When thyroid carcinoma goes bad: a morphological and molecular analysis

The association between thyroid differentiation score and survival outcomes in papillary thyroid carcinoma

BACKGROUND

Thyroid differentiation score (TDS), calculated based on mRNA expression levels of 16 genes controlling thyroid metabolism and function, has been proposed as a measure to quantify differentiation in PTC. The objective of this study is to determine whether TDS is associated with survival outcomes across patient cohorts.

METHODS

Two independent cohorts of PTC patients were used: 1) the Cancer Genome Atlas (TCGA) thyroid cancer study (N=372), 2) MD Anderson Cancer Center (MDACC) cohort (N=111). The primary survival outcome of interest was progression-free interval (PFI). Association with overall survival (OS) was also explored. The Kaplan-Meier method and Cox proportional hazards models were used for survival analyses.

RESULTS

In both cohorts, TDS was associated with tumor and nodal stage at diagnosis as well as tumor driver mutation status. High TDS was associated with longer PFI on univariable analyses across cohorts. After adjusting for overall stage, TDS remained significantly associated with PFI in the MDACC cohort only (aHR 0.67, 95%CI 0.52-0.85). In subgroup analyses stratified by tumor driver mutation status, higher TDS was most consistently associated with longer PFI in BRAFV600E-mutated tumors across cohorts after adjusting for overall stage (TCGA: aHR 0.60, 95% CI: 0.33-1.07; MDACC: aHR 0.59, 95% CI: 0.42-0.82). For OS, increasing TDS was associated with longer OS in the overall MDACC cohort (aHR=0.78, 95% CI:0.63-0.96), where the median duration of follow-up was 12.9 years.

CONCLUSION

TDS quantifies the spectrum of differentiation status in PTC and may serve as a potential prognostic biomarker in PTC, mostly promisingly in BRAFV600E-mutated tumors.

Enhancing Angioinvasion Assessment in Papillary Thyroid Cancer Via a Biomarker Panel Involving TAC, 8-OHdG, and Sortilin

CONTEXT

Papillary thyroid cancer (PTC) aggressiveness and metastatic potential are closely associated with angioinvasion. Identifying angioinvasion accurately is imperative for treatment planning and prognosis.

OBJECTIVE

This study explores serum biomarkers, including 8-hydroxydeoxyguanosine (8-OHdG) and oxidative status markers (total oxidative capacity, total antioxidant capacity [TAC], and sortilin), as potential indicators of angioinvasion in PTC.

DESIGN

A cross-sectional study involving 50 angioinvasive patients with PTC (study group) and 30 patients with PTC with low-risk features (reference group). Serum levels of biomarkers were analyzed to determine their association with angioinvasion.

SETTING

Patients were recruited from Department of Endocrinology, Diabetology, and Internal Diseases, Medical University of Bialystok, Poland, ensuring representation from a diverse clinical context.

PATIENTS OR OTHER PARTICIPANTS

Participants included patients with PTC, with 50 in the study group and 30 in the reference group. Selection criteria, matching characteristics, and participant completion rates were duly recorded.

INTERVENTION(S)

Serum biomarkers were measured to evaluate their association with PTC angioinvasion.

MAIN OUTCOME MEASURE(S)

Primary outcome measures included serum levels of 8-OHdG, total oxidative capacity, TAC, and sortilin.

RESULTS

Serum levels of 8-OHdG and sortilin were significantly elevated in angioinvasive PTC, whereas TAC showed a notable decrease (all P < .01). A regression panel combining TAC, 8-OHdG, and sortilin demonstrated a high area under the curve value (0.963) for angioinvasion discernment.

CONCLUSION

Measuring TAC, 8-OHdG, and sortilin levels may serve as potential biomarkers for identifying angioinvasion in PTC. The combined assessment of these biomarkers enhances angioinvasion discernment, aiding risk stratification and personalized treatment decisions. Further validation studies are required before integrating these biomarkers into routine clinical practice. The study adheres to the provided structure, providing concise and supported conclusions based on the results.

Pathology and new insights in thyroid neoplasms in the 2022 WHO classification

PURPOSE OF REVIEW

The assessment of thyroid nodules is a common clinical problem, linked to the high incidence of thyroid nodules in the population and the low incidence of aggressive thyroid carcinoma. The screening is therefore one of the strengths of our patient care. Recently, the 2023 Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) and 2022 WHO classification of thyroid neoplasms have been released based on the definition of new entities and the growing impact of molecular testing. The aim of this review is to analyze how these upgrades can help us in the daily routine practice diagnosis of thyroid cancer.

RECENT FINDINGS

Our review is focused on the most frequent thyroid tumors derived from thyroid follicular cell. Fine needle aspiration (FNA) is the gold standard for the screening of thyroid nodules with very high levels of sensitivity and specificity. These sensitivity and specificity are improved by molecular testing, which refines the risk of malignancy. The 2023 TBSRTC integrates molecular data and the upgrades integrated in the 2022 WHO classification such as the 'low-risk neoplasms' and the 'high-grade follicular-cells derived carcinoma'. The morphological examination remains crucial since the capsular and/or vascular invasion are key features of malignancy in the follicular thyroid neoplasms. Low-risk neoplasms represent a clinical challenge since no specific guidelines are available. Challenges remain regarding oncocytic thyroid lesions, which are not associated with specific diagnostic molecular biomarkers. Molecular testing can help not only in deciphering the prognosis but also in the targeted therapeutic strategy.

SUMMARY

While molecular testing has succeeded to substantially improve the pre and postoperative diagnosis and risk stratification of thyroid tumors, the morphological examination is still central in the daily routine diagnosis of thyroid pathology. Future is the integrated diagnosis of clinical, morphological, molecular and epigenetic features with the help of artificial intelligence algorithms.

Association of Polygenic Score With Tumor Molecular Subtypes in Papillary Thyroid Carcinoma

CONTEXT

Genome-wide association studies have identified germline variants associated with elevated PTC risk. It is also known that somatic driver mutations contribute to PTC development and as such PTCs can be further categorized into different molecular subtypes based on their somatic alterations. However, it remains unknown whether identified germline variants predictive of PTC risk are associated with specific molecular subtypes.

OBJECTIVE

The primary goal of the present study is to determine whether germline genetic risk, as assessed using a polygenic score (PGS) is associated with molecular subtypes of papillary thyroid carcinoma (PTC), defined based on tumor driver mutation status.

METHODS

This study was carried out using data from The Cancer Genome Atlas (TCGA) thyroid cancer study. A previously validated 10-single-nucleotide variation PGS for PTC derived from genome-wide association study hits was calculated to ascertain germline genetic risk. The primary molecular subtypes of interest were defined by tumor driver mutation status (BRAFV600E-mutated vs RAS-mutated vs "other"). We also explored associations between PGS and molecular subtypes defined by messenger RNA (mRNA) expression, microRNA expression, and DNA methylation patterns. Polytomous logistic regression analysis was used to assess the association between PGS and PTC molecular subtype with and without adjustment for clinical variables. Odds ratios (ORs) with their 95% CIs were estimated.

RESULTS

A total of 359 patients were included in the study. PGS was significantly associated specific tumor molecular subtypes defined by tumor driver mutation status. Increasing germline risk was associated with having a higher odd of BRAFV600E-mutated PTC compared to PTCs without driver mutations in the "other" category. No significant difference was detected in terms of PGS tumor categorization in the RAS subtype compared to BRAFV600E. In exploratory analyses, PGS was also associated with mRNA-, microRNA-, and DNA methylation-defined molecular subtypes, as defined by the TCGA PTC study.

CONCLUSION

PGS has molecular subtype-specific associations in PTC, which has implications for their use in risk prediction.

Exploring the clinical utility of angioinvasion markers in papillary thyroid cancer: a literature review

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer, and angioinvasion, the invasion of blood vessels by cancer cells, is a crucial pathological feature associated with disease progression and poor prognosis. Thus, a comprehensive search of scientific databases was conducted to identify relevant studies investigating angioinvasion markers in PTC. The selected studies were reviewed and analyzed to assess the clinical significance and potential utility of these markers in predicting angioinvasion and guiding treatment decisions. Numerous studies have investigated various markers associated with angioinvasion in PTC, including oxidative stress, vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMPs), and other angiogenic factors. The results indicate that increased expression of these markers is correlated with the presence and extent of angioinvasion in PTC. Moreover, some studies suggest that these markers can serve as prognostic indicators and guide therapeutic strategies, such as selecting patients for more aggressive treatment approaches or targeted therapies. The findings from the reviewed literature highlight the potential clinical utility of angioinvasion markers in PTC. The identification and validation of reliable markers can aid in assessing the risk of angioinvasion, predicting disease progression, and optimizing treatment decisions for patients with PTC. However, further research and validation on larger patient cohorts are necessary to establish the robustness and generalizability of these markers in clinical practice.

Clinical and Pathological Features and Gene Expression Profiles of Clinically Aggressive Papillary Thyroid Carcinomas

Papillary thyroid carcinoma (PTC) is considered an indolent neoplasm but it may demonstrate aggressive behavior. We aimed to identify clinical and pathological characteristics and molecular signatures associated with aggressive forms of PTCs. We selected 43 aggressive PTC cases based on the presence of metastases at the time of diagnosis, the development of distant metastasis during follow-up, and/or biochemical recurrence, and 43 PTC patients that were disease-free upon follow-up, matching them according to age, sex, pT, and pN parameters. Twenty-four pairs (a total of 48 cases) and 6 normal thyroid tissues were studied using targeted mRNA screening of cancer-associated genes employing NanoString nCounter® technology. In general, aggressive PTCs showed distinctive clinical and morphological features. Among adverse prognostic parameters, the presence of necrosis and an increased mitotic index were associated with shorter disease-free and overall survivals. Other parameters associated with shorter disease-free or overall survivals include a lack of tumor capsule, the presence of vascular invasion, tumor-infiltrating lymphocytes, fibrosclerotic changes, age > 55 years, and a high pTN stage. Various pathways were differentially regulated in non-aggressive as compared to aggressive PTC, including the DNA damage repair, the MAPK, and the RAS pathways. In particular, the hedgehog pathway was differentially de-regulated in aggressive PTC as compared to non-aggressive PTC cases, being WNT10A and GLI3 genes significantly up- and down-regulated in aggressive PTC and GSK3B up-regulated in non-aggressive PTC cases. In conclusion, our study revealed specific molecular signatures and morphological features in aggressive PTC that may be useful to predict more aggressive behavior in a subset of PTC patients. These findings may be useful when developing novel, tailored treatment options for these patients.

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.

Role of Suprabasin in the Dedifferentiation of Follicular Epithelial Cell-Derived Thyroid Cancer and Identification of Related Immune Markers

Background: Aberrant regulation of suprabasin (SBSN) is associated with the development of cancer and immune disorders. SBSN influences tumor cell migration, proliferation, angiogenesis, and immune resistance. In this study, we investigated the potential correlation between SBSN expression and immune infiltration in thyroid cancer.

Methods: The expression of SBSN in 80 papillary thyroid carcinoma (PTC) specimens was determined using quantitative reverse-transcription polymerase chain reaction, western blotting, and immunohistochemical staining. The expression of SBSN in 9 cases of poorly differentiated thyroid carcinoma (PDTC) and 18 cases of anaplastic thyroid carcinoma (ATC) was evaluated by immunohistochemical staining. Comprehensive bioinformatics analysis of SBSN expression was performed using The Cancer Genome Atlas and Gene Expression Omnibus datasets, and the relationship of SBSN expression with M2 macrophages and T regulatory cells (Tregs) in ATC and PTC was verified by immunohistochemical staining.

Results: Compared with those in adjacent normal tissues, the expression levels of SBSN mRNA and protein were significantly higher in PTC tissues. SBSN expression level was correlated with that of cervical lymph node metastasis in PTC patients. Immunohistochemical staining results showed statistically significant differences among high-positive expression rates of SBSN in PTC, PDTC, and ATC. Functional enrichment analysis showed that SBSN expression was associated with pathways related to cancer, cell signaling, and immune response. Furthermore, analysis of the tumor microenvironment (using CIBERSORT-ABS and xCell algorithms) showed that SBSN expression affected immune cell infiltration and the cancer immunity cycle, and immunohistochemistry confirmed a significant increase in M2 macrophage and Treg infiltration in tumor tissues with high-positive SBSN expression.

Conclusion: These findings reveal that SBSN may be involved in thyroid carcinogenesis, tumor dedifferentiation progression, and immunosuppression as an important regulator of tumor immune cell infiltration.

Characterization of the CpG island methylator phenotype subclass in papillary thyroid carcinoma

CpG island methylator phenotype (CIMP), characterized by the concurrent and widespread hypermethylation of a cluster of CpGs, has been reported to play an important role in carcinogenesis. Limited studies have explored the role of CIMP in papillary thyroid carcinomas (PTCs). Here, in genome-wide DNA methylation analysis of 350 primary PTCs from the Cancer Genome Atlas database that were assessed using the Illumina HumanMethylation450K platform, our study helps to identify two subtypes displayed markedly distinct DNA methylation levels, termed CIMP (high levels of DNA methylation) and nCIMP subgroup (low levels of DNA methylation). Interestingly, PTCs with CIMP tend to have a higher degree of malignancy, since this subtype was tightly associated with older age, advanced pathological stage, and lymph node metastasis (all P < 0.05). Differential methylation analysis showed a broad methylation gain in CIMP and subsequent generalized gene set testing analysis based on the significantly methylated probes in CIMP showed remarkable enrichment in epithelial mesenchymal transition and angiogenesis hallmark pathways, confirming that the CIMP phenotype may promote the tumor progression from another perspective. Analysis of tumor microenvironment showed that CIMP PTCs are in an immune-depletion status, which may affect the effectiveness of immunotherapy. Genetically, the significantly higher tumor mutation burden and copy number alteration both at the genome and focal level confirmed the genomic heterogeneity and chromosomal instability of CIMP. tumor Corresponding to the above findings, PTC patients with CIMP showed remarkable poor clinical outcome as compared to nCIMP regarding overall survival and progression-free survival. More importantly, CIMP was associated with worse survival independent of known prognostic factors.

Hobnail variant of papillary thyroid carcinoma with anaplastic dedifferentiation co-existent with tuberculosis lymphadenitis

Introduction

The current study aims to report a rare case of metastatic papillary thyroid carcinoma (PTC) of the cervical lymph nodes with hobnail variant and anaplastic de-differentiation. In addition to the primary disease, there was a second pathology which was caseating granulomatous lymph adenitis suggestive of tuberculosis.

Case report

A 91-year-old female presented with a painful right sided neck swelling for two weeks, increased in size suddenly. On clinical examination, there was a well-defined firm painful right sided neck mass. On ultrasound examination, there was multiple well defined solid hypoechoic, hypervascular nodules. These resembled lymph nodes of variable size and shape, mostly in the right side. The patient underwent right lateral cervical lymph node dissection. After the operation, she was sent for radiotherapy.

Discussion

The hobnail variant of PTC is genetically identical to poorly differentiated thyroid carcinoma in that its mutations are in the p53 and TERT promoters are more common in this variant than in conventional PTCs. The proportion of hobnail features have no effect on the outcome. Additionally, 10% of tumor cells with hobnail features were previously linked to a more aggressive clinicopathological aspect.

Conclusion

Although it is rare, metastatic PTC with hobnail variant could undergo anaplastic dedifferentiation.

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Thyroid carcinoma accounts for nearly 1% of all malignancies.

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The hobnail variant of papillary thyroid carcinoma (HPTC) is a rare condition.

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Anaplastic thyroid carcinoma (ATC) is a rare form of thyroid cancer.

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Malignant lesions and tuberculosis coexisting at the same site is exceedingly unusual.

Micro-RNA-451 Reduces Proliferation of B-CPAP Human Papillary Thyroid Cancer Cells by Downregulating Expression of Activating Transcription Factor 2

Background

MicroRNAs (miRNAs) are novel biomarkers that are important in tumorigenesis and cancer treatment resistance. miR-451 is expressed in human papillary thyroid carcinoma (PTC) tissues and is associated with tumor progression. This study investigated the molecular mechanism associated with the effects of miR-451 on B-CPAP human PTC cells in vitro.

Material/Methods

Binding of miRNAs to the 3′ untranslated region (3′UTR) of messenger RNA (mRNA) was determined with a luciferase reporter assay. miRNAs and plasmids were transfected into human PTC B-CPAP cells with Lipofectamine 2000 Transfection Reagent. Cell viability was tested with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay. The levels of miRNAs and mRNA were determined with quantitative polymerase chain reaction and protein levels were analyzed with immunoblotting.

Results

miR-451 bound to wild-type but not mutant 3′-UTR of activating transcription factor 2 (ATF2). MiR-451 mimics inhibited the growth of B-CPAP cells and reduced mRNA and protein levels in ATF2, whereas miR-451 inhibitors promoted the growth of B-CPAP cells and increased mRNA and protein levels in ATF2.

Conclusions

miR-451 directly bound to the 3′UTR of ATF2, decreased mRNA and protein levels in ATF2, and inhibited growth of B-CPAP cells. Our findings suggest that miR-451 may be a potential therapeutic target for PTC.

Progression and dormancy in metastatic thyroid cancer: concepts and clinical implications

Distant metastasis classically has been defined as a late-stage event in cancer progression. However, it has become clear that metastases also may occur early in the "lifetime" of a cancer and that they may remain stable at distant sites. This stability of metastatic cancer deposits has been termed "metastatic dormancy" or, as we term it, "metastatic progression dormancy" as the progression either may reflect growth of already existing metastases or new cancer spread. Biologically, dormancy is the presence of nongrowing, static metastatic cells that survive over time. Clinically, dormancy is defined by stability in tumor markers, imaging, and clinical course. Metastatic well-differentiated thyroid cancer offers an excellent tumor type to understand these processes for several reasons: (1) primary therapy often includes removal of the entire gland with ablation of residual normal tissue thereby removing one source for new metastases; (2) the presence of a sensitive biochemical and radiographic monitoring tests enabling monitoring of metastasis throughout the progression process; and (3) its tendency toward prolonged clinical dormancy that can last for years or decades be followed by progression. This latter factor provides opportunities to define therapeutic targets and/or markers of progression. In this review, we will discuss concepts of metastatic progression dormancy and the factors that drive both long-term stability and loss of dormancy with a focus on thyroid cancer.

Late-onset distant metastases confer poor prognosis in patients with well-differentiated thyroid cancer

Background

Distant metastases from well-differentiated thyroid carcinoma (WDTC) occasionally occur over a wide range of time intervals after primary thyroid surgery. The prognostic impact of the timing of distant metastasis onset remains unclear.

Methods

We retrospectively reviewed the clinicopathologic features and clinical outcomes of 57 patients with WDTC and distant metastases, and evaluated the mutational profiles of BRAF, RAS, and TERT promoter genes. All patients underwent thyroidectomy and radioactive iodine (RAI) ablation using the same treatment protocol. Synchronous distant metastases were defined as those detected within 12 months of the primary WDTC diagnosis. Metachronous metastases were considered early- and late-onset diseases if detected 1-5 and ≥5 years after the primary diagnosis, respectively.

Results

In all patients, the 5- and 10-year cancer-specific survival (CSS) rates after the diagnosis of distant metastasis were 86% and 57%, respectively. Late-onset (≥5 years) metachronous distant metastasis was associated with age of ≥55 years (P=0.043) and patients refractory to RAI therapy (P=0.026). TERT promoter mutations were associated with RAI refractivity (P=0.026). BRAF V600E and RAS mutations had no prognostic significance. Bone metastasis (P=0.002) and the onset time of distant metastasis (P=0.004) were associated with poor CSS. There was no significant difference in CSS between patients with synchronous distant metastases and those with early-onset (1-5 years) metachronous distant metastases. In the multivariate analysis, bone metastasis [hazard ratio (HR) =10.24; 95% confidence interval (CI): 1.25-83.74; P=0.030] and late-onset (≥5 years) metachronous distant metastasis (HR =5.20; 95% CI: 1.01-26.63; P=0.048) were independent predictors for worse CSS.

Conclusions

The prognosis of patients with WDTC was poorer for late metachronously detected metastases than for synchronous or early metachronous metastases. Patients with distant metastasis occurring 5 years later after primary thyroid diagnosis should, therefore, be more carefully treated.

The Prognostic Value of MicroRNAs in Thyroid Cancers-A Systematic Review and Meta-Analysis

Thyroid cancer (TC) includes various phenotypes, from indolent to highly aggressive cancer. The limitations of the current prognostication systems to predict the recurrence risk and the variability in expression of the genes involved in the thyroid carcinogenesis uncover the need for new prognostic biomarkers by taking into account potential epigenetic differences. We aimed to summarize the current knowledge regarding the prognostic impact of microRNAs (miRNAs) in TC. A literature search was conducted in PubMed, Embase, Scopus, and Web of Science databases. Both upregulated and downregulated miRNAs are significantly correlated with worse overall survival (hazard ratio (HR) = 5.94, 95% CI: 2.73-12.90, p < 0.001; HR = 0.51, 95% CI: 0.26-0.96, p = 0.048) disease/recurrence-free survival (HR = 1.58, 95% CI: 1.08-2.32, p = 0.003; HR = 0.37, 95%, CI: 0.24-0.60, p < 0.001). Sensitivity analysis revealed a significant association between the higher expression of miR-146b, miR-221, and miR-222 and the recurrence of papillary TC (OR = 9.11, 95% CI 3.00 to 27.52; p < 0.001; OR = 3.88, 95% CI 1.34 to 11.19, p < 0.001; OR = 6.56, 95% CI 2.75 to 15.64, p < 0.001). This research identified that miR-146b, miR-221, and miR-222 could serve as potential prognostic biomarkers in TC, particularly in PTC. Further studies are needed to strengthen these findings and sustain its clinical applicability.

Gastric metastasis presenting as an overt upper gastrointestinal bleeding treated with chemoembolisation in a patient diagnosed with papillary thyroid carcinoma

We present a case of a patient with known papillary thyroid carcinoma presenting with overt upper gastrointestinal bleeding from a metastatic gastric mass. The gastric mass was diagnosed through transnasal endoscopy with tissue biopsies, revealing papillary thyroid carcinoma cells on histopathological studies. Bleeding was persistent despite standard medical therapy. Chemoembolisation of the major feeding vessels of such tumour provided resolution of bleeding.

De-differentiation of papillary thyroid carcinoma into squamous cell carcinoma in an elderly patient: A case report

RATIONALE

The unpredictability of thyroid cancer can be striking, as the disease may rapidly progress to death in some individuals. Herein, we reported a rare case of aggressive papillary thyroid cell carcinoma (PTC) in an elderly patient de-differentiated into squamous cell carcinoma (SCC).

PATIENT CONCERNS

We describe a case of a 79-year-old Thai woman presented with hoarseness and neck mass for 2 months and she had been diagnosed with a 3-cm papillary thyroid carcinoma (PTC) in the right side of the thyroid gland. Later on PTC de-differentiated into SCC within 3 years after initial presentation.

DIAGNOSIS

De-differentiation from papillary thyroid carcinoma to squamous cell carcinoma.

INTERVENTIONS

The patient underwent a total thyroidectomy at the initial hospital and received high dose radioactive iodine (RAI) treatment at our hospital 1 month following the surgery and then was lost to follow-up. Two years later she came back with new development of right solid-cystic neck mass which was found to be recurrent PTC. A radical neck dissection was done and another high dose RAI treatment was given. However, she developed recurrent mass with tenderness at the site above previous solid cystic mass 6 months later. Re-exploration of the neck mass revealed an inflamed midline mass 2 cm with enlarged right lateral cervical lymph nodes.

OUTCOMES

A histopathological examination of the midline neck mass showed poorly differentiated SCC with lymphatic invasion. The intermingling of two morphologically distinct tumors, a typical PTC and a poorly differentiated SCC, had been identified in 1 out of 14 excised cervical lymph nodes. The patient underwent external beam radiation without chemotherapy. She is still in stable condition at 18 months post-treatment.

LESSONS

This case clearly demonstrated that SCC transformed from a pre-existing PTC. The clinician should consider a possible transformation of papillary thyroid cancer into more aggressive histological types in elderly patients who present with rapidly progressive clinical behavior. However, some patients could have long-term survival if the tumor did not transform into anaplastic thyroid cancer.

Survival With Lenvatinib for the Treatment of Progressive Anaplastic Thyroid Cancer: A Single-Center, Retrospective Analysis

Background: Survival rates for anaplastic thyroid cancer (ATC) have not improved in the past four decades; however, preliminary clinical data indicate that lenvatinib may provide efficacy benefits for patients with ATC. This real-world study aimed to define the potential role of lenvatinib in ATC by examining the impact of treatment administered alongside existing therapies. Methods: This was a retrospective, single-center analysis of Korean patients with confirmed ATC who received lenvatinib between October 2015 and February 2018. Eighteen patients were included (mean ± standard deviation age, 64.9 ± 11.1 years; 61.1% female). Six [33.3%] had resectable disease that progressed after a combination of surgery, radiotherapy, and chemotherapy, and 12 [66.7%] had unresectable disease that progressed after radiation treatment and chemotherapy. Study endpoints were overall survival (OS) and change in volume of the largest tumor assessed via imaging. Results: Median OS for the 18 lenvatinib-treated patients was 230 days (range 64-839 days). Survival rates at 6 months and 1 year were 61.1 and 22.2%, respectively. Three patients (16.7%) survived beyond 1 year; 15 patients died, of whom four (26.7%) had local disease and 11 (73.3%) had distant metastasis. Two patients (11.1%) had tumor volume increases of 9-10%. The other 16 patients (88.9%) had tumor volume reductions of 2-69%. Six patients (33.3%) had tumor volume reductions ≥50%. Conclusions: In patients with ATC who had progressed on prior therapy, addition of lenvatinib could improve survival duration and reduce tumor volume. Further studies of lenvatinib in ATC are warranted.

Mouse models of thyroid cancer: Bridging pathogenesis and novel therapeutics

Due to a global increase in the incidence of thyroid cancer, numerous novel mouse models were established to reveal thyroid cancer pathogenesis and test promising therapeutic strategies, necessitating a comprehensive review of translational medicine that covers (i) the role of mouse models in the research of thyroid cancer pathogenesis, and (ii) preclinical testing of potential anti-thyroid cancer therapeutics. The present review article aims to: (i) describe the current approaches for mouse modeling of thyroid cancer, (ii) provide insight into the biology and genetics of thyroid cancers, and (iii) offer guidance on the use of mouse models for testing potential therapeutics in preclinical settings. Based on research with mouse models of thyroid cancer pathogenesis involving the RTK, RAS/RAF/MEK/ERK, PI3K/AKT/mTOR, SRC, and JAK-STAT signaling pathways, inhibitors of VEGFR, MEK, mTOR, SRC, and STAT3 have been developed as anti-thyroid cancer drugs for "bench-to-bedside" translation. In the future, mouse models of thyroid cancer will be designed to be ''humanized" and "patient-like," offering opportunities to: (i) investigate the pathogenesis of thyroid cancer through target screening based on the CRISPR/Cas system, (ii) test drugs based on new mouse models, and (iii) explore the underlying mechanisms based on multi-omics.

Anaplastic thyroid carcinoma diagnosed after treatment of lenvatinib for papillary thyroid carcinoma

SUMMARY

Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare. The objective this study is to report a case of anaplastic transformation of locally advanced papillary thyroid carcinoma after treatment with lenvatinib. A 74-year-old woman consulted a local physician because of cough and bloody sputum. Thyroid cancer with tracheal invasion was suspected on computed tomography (CT) imaging, and she visited our hospital for treatment. We suspected anaplastic thyroid cancer (ATC) and core needle biopsy was performed. Histologic sections of the core needle biopsy showed that the tumor formed a papillary structure, and we diagnosed papillary thyroid carcinoma. Surgery would have been difficult, and we initiated lenvatinib at a low dose of 8 mg/day. CT on day 40 of lenvatinib treatment revealed that the thyroid tumor had shrunk remarkably. CT on day 111 revealed that tumor regrowth and tracheal invasion had been exacerbated. Core needle biopsy was performed, and histologic sections of the core needle biopsy that was performed after regrowth of the tumor showed that individual cancer cells had large, irregular nuclei, and necrosis was also observed. The immunohistochemical findings were negative for thyroglobulin, and only a few cells were positive for thyroid transcription factor 1, and we diagnosed ATC. Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

LEARNING POINTS

Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare. The resistance mechanism of lenvatinib in treatment for differentiated thyroid carcinoma has not been clarified. Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

Columnar cell papillary thyroid carcinoma prognosis: findings from the SEER database using propensity score matching analysis

BACKGROUND

Columnar cell papillary thyroid carcinoma (CCPTC) is a rare variant of papillary thyroid carcinoma (PTC), whose prognosis, as defined by the American Thyroid Association (ATA) guidelines, is considered poor, although available evidence is insufficient for reliable assessment. This study aimed to investigate the CCPTC prognosis using the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

Data of thyroid cancer patients, recorded from 2004 to 2013, were extracted to assess the CCPTC prognosis. All-cause and cancer-specific mortality rates associated with thyroid cancer types were evaluated using the Kaplan-Meier method and Cox proportional hazards regression. Propensity score matching analysis was used to adjust for potential confounders.

RESULTS

Cancer-specific mortality per 1000 person-years was higher for CCPTC than for classic papillary thyroid cancer (CPTC) and follicular thyroid cancer (FTC). The multivariate Cox regression model revealed that the cancer-specific and all-cause mortality rates were higher for CCPTC than for CPTC but not FTC. However, propensity score matching analysis demonstrated a significantly lower survival for CCPTC than for both CPTC and FTC.

CONCLUSIONS

Our findings provide evidence to support the poor prognosis associated with CCPTC. These findings may serve to improve the diagnosis of CCPTC, provide reliable reference data for clinical use, and increase the comprehensiveness of current guidelines.

Functions of stem cells of thyroid glands in health and disease

Thyroid gland has been implicated in the regulation of many functions using endocrine, paracrine and autocrine signals. Functional thyroid follicular cells derived from stem cells attracted a great interest from researchers as a strategy for thyroid's regenerative therapy. Thyroid has a very low rate of turnover; however, studies showed that the regenerative ability is enhanced following diseases or thyroidectomy, which promotes the role of stem cell. The objective of this review is to summarize the morphological characterization and the expression of stem cell genes/markers in the thyroid. Also, to highlight the mechanisms of tumor formation in thyroid via its stem cells. The most important thyroid stem cell's markers are: stem cell antigen 1 (SCA-1), octamer-binding transcription 4 (OCT-4), p63, CD34+ CD45-, paired box gene 8 (PAX-8), thyroid transcription factor 1 (TTF-1), thyroid transcription factor 2 (TTF-2), hematopoietically expressed homeobox protein HHEX, the transcription factor GATA-4, hepatocyte nuclear factor 4-α (HNF-4-α) and homeobox transcription factor Nanog (hNanog). This review highlights the functional characterization describing the mechanisms of stem cell's differentiation into functional thyroid follicle and proposing mechanisms involving in cancer formation through one of these cell types: fetal cell, thyroblasts, prothyrocytes, certain genetic mutation in the mature thyroid cells or presence of a special type of cells (cancer stem cell) which are responsible for different types of cancer formation. Understanding the mechanisms of thyroid's stem cell in cancer formation and the expression of the biomarkers in normal and abnormal thyroid status are promising physiological tools in promoting thyroid regeneration and in provision management for thyroid cancer.

The Current Histologic Classification of Thyroid Cancer

Thyroid cancers of follicular cell derivation provide excellent phenotype-genotype correlations. Current morphologic classifications are complex and require simplification. Benign adenomas have follicular or papillary architecture and bland cytology. Well-differentiated thyroid carcinomas exhibit follicular architecture, expansile growth, and variable cytologic atypia and invasiveness; low-risk tumors have excellent prognosis after surgical resection whereas widely-invasive and angioinvasive tumors warrant total thyroidectomy and radioablation. Papillary carcinoma is less differentiated; indolent microcarcinomas can be managed by active surveillance, whereas clinical lesions with local or distant spread require therapy. Progression gives rise to poorly differentiated and anaplastic carcinomas that are less common but far more aggressive.

Columnar Cell Variant of Papillary Thyroid Carcinoma: Ultrasonographic and Clinical Differentiation between the Indolent and Aggressive Types

Objective

To evaluate the ultrasonography (US) features and clinical characteristics of columnar cell variant of papillary thyroid carcinoma (CCV-PTC) that can predict disease progression.

Materials and Methods

Six cases of CCV-PTC were identified via surgical pathology analysis at our institution from 1994 to 2016. The histological, architectural, and cytological features met the diagnostic criteria of CCV-PTC. We reviewed the US features and clinicopathological findings in the six cases.

Results

An indolent clinical course was observed in four young female patients aged 27–34 years (median: 32 years), while two older patients aged 55 years or 70 years had an aggressive clinical course. All patients underwent total thyroidectomy and radioiodine therapy. The indolent group included patients with T1 and nodal metastasis, where the disease was not observed during the follow-up period (range: 8–17 years). On the other hand, a larger tumor size (1.8 cm and 6.0 cm), gross extrathyroidal extension to the muscle and lymph node, and distant metastasis were observed in the aggressive group. In one male patient, recurrence occurred immediately after operation, and this patient died 4 years after the diagnosis of thyroid cancer. Based on US, the individuals from the indolent group had a smooth margin, except for one. Both cases in the aggressive group had a microlobulated margin.

Conclusion

Favorable prognosis in CCV-PTC is observed in young patients with T1 staging and demonstrates a smooth margin at US. These US findings might help exclude the same treatment as the aggressive type in the indolent type of CCV-PTC.

The epigenetic landscape of differentiated thyroid cancer

Differentiated thyroid carcinoma of follicular cell-derivation is the most common endocrine neoplasm with a rapidly increasing incidence. The majority represent papillary carcinomas; more rarely, they are follicular carcinomas. The vast majority have indolent behavior, however a significant proportion progress to develop lymph node metastases and a smaller proportion disseminate systemically. While common and frequent genetic events have been described to underlie the development of these neoplasms, the factors contributing to differing behaviors among tumors with similar genetic alterations remain unclear. This review focuses on epigenetic mechanisms targeting major signaling pathways that underlie the spectrum of biological behaviors and that may have potential diagnostic, prognostic and therapeutic value.

Seemingly Harmless Differentiated Thyroid Carcinoma Presenting as Bone Metastasis

Thyroid carcinoma is the most common endocrine neoplasia. Differentiated thyroid carcinomas (DTCs) represent the majority of cases, which usually follow an indolent clinical course with low mortality rates. The authors describe two cases of well DTC without classic histological poor prognosis features, presenting as extensive and unresectable osteolytic bone metastases. DTCs are considered harmless tumours, due to their benign and silent behaviour. The authors want to underline the importance of clinical awareness during follow-up in cases of DTC, which can be aggressive in presentation and behaviour. Timely identification and diagnosis of these tumours are essential for prompt treatment initiation and improvement of overall survival.

Kallikreins Stepwise Scoring Reveals Three Subtypes of Papillary Thyroid Cancer with Prognostic Implications

BACKGROUND

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Unlike most cancers, its incidence has dramatically increased in the last decades mainly due to increased diagnosis of indolent PTCs. Adequate risk stratification is crucial to avoid the over-treatment of low-risk patients, as well as the under-treatment of high-risk patients, but the currently available markers are still insufficient. Kallikreins (KLKs) are emergent biomarkers in cancer, but their involvement in PTC is unknown.

METHODS

This study analyzed DNA methylation (HumanMethylation arrays) and gene expression (RNA-Seq) of KLKs, BRAF and RAS mutations, and clinical data from four published thyroid cancer data sets including normal and tumor tissues (n = 73, n = 475, n = 20, and n = 82) as discovery, training, and validation series. The C4.5 classification algorithm was used to generate a decision tree. Disease-free survival was estimated using Kaplan-Meier and Cox approaches. Specific analyses were performed using real-time polymerase chain reaction and immunohistochemistry.

RESULTS

The entire KLK family was deregulated in PTC, displaying a specific epigenetic and transcriptional profile strongly associated with BRAF^V600E or RAS mutations. Thus, a decision-tree algorithm was developed based on three KLKs with >80% sensitivity and >95% specificity, identifying BRAF- and RAS-mutated tumors. Notably, tumors lacking these mutations were classified as BRAF- or RAS-like. Most importantly, the KLK algorithm uncovered a novel PTC subtype showing favorable prognostic features.

CONCLUSIONS

The KLK algorithm could lead to a new clinically applicable strategy with important implications for the risk stratification of PTC and the management of patients.

Gene master regulators of papillary and anaplastic thyroid cancers

We hypothesize that distinct cell phenotypes are governed by different sets of gene master regulators (GMRs) whose strongly protected (by the homeostatic mechanisms) abundance modulates most cell processes by coordinating the expression of numerous genes from the corresponding functional pathways. Gene Commanding Height (GCH), a composite measure of gene expression control and coordination, is introduced to establish the gene hierarchy in each phenotype. If the hypothesis is true, than one can selectively destroy cancer nodules from a heterogeneous tissue by altering the expression of genes whose GCHs are high in cancer but low in normal cell phenotype. Here, we test the hypothesis and show its utility for the thyroid cancer (TC) gene therapy. First, we prove that malignant and cancer free surrounding areas of a surgically removed papillary TC (PTC) tumor are governed by different GMRs. Second, we show that stable transfection of a gene induces larger transcriptomic alterations in the cells where it has higher GCH than in other cells. For this, we profiled the transcriptomes of the papillary BCPAP and anaplastic 8505C TC cell lines before and after stable transfection with NEMP1, DDX19B, PANK2 or UBALD1. The four genes were selected to have similar expression levels but significantly different GCH scores in the two cell lines before transfection. Indeed, each of the four genes triggered larger alterations in the cells where they had larger GCH. Our results prove the feasibility of a personalized gene therapy approach that selectively targets the cancer cells from a tissue.

Digitalislike Compounds Restore hNIS Expression and Iodide Uptake Capacity in Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is a rare malignancy that accounts for 1%-2% of all thyroid cancers. ATC is one of the most aggressive human cancers, with rapid growth, tumor invasion, and development of distant metastases. The median survival is only 5 mo, and the 1-y survival is less than 20%. Moreover, as a result of severe dedifferentiation, including the loss of human sodium iodide symporter (hNIS) expression, radioactive iodide (RAI) therapy is ineffective. Recently, we have demonstrated beneficial effects of autophagy-activating digitalislike compounds (DLCs) on redifferentiation and concomitant restoration of iodide uptake in RAI-refractory papillary and follicular thyroid cancer cell lines. In the current study, the effects of DLCs on differentiation and proliferation of ATC cell lines were investigated. Methods: Autophagy activity was assessed in ATC patient tissues by immunofluorescent staining for the autophagy marker microtubule-associated protein 1A/1B-light chain 3 (LC3). In addition, the effect of autophagy-activating DLCs on the proliferation, gene expression profile, and iodide uptake capacity of ATC cell lines was studied. Results: Diminished autophagy activity was observed in ATC tissues, and in vitro treatment of ATC cell lines with DLCs robustly restored hNIS and thyroglobulin expression and iodide uptake capacity. In addition, proliferation was strongly reduced by induction of cell cycle arrest and, to some extent, cell death. Mechanistically, reactivation of functional hNIS expression could be attributed to activation of the transcription factors activating transcription factor 3 and protooncogene c-fosConclusion: DLCs could represent a promising adjunctive therapy for restoring iodide avidity within the full spectrum from RAI-refractory dedifferentiated to ATC.

CTLA-4 gene polymorphisms associate with efficacy of postoperative radioiodine-131 for differentiated thyroid carcinoma

AIM

To investigate the association of CTLA-4 polymorphisms with efficacy of postoperative radioiodine-131 (I-131) treatment for differentiated thyroid carcinoma (DTC).

METHODS

A total of 324 DTC patients and 350 healthy individuals were enrolled in our study. Patients received I-131 remnant ablation following surgical resection. Based on the treatment efficacy, patients were divided into the effective (n = 183) and ineffective groups (n = 141). CTLA-4 polymorphisms (+49A>G, CT60A>G and -318C>T) were genotyped by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS

AG + AA genotype distribution and A allele frequency of +49A>G and CT60A>G polymorphisms were higher in the effective group than the ineffective group.

CONCLUSION

+49A>G and CT60A>G polymorphisms were associated with the efficacy of postoperative I-131 treatment for DTC; and they might be bioindicators related to the prognosis of I-131 treatment.

The evolution of differentiated thyroid cancer

Differentiated thyroid tumours of follicular cell derivation have traditionally been classified based on architecture, cytology, or both. The features that distinguish the various entities are controversial and diagnostic criteria are inconsistent and often irreproducible. The complexity of classification schemes has not been substantiated by molecular profiling. In this review, a simplistic approach to the diagnosis of well differentiated thyroid neoplasia is provided to challenge the dogma. The proposed classification matches the molecular profiles of these lesions and simplifies the criteria for diagnosis. This approach can be used to support rational treatment algorithms.

Papillary thyroid carcinoma with nodular fasciitis-like stroma and β-catenin mutations should be renamed papillary thyroid carcinoma with desmoid-type fibromatosis

Various histological variants of papillary thyroid carcinoma have been reported, some with clinical implications, some with peculiar, sometimes misleading morphologies. One of these rare and poorly characterized variants is papillary thyroid carcinoma with nodular fasciitis-like stroma, of which fewer than 30 cases have been documented, mostly as isolated reports. It is a dual tumor comprising a malignant epithelial proliferation that harbors typical features of conventional papillary thyroid carcinoma, admixed with a prominent mesenchymal proliferation resembling nodular fasciitis or fibromatosis. Thus, the terms papillary thyroid carcinoma with nodular fasciitis-like stroma and papillary thyroid carcinoma with fibromatosis-like stroma are used interchangeably; however, the former term suggests a self-limited and regressing disease, whereas the latter one suggests a recurrent and potentially aggressive one. Better genetic and ultrastructural characterization could lead to more appropriate terminology and management. We performed detailed clinicopathological and molecular analyses of two cases of PTC with prominent mesenchymal proliferation that developed in the thyroid gland of two male patients aged 34 and 48. In both cases, the epithelial component harbored a heterozygous somatic activating BRAF mutation (p.V600E). Also, in both cases, the mesenchymal component showed typical aberrant nuclear and cytoplasmic immunoreactivity for β-catenin and harbored a heterozygous somatic activating mutation in the corresponding CTNNB1 gene (p.S45P). This mutation has never been reported in thyroid stroma; in other tissues, it is typical of desmoid-type fibromatosis rather than nodular fasciitis-like stroma. We therefore propose that in cases of papillary thyroid carcinoma with a prominent mesenchymal component, mutations in CTNNB1 should be sought; when they are present, the term 'papillary thyroid carcinoma with desmoid-type fibromatosis' should be used. As the mesenchymal component of these tumors is not expected to concentrate radioactive iodine, special considerations apply to clinical evaluation and follow-up, which should be brought to the attention of the treating specialist.

Metastatic Papillary Thyroid Carcinoma with Multifocal Synchronous Transformation to Anaplastic Thyroid Carcinoma

Papillary thyroid carcinoma is a common malignancy to affect the thyroid and is typified by a nonaggressive nature and low rates of mortality. In contrast, anaplastic thyroid carcinoma is the most aggressive thyroid malignancy with a mortality rate of nearly 90% and survival typically of only six months after the diagnosis is made. The transformation of papillary thyroid carcinoma to anaplastic thyroid carcinoma is well documented in the literature but is uncommon and in most instances is reported as a case report or small series only. Transformation of papillary thyroid carcinoma to anaplastic thyroid carcinoma usually takes place in the thyroid itself or in the adjacent lymph nodes. Only on rare occasions does a transformation occur in a papillary thyroid carcinoma metastasis outside of these locations. In the present case report and subsequent discussion we highlight an unusual case of PTC with transformation to anaplastic thyroid carcinoma, which is shown to involve numerous locations to include near total lung parenchyma obliteration. We also discuss the differential diagnostic challenges when faced with a thyroid malignancy that is negative for thyroglobulin.

PREDICTIVE VALUE OF SOMATIC MUTATIONS FOR THE DEVELOPMENT OF MALIGNANCY IN THYROID NODULES BY CYTOPATHOLOGY

OBJECTIVE

The purpose of our prospective longitudinal study was to evaluate the predictive efficacy of genetic testing for malignancies in fine-needle aspiration biopsy samples that are cytologically benign at the time of biopsy.

METHODS

A total of 779 aspirated cytological samples collected from thyroid nodules of 626 patients were included in a 3-year follow-up study. Consecutive patients with cytologically benign thyroid nodules by the Bethesda System for Reporting Thyroid Cytopathology were enrolled in the study. At enrollment, somatic 1-point nucleotide polymorphisms of BRAF and RAS family genes were tested by melting-point analysis, while RET/PTC and PAX8/PPAR-gamma rearrangements were examined by real-time polymerase chain reaction. The genetic test was considered to be positive if a somatic mutation was found. Malignant cytopathologic diagnoses were confirmed by histopathology.

RESULTS

In samples collected from 779 thyroid nodules, there were 39 BRAF, 33 RAS mutations, and 1 RET/PTC rearrangements found at the beginning of the study. No PAX8/PPAR-gamma rearrangement was identified. There were 52 malignant thyroid tumors removed during follow-up, out of which 24 contained a somatic mutation. The specificity of the presence of somatic mutations for malignancies was as high as 93.3%, and sensitivity was 46.2%. The negative predictive value of genetic testing reached 96.0%.

CONCLUSION

Our results show that our set of genetic tests can predict the appearance of malignancy in benign thyroid nodules (at the beginning of follow-up) with high specificity and strong negative predictive value.

ABBREVIATIONS

BRAF = v-raf murine sarcoma viral oncogene homolog B1 FLUS = follicular lesion of undetermined significance FNAB = fine-needle aspiration biopsy FTC = follicular thyroid carcinoma HRAS = homologous to the oncogene from the Harvey rat sarcoma virus KRAS = homologous to the oncogene from the Kirsten rat sarcoma virus NRAS = first isolated from a human neuroblastoma/neuroblastoma RAS = viral oncogene homolog PAX8 = paired box 8 PCR = polymerase chain reaction PPAR-gamma = peroxisome proliferator-activated receptor gamma PTC = papillary thyroid carcinoma RAS = rat sarcoma RET = rearranged during transfection tyrosine-kinase proto-oncogene SM = somatic mutation SNP = single-nucleotide polymorphism.

Molecular cytopathology for thyroid nodules: A review of methodology and test performance

Advances in the molecular characterization of thyroid cancers have fueled the development of genetic and gene expression-based tests for thyroid fine-needle aspirations. Collectively, these tests are designed to improve the diagnostic certainty of thyroid cytology. This review summarizes the early published experience with the commercially available versions of these tests: the Afirma Gene Expression Classifier, ThyGenX (formerly miRInform)/ThyraMIR, and ThyroSeq. Key differences in testing approaches and issues regarding test performance and interpretation are also discussed.