Papillary Thyroid Carcinoma: Case Report and Review of Literature

Papillary thyroid carcinoma (PTC) is the most common differentiated thyroid neoplasm. Common sites of regional and distant metastasis includes lymph nodes, lungs and bone. 51 year old female patient who was a known case of PTC with a history of multiple surgeries, radioactive iodine therapy (RAI) and oral chemotherapy presented with a painful right parotid mass. PET scan demonstrated FDG avid lesions in the right parotid gland, cervical lymph nodes and other distant sites. Cytology report showed features of metastatic PTC. Patient underwent extended total parotidectomy with facial nerve resection, skin and masseter muscle resection and extended radical neck dissection. Final histopathology (HPE) report showed metastatic papillary carcinoma thyroid. Patient is currently on oral chemotherapy and on regular follow up. PTC rarely metastasizes to parotid gland and such cases have to be treated with surgery alone or with a combination of surgery and RAI based on tumour burden.

Histological Variants of Papillary Thyroid Cancer in Relation to Clinical and Morphological Parameters and Prognosis

The correlation of histological features of papillary thyroid cancer with clinical and morphological prognostic factors and cause-specific mortality was analyzed in a case-control study within a cohort of patients from the Altai Regional Oncology Center (25 cases with lethal outcome and 64 follow-up controls). Significant variability was revealed in the histological structure of papillary thyroid cancer with the prevalence of classic (62%) and less frequent follicular (19%), tall cell (8%), and solid (7%) variants. In comparison with the classic variant, the solid variant was more often associated with male sex and large tumor size; follicular and tall cell variant was associated with more frequent metastases to regional lymph nodes; follicular and solid variants were associated with an increased proportion of cases with disease stages III-IV. The main differences reflecting the effect of histological factor on the disease outcome were associated with the solid variant of papillary thyroid cancer that was detected in 21% of lethal cases and only in 2% of control subjects. The detection of this variant can be of importance as an additional prognostic factor of the postoperative survival in papillary thyroid cancer.

Papillary Thyroid Carcinomas with Tall Cell Features: An Intermediate Entity between Classic and Tall Cell Subtypes

BACKGROUND While the diagnosis of papillary thyroid carcinomas with tall cell features (PTCtcf) is often made for carcinomas with histologic features intermediate between classic and tall cell subtypes of PTC (tcPTC), its comparative signature to that of either tcPTC or classic PTC is less clear. The objective of this study was to perform an integrative clinicopathologic and genomic analysis elucidating the spectrum of tcPTC, PTCtcf and classic PTC. METHODS We analyzed all consecutive patients with tcPTC and PTCtcf evaluated at a tertiary academic referral center between 2005-2020, as well as a comparative cohort of classic PTC, in a retrospective observational cohort analysis. Clinicopathological data were compared among the three groups, including progression-free survival (PFS), recurrent/persistent disease, and a negative composite outcome of death, progression, or need for advanced therapy. To specifically understand differences between tcPTC and PTCtcf, targeted next-generation sequencing (NGS) was performed in a subset of these cohorts. RESULTS A total of 292 patients were analyzed (81 tcPTC, 65 PTCtcf, 146 classic PTC). Thirteen percent tcPTC vs. 8% PTCtcf vs. 1% classic PTC had advanced AJCC stage (p=0.002). Similarly, macroscopic extrathyroidal extension was observed in 38% of tcPTC, 14% of PTCtcf and 12% of classic PTC (p<0.001). The 5-year PFS was 76.5%, 81.5% and 88.3% for tcPTC, PTCtcf and classic PTC, respectively, while the rates of the negative composite outcome 40.2% for tcPTC, 20.7% for PTCtcf and 11.2% for classic PTC (p<0.001). In a multivariable Cox regression analysis, the negative composite outcome was independently associated with tcPTC [HR 4.3 95% CI (1.1-16.1), p=0.03]. tcPTC demonstrated substantially more hotspot TERT promoter mutations than PTCtcf (44% vs. 6%, p=0.012). CONCLUSIONS Our study demonstrates a continuum of disease-specific risk of PTC, pointing at PTCtcf as an intermediate entity between tcPTC and classic PTC. These data provide a more refined understanding of risk at time of presentation, while better elucidating the diversity of genomic drivers.

The Presence of Typical "BRAFV600E-Like" Atypia in Papillary Thyroid Carcinoma is Highly Specific for the Presence of the BRAFV600E Mutation

Papillary thyroid carcinomas (PTCs) are driven by a variety of molecular abnormalities including BRAF, RAS, ALK, RET, and NTRK alterations. PTCs driven by the BRAFV600E mutation, or tumours which demonstrate a similar gene expression profile to PTCs driven by this mutation, have been reported to demonstrate specific morphological features sometimes termed "BRAFV600E-like" atypia. BRAFV600E-like atypia is characterised by a well-developed papillary architecture, infiltrative growth, marked nuclear clearing, prominent intranuclear pseudoinclusions, abundant eosinophilic cytoplasm, and scattered psammoma bodies. We sought to investigate the sensitivity and specificity of these morphological features for the presence of BRAFV600E mutation in PTCs as determined by mutation specific immunohistochemistry. An unselected cohort of 495 PTCs was reviewed by a single pathologist and categorised into three groups: typical BRAFV600E-like atypia (145 cases, 29%), possible BRAFV600E-like atypia (166 cases, 33%) and little/no BRAFV600E-like atypia (184 cases, 37%). The specificity and sensitivity of typical BRAFV600E-like atypia for the BRAFV600E mutation was 97.2% and 44.3%, respectively. When typical and possible BRAFV600E-like atypia were analysed together, the specificity was 70.6% and the sensitivity was 81.7%. In the morphologically little/no BRAFV600E-like atypia group, 58 cases (31.5%) had a BRAFV600E mutation. We conclude that typical BRAFV600E-like atypia is highly specific for the presence of the BRAFV600E mutation; however, the absence of BRAFV600E-like atypia does not exclude this mutation.

Brain metastases of papillary thyroid carcinoma origin are derived from aggressive histologic variants and demonstrate similar adverse morphology in the metastatic lesion

BACKGROUND

Distant metastases of papillary thyroid carcinoma are exceedingly rare. We analyzed all cases of brain metastases of papillary thyroid cancer at our institution and performed a literature review over the past ten years to identify histologic and molecular features of primary and metastatic tumors.

METHODS

Following institutional review board approval, the entire pathology archives at our institution were searched for cases of papillary thyroid carcinoma metastatic to brain. Patient demographics, histologic features of both primary and metastatic tumors, molecular information, and clinical outcomes were investigated.

RESULTS

We identified 8 cases of metastatic papillary thyroid carcinoma to brain. The average age at time of diagnosis of metastases was 56.3 years (range: 30-85). Average time from diagnosis of primary thyroid cancer to brain metastasis was 9.3 years (range: 0-24 years). All primary thyroid carcinomas demonstrated aggressive sub-types which were correspondingly seen in brain metastases. Next-generation sequencing revealed the most common mutations were identified in BRAFV600E, NRAS, and AKT1 with one tumor harboring a TERT promoter mutation. Six out of eight patients were deceased at the time of study with an average survival time of 2.3 years (range: 0.17-7 years) following diagnosis of brain metastasis.

CONCLUSIONS

Based on our study, it is highly unlikely that a low-risk variant of papillary thyroid carcinoma will metastasize to the brain. Therefore, careful and accurate reporting of the papillary thyroid carcinoma subtype in primary thyroid tumors is warranted. Certain molecular signatures are associated with more aggressive behavior and worse patient outcomes and next-generation sequencing should be performed on metastatic lesions.

Bilateral multifocality is an independent predictor of patients' outcome in Middle Eastern papillary thyroid carcinoma

Background

Tumor multifocality is frequently seen in Papillary thyroid carcinoma (PTC). However, few studies have analysed the impact of bilateral multifocality in PTC. The incidence of bilateral multifocality, its clinico-pathological associations and prognostic impact in PTC from Middle Eastern ethnicity remains unestablished.

Methods

We retrospectively evaluated 1283 patients who underwent total thyroidectomy for PTC. Bilateral and unilateral multifocality were decided based on the final pathology result. Primary outcome was recurrence free survival (RFS). Risk factors for bilateral multifocality were analyzed by multivariate logistic regression analysis.

Results

Multifocal PTC was found in 54.3% (697/1283) of patients. Among the 697 multifocal PTCs, 210 patients (30.1%) had unilateral multifocal PTC and 487 patients (69.9%) had bilateral multifocality. Bilateral multifocality was significantly associated with older age at diagnosis (p = 0.0263), male gender (p = 0.0201), gross extrathyroidal extension (p = 0.0332), larger primary tumor size (>4cm; p = 0.0002), lateral lymph node metastasis (p = 0.0008), distant metastasis at diagnosis (p = 0.0195) and recurrence (p = 0.0001). Bilateral multifocality was also found to be an independent predictor of RFS (Hazard ratio = 1.60; 95% Confidence Interval = 1.05 - 2.55; p = 0.0300). Multivariate logistic regression analysis demonstrated tumor diameter >4cm to be the only independent risk factors for bilaterality in multifocal PTC (Odds ratio = 1.86; 95% Confidence Interval = 1.13 - 3.07; p = 0.0155).

Conclusions

Incidence of bilateral multifocality is high in Middle Eastern PTC. Tumor diameter >4cm can be considered as a predictive factor for bilateral multifocal PTC. Bilateral multifocality appears to be an important prognostic factor for PTC and an independent predictor of RFS. Therefore, patients with bilateral multifocal PTC may benefit from more frequent follow-up to identify recurrences earlier.

Molecular and clinical features of papillary thyroid cancer in adult patients with a non-classical phenotype

Purpose

Genotyping is fundamental in papillary thyroid cancer (PTC) and helps to enhance diagnosis and prognosis and determine appropriate treatments. The phenotype-genotype association in PTC was previously studied, with BRAF V600E characterizing classic PTC and tall-cell PTC and RAS mutations characterizing follicular-variant PTC. In clinic, some non-classical histological subtypes of PTC were also identified, however, their genotype remains unclear. In this study, we collected samples of these non-classical PTC after the exclusion of classic phenotypes and examined their phenotypes, genotype and the relationship between phenotype and genotype.

Methods

We screened out non-classical PTC by excluding classical PTC from 1,059 different thyroid samples, and a total of 24 cases was obtained and described from the morphological features, which is rare in differentiated PTC. DNA/RNA sequencing was performed using 18 available samples to describe the genetic features.

Results

PTC with the non-classical phenotype were characterized cuboidal to low columnar tumor cells with subtle nuclear features of PTC and without discernible nuclear elongation, concurrently with dense microfollicles, delicate papillae or solid nodules with delicate fibrovascular cores. They were associated with lymphatic vessel invasion (P<0.001) but not with a worse prognosis (P=0.791). Gene fusions were identified in 14 of 18 (77.8%) cases, including eight fusions of NTRK and six fusions of RET. The high percentage of fusions in this papillary thyroid cancer subgroup suggested a correlation of gene fusions with the phenotype that does not belong to the BRAF V600E-mutant or RAS-mutant group.

Conclusions

Our study retrospectively screened a large cohort of different thyroid tissue samples, and presented the histopathological and genetic features of a non-classical phenotype of PTC from 24 patients. It may contribute to diagnose in PTC, and patients of these non-classical phenotype may benefit from targeted therapy, compared to a natural patient cohort without selection.

Risk Factors Associated With Recurrence and Death in Patients With Tall Cell Papillary Thyroid Cancer: A Single-Institution Cohort Study With Predictive Nomogram

Importance

Tall cell morphology (TCM) is a rare and aggressive variant of papillary thyroid carcinoma (PTC) that has been associated with poor outcomes; however, the risk factors for worse survival are not well characterized.

Objective

To identify prognostic factors associated with cancer recurrence and death in patients with PTC-TCM.

Design, Setting, and Participants

All patients treated for PTC-TCM at a single tertiary-level academic health care institution from January 1, 1997, through July 31, 2018, were included. Tall cell variant (TCV) was defined as PTC with TCM of 30% or more; and tall cell features (TCF) was defined as PTC with TCM of less than 30%. Patients with other coexisting histologic findings and/or nonsurgical management were excluded. Clinicopathologic features associated with worse outcomes were identified using Kaplan-Meier and Cox proportional-hazards model. Data were analyzed from March 1, 2018, to August 15, 2018.

Main Outcomes and Measures

Locoregional recurrence-free survival (LRRFS), distant recurrence-free survival (DRFS), and overall survival (OS) after surgery.

Results

A total of 365 patients (median [range] age, 51.8 [15.9-91.6] years; 242 [66.3%] female) with PTC-TCM (TCV, 32%; TCF, 68%) were evaluable. Total thyroidectomy was performed in 336 (92%) patients; 19 (5.2%) received radiotherapy; and 15 (4.1%) received radioactive iodine. Clinical features were pT3 or T4, 65%; node-positive, 53%; and positive surgical margins, 24%. LRRFS at 1-, 3-, 5-, and 10-year was 95%, 87%, 82%, and 73%, respectively. On multivariable analysis, male sex and age were not independent predictors of inferior 5-year LRRFS, whereas positive surgical margins (HR, 3.5; 95% CI, 2.0-6.3), positive lymph nodes (HR, 2.8; 95% CI, 1.4-5.8), and primary tumor size of 3 cm or more (HR, 3.3; 95% CI, 1.4-7.8) were strongly associated with worse LRRFS. Age 55 years or older (HR, 3.2; 95% CI, 1.5-7.0), male sex (HR 4.5; 95% CI, 2.1-10.0), positive surgical margins (HR, 2.7; 95% CI, 1.2-6.0), nodal positivity (HR, 3.1; 95% CI, 1.3-7.7), tumor diameter of 1.5 cm or more (HR, 20.6; 95% CI, 2.8-152.1), and TCV vs TCF (HR, 3.1; 95% CI, 1.5-6.7) were associated with worse DRFS. Male sex (HR, 3.1; 95% 1.4-6.8) and tumor diameter of 1.5 cm or more (HR, 2.8; 95% CI, 1.0-7.4) were associated with worse OS. A findings-based nomogram was constructed to predict 10-year LRRFS (C index, 0.8).

Conclusions and Relevance

This retrospective cohort study found that in patients with PTC-TCM, positive surgical margins, node positive disease, and tumor size of 3 cm or more were risk factors for worse LRRFS. Intensified locoregional therapy, including adjuvant radiation, may be considered for treating these patients.

A new molecular subclassification and in silico predictions for diagnosis and prognosis of papillary thyroid cancer by alternative splicing profile

Introduction: Papillary thyroid cancer (PTC) is the most common endocrine malignancy. However, different PTC variants reveal high heterogeneity at histological, cytological, molecular and clinicopathological levels, which complicates the precise diagnosis and management of PTC. Alternative splicing (AS) has been reported to be potential cancer biomarkers and therapeutic targets. Method: Here, we aim to find a more sophisticated molecular subclassification and characterization for PTC by integrating AS profiling. Based on six differentially expressed alternative splicing (DEAS) events, a new molecular subclassification was proposed to reclassify PTC into three new groups named as Cluster0, Cluster1 and Cluster2 respectively. Results: An in silico prediction was performed for accurate recognition of new groups with the average accuracy of 91.2%. Moreover, series of analyses were implemented to explore the differences of clinicopathology, molecular and immune characteristics across them. It suggests that there are remarkable differences among them, but Cluster2 was characterized by poor prognosis, higher immune heterogeneity and more sensitive to anti-PD1 therapy. The splicing correlation networks proved the complicated regulation relationships between AS events and splicing factors (SFs). An independent prognostic indicator for PTC overall survival (OS) was established. Finally, three compounds (orantinib, tyrphostin-AG-1295 and AG-370) were discovered to be the potential therapeutic agents. Discussion: Overall, the six DEAS events are not only potential biomarkers for precise diagnosis of PTC, but also the probable prognostic predictors. This research would be expected to highlight the effect of AS events on PTC characterization and also provide new insights into refining precise subclassification and improving medical therapy for PTC patients.

Evaluation of the role of prophylactic bilateral central neck lymph node dissection in patients with papillary thyroid carcinoma: a case controlled study

Thyroid cancer is the most common malignancy in the endocrine system. Papillary thyroid carcinoma (PTC) is the most common differentiated thyroid cancer. There are considerable discrepancies regarding the role and extent of prophylactic central lymph node dissection (PCLND) for patients with PTC. Our primary goal was the evaluation of CLN involvement based on the tumor features and staging on the eight version of the American Joint Committee on Cancer and also the TNM method. Our secondary aim was to evaluate the features of the CLNs with tumoral features and also features associated with the development of transient hypoparathyroidism. This prospective case-controlled study was performed among PTC patients. Total thyroidectomy and bilateral dissection of the CLNs of the central compartment of the neck was performed, and samples were sent for pathological evaluation. CLN involvement, tumoral features and transient hypoparathyroidism were cross-evaluated and analyzed with SPSS version 26.0. In this study, out of 61 patients, 11 (18%) were male, the average age was 37.3 ± 13.7 years, based on AJCC staging, 53 (86.9%) were stage I and 8 (13.1%) were stage II, and based on TNM staging, 39 patients (66.1%) were T1, including 13 (22.0%) T1a and 26 (44.1%) T1b, 15 patients (25.4%) were T2, and five patients (8.5%) were T3. Based on permanent pathology evaluation, the majority of patients (n = 48; 78.7%) had CLN involvement. None of the preoperative and tumor features had a significant association with CLN involvement. 75% of stage I and 100% of stage two cases, while 76.9% of T1, 86.7% of T2, and 80.0% of T3 cases had CLN involvement. There was no significant association between the involvement of CLN and the AJCC staging (P = 0.184) or TNM staging (P = 0.875). The involved to dissected CLN ratio was significantly higher in stage II patients compared to stage I (72.5 vs. 34.8%; P = 0.006), and also with higher T staging (0.009). There was a statistically significant association between the larger CLN size and older patients' age, higher postoperative thyroglobulin levels, and smaller tumor size. Higher postoperative thyroglobulin level was significantly associated with larger tumors size and thyroid capsule invasion. Also, 26 (44.8%) of patients developed transient hypoparathyroidism, which was significantly associated with vascular invasion (P = 0.048), bilateral location of tumor (P = 0.048) or on the right side (0.005), and larger size of the tumor (P = 0.016). Tumor features and staging were not associated with CLN involvement features. Therefore, full extent PCLND should be carried out to avoid reoperation or metastasis in PTC patients.

The Italian Consensus for the Classification and Reporting of Thyroid Cytology: Cytohistologic and molecular correlations on 37,371 nodules from a single institution

BACKGROUND

The Italian Consensus for the Classification and Reporting of Thyroid Cytology (ICCRTC) includes six diagnostic categories (TIR 1/1C, TIR 2, TIR 3A, TIR 3B, TIR 4, and TIR 5), each indicating a different risk of malignancy. The objective of this monocentric retrospective study was to evaluate the distribution of the ICCRTC classes at the authors' institution and assess their cytohistologic correlations.

METHODS

The authors retrospectively collected 37,371 consecutive cytologic reports of thyroid nodules and described the clinical-pathologic features of the different cytologic categories. The cytologic diagnoses also were compared with histologic outcomes in a subset of patients.

RESULTS

The cytologic classes were distributed as follows: nondiagnostic, 15.6%; benign, 66.5%; low-risk indeterminate, 10% (TIR 3A); high-risk indeterminate, 3.5% (TIR 3B); suspicious, 1.7%; and malignant, 2.6%. According to histology, the risk of malignancy was very high in the nondiagnostic category (29.8%), with young male patients more exposed to malignancy, and it was relatively high among benign (7.8%) and indeterminate nodules (32.5% in TIR 3A; 52.1% in TIR 3B), mainly because of the high prevalence of follicular architecture in malignant tumors. On histology, the malignancy rates were 92.4% and 99.3% for the suspicious and malignant categories, respectively; aggressive variants of papillary thyroid carcinoma were mostly diagnosed in these categories.

CONCLUSIONS

In this series, nondiagnostic nodules showed high prevalence and, surprisingly, high malignancy rates. Malignant tumors with follicular architecture represented a diagnostic pitfall in benign and indeterminate nodules. The suspicious and malignant categories had high specificity for malignancy. Importantly, the ICCRTC had high reliability for identifying preoperatively aggressive histotypes of thyroid carcinoma.

Nuclear interaction of Arp2/3 complex and BRAFV600E promotes aggressive behavior and vemurafenib resistance of thyroid cancer

The presence of mutant BRAF V600E correlates with the risk of recurrence in papillary thyroid cancer (PTC) patients. However, not all PTC patients with BRAF V600E are associated with poor prognosis. Thus, understanding the mechanisms by which certain PTC patients with nuclear BRAF V600E become aggressive and develop resistance to a selective BRAF inhibitor, PLX-4032, is urgently needed. The effect of nuclear localization of BRAFV600E using in vitro studies, xenograft mouse-model and human tissues was evaluated. PTC cells harboring a nuclear localization signal (NLS) of BRAFV600E were established and examined in nude mice implanted with TPC1-NLS-BRAFV600E cells followed by PLX-4032 treatment. Immunohistochemical (IHC) analysis was performed on 100 PTC specimens previously confirmed that they have BRAFV600E mutations. Our results demonstrate that 21 of 100 (21%) PTC tissues stained with specific BRAFV600E antibody had nuclear staining with more aggressive features compared to their cytosolic counterparts. In vitro studies show that BRAFV600E is transported between the nucleus and the cytosol through CRM1 and importin (α/β) system. Sequestration of BRAFV600E in the cytosol sensitized resistant cells to PLX-4032, whereas nuclear BRAFV600E was associated with aggressive phenotypes and developed drug resistance. Proteomic analysis revealed Arp2/3 complex members, actin-related protein 2 (ACTR2 aliases ARP2) and actin-related protein 3 (ACTR3 aliases ARP3), as the most enriched nuclear BRAFV600E partners. ACTR3 was highly correlated to lymph node stage and extrathyroidal extension and was validated with different functional assays. Our findings provide new insights into the clinical utility of the nuclear BRAFV600E as a prognostic marker for PTC aggressiveness and determine the efficacy of selective BRAFV600E inhibitor treatment which opens new avenues for future treatment options.

Papillary Thyroid Carcinoma: Current Position in Epidemiology, Genomics, and Classification

Papillary thyroid carcinoma is the most common type of thyroid malignancy both in adults and pediatric population. Since the 1980s, there are changes in criteria in labelling thyroid lesions as "papillary thyroid carcinomas." Radiation exposure is a well-established risk factor for papillary thyroid carcinoma. Other environmental risk factors include dietary iodine, obesity, hormones, and environmental pollutants. Papillary thyroid carcinomas could occur in familial settings, and 5% of these familial cases have well-studied driver germline mutations. In sporadic papillary thyroid carcinoma, BRAF mutation is common and is associated with clinicopathologic and prognostic markers. The mutation could aid in the clinical diagnosis of papillary thyroid carcinoma. Globally, thyroid cancer is among the top ten commonest cancer in females. In both adult and pediatric populations, there are variations of prevalence of thyroid cancer and rising incidence rates of thyroid cancer worldwide. The increase of thyroid cancer incidence was almost entirely due to the increase of papillary thyroid carcinoma. The reasons behind the increase are complex, multifactorial, and incompletely understood. The most obvious reasons are increased use of diagnostic entities, change in classification of thyroid neoplasms, as well as factors such as obesity, environmental risk factors, and radiation. The prognosis of the patients with papillary thyroid carcinoma is generally good after treatment. Nevertheless, cancer recurrence and comorbidity of second primary cancer may occur, and it is important to have awareness of the clinical, pathological, and molecular parameters of papillary thyroid carcinoma.

MicroRNA-203a-3p may prevent the development of thyroid papillary carcinoma via repressing MAP3K1 and activating autophagy

Background

Papillary thyroid carcinoma (PTC) grows slowly but has a great risk of metastasis. MicroRNAs are well known as vital tumor‐related gene regulators. In PTC, the role of miR‐203a‐3p and the underlying mechanisms remain not completely understood.

Methods

We conducted CCK8 assay, wound healing assay, transwell experiment and flow cytometry analyses to investigate the function of miRNA‐203a‐3p. The interaction of miRNA‐203a‐3p with its gene MAP3K1 was characterized by quantitative real‐time polymerase chain reaction, western blotting and luciferase assay.

Results

We found that the levels of miRNA‐203a‐3p were statistically decreased in PTC tissues. When mimics were delivered to TPC‐1 and KTC‐1 cells to upregulate miR‐203a‐3p, it was observed that cell proliferation, metastatic abilities and cell cycle process were prevented but cell apoptosis was enhanced. Furthermore, we proved the interaction between MAP3K1 and miR‐203a‐3p. Intriguingly, similar to miR‐203a‐3p mimics, siMAP3K1 showed a tumor‐suppressive effect, and this effect could be reversed when miR‐203a‐3p was simultaneously inhibited. Finally, selected autophagy‐linked proteins such as LC3 Beclin‐1 were detected and found to be increased when miR‐203a‐3p was upregulated or MAP3K1 was inhibited.

Conclusion

Overall, miR‐203a‐3p inhibits the oncogenic characteristics of TPC‐1 and KTC‐1 cells via suppressing MAP3K1 and activating autophagy. Our findings might enrich the understanding and the therapeutic strategies of PTC.

Dissection of molecular and histological subtypes of papillary thyroid cancer using alternative splicing profiles

Despite growing evidence of the relevance of alternative splicing (AS) to cancer development and progression, the biological implications of AS for tumor behaviors, including papillary thyroid cancer (PTC), remain elusive. With the aim of further understanding the molecular and histological subtypes of PTC, we in this study explored whether AS events might act as new molecular determinants. For this purpose, AS profiles were analyzed in RNA-sequencing data from The Cancer Genome Atlas (TCGA) and from a Korean patient dataset. A total of 23 distinct exon-skipping (ES) events that correlated significantly with PTC oncogenic activity and differentiation scores were identified. The two top-ranked ES events, NUMA1_17515 in exon 18 of NUMA1 and TUBB3_38175 in exon 6 of TUBB3, showed high correlations with oncogenic activities and discriminated histological and molecular subtypes of PTC. Furthermore, two novel intron-retention (IR) events for TUBB3 were uncovered. All ES and IR events for the TUBB3 gene were predicted to induce nonsense-mediated mRNA decay. The relative abundances of intron reads in the PTC dataset from TCGA showed IR levels to differ significantly among PTC subtypes, possibly reflecting their different tumor behaviors. This study provides a landscape of AS changes among PTC subtypes and identified two significant AS events, NUMA1_17515 and TUBB3_38175, as potential AS biomarkers for PTC subclassification and characterization. The AS events identified in this study may be involved in the development of phenotypic differences underlying the functional characteristics and histological differentiation of PTCs.

Two potential biomarkers uncovered by scientists in South Korea may help more accurately classify subtypes of papillary thyroid cancer, the most common form of thyroid cancer, and improve treatment regimens. Ascertaining the correct papillary thyroid cancer (PTC) subtype is important for patient prognoses and treatment plans. Growing evidence suggests that cancer progression may be influenced by ‘alternative splicing’ events, alterations to mRNA that change the structure of mRNA transcripts and affect the function of encoded proteins. Yeun-Jun Chung and Sug Hyung Lee at the Catholic University of Korea, Seoul, and co-workers explored alternative splicing events in PTC patient samples. They identified 25 distinct events associated with oncogenic activity and differentiation between PTC subtypes. Of these, two events associated with two separate genes are particularly significant and could prove useful as biomarkers for disease classification and characterisation.

Papillary thyroid carcinoma tall cell variant shares accumulation of mitochondria, mitochondrial DNA mutations, and loss of oxidative phosphorylation complex I integrity with oncocytic tumors

Papillary thyroid carcinoma tall cell variant (PTC-TCV), a form of PTC regarded as an aggressive subtype, shares several morphologic features with oncocytic tumors. Pathogenic homoplasmic/highly heteroplasmic somatic mitochondrial DNA (mtDNA) mutations, usually affecting oxidative phosphorylation (OXPHOS) complex I subunits, are hallmarks of oncocytic cells. To clarify the relationship between PTC-TCV and oncocytic thyroid tumors, 17 PTC-TCV and 16 PTC non-TCV controls (cPTC) were subjected to: (1) transmission electron microscopy (TEM) to assess mitochondria accumulation, (2) next-generation sequencing to analyze mtDNA and nuclear genes frequently mutated in thyroid carcinoma, and (3) immunohistochemistry (IHC) for prohibitin and complex I subunit NDUFS4 to evaluate OXPHOS integrity. TEM showed replacement of cytoplasm by mitochondria in PTC-TCV but not in cPTC cells. All 17 PTC-TCV had at least one mtDNA mutation, totaling 21 mutations; 3/16 cPTC (19%) had mtDNA mutations (p < 0.001). PTC-TCV mtDNA mutations were homoplasmic/highly heteroplasmic, 16/21 (76%) mapping within mtDNA-encoded complex I subunits. MtDNA mutations in cPTC were homoplasmic in 2 cases and at low heteroplasmy in the third case, 2/3 mapping to mtDNA-encoded complex I subunits; 2/3 cPTC with mtDNA mutations had small tall cell subpopulations. PTC-TCV showed strong prohibitin expression and cPTC low-level expression, consistent with massive and limited mitochondrial content, respectively. All 17 PTC-TCV showed NDUFS4 loss (partial or complete) and 3 of 16 cPTC (19%) had (partial) NDUFS4 loss, consistent with lack of complex I integrity in PTC-TCV (p < 0.001). IHC loss of NDUFS4 was associated with mtDNA mutations (p < 0.001). Four BRAF V600E mutated PTCs had loss of NDUSF4 expression limited to neoplastic cell subpopulations with tall cell features, indicating that PTCs first acquire BRAF V600E and then mtDNA mutations. Similar to oncocytic thyroid tumors, PTC-TCV is characterized by mtDNA mutations, massive accumulation of mitochondria, and loss of OXPHOS integrity. IHC loss of NDUFS-4 can be used as a surrogate marker for OXPHOS disruption and to reliably diagnose PTC-TCV.

Lymph node ratio is superior to AJCC N stage for predicting recurrence in papillary thyroid carcinoma

OBJECTIVE

Recently, lymph node ratio (LNR) has emerged as an alternative to American Joint Committee on Cancer (AJCC) N stage, with superior prognostic value. The utility of LNR in Middle Eastern papillary thyroid carcinoma (PTC) remains unknown. Therefore, we retrospectively analyzed a large cohort of 1407 PTC patients for clinicopathological associations of LNR.

METHODS

Receiver operating characteristics (ROC) curve was used to determine the cut-off for LNR. We also performed multivariate logistic regression analysis to determine whether LNR or AJCC N stage was superior in predicting recurrence in PTC.

RESULTS

Based on ROC curve analysis, a cut-off of 0.15 was chosen for LNR. High LNR was significantly associated with adverse clinicopathological characteristics such as male sex, extrathyroidal extension, lymphovascular invasion, multifocality, bilateral tumors, T4 tumors, lateral lymph node (N1b) involvement, distant metastasis, advanced tumor stage, American Thyroid Association (ATA) high-risk category and tumor recurrence. On multivariate analysis, we found that LNR was a better predictor of tumor recurrence than AJCC N stage (odds ratio: 1.96 vs 1.30; P value: 0.0184 vs 0.3831). We also found that LNR combined with TNM stage and ATA risk category improved the prediction of recurrence-free survival, compared to TNM stage or ATA risk category alone.

CONCLUSIONS

The present study suggests LNR is an independent predictor of recurrence in Middle Eastern PTC. Integration of LNR with 8th edition AJCC TNM staging system and ATA risk stratification will improve the accuracy to predict recurrence in Middle Eastern PTC and help in tailoring treatment and surveillance strategies in these patients.

Risk Factors for Central Lymph Node Metastases and Benefit of Prophylactic Central Lymph Node Dissection in Middle Eastern Patients With cN0 Papillary Thyroid Carcinoma

Background

Prophylactic central lymph node dissection (PCLND) for adult patients with papillary thyroid carcinoma (PTC) is still a matter of debate. Data on incidence, risk and benefits of PCLND in Middle Eastern patients is lacking. Therefore, we aimed to identify the incidence and predictive clinico-pathological and molecular marker of PCLND in adult patients with clinically node negative (cN0) Middle Eastern PTC.

Methods

This retrospective study included 942 adult Middle Eastern patients with cN0 PTC who underwent total thyroidectomy (TT) or TT+PCLND. Clinico-pathological associations of central lymph node metastasis (CLNM) were assessed. Multivariate analysis was performed using logistic regression and Cox proportional hazards model.

Results

213 patients underwent PCLND and 38.0% (81/213) had positive CLNM. Multivariate analysis demonstrated age ≤55 years (Odds Ratio (OR) = 7.38; 95% Confidence Interval (CI) = 1.59 – 34.31; p = 0.0108), tumor bilaterality (OR = 3.01; 95% CI = 1.01 – 9.21; p = 0.0483), lymphovascular invasion (OR = 2.92; 95% CI = 1.18 – 7.23; p = 0.0206) and BRAF mutation (OR = 3.24; 95% CI = 1.41 – 7.49; p = 0.0058) were independent predictors of CLNM in adult PTC. Furthermore, patients who underwent PCLND showed significant association with improved recurrence-free survival (RFS; p = 0.0379). Multivariate analysis demonstrated that PCLND was an independent predictor of improved recurrence-free survival.

Conclusions

cN0 Middle Eastern PTC patients treated with PCLND showed a significantly better prognosis. PCLND was effective in improving RFS in Middle Eastern PTC patients and should be encouraged for patients with potential risk factors for CLNM.

The Prognostic Implication of the BRAF V600E Mutation in Papillary Thyroid Cancer in a Chinese Population

BACKGROUND

The BRAF V600E mutation is an important genetic event in papillary thyroid cancer (PTC). This study aimed to provide additional information regarding the association of the BRAF V600E mutation with PTC prognosis.

METHODS

A retrospective single-center study based on a Chinese population was performed to analyze the association of the BRAF V600E mutation with several clinicopathological features. Kaplan-Meier survival curves and Cox proportional hazards regression analysis were applied to implement the survival analysis.

RESULTS

The BRAF V600E mutation was present in 1102 (87.7%) of the 1257 patients and was significantly associated with older age, conventional subtype, multifocality, advanced TNM stage, and a reduced prevalence of Hashimoto's thyroiditis. The Kaplan-Meier survival curves demonstrated that the difference between the BRAF V600E-positive and BRAF V600E-negative groups was significant with a log-rank P-value of 0.048. The Cox proportional hazards regression analysis adjusted HR was 3.731 (95% CI, 1.457 to 9.554). We further demonstrated that larger tumor size (>1 cm), extrathyroidal extension (ETE), and lateral lymph node metastasis (LNM) were associated with a higher probability of PTC recurrence in patients harboring the BRAF V600E mutation.

CONCLUSIONS

The BRAF V600E mutation remains an independent risk factor for PTC recurrence and may be useful for clinical decisions when it combines with some pathological factors.

The Combined Utility of HBME-1 and Galectin-3 Immunohistochemistry and BRAF V600E Mutations in the Diagnosis of Papillary Thyroid Carcinoma

Newer diagnostic modalities have revolutionized the pathologist’s approach to diagnosing thyroid malignancies. Molecular characterization of these malignancies has helped circumvent common morphologic diagnostic difficulties by integrating their genotypic, phenotypic, and immunohistochemical features. BRAF V600E mutation has been characterized as highly specific for thyroid carcinoma, especially papillary thyroid carcinoma (PTC); human bone marrow endothelial marker-1 (HBME-1) and galectin-3 are also such markers that are highly specific for PTC. We propose to study HBME-1 and galectin-3 expression and BRAF V600E mutation in thyroid neoplasms and do a comparative analysis to determine whether there is a correlation between BRAF V600E expression and that of HBME-1 and galectin-3. We further propose to analyze the individual and combined diagnosed utility of the above-mentioned ancillary diagnostic techniques.

Case of papillary thyroid cancer presenting with an inoperable cervical mass successfully treated with high-dose radiation therapy

External-beam radiation therapy (EBRT) for differentiated thyroid cancer has been controversial. Palliative irradiation is usually recommended for patients with treatment-resistant relapse and/or distant metastases, but high-dose EBRT is not often indicated in this situation. A 50-year-old man had treatment-resistant recurrence of an inoperable cervical mass and multiple lung metastases after total thyroidectomy and neck dissection. Because the patient had good performance status and no other life-threatening metastases, he received high-dose intensity-modulated radiation therapy (IMRT). Remarkably, the tumour shrank during treatment. After 3 months, he had bleeding from the internal carotid artery. The bleeding was outside the high-dose irradiation site and was likely due to infection; emergency interventional radiology was performed. The post-EBRT clinical course was favourable and the cervical mass almost disappeared. The patient remained alive for 3 years post treatment. It is possible to extend the indication of high-dose intensity-IMRT in selected patients with differentiated thyroid cancer.

Diagnostic Test Accuracy of Ultrasonography vs Computed Tomography for Papillary Thyroid Cancer Cervical Lymph Node Metastasis: A Systematic Review and Meta-analysis

Importance

The use of ultrasonography (US) vs cross-sectional imaging for preoperative evaluation of papillary thyroid cancer is debated.

Objective

To compare thyroid US and computed tomography (CT) in the preoperative evaluation of papillary thyroid cancer for cervical lymph node metastasis (CLNM), as well as extrathyroidal disease extension.

Data Sources

MEDLINE and Embase were searched from January 1, 2000, to July 18, 2020.

Study Selection

Studies reporting on the diagnostic accuracy of US and/or CT in individuals with treatment-naive papillary thyroid cancer for CLNM and/or extrathyroidal disease extension were included. The reference standard was defined as histopathology/cytology or imaging follow-up. Independent title and abstract review (2515 studies) followed by full-text review (145 studies) was completed by multiple investigators.

Data Extraction and Synthesis

PRISMA guidelines were followed. Methodologic and diagnostic accuracy data were abstracted independently by multiple investigators. Risk of bias assessment was conducted using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool independently and in duplicate. Bivariate random-effects model meta-analysis and multivariable meta-regression modeling was used.

Main Outcomes and Measures

Diagnostic test accuracy of US and CT of the neck for lateral and central compartment CLNM, as well as for extrathyroidal disease extension, determined prior to study commencement.

Results

A total of 47 studies encompassing 31 942 observations for thyroid cancer (12 771 with CLNM; 1747 with extrathyroidal thyroid extension) were included; 21 and 26 studies were at low and high risk for bias, respectively. Based on comparative design studies, US and CT demonstrated no significant difference in sensitivity (73% [95% CI, 64%-80%] and 77% [95% CI, 67%-85%], respectively; P = .11) or specificity (89% [95% CI, 80%-94%] and 88% [95% CI, 79%-94%], respectively; P = .79) for lateral compartment CLNM. For central compartment metastasis, sensitivity was higher in CT (39% [95% CI, 27%-52%]) vs US (28% [95% CI, 21%-36%]; P = .004), while specificity was higher in US (95% [95% CI, 92%-98%]) vs CT (87% [95% CI, 77%-93%]; P < .001). Ultrasonography demonstrated a sensitivity of 91% (95% CI, 81%-96%) and specificity of 47% (95% CI, 35%-60%) for extrathyroidal extension.

Conclusions and Relevance

The findings of this systematic review and meta-analysis suggest that further study is warranted of the role of CT for papillary thyroid cancer staging, possibly as an adjunct to US.

Papillary Thyroid Cancer Prognosis: An Evolving Field

Simple Summary

Over the last couple of decades, the prognostic stratification systems of differentiated thyroid cancer (DTC) patients have been revised several times in an attempt to achieve a tailored clinical management reflecting the single patients’ needs. Such revisions are likely to continue in the near future, since the prognostic value of a number of promising clinicopathological features and new molecular biomarkers are being evaluated. Here, we will review the current staging systems of thyroid cancer patients and discuss the most relevant clinicopathological parameters and new molecular markers that are potentially capable of refining the prognosis.

Abstract

Over the last few years, a great advance has been made in the comprehension of the molecular pathogenesis underlying thyroid cancer progression, particularly for the papillary thyroid cancer (PTC), which represents the most common thyroid malignancy. Putative cancer driver mutations have been identified in more than 98% of PTC, and a new PTC classification into molecular subtypes has been proposed in order to resolve clinical uncertainties still present in the clinical management of patients. Additionally, the prognostic stratification systems have been profoundly modified over the last decade, with a view to refine patients’ staging and being able to choose a clinical approach tailored on single patient’s needs. Here, we will briefly discuss the recent changes in the clinical management of thyroid nodules, and review the current staging systems of thyroid cancer patients by analyzing promising clinicopathological features (i.e., gender, thyroid auto-immunity, multifocality, PTC histological variants, and vascular invasion) as well as new molecular markers (i.e., BRAF/TERT promoter mutations, miRNAs, and components of the plasminogen activating system) potentially capable of ameliorating the prognosis of PTC patients.

BRAF V600E Status Sharply Differentiates Lymph Node Metastasis-associated Mortality Risk in Papillary Thyroid Cancer

CONTEXT

How lymph node metastasis (LNM)-associated mortality risk is affected by BRAF V600E in papillary thyroid cancer (PTC) remains undefined.

OBJECTIVE

To study whether BRAF V600E affected LNM-associated mortality in PTC.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed the effect of LNM on PTC-specific mortality with respect to BRAF status in 2638 patients (2015 females and 623 males) from 11 centers in 6 countries, with median age of 46 [interquartile range (IQR) 35-58] years and median follow-up time of 58 (IQR 26-107) months.

RESULTS

Overall, LNM showed a modest mortality risk in wild-type BRAF patients but a strong one in BRAF V600E patients. In conventional PTC (CPTC), LNM showed no increased mortality risk in wild-type BRAF patients but a robustly increased one in BRAF V600E patients; mortality rates were 2/659 (0.3%) vs 4/321 (1.2%) in non-LNM vs LNM patients (P = 0.094) with wild-type BRAF, corresponding to a hazard ratio (HR) (95% CI) of 4.37 (0.80-23.89), which remained insignificant at 3.32 (0.52-21.14) after multivariate adjustment. In BRAF V600E CPTC, morality rates were 7/515 (1.4%) vs 28/363 (7.7%) in non-LNM vs LNM patients (P < 0.001), corresponding to an HR of 4.90 (2.12-11.29) or, after multivariate adjustment, 5.76 (2.19-15.11). Adjusted mortality HR of coexisting LNM and BRAF V600E vs absence of both was 27.39 (5.15-145.80), with Kaplan-Meier analyses showing a similar synergism.

CONCLUSIONS

LNM-associated mortality risk is sharply differentiated by the BRAF status in PTC; in CPTC, LNM showed no increased mortality risk with wild-type BRAF but a robust one with BRAF mutation. These results have strong clinical relevance.

Whole Tumor Capsule Is Prognostic of Very Good Outcome in the Classical Variant of Papillary Thyroid Cancer

CONTEXT

Tumor capsule integrity is becoming a relevant issue to predict the biological behavior of human tumors, including thyroid cancer.

OBJECTIVE

This work aims to verify whether a whole tumor capsule in the classical variant of papillary thyroid carcinoma (CVPTC) could have as a predictive role of a good outcome as for follicular variant (FVPTC).

METHODS

FVPTC (n = 600) and CVPTC (n = 554) cases were analyzed. We distinguished between encapsulated-FVPTC (E-FVPTC) and encapsulated-CVPTC (E-CVPTC) and, thereafter, invasive (Ei-FVPTC and Ei-CVPTC) and noninvasive (En-FVPTC and En-CVPTC) tumors, according to the invasion or integrity of the tumor capsule, respectively. Cases without a tumor capsule were indicated as invasive-FVPTC (I-FVPTC) and invasive-CVPTC (I-CVPTC). The subgroup of each variant was evaluated for BRAF mutations.

RESULTS

E-FVPTC was more frequent than E-CVPTC (P < .001). No differences were found between En-FVPTC and En-CVPTC or between Ei-FVPTC and Ei-CVPTC. After 18 years of follow-up, a greater number of not-cured cases were observed in Ei-CVPTC with respect to Ei-FVPTC, but not in En-CVPTC to En-FVPTC. Multivariate clustering analysis showed that En-FVPTC, En-CVPTC, and Ei-FVPTC have similar features but different from I-FVPTC and I-CVPTC and, to a lesser extent, from Ei-CVPTC. A total of 177 of 614 (28.8%) cases were BRAFV600E mutated, and 10 of 614 (1.6%) carried BRAF-rare alterations. A significantly higher rate of En-CVPTC (22/49, 44.9%) than En-FVPTC (15/195, 7.7%) (P < .0001) were BRAFV600E mutated.

CONCLUSION

En-CVPTC is less prevalent than En-FVPTC. However, it has good clinical/ pathological behavior comparable to En-FVPTC. This finding confirms the good prognostic role of a whole tumor capsule in CVPTC as well. New nomenclature for En-CVPTC, similar to that introduced for En-FVPTC (ie, noninvasive follicular thyroid neoplasm with papillary-like nuclear features; NIFTP) could be envisaged.

Highly accurate diagnosis of papillary thyroid carcinomas based on personalized pathways coupled with machine learning

Thyroid nodules are neoplasms commonly found among adults, with papillary thyroid carcinoma (PTC) being the most prevalent malignancy. However, current diagnostic methods often subject patients to unnecessary surgical burden. In this study, we developed and validated an automated, highly accurate multi-study-derived diagnostic model for PTCs using personalized biological pathways coupled with a sophisticated machine learning algorithm. Surprisingly, the algorithm achieved near-perfect performance in discriminating PTCs from non-tumoral thyroid samples with an overall cross-study-validated area under the receiver operating characteristic curve (AUROC) of 0.999 (95% confidence interval [CI]: 0.995-1) and a Brier score of 0.013 on three independent development cohorts. In addition, the algorithm showed excellent generalizability and transferability on two large-scale external blind PTC cohorts consisting of The Cancer Genome Atlas (TCGA), which is the largest genomic PTC cohort studied to date, and the post-Chernobyl cohort, which includes PTCs reported after exposure to radiation from the Chernobyl accident. When applied to the TCGA cohort, the model yielded an AUROC of 0.969 (95% CI: 0.950-0.987) and a Brier score of 0.109. On the post-Chernobyl cohort, it yielded an AUROC of 0.962 (95% CI: 0.918-1) and a Brier score of 0.073. This algorithm also is robust against other various types of clinical scenarios, discriminating malignant from benign lesions as well as clinically aggressive thyroid cancer with poor prognosis from indolent ones. Furthermore, we discovered novel pathway alterations and prognostic signatures for PTC, which can provide directions for follow-up studies.

Clinicopathological Characteristics and Recurrence-Free Survival of Rare Variants of Papillary Thyroid Carcinomas in Korea: A Retrospective Study

BACKGROUND

We aimed to evaluate the clinicopathological features and biological behaviors of Korean thyroid cancer patients with rare variants of papillary thyroid carcinoma (PTC) to address the ambiguity regarding the prognostic consequences of these variants.

METHODS

We retrospectively reviewed the medical records of 5,496 patients who underwent thyroid surgery for PTC, between January and December 2012, in nine tertiary hospitals. Rare PTC variants included tall cell (TCV), columnar cell (CCV), diffuse sclerosing (DSV), cribriform-morular (CMV), solid (SV), hobnail, and Warthin-like variants. Recurrence-free survival (RFS) was defined as the time from the date of thyroidectomy until recurrence.

RESULTS

Rare variants accounted for 1.1% (n=63) of the PTC patients; with 0.9% TCV, 0.02% CCV, 0.1% DSV, 0.1% CMV, and 0.1% SV. The mean age of patients and primary tumor size were 42.1±13.1 years and 1.3±0.9 cm, respectively. Extrathyroidal extension and cervical lymph node metastasis were observed in 38 (60.3%) and 37 (58.7%) patients, respectively. Ultrasonographic findings revealed typical malignant features in most cases. During a median follow-up of 7 years, 6.3% of patients experienced a locoregional recurrence. The 5-year RFS rates were 71.4% in patients with DSV or SV, 95.9% for TCV, or CCV, and 100% for other variants. DSV emerged an independent risk factor associated with shorter RFS.

CONCLUSION

In this multicenter Korean cohort, rare variants accounted for 1.1% of all PTC cases, with TCV being the most frequent subtype. DSV emerged as a significant prognostic factor for RFS.

Follicular Lesions with Papillary Nuclear Characteristics: Differences in Chromatin Detected by Computerized Image Analysis

Objective

Follicular lesions of the thyroid with papillary carcinoma nuclear characteristics are classified as infiltrative follicular variant of papillary thyroid carcinoma-FVPTC (IFVPTC), encapsulated/well demarcated FVPTC with tumour capsular invasion (IEFVPTC), and the newly described category "non-invasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) formerly known as non-invasive encapsulated FVPTC. This study evaluated whether computerized image analysis can detect nuclear differences between these three tumour subtypes.

Methods

Slides with histological material from 15 cases of NIFTP and 33 cases of FVPTC subtypes (22 IEFVPTC, and 11 IFVPTC) were analyzed using the Image J image processing program. Tumour cells were compared for both nuclear morphometry and chromatin textural characteristics.

Results

Nuclei from NIFTP and IFVPTC tumours differed in terms of chromatin textural features (grey intensity): mean (92.37 ± 21.01 vs 72.99 ± 14.73, p = 0.02), median (84.93 ± 21.17 vs 65.18 ± 17.08, p = 0.02), standard deviation (47.77 ± 9.55 vs 39.39 ± 7.18; p = 0.02), and coefficient of variation of standard deviation (19.96 ± 4.01 vs 24.75 ± 3.31; p = 0.003). No differences were found in relation to IEFVPTC.

Conclusion

Computerized image analysis revealed differences in nuclear texture between NIFTP and IFVPTC, but not for IEFVPTC.

Ablation therapy using a low dose of radioiodine may be sufficient in low- to intermediate-risk patients with follicular variant papillary thyroid carcinoma

OBJECTIVES

Follicular variant papillary thyroid carcinoma (FVPTC) is treated similarly to classical variant papillary thyroid carcinoma (cPTC). However, FVPTC has unique tumour features and behaviours. We investigated whether a low dose of radioiodine was as effective as a high dose for remnant ablation in patients with FVPTC and evaluated the recurrence of low-intermediate risk FVPTC.

METHODS

Data from cPTC and FVPTC patients treated with I-131 from 2004 to 2014 were reviewed. Demographics, tumour behaviour, lymph node metastasis, and local recurrence data were compared between FVPTC and cPTC patients. Then, low-intermediate risk FVPTC patients were divided into low, intermediate, and high I-131 dose groups, and postoperative I-131 activities were analysed to evaluate the effectiveness of I-131 therapy for thyroid remnant ablation.

RESULTS

In total, 799 cases of FVPTC (n = 168) and cPTC (n = 631) treated with I-131 were identified. Patients with FVPTC had a larger primary nodule size than cPTC, but lymph node metastases and local recurrence were more prevalent in cPTC than in FVPTC. For the low-, intermediate-, and high-dose groups, success rates of ablation did not differ (82.0%, 80%, and 81.3%, respectively).

CONCLUSION

FVPTC differs from cPTC in behaviour. Low-dose ablation may be sufficient in FVPTC patients with low-intermediate disease risk.

A population-based study of the three major variants of papillary thyroid carcinoma

Objective

To explore the clinicopathological features and relative prognostic risks of the three major variants of papillary thyroid carcinoma (PTC).

Methods

We retrospectively analyzed the clinicopathological characteristics and prognoses of patients with the three major PTC variants, conventional papillary thyroid carcinoma (CPTC), follicular-variant papillary carcinoma (FVPTC), and tall-cell papillary thyroid carcinoma (TCPTC), based on data from the Surveillance, Epidemiology, and End Results database from 2005 to 2009.

Results

A total of 29,555 patients were enrolled. In terms of their demographic and clinicopathological characteristics, TCPTC had the highest prevalence of older patients, men, patients with locally advanced stage (T stage and N stage), and mortality, while FVPTC had the lowest prevalence in relation to these factors. The three variants differed significantly in terms of 5-year overall survival and 5-year disease-specific survival. Cox regression analysis identified male sex, age ≥45 years, and higher American Joint Committee on Cancer and TNM stage as independent factors predicting a poor prognosis in relation to both overall and disease-specific survival.

Conclusions

CPTC, FVPTC, and TCPTC have different clinicopathological characteristics and prognoses, indicating the need for different treatment strategies for these three variants of PTC.

Papillary thyroid microcarcinomas: does subtyping predict aggressive clinical behavior?

The most common malignant neoplasm affecting the thyroid gland is papillary thyroid carcinoma (PTC). PTC can demonstrate a number of morphologic variants including, but not limited to, classic, follicular, and tall cell. Each of these morphologic subtypes carry distinct clinical characteristics such that certain variants, like tall cell, behave more aggressively than others. PTCs measuring less than or equal to 1.0 cm are classified as microcarcinomas. Although these lesions are thought to be clinically indolent, we hypothesized that, like their larger counterparts, certain histologic variants may lead to worse patient outcomes. To test our hypothesis, we analyzed our pathology archives between the years 2009 and 2020 for papillary thyroid microcarcinomas and assessed whether different morphologic features correlated with more aggressive clinical behavior. Our findings suggest that certain variants exhibit features that portend a more worrisome clinical course and thus papillary thyroid microcarcinomas should be subtyped to help predict patient outcome.

Basal and pentagastrin-stimulated calcitonin cut-off values in diagnosis of preoperative medullary thyroid cancer

Background/aim

Medullary thyroid cancer (MTC) originates from parafollicular cells (C cell) and produces calcitonin (CT). Basal serum CT was used in the diagnosis and treatment of MTC. If basal CT level is 100 pg/mL or higher, it is likely to have MTC, but if basal CT level is below 10 pg/mL, the probability of developing thyroid disease is low. In cases with basal CT level between 10–100 pg/mL, pentagastrin-stimulated (PS) CT level is studied to evaluate MTC and C cell hyperplasia (CHH). This study aimed to determine cut-off value for basal and PS peak CT level for diagnosis of MTC.

Materials and methods

We retrospectively reviewed files of patients presented to endocrine outpatient clinic of Ege University, Medicine School, between 2010 and 2019; 176 patients with basal CT level of 10–100 pg/mL and patients with PS test were included to the study.

Results

The receiver operating characteristic curve (ROC) analysis was used to determine cut-off value for basal CT that can discriminate cases with MTC and those with nodular goiter. Cut-off value for basal CT was calculated as 46.5 pg/mL (specificity; 100 %, sensitivity; 74 %). In the ROC analysis for peak PS CT, cut-off value was calculated as 285 pg/mL (specificity:100 %; sensitivity:82 %). When peak CT level was > 290 pg/mL in PS test, both specificity and sensitivity for MTC were determined as 100 %. The PS peak CT level > 285 pg/mL was significant for MTC diagnosis while range of 117–274 pg/mL was significant for CHH.

Conclusion

In this study, cut-off value was calculated as 46.5 pg/mL for basal CT, whereas 285 pg/mL for PS peak CT in the diagnosis of preoperative MTC.

The intratumor microbiome predicts prognosis across gender and subtypes in papillary thyroid carcinoma

While the intratumor microbiome has become increasingly implicated in cancer development, the microbial landscape of papillary thyroid carcinoma (PTC) is essentially uninvestigated. PTC is characterized by varied prognosis between gender and cancer subtype, but the cause for gender and subtype-based dissimilarities is unclear. Women are more frequently diagnosed with PTC, while men suffer more advanced-staged PTC. In addition, tall cell variants are more aggressive than classical and follicular variants of PTC. We hypothesized that intratumor microbiome composition distinctly alters the immune landscape and predicts clinical outcome between PTC subtypes and between patient genders. Raw whole-transcriptome RNA-sequencing, Level 3 normalized mRNA expression read counts, and DNA methylation 450 k sequencing data for untreated, nonirradiated tumor, and adjacent normal tissue were downloaded from the Genomic Data Commons (GDC) legacy archive for 563 thyroid carcinoma patients. Microbe counts were extracted using Pathoscope 2.0 software. We correlated microbe abundance to clinical variables and immune-associated gene expression. Gene-set enrichment, mutation, and methylation analyses were conducted to correlate microbe abundance to characterize microbes' roles. Overall, PTC tumor tissue significantly lacked microbes that are populated in adjacent normal tissue, which suggests presence of microbes may be critical in controlling immune cell expression and regulating immune and cancer pathways to mitigate cancer growth. In contrast, we also found that microbes distinctly abundant in tall cell and male patient cohorts were also correlated with higher mutation expression and methylation of tumor suppressors. Microbe dysbiosis in specific PTC types may explain observable differences in PTC progression and pathogenesis. These microbes provide a basis for developing specialized prebiotic and probiotic treatments for varied PTC tumors.

Molecular Pathology of Non-familial Follicular Epithelial-Derived Thyroid Cancer in Adults: From RAS/BRAF-like Tumor Designations to Molecular Risk Stratification

This review addresses the impact of molecular alterations on the diagnosis and prognosis of differentiated thyroid carcinoma (DTC), including papillary, follicular, and well-differentiated carcinoma NOS, as well as oncocytic neoplasms. The molecular characterization of DTC is based upon the well-established dichotomy of BRAF-like and RAS-like designations, together with a remaining third group, less homogeneous, composed of non-BRAF-/non-RAS-like tumors. The role of BRAF V600E mutation in risk stratification is discussed in the clinico-pathological context, namely, staging and invasive features of classic papillary thyroid carcinoma (PTC) and histopathological variants carrying an excellent prognosis (microPTC) or a guarded prognosis, including the aggressive variants tall cell and hobnail cell PTCs. In follicular patterned tumors, namely, follicular thyroid carcinoma (FTC), with or without oncocytic features, the most prevalent molecular alteration are RAS mutations that do not carry prognostic significance. The only genetic alteration that has been proven to play a role in risk stratification of PTC and FTC is TERT promoter (TERTp) mutation.

Overexpression of miR-127 Predicts Poor Prognosis and Contributes to the Progression of Papillary Thyroid Cancer by Targeting REPIN1

Papillary thyroid cancer (PTC) is a major kind of thyroid cancer with increasing recurrence and metastasis. MiR-127 has been demonstrated to play roles in many cancers with dysregulation. However, the function of miR-127 is still unknown. This study aimed to explore a novel biomarker for the progression and prognosis of PTC. A set of 118 patients with PTC were collected from the Affiliated Hospital of Qingdao University. qRT-PCR was used to detect the expression of miR-127 in PTC tissues and cells. The association between miR-127 expression and the clinicopathological features of patients were evaluated by the χ² test, and the prognostic value of miR-127 was evaluated by Kaplan-Meier analysis and Cox regression analysis. The effect of miR-127 on cell proliferation, migration, and invasion of PTC was analyzed by CCK-8 and transwell assay. miR-127 was found to be upregulated in PTC tissues and cells correlated with the TNM stage and poor prognosis of PTC patients. MiR-127 and the TNM stage were considered as two independent prognostic indicators for PTC. Moreover, overexpression of miR-127 significantly enhanced cell proliferation, migration, and invasion of PTC by targeting REPIN1. miR-127 may be involved in the progression of PTC, which provides a new therapeutic strategy for PTC.

Radioactive iodine therapy may not improve disease-specific survival in follicular variant papillary thyroid cancer without distant metastasis: A propensity score-matched analysis

BACKGROUND

Whether radioactive iodine (RAI) therapy is effective in improving disease-specific survival (DSS) in patients with follicular variant papillary thyroid cancer (FVPTC) without distant metastasis remains unclear.

METHODS

Patients with FVPTC were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. The Kaplan-Meier method and the Cox proportional hazards regression model were used to evaluate DSS. Propensity score-matched analysis was performed to reduce the influence of confounding bias.

RESULTS

RAI did not improve DSS, even in patients with aggressive features such as T4 classification (p = 0.658), extrathyroidal extension (p = 0.083), lateral lymph node metastasis (p = 0.544), and ≥5 metastatic lymph nodes (p = 0.599).

CONCLUSION

RAI did not affect DSS in patients with FVPTC without distant metastases in this SEER database study. Multicenter, prospective studies including recurrence and molecular information should be conducted to comprehensively evaluate the effects of RAI on FVPTC.

Identification of differentially expressed genes and signaling pathways in papillary thyroid cancer: a study based on integrated microarray and bioinformatics analysis

Background

The techniques of DNA microarray and bioinformatic analysis have exhibited efficiency in identifying dysregulated gene expression in human cancers. In this study, we used integrated bioinformatics analysis to improve our understanding of the pathogenesis of papillary thyroid cancer (PTC).

Methods

In this study, we integrated four Gene Expression Omnibus (GEO) datasets, GSE33630, GSE35570, GSE60542 and GSE29265, including 136 normal samples and 157 PTC specimens. The contents of the four datasets are based on GPL570, an Affymetrix Human Genome U133 Plus 2.0 array. Gene ontology (GO) analysis was used to identify characteristic the biological attributes of differentially expressed genes (DEGs) between PTC and normal samples. GO annotation was performed on the DEGs obtained, and the process relied on the DAVID online tool. Kyoto Encyclopedia of Genes and Genomes (KEGG) approach enrichment analyses were adopted to obtain the basic functions of the DEGs. The KOBAS online analysis database was used to complete DEG KEGG pathway comparison and analysis. The search tool (STRING) database was mainly used to search for interacting genes and complete the construction of protein-protein interaction (PPI) networks.

Results

Five hundred-ninety DEGs were consistently expressed in the four datasets; 327 of them were upregulated, while 263 were downregulated. Ten DEGs, including five upregulated (ENTPD1, THRSP, KLK10, ADAMTS9, MIR31HG) and five downregulated (SCARA5, EPHB1, CHRDL1, LOC440934, FOXP2) genes, were randomly selected for q-PCR in our own tissue samples to validate the integrated data. The most highly enriched GO terms were extracellular exosome (GO:0070062), cell adhesion (GO:0070062), positive regulation of gene expression (GO:0010628), and extracellular matrix (ECM) organization (GO:0030198). KEGG pathway analysis was performed, and it was found that abnormally expressed genes effectively participated in pathways such as tyrosine metabolism, complement and coagulation cascades, cell adhesion molecules (CAMs), transcriptional misregulation and ECM-receptor interaction pathways.

Conclusions

Five hundred-ninety DEGs were identified in PTC by integrated microarray analysis. The GO and KEGG analyses presented here suggest that the DEGs were enriched in extracellular exosome, tyrosine metabolism, CAMs, complement and coagulation cascades, transcriptional misregulation and ECM-receptor interaction pathways. Functional studies of PTC should focus on these pathways.

CHD4 Predicts Aggressiveness in PTC Patients and Promotes Cancer Stemness and EMT in PTC Cells

Chromodomain-helicase-DNA-binding protein 4 (CHD4), a core subunit of the nucleosome remodeling and deacetylation (NuRD) complex is highly expressed in several cancers. However, its role in the pathogenesis and progression of papillary thyroid carcinoma (PTC) has not been investigated. We investigated the prognostic significance of CHD4 in a large cohort of Middle Eastern PTC patients and explored the functional role of CHD4 in regulating cancer stemness and EMT in PTC cells. CHD4 overexpression was observed in 45.3% (650/1436) of PTCs, and was associated with aggressive clinico-pathological parameters and worse outcome. Functional analysis using PTC cell lines showed that forced expression of CHD4 promoted cell proliferation, spheroid growth, migration, invasion and progression of epithelial to mesenchymal transition (EMT) in PTC cells whereas its knockdown reversed the effect. Methylation of E-cadherin was associated with loss of expression in CHD4 expressing cells, while CHD4 depletion reactivated E-cadherin expression. Most importantly, knockdown of mesenchymal transcriptional factors, Snail1 or Zeb1, attenuated the spheroid growth in CHD4 expressing PTC cells, showing a potential link between EMT activation and stemness maintenance in PTC. These findings suggest that CHD4 might be a promising therapeutic target in the treatment of patients with an aggressive subtype of PTC.

Cytomorphologic features as predictors of aggressiveness in patients with pT1 papillary thyroid carcinoma: a retrospective study of associations with clinicopathological parameters in 226 fine-needle aspirates

Background

Distinguishing aggressive pT1 papillary thyroid carcinomas (PTCs) from indolent PTCs before or during surgery is important. To the best of our knowledge, few reports in the literature have examined the value of the cytomorphologic features of PTC as predictors of aggressiveness.

Methods

This retrospective study included 226 pT1 PTC patients who underwent preoperative fine-needle aspiration cytology (FNAC) and surgery at Peking University Cancer Hospital between January 2018 and December 2019. Data on the clinical characteristics and pathological results were obtained from the electronic medical record database. All FNAC smears were blindly reviewed by two independent cytopathologists, and the associations between nine cytomorphologic features (lymphocytes, multinucleated giant cells, cellularity, cellular adhesiveness, nuclear size, nuclear pleomorphism, nuclear membrane regularity, intranuclear pseudoinclusions and the amount of cytoplasm) and clinicopathological parameters were statistically analyzed.

Results

Univariate analysis showed that cellularity, intranuclear pseudoinclusions, cellular adhesiveness, nuclear size, and nuclear pleomorphism were strong predictors of some clinicopathological parameters such as extracapsular invasion (ECI) and lymph node metastasis (LNM). Multivariate analysis confirmed that cellular adhesiveness was a strong independent predictor of ECI (P=0.001) and LNM (P<0.001), and the amount of cytoplasm can also predict LNM (P=0.024).

Conclusions

Cytomorphologic features including cellular adhesiveness and the amount of cytoplasm in preoperative FNAC smears could be a valuable tool for predicting ECI or LNM and may be predictors of aggressiveness in patients with pT1 PTC.

High Incidence of Distant Metastasis Is Associated With Histopathological Subtype of Pediatric Papillary Thyroid Cancer - a Retrospective Analysis Based on SEER

OBJECTIVE

Children with papillary thyroid cancer (PTC) have a higher invasive rate and distant metastasis rate, but the mortality rate is lower with unknown reasons. The majority of PTC cases comprise classical papillary thyroid carcinoma (CPTC) and follicular variant papillary thyroid carcinoma (FVPTC). This study aimed to determine the relationship between histopathological subtype and rate of distant metastasis and investigate factors influencing distant metastasis in pediatric PTC.

METHODS

A total of 102,981 PTC patients were recruited from SEER registry, 2004-2015. Proportion of distant metastasis between children (≤18 years) and adults with different histopathological subtypes was compared by propensity score matching. The cut-off age for distant metastasis in children was calculated by receiver operating characteristic (ROC) curve, and the risk factors for distant metastasis in pediatric patients were analyzed by logistic regression models.

RESULTS

Among the 1,484 children and 101,497 adults included in the study, the incidence of CPTC patients with distant metastasis in children was higher than that in adults (p<0.001). The ROC curve was calculated, which yielded a cut-off age for distant metastasis in CPTC children as 16 years old. In CPTC, the proportion of young children (2-16 years) with distant metastasis was higher than that of adolescents (17-18 years) and adults (>18 years) (both p<0.001). While there was no such trend in FVPTC. In young children (2-16 years), the incidence of CPTC with distant metastasis was higher than FVPTC (p=0.006). There was no difference between the proportion of CPTC and FVPTC with distant metastasis in adolescents (17-18 years) and adults. Logistic regression models revealed that extrathyroidal extension, lymph node metastasis and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2 -16 years.

CONCLUSIONS

In CPTC, the incidence of distant metastasis in young children (2-16 years) was significantly higher than that in adolescents (17-18 years) and adults (>18 years). In patients with distant metastasis aged 2-16 years, the proportion of CPTC was higer than that of FVPTC. Extrathyroidal extension, lymph node metastasis, and CPTC histopathological subtype were risk factors for distant metastasis in young children aged 2-16 years.

Tall Cell Variant versus Conventional Papillary Thyroid Carcinoma: A Retrospective Analysis in 351 Consecutive Patients

Background: The aim of this retrospective study was to investigate clinical and pathological characteristics of the tall cell variant of papillary thyroid carcinoma compared to conventional variants. Methods: The clinical records of patients who underwent surgical treatment between 2009 and 2015 were analyzed. The patients were divided into two groups: those with a histopathological diagnosis of tall cell papillary carcinoma were included in Group A, and those with a diagnosis of conventional variants in Group B. Results: A total of 35 patients were included in Group A and 316 in Group B. All patients underwent total thyroidectomy. Central compartment and lateral cervical lymph node dissection were performed more frequently in Group A (42.8% vs. 18%, p = 0.001, and 17.1% vs. 6.9%, p = 0.04). Angiolymphatic invasion, parenchymal invasion, extrathyroidal extension, and lymph node metastases were more frequent in Group A, and the data reached statistical significance. Local recurrence was more frequent in Group A (17.1% vs. 6.3%, p = 0.02), with two patients (5.7%) in Group A showing visceral metastases, whereas no patient in Group B developed metastatic cancer (p = 0.009). Conclusions: Tall cell papillary carcinoma is the most frequent aggressive variant of papillary thyroid cancer. Tall cell histology represents an independent poor prognostic factor compared to conventional variants.

Evaluation of Clinicopathological and Molecular Parameters on Disease Recurrence of Papillary Thyroid Cancer Patient: A Retrospective Observational Study

Simple Summary

Papillary thyroid cancer (PTC) patients are staged according to the Tumor-Node-Metastasis staging system (TNM). This work was aimed at comparing the usefulness of the 8th edition of TNM (TNM-8), currently used, and that of the previous one (TNM-7) for predicting disease-free interval (DFI) in a cohort of 1148 patients. Moreover, clinicopathological and molecular factors were statistically evaluated in order to determine which of these was/were the best predictor(s) of DFI. Results obtained from the multivariate analysis indicated that advanced tumor stages were independent risk factors for a lower DFI regardless of TNM, but the statistical model created with the TNM-7 was most accurate. When stage-determining factors were included individually in the multivariate analysis, LN metastases, tall cell variant, and age emerged as independent risk factors for a shorter DFI, with lateral LN metastases being the most relevant. No molecular parameters could improve the prediction of DFI provided by LN metastases.

Abstract

The American Joint Committee on Cancer has revised the Tumor-Node-Metastasis (TNM) staging system for papillary thyroid cancer (PTC) patients. We examined the impact of this new classification (TNM-8) on patient stratification and estimated the prognostic value of clinicopathological features for the disease-free interval (DFI) in a cohort of 1148 PTC patients. Kaplan–Meier analyses showed that all clinicopathological parameters analyzed, except age and multifocality, were associated significantly with DFI. Cox regression identified tall cell PTC variant and stage as independent risk factors for DFI. When the stage was replaced with age, tumor size, and lymph node (LN) metastases in the set of covariates, the lateral LN metastases stood out as the strongest independent predictor of DFI, followed by tall cell variant and age. A noteworthy result emerging from these analyzes is that regression models had lower Akaike and Bayesian information criterions if variables were categorized based on the TNM-7. In addition, we examined data from a different PTC patient cohort, acquired from The Cancer Genome Atlas database, to verify whether the DFI prediction could be enhanced by further clinicopathological and molecular parameters. However, none of these was found to be a significant predictor of DFI in the Cox model.