The changing landscape of papillary thyroid cancer: Epidemiology, management, and the implications for patients

Long noncoding RNA SNHG22 increases ZEB1 expression via competitive binding with microRNA-429 to promote the malignant development of papillary thyroid cancer

Long noncoding RNA termed small nucleolar RNA host gene 22 (SNHG22) is a crucial regulator in epithelial ovarian carcinoma. Nevertheless, the regulatory functions of SNHG22 in papillary thyroid cancer (PTC) progression and its mechanisms of action remain poorly defined. Therefore, the present study aimed to investigate the role of SNHG22 in the malignant phenotype of PTC and determine whether SNHG22 regulates PTC progression via a ceRNA mechanism. SNHG22 expression in PTC was detected using reverse transcription-quantitative polymerase chain reaction analysis. The biological actions of SNHG22 silencing in PTC cells were evaluated both in vitro (using Cell Counting Kit-8 assay, flow cytometry analysis, and cell migration and invasion assays) and in vivo (using tumorigenicity assay). Herein, high SNHG22 expression was observed in PTC tissues and cell lines. This high SNHG22 level was closely associated with unfavorable clinicopathological characteristics and worse overall survival in patients with PTC. SNHG22 knockdown effectively suppressed PTC cell proliferation, migration, and invasion in vitro; accelerated cell apoptosis; and hindered tumor growth in vivo. Mechanistic experiments revealed that SNHG22 directly interacts with microRNA-429 (miR-429) as an miRNA sponge and positively modulates ZEB1 expression. Rescue assays found that miR-429 inhibition or ZEB1 upregulation can offset the actions of SNHG22 knockdown in PTC cells. In sum, SNHG22, miR-429, and ZEB1 form an interactive regulatory network with cancer-promoting roles in PTC cells, suggesting that the SNHG22/miR-429/ZEB1 pathway is a novel diagnostic and therapeutic target.

Herbal Active Ingredients: An Emerging Potential for the Prevention and Treatment of Papillary Thyroid Carcinoma

Papillary thyroid carcinoma (PTC) is the most common subtype of differentiated thyroid cancers in Asian coastal cities, where the patients have increased risk of potentially high or excessive iodine intake. Given the high metastasis and recurrence of patients with BRAF^V600E mutation, the mortality rate of thyroid cancer has recently shown an upward trend. A variety of therapies, including surgery, radiotherapy, and chemotherapy, have been used to treat thyroid cancer, but these therapies still have limitations, including postoperative complications, drug resistance, poor efficacy, or serious side effects. Recent studies have shown the potential of active ingredients derived from herbal medicine in inhibiting PTC via various cell signaling pathways. Some plant-derived compounds, such as apigenin, genistein, and curcumin, are also known to prevent and treat PTC. This article summarizes the recent advances in the structure-functional impact of anti-PTC active ingredients and their effects on PTC cells and tumor microenvironments with an emphasis on their challenges from basic research to clinical practice.

miR-873-5p Inhibits Cell Migration and Invasion of Papillary Thyroid Cancer via Regulation of CXCL16

Aim

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer with an increasing morbidity. MicroRNAs (miRNAs) play the pivotal roles in PTC occurrence and development. The aim of this study was to investigate the biological functions of miR-873-5p and its underlying molecular mechanisms in PTC.

Methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect miR-873-5p expressions in PTC tissues and cell lines. The target gene of miR-873-5p was predicted by TargetScan and confirmed by dual-luciferase reporter assay. Furthermore, cell proliferation, migration and invasion were assessed by CCK-8, wound healing assay and transwell assay, respectively. Additionally, the expressions of CXCL16, MMP1, MMP9 and MMP13 were measured by RT-qPCR and Western blot methods, and p65, Rel-B and their phosphorylation levels were examined by Western blot.

Results

We found that miR-873-5p expression was downregulated in PTC tissues and cell lines. Moreover, CXCL16 was identified as a target of miR-873-5p, and its expression was upregulated in PTC tissues and cells at both mRNA and protein levels. Functionally, overexpression of miR-873-5p inhibited PTC cell proliferation, migration and invasion, while co-transfection of CXCL16 overexpression plasmid reversed the anti-tumor behaviors induced by miR-873-5p. In addition, miR-873-5p overexpression suppressed the phosphorylation of p65 and Rel-B, and decreased the mRNA and protein expression of MMP1, MMP9 and MMP13, while overexpression of CXCL16 partially abrogated the effects of miR-873-5p.

Conclusion

MiR-873-5p functions as a tumor suppressor in PTC by inhibiting the proliferation, migration and invasion of the PTC cells via targeting CXCL16. These findings might provide a potential novel target for the therapy of PTC.

The association of preoperative thyroid-stimulating hormone level and the risk of differentiated thyroid cancer in patients with thyroid nodules: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis was conducted to determine the value of preoperative thyroid-stimulating hormone (TSH) levels in assessing the risk of differentiated thyroid cancer (DTC) in patients with thyroid nodules.

METHODS

This meta-analysis included 23,799 subjects (15,406 non-Chinese and 8,393 Chinese) with thyroid nodules. Multivariate and individual adjusted odds ratios (OR) were calculated for a 1 mU/L increase in preoperative TSH levels to determine the risk of malignant DTC.

RESULTS

The OR for DTC in relation to preoperative TSH levels was significant in Chinese (1.25 [1.11, 1.40], Z = 3.67, p = 0.0002) and non-Chinese subjects (1.12 [1.03, 1.22], Z = 2.72, p = 0.006). The overall random-effects model indicated that there was a significantly increased risk for DTC in patients with thyroid nodules (OR 1.16 [1.06, 1.27], Z = 3.29, p = 0.007).

CONCLUSIONS

A significant association between higher TSH levels and risk of DTC was observed in both population groups investigated, with higher ORs for Chinese subjects.

Silencing of PPM1D inhibits cell proliferation and invasion through the p38 MAPK and p53 signaling pathway in papillary thyroid carcinoma

Endeavors towards identifying key molecular markers for early diagnosis and treatment are driving the clinical study of papillary thyroid carcinoma (PTC). Recent studies have indicated that protein phosphatase, Mg²⁺/Mn²⁺ dependent, 1D (PPM1D) exerts an oncogenic function by increasing cell proliferation, migration and invasion in various cancer types. In addition, PPM1D has a high frequency of genetic alterations and has been proposed as a tumor driver in thyroid cancer, making PPM1D an attractive potential oncotarget for cancer treatment. The aims of the present study were to investigate the downstream targets of PPM1D and the potential molecular mechanisms of its oncogenic activities, as well as its clinical significance in PTC. As anticipated, PPM1D overexpression was confirmed in PTC clinical specimens. Furthermore, knockdown of PPM1D in thyroid cancer cell lines significantly suppressed the proliferation, migration and invasion but facilitated cell apoptosis. The protein levels of phosphorylated p38 mitogen-activated protein kinase (MAPK), p53 and Bax were increased in PPM1D-knockdown cells, while inhibition of p38 phosphorylation restored cell migration, proliferation and cell apoptosis. In addition, silencing of PPM1D expression induced nuclear translocation of p53 in K-1 and TPC-1 cells. The present results demonstrated that PPM1D regulated p38 MAPK and p53 signaling pathways to promote thyroid cancer progression. Collectively with the clinical results, these data qualified PPM1D as a potential diagnostic biomarker and therapeutic target in human thyroid cancer.

Machine learning-based multiparametric MRI radiomics for predicting the aggressiveness of papillary thyroid carcinoma

PURPOSE

To investigate the predictive capability of machine learning-based multiparametric magnetic resonance (MR) imaging radiomics for evaluating the aggressiveness of papillary thyroid carcinoma (PTC) preoperatively.

METHODS

This prospective study enrolled consecutive patients who underwent neck MR scans and subsequent thyroidectomy during the study interval. The diagnosis and aggressiveness of PTC were determined by pathological evaluation of thyroidectomy specimens. Thyroid nodules were segmented manually on the MR images, and radiomic features were then extracted. Predictive machine learning modelling was used to evaluate the prediction of PTC aggressiveness. Area under the receiver operating characteristic curve (AUC) values for the model performance were obtained for radiomic features, clinical characteristics, and combinations of radiomic features and clinical characteristics.

RESULTS

The study cohort included 120 patients with pathology-confirmed PTC (training cohort: n = 96; testing cohort: n = 24). A total of 1393 features were extracted from T2-weighted, apparent diffusion coefficient (ADC) and contrast-enhanced T1-weighted MR images for each patient. The combination of Least Absolute Shrinkage and Selection Operator for radiomic feature selection and Gradient Boosting Classifier for classifying PTC aggressiveness achieving the AUC of 0.92. In contrast, clinical characteristics alone poorly predicted PTC aggressiveness, with an AUC of 0.56.

CONCLUSIONS

Our study showed that machine learning-based multiparametric MR imaging radiomics could accurately distinguish aggressive from non-aggressive PTC preoperatively. This approach may be helpful for informing treatment strategies and prognosis of patients with aggressive PTC.

Financial burden of thyroid cancer in the United States: An estimate of economic and psychological hardship among thyroid cancer survivors

BACKGROUND

Annual cancer-related healthcare expenditure in the United States is estimated to exceed $150 billion by 2020. As the prevalence of thyroid cancer increases worldwide, thyroid cancer survivorship is associated with increasing personal and cumulative costs. Few studies have examined the psychological and material economic costs experienced by thyroid cancer survivors. We seek to estimate the comparative prevalence of financial and psychological hardship among thyroid cancer and non-thyroid cancer patients in the United States.

METHODS

The 2011 Medical Expenditure Panel Survey Experiences with Cancer databank was queried to identify thyroid and non-thyroid (colon, breast, lung, prostate) cancer survivors. This survey includes assessments of financial stress, material hardship, and psychological financial hardship. Cancer incidence-based weighted estimates of responses were compared between thyroid and non-thyroid cancer survivors. Independent predictors of material and psychological financial burden were identified through separate multivariate regression models.

RESULTS

Thyroid cancer survivors more frequently reported psychological financial burden compared to non-thyroid cancer (46.1% vs 24.0%, P = .04). Material financial hardship (28.1% vs 19.9%, P = .37) and concurrent material and psychological hardship (25.1% vs 12.5%, P = .09) were noted at similar frequencies between thyroid and non-thyroid cancer survivors. However, on multivariate analysis, only younger age and lack of health insurance coverage were independently associated with psychological financial hardship.

CONCLUSION

Thyroid cancer survivors report greater psychological financial hardship than non-thyroid cancer survivors. Because this financial burden may be underrecognized in the medical community, further studies should be conducted to aid physicians in better understanding the impact of a thyroid cancer diagnosis.

Altered levels of circulating nuclear and mitochondrial DNA in patients with Papillary Thyroid Cancer

Papillary thyroid cancer is the most common thyroid cancer type. However, diagnostics based on fine needle biopsy cannot make a definitive diagnosis in 25% of thyroid nodules. Additionally, approximately 70% to 80% of thyroid lobectomies performed just for diagnostic purposes are benign. Despite this, biopsy still remains the main method of evaluation of thyroid nodules. Cell-free DNA (cf-DNA) measurement could give a new diagnostic opportunities which may reduce the number of unnecessary thyroid procedures. In this study, using a qPCR, we have examined the nuclear cf-DNA and mitochondrial cf-DNA in the plasma of 32 patients. We have found that the level of nuclear cf-DNA is almost 2-fold increased (median 3 089 vs. 1 872, p = 0.022), whereas mitochondrial cf-DNA content was significantly decreased in respect to healthy controls (median 44 992 vs. 92 220, p = 0.010). The ROC curve analysis showed high specificity for nuclear cf-DNA and mitochondrial cf-DNA, which may serve as a useful tool to decrease the number of unneeded surgeries. Our study reports the first epidemiological evidence for lower mitochondrial cf-DNA content in the patient group, what suggests that apart from nuclear cf-DNA also mitochondrial cf-DNA is affected by disease development.

Extent of surgery for low-risk thyroid cancer in the elderly: Equipoise in survival but not in short-term outcomes

BACKGROUND

Total thyroidectomy is more common than lobectomy for low-risk papillary thyroid cancer, despite equipoise in survival. Because postoperative morbidity increases with age, we aimed to investigate how the extent of thyroidectomy affects short-term outcomes among older patients.

METHODS

Using the Surveillance, Epidemiology, and End Results-Medicare database, we identified patients aged ≥66 years who were treated between 1996 and 2011 for papillary thyroid cancer with tumors ≤2 cm in diameter. We used multivariable logistic regression to evaluate the effect of extent of surgery on complications, emergency-department visits, and unplanned readmissions.

RESULTS

Among 3,341 selected patients, 77.3% were female, mean age was 72.9 years, and tumors averaged 0.8 cm in diameter. A total of 67.6% of patients underwent total thyroidectomy, and 32.4% underwent lobectomy. Total thyroidectomy was associated with complications (odds ratio = 1.99) and readmissions (odds ratio = 1.59; both P < 0.01). Complications were higher in female patients (odds ratio = 1.34), black patients (versus white patients, odds ratio = 1.65), and those with ≥2 comorbidities (vs 0, odds ratio = 1.43; all P < 0.01). Black patients and those with ≥2 comorbidities had more emergency-department visits (odds ratio = 1.50 and 1.92, respectively) and readmissions (odds ratio = 2.19 and 2.29, respectively; all P < 0.01).

CONCLUSION

Total thyroidectomy for older adults with low-risk papillary thyroid cancer may lead to potentially avoidable complications and readmissions, particularly for black and female patients. In many cases, lobectomy may be a safer and less costly alternative.

Low-Risk Thyroid Cancer in Elderly: Total Thyroidectomy/RAI Predominates but Lacks Survival Advantage

BACKGROUND

Papillary thyroid cancer (PTC) is the fastest increasing cancer in the United States; incidence increases with age. It generally has a favorable prognosis but may behave more aggressively in older patients. This study aims to describe national treatment patterns for low-risk PTC in older adults.

MATERIALS AND METHODS

The Surveillance, Epidemiology, and End Results-Medicare database was used to identify patients ≥66 y treated for clinical T1N0M0 PTC between 1996 and 2011. Multivariable logistic regression was used to identify factors associated with extent of surgery (total thyroidectomy versus lobectomy) and radioactive iodine (RAI) administration. Cox proportional hazards modeling was used to estimate the effect of treatment type on disease-specific survival (DSS).

RESULTS

Three thousand two hundred and fourteen patients met inclusion criteria; 77.6% were women, median age was 72 y, and mean tumor size was 0.7 cm. 42.7% had preoperatively diagnosed PTC (versus incidental). 65.4% underwent total thyroidectomy, 29.0% lobectomy, and 5.6% lobectomy followed by completion thyroidectomy; 33.4% received postoperative RAI. Five- and 10-year DSS were 98.9% and 98.3%, respectively. After adjustment, larger tumor size (1.1-2 cm), multifocality, and a preoperative PTC diagnosis were associated with greater odds of undergoing more extensive surgery and receiving RAI (P < 0.0001). DSS was not associated with extent of surgery or RAI administration (P > 0.05).

CONCLUSIONS

Most older adults with PTC underwent total thyroidectomy and a third received RAI; neither treatment improved DSS. In the growing elderly population, less extensive interventions for PTC may reduce morbidity and improve quality of life while preserving an excellent prognosis.

Downregulated LRRK2 gene expression inhibits proliferation and migration while promoting the apoptosis of thyroid cancer cells by inhibiting activation of the JNK signaling pathway

Emerging studies have indicated that leucine-rich repeat kinase 2 (LRRK2) is associated with thyroid cancer (TC). The present study investigated the effect of LRRK2 on the cell cycle and apoptosis in TC, and examined the underlying mechanisms in vitro. To screen TC-associated differentially expressed genes, gene expression microarray analysis was conducted. Retrieval of pathways associated with TC from the Kyoto Encyclopedia of Genes and Genomes database indicated that the c-Jun N-terminal kinase (JNK) signaling pathway serves an essential role in TC. SW579, IHH-4, TFC-133, TPC-1 and Nthy-ori3-1 cell lines were used to screen cell lines with the highest and lowest LRRK2 expression for subsequent experiments. The two selected cell lines were transfected with pcDNA-LRRK2, or small interfering RNA against LRRK2 or SP600125 (a JNK inhibitor). Subsequently, flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, a 5-ethynyl-2′-deoxyuridine assay and a scratch test was conducted to detect the cell cycle distribution, apoptosis, proliferation and migration, respectively, in each group. The LRRK2 gene was determined to be elevated in TC based on the microarray data of the GSE3678 dataset. The SW579 cell line was identified to exhibit the highest LRRK2 expression, while IHH-4 cells exhibited the lowest LRRK2 expression. LRRK2 silencing, through inhibiting the activation of the JNK signaling pathway, increased the expression levels of genes and proteins associated with cell cycle arrest and apoptosis in TC cells, promoted cell cycle arrest and apoptosis, and inhibited cell migration and proliferation in TC cells, indicating that LRRK2 repression could exert beneficial effects through the JNK signaling pathway on TC cells. These observations demonstrate that LRRK2 silencing promotes TC cell growth inhibition, and facilitates apoptosis and cell cycle arrest. The JNK signaling pathway may serve a crucial role in mediating the anti-carcinogenic activities of downregulated LRRK2 in TC.

Assessment of risk based on variant pathways and establishment of an artificial neural network model of thyroid cancer

BACKGROUND

This study aimed to establish an artificial neural network (ANN) model based on variant pathways to predict the risk of thyroid cancer.

METHODS

The RNASeq data of 482 thyroid cancer samples were downloaded from the TCGA database. The samples were divided into low-risk and high-risk groups, followed by identification of differentially expressed genes (DEGs). Co-expression analysis and pathway enrichment analysis were then performed. The variant pathways were screened according to the functional deviation score of each pathway, and an ANN model was established. Finally, the efficiency of the ANN model for risk assessment was validated by survival analysis and analysis of an independent microarray dataset (GSE34289) for thyroid cancer.

RESULTS

In total, 190 DEGs (85 up-regulated and 105 down-regulated) were identified between the low-risk and high-risk groups. Ten risk-related variant pathways were identified between the low-risk and high-risk groups, which were related to inflammatory and immune responses. Based on these variant pathways, an ANN model was built, consisting of an input layer, two hidden layers, and an output layer, corresponding to 15, 8, 5, and 1 neuron, respectively. Survival analysis showed that this model could effectively distinguish the samples with different risks. Analysis of microarray dataset GSE34289 showed that the accuracy of this model for predicating low-risk and high-risk samples was 77.5 and 86.0%, respectively.

CONCLUSIONS

This study suggests that the ANN model based on variant pathways can be used for effectively evaluating the risk of thyroid cancer.

Clinical factors associated with worse quality-of-life scores in United States thyroid cancer survivors

INTRODUCTION

Thyroid cancer survivors are a rapidly growing population in the United States. The factors that drive health-related quality of life (HRQOL) in this population have not been well characterized. We hypothesized that more aggressive treatments and greater treatment-related adverse effects would be associated with worse HRQOL scores in thyroid cancer survivors.

METHODS

Thyroid cancer survivors (18-89 years of age) completed an online survey regarding their clinical history in addition to the Patient-Reported Outcomes Measurement Information System (PROMIS) 29 instrument. Univariable and multivariable modeling were performed to evaluate factors associated with worse HRQOL scores. We generated β-values and 95% confidence intervals to quantify the effect of each independent variable in the model.

RESULTS

Thyroid cancer survivors (n = 1,743) reported a high incidence of complications related to surgery and radioactive iodine ablation. Postoperative dysphonia (ß 1.83-3.07) and dysphagia (ß 2.05-3.65) predicted worse HRQOL scores across multiple PROMIS domains. Younger patient age (age <45 years) and short- or long-term complications of radioactive iodine, including gastrointestinal symptoms (51.9%), appetite changes (71.2%), sialadenitis (58.1%), xerostomia (73.3%), and xerophthalmia (45.1%) were associated with worse HRQOL scores (P < .01).

CONCLUSION

The factors associated with significantly worse HRQOL scores across multiple PROMIS domains for thyroid cancer survivors included patient age <45 years, postoperative hypocalcemia, dysphonia, dysphagia, scar appearance, and complications from radioactive iodine. Methods of evaluation, management, and prevention of these factors might positively impact HRQOL.

Implementing Key Changes in the American Thyroid Association 2015 Thyroid Nodules/Differentiated Thyroid Cancer Guidelines Across Practice Types

OBJECTIVE

This article provides suggestions to help clinicians implement important changes in the 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma ("ATA 2015") across diverse settings.

METHODS

Key ATA 2015 changes are summarized regarding: ( 1) thyroid nodule management; ( 2) lobectomy versus thyroidectomy for differentiated thyroid carcinoma (DTC); and ( 3) surveillance following primary treatment of DTC. Advice to facilitate implementation is based on clinical experience and selected literature.

RESULTS

Strategies are described to enhance acquisition of high-quality information that helps identify patients who may possibly avoid fine-needle aspiration (FNA) of thyroid nodules or total thyroidectomy for DTC, or undergo less intense postoperative surveillance. Sonographic imaging of nodules may improve if sonograms are obtained by clinicians ordering or performing FNA or trusted high-volume sonographers. Cytopathologic assessment and reporting can be improved by working with regional or national experts. Pre-operative evaluation by endocrinologists is important so that patients are referred to experienced, proficient surgeons and assisted with well-informed decision-making regarding surgical radicality. Endocrinologists and surgeons should ensure performance of pre-operative neck ultrasonography, voice/laryngeal evaluation, and contrast-enhanced cross-sectional imaging when appropriate. Findings should be disseminated to all healthcare team members, ideally through a comprehensive medical record accessible to the entire team.

CONCLUSION

Optimization of the sequence of specialist visits and assembly of interactive multidisciplinary teams coupled with intensified interdisciplinary and patient communication may enable clinicians to more effectively implement ATA 2015, which calls for more individualized, and often, less "invasive" management of thyroid nodules and DTC.

ABBREVIATIONS

ATA 2009 = 2009 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; ATA 2015 = 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Carcinoma; DTC = differentiated thyroid carcinoma; FNA = fine-needle aspiration; PET/CT = positron emission tomography/computed tomography.

Papillary thyroid carcinoma metastatic to the pancreas: Case report

Papillary thyroid carcinoma (PTC) is generally associated with an excellent long-term outcome. Distant metastasis is rare with only 5-7% of patients developing distant disease. Metastasis of PTC to the pancreas is an exceedingly rare occurrence. To date, few cases have been reported. We present the case of an 81-year-old man with past medical history of PTC status post total thyroidectomy with local recurrence treated with radioactive iodine and selective neck dissection. Ten years after his initial diagnosis, PET-CT scan revealed a new hypermetabolic 1.1 cm × 0.9 cm left lower lobe lung nodule and hypermetabolism in the proximal body of the pancreas. Follow-up MRI cholangiogram showed a 1.0 × 0.8 cm T1 hypointense lesion in the proximal body of the pancreas. Endoscopic ultrasound-guided fine-needle aspiration biopsy of the pancreatic mass showed neoplastic epithelial cells arranged in papillary clusters with fibrovascular cores and syncytial sheets with high nuclear to cytoplasmic ratio, visible nucleoli, nuclear pallor, focal nuclear grooves, and rare intranuclear pseudoinclusions. Immunohistochemical stains performed on the smears showed positive nuclear expression of TTF-1 and PAX-8. The findings were consistent with metastatic PTC. Surgical resection of the lung nodule confirmed metastatic PTC. Pancreatic metastases usually occur after long time intervals with reports of up to 8 years in PTC. This makes the diagnosis more challenging, and metastatic disease should always be in the differential diagnosis in cases presenting with a pancreatic mass, especially in patients with a prior malignancy.

Thyroid surgery for differentiated thyroid cancer - recent advances and future directions

Population-based studies have demonstrated that an increasing number of incidental thyroid nodules are being identified. The corresponding increase in thyroid-based diagnostic procedures, such as fine-needle aspiration biopsy, has in part led to an increase in the diagnoses of thyroid cancers and to more thyroid surgeries being performed. Small papillary thyroid cancers account for most of this increase in diagnoses. These cancers are considered to be low risk because of the excellent patient outcomes, with a 5-year disease-specific survival of >98%. As a result, controversy remains regarding the optimal management of newly diagnosed differentiated thyroid cancer, as the complications related to thyroidectomy (primarily recurrent laryngeal nerve injury and hypoparathyroidism) have considerable effects on patient quality of life. This Review highlights current debates, including undertaking active surveillance versus thyroid surgery for papillary thyroid microcarcinoma, the extent of thyroid surgery and lymphadenectomy for low-risk differentiated thyroid cancer, and the use of molecular testing to guide decision-making about whether surgery is required and the extent of the initial operation. This Review includes a discussion of current consensus guideline recommendations regarding these topics in patients with differentiated thyroid cancer. Additionally, innovative thyroidectomy techniques (including robotic and transoral approaches) are discussed, with an emphasis on patient preferences around decision-making and outcomes following thyroidectomy.

Copper Chelation as Targeted Therapy in a Mouse Model of Oncogenic BRAF-Driven Papillary Thyroid Cancer

Purpose: Sixty percent of papillary thyroid cancers (PTC) have an oncogenic (V600E) BRAF mutation. Inhibitors of BRAF and its substrates MEK1/2 are showing clinical promise in BRAFV600E PTC. PTC progression can be decades long, which is challenging in terms of toxicity and cost. We previously found that MEK1/2 require copper (Cu) for kinase activity and can be inhibited with the well-tolerated and economical Cu chelator tetrathiomolybdate (TM). We therefore tested TM for antineoplastic activity in BRAFV600E -positive PTC.Experimental Design: The efficacy of TM alone and in combination with current standard-of-care lenvatinib and sorafenib or BRAF and MEK1/2 inhibitors vemurafenib and trametinib was examined in BRAFV600E-positive human PTC cell lines and a genetically engineered mouse PTC model.Results: TM inhibited MEK1/2 kinase activity and transformed growth of PTC cells. TM was as or more potent than lenvatinib and sorafenib and enhanced the antineoplastic activity of sorafenib and vemurafenib. Activated ERK2, a substrate of MEK1/2, overcame this effect, consistent with TM deriving its antineoplastic activity by inhibiting MEK1/2. Oral TM reduced tumor burden and vemurafenib in a BrafV600E -positive mouse model of PTC. This effect was ascribed to a reduction of Cu in the tumors. TM reduced P-Erk1/2 in mouse PTC tumors, whereas genetic reduction of Cu in developing tumors trended towards a survival advantage. Finally, TM as a maintenance therapy after cessation of vemurafenib reduced tumor volume in the aforementioned PTC mouse model.Conclusions: TM inhibits BRAFV600E -driven PTC through inhibition of MEK1/2, supporting clinical evaluation of chronic TM therapy for this disease. Clin Cancer Res; 24(17); 4271-81. ©2018 AACR.

Papillary Thyroid Carcinoma (PTC) in Children and Adults: Comparison of Initial Presentation and Long-Term Postoperative Outcome in 4432 Patients Consecutively Treated at the Mayo Clinic During Eight Decades (1936-2015)

BACKGROUND

Contemporary guidelines for managing PTC advise an approach wherein primary tumor and regional metastases (RM) are completely resected at first surgery and radioiodine remnant ablation (RRA) is restricted to high-risk patients, policies our group has long endorsed. To assess our therapeutic efficacy, we studied 190 children and 4242 adults consecutively treated during 1936-2015.

SUBJECTS AND METHODS

Mean follow-up durations for children and adults were 26.9 and 15.2 years, respectively. Bilateral lobar resection was performed in 86% of children and 88% of adults, followed by RRA in 30% of children and 29% of adults; neck nodes were excised in 86% of children and 66% of adults. Tumor recurrence (TR) and cause-specific mortality (CSM) details were taken from a computerized database.

RESULTS

Children, when compared to adults, had larger primary tumors which more often were grossly invasive and incompletely resected. At presentation, children, as compared to adults, had more RM and distant metastases (DM). Thirty-year TR rates were no different in children than adults at any site. Thirty-year CSM rates were lower in children than adults (1.1 vs. 4.9%; p = 0.01). Comparing 1936-1975 (THEN) with 1976-2015 (NOW), 30-year CSM rates were similar in MACIS <6 children (p = 0.67) and adults (p = 0.08). However, MACIS <6 children and adults in 1976-2015 had significantly higher recurrence at local and regional, but not at distant, sites. MACIS 6+ adults, NOW, compared to THEN, had lower 30-year CSM rates (30 vs. 47%; p < 0.001), unassociated with decreased TR at any site.

CONCLUSIONS

Children, despite presenting with more extensive PTC when compared to adults, have postoperative recurrences at similar frequency, typically coexist with DM and die of PTC less often. Since 1976, both children and adults with MACIS <6 PTC have a <1% chance at 30 years of CSM; adults with higher MACIS scores (6 or more) have a 30-year CSM rate of 30%.

Prognosis of Differentiated Thyroid Carcinoma with Initial Distant Metastasis: A Multicenter Study in Korea

BACKGROUND

Most patients with differentiated thyroid cancer (DTC) have a favorable prognosis. However, patients with DTC and initial distant metastasis have not been commonly found, and their clinical characteristics have seldom been reported. In this study, we analyzed the clinical features and prognosis of patients with DTC and initial distant metastasis in Korea.

METHODS

We retrospectively reviewed the clinical data of 242 patients with DTC and initial distant metastasis treated from 1994 to 2013, collected from five tertiary hospitals in Korea.

RESULTS

The patients' median age was 51 years, and 65% were women. They were followed for a median of 7 years. Lung was the most common site of distant metastasis: only lung 149 patients (62%), only bone 49 (20%), other single site one (pleura), and combined sites 43 (40 were lung and bone, two were bone and other site, and one was lung and other site). At the time of diagnosis, 50 patients (21%) had non-radioactive iodine (RAI) avidity. Five-year disease-specific survival (DSS) was 85% and 10-year DSS was 68%, which were better than those in previous studies. After multivariate analysis, old age, male sex, metastatic site, and histologic type (follicular type) were significant factors for poor prognosis. However, negative RAI avidity status was not a significant prognostic factor after adjusting for other variables.

CONCLUSION

The prognosis of Korean patients with DTC and initial distant metastasis was better than in previous studies. Old age, male sex, metastasis site, and histologic type were significant prognostic factors.

Network-based meta-analysis in the identification of biomarkers for papillary thyroid cancer

Papillary thyroid carcinoma (PTC) has been increasing across the world with incomplete understanding of its pathogenesis. We aimed to investigate gene alterations and biomarkers contributing to PTC development. A total of five eligible microarray datasets including 94 PTC and 81 normal thyroid samples were included to identify gene expression signatures. Using integrative meta-analysis of expression data (INMEX) program, we identified a total of 2699 differentially expressed genes (DEGs) (1333 overexpressed and 1366 underexpressed genes) in PTC relative to normal thyroid samples. The top 100 upregualted and downregulated DEGs identified in the meta-analysis were further validated in The Cancer Genome Atlas (TCGA) dataset for PTC with high consistency. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed pathways in cancer, proteoglycans in cancer, focal adhesion, axon guidance, and ECM-receptor interaction among the top 5 most enriched pathways. Network-based meta-analysis identified FN1 and TRAF6 to be the most highly ranked hub genes among the overexpressed and underexpressed genes, respectively, both of which are involved in pathways in cancer. The most enriched terms for Gene Ontology (GO) of biological processes, cellular component, and molecular function were signal transduction, cytoplasm, and protein binding, respectively. Our meta-analysis comprehensively investigated DEGs, hub genes, enriched pathways and GO terms for PTC, which might provide additional approaches to explore the molecular mechanisms underlying the pathophysiology of PTC, and identify biomarkers and therapeutic targets toward PTC.

Verteporfin inhibits papillary thyroid cancer cells proliferation and cell cycle through ERK1/2 signaling pathway

Verteporfin, a FDA approved second-generation photosensitizer, has been demonstrated to have anticancer activity in various tumors, but not including papillary thyroid cancer (PTC). In current pre-clinical pilot study, we investigate the effect of verteporfin on proliferation, apoptosis, cell cycle and tumor growth of PTC. Our results indicate verteporfin attenuates cell proliferation, arrests cell cycle in G2/S phase and induces apoptosis of PTC cells. Moreover, treatment of verteporfin dramatically suppresses tumor growth from PTC cells in xenograft mouse model. We further illustrate that exposure to MEK inhibitor U0126 inactivates phosphorylation of ERK1/2 and MEK in verteporfin-treated PTC cells. These data suggest verteporfin exhibits inhibitory effect on PTC cells proliferation and cell cycle partially via ERK1/2 signalling pathway, which strongly encourages the further application of verteporfin in the treatment against PTC.

Analysis of circulating tumor DNA does not improve the clinical management of patients with locally advanced and metastatic papillary thyroid carcinoma

BACKGROUND

Circulating cell-free tumor DNA (ctDNA) in plasma is a promising noninvasive instrument for cancer monitoring. Detection of BRAF^V600E on ctDNA of patients with papillary thyroid carcinoma (PTC) may represent an indicator of tumor aggressiveness and progression.

METHODS

Eighty-three plasma samples were collected from 70 patients with thyroid nodules undergoing surgery and from 13 patients with PTC causing distant metastases. A total of 59 PTCs from both groups were evaluated for BRAF mutation on tumor tissue and on ctDNA from plasma samples by real-time polymerase chain reaction (PCR) and digital PCR.

RESULTS

Of 59 PTCs, 22 were BRAF^V600E mutated (37.3%). The corresponding ctDNA was negative by using both techniques.

CONCLUSION

Although highly sensitive techniques were used, in our study, circulating BRAF^V600E alleles were never detected in the plasma of patients with PTC; therefore, our results raise the question about the clinical usefulness of BRAF^V600E analysis on ctDNA of patients with PTC.

Paradoxes in thyroid carcinoma treatment: analysis of the SEER database 2010-2013

Thyroid cancer is a common malignant disease with high survival rate (98.1%, 2006-2012, Surveillance Epidemiology and End Results (SEER) program). In this study, we investigated the treatment paradoxes in thyroid T0 and micro-carcinoma patients. 48,234 thyroid carcinoma patients were identified from 2010 to 2013 in SEER*Stat database (version 8.2.1) released in 2016. Survival analysis showed a significantly lower thyroid carcinoma-specific survival in T0 patients compared with T1-T3 patients. In propensity score analysis, T0 patients had a similar survival curve with T1-T3 patients when lymph node and distant metastasis stages were matched. When all variables, including radiation and surgery treatment, were matched, T0 patients had significantly higher survival compared to T3 patients. These findings suggested that more metastasis and less treatment led to poorer prognosis in T0 patients. Another paradox is about thyroid micro-carcinoma. The survival rate of micro-carcinoma patients was high (4 years survival rate was 99.92%), and more than 99% micro-carcinoma patients received surgery. Interestingly, all the patients who died because of thyroid carcinoma received surgery. Survival analysis showed no difference in survival when patients stratified by surgery or radiation. In conclusion, we suggested paradoxes in thyroid carcinoma treatment: over-treated in micro-carcinoma patients and less-treated in T0 patients.

Downregulation of CSN6 attenuates papillary thyroid carcinoma progression by reducing Wnt/β-catenin signaling and sensitizes cancer cells to FH535 therapy

The incidence of thyroid cancer has increased worldwide at a rate higher than that of any other cancer. CSN6 is overexpressed in many types of cancers, and such expression is linked to oncogenic activity. However, the detailed biological functions of CSN6 in papillary thyroid cancer (PTC) have not been well characterized. We investigated CSN6 expression in PTC specimens and cell lines. We used short-hairpin RNA-mediated gene silencing to explore the biological effects of CSN6 depletion in PTC cells. The combined effects of CSN6 silencing and FH535 therapy were assessed in terms of cell viability. The mechanism by which CSN6 regulated β-catenin expression was also analyzed. CSN6 levels were determined by real-time polymerase chain reaction (PCR) (mRNA), Western blotting, and immunochemistry (protein). The CCK-8 and migration assays and orthotopic xenograft transplantation were used to investigate the biological effects of CSN6. We assessed the combined effects of CSN6 silencing and FH535 on cell viability in vitro. We also analyzed the relationship between the CSN6 level and clinical pathological status. CSN6 was overexpressed in human PTCs, and loss of CSN6 attenuated tumor proliferation and migration both in vitro and in vivo. CSN6 stabilized β-catenin and facilitated the epidermal-to-mesenchymal transition (EMT) in PTC cells. CSN6 positively regulated β-catenin expression in a β-Trcp-dependent manner and triggered expression of several EMT-related genes regulated by β-catenin. CSN6 silencing sensitized PTC cells to FH535 therapy via downregulation of the Wnt/β-catenin signaling pathway. Finally, in PTC patients, the level of CSN6 was significantly (inversely) correlated with tumor size, the presence of multifocal lesions, and TNM stage. CSN6 overexpression in PTC is a strong indicator of enhanced tumor aggressiveness. CSN6 promotes PTC progression by inducing the EMT. CSN6 knockdown sensitizes PTC cells to FH535 therapy via downregulation of the Wnt/β-catenin signaling pathway.

Hyperplastic thymus with increased angiogenesis is correlated with elevated serum thyroglobulin level in differentiated thyroid cancer patients with TENIS syndrome

Aims

To investigate the association between angiogenetic activity of hyperplastic thymus and serum thyroglobulin (Tg) level in differentiated thyroid carcinoma patients with thyroglobulin (Tg)-elevated Negative Iodine Scintigraphy (TENIS) Syndrome.

Methods

A cohort of 30 consecutive patients who underwent total thyroidectomy followed by radioiodine ablation and had TENIS syndrome received integrin α_vβ₃ targeted imaging with ^99mTc-HYNIC-PEG4-E[PEG4-c(RGDfk)]2 (^99mTc-3PRGD2). The correlation of angiogenetic activity of the thymus and the serum Tg levels was evaluated in patients with enlarged thymus.

Results

Enlarged thymus was detected in 9 out of the 30 TENIS patients and all hyperplastic thymus showed an increased accumulation of the tracer (median tumor/background ratio: 2.8). Five of them had only mediastinal uptake and surgical removal of the mediastinal mass in one provided histopathologic evidence of thymic tissue. The other four were not assigned further treatment and were free of disease in the follow-up, though their stimulated Tg levels consistently increased. Four out of the 9 patients showed ^99mTc-3PRGD2 uptake outside the mediastinum were assigned surgery followed by radioiodine treatment. Their stimulated Tg levels decreased after iodine ablation, but not drop back to normal. A significant linear correlation was observed between serum Tg levels and the degree of angiogenesis in the hyperplastic thymus.

Conclusions

The angiogenetic activity in hyperplastic thymus was related with the consistently elevated serum Tg levels in TENIS syndrome patients. Based on the existing literature and current data, we propose further intervention for patients with RGD uptake outside thymus, while close follow-up for patients with only mediastinal uptake.

"Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features" With Focal Spindle Cell Metaplasia

"Noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) is a recent reclassification of the encapsulated follicular variant of papillary thyroid carcinoma, which is supposed to reflect its indolent clinical behavior and to prevent overtreatment of patients with this neoplasm. The diagnosis of NIFTP can only be made histologically on the surgical specimen according to specific inclusion and exclusion criteria, which requires the examination of the whole nodule and its capsule. Spindle cell proliferations, especially of follicular cell origin, arising within thyroid follicular neoplasms are very rare and may cause diagnostic difficulties. Few reports described spindle cell proliferations arising in follicular thyroid adenoma and papillary thyroid carcinoma. To the best of our knowledge, only one case has been reported in NIFTP so far. In this article, we report a unique case of NIFTP associated with a spindle cell proliferation that was characterized immunohistochemically. Specific issues related to this case are discussed.

Hobnail Variant of Papillary Thyroid Carcinoma: a Literature Review

Papillary thyroid carcinoma is the most common thyroid malignancy and it is usually associated with a good prognosis. However, recurrence, metastases, and cancer death may occur in 10 to 15% of patients with more aggressive types of papillary thyroid carcinoma, such as tall cell, columnar cell, solid variant, or the more recently described hobnail variant of papillary thyroid carcinoma. Papillary thyroid carcinoma with a prominent hobnail pattern is a moderately differentiated papillary thyroid carcinoma variant with aggressive clinical behavior and significant mortality. The hobnail variant of papillary thyroid carcinoma shows prominent hobnail features, which have also been referred to as micropapillary. The typical hobnail/micropapillary morphological features show loss of cellular polarity/cohesiveness and support an epithelial-mesenchymal transition as a possible mechanism of metastasis. BRAF p.V600E is the most common mutation in papillary thyroid carcinoma, including the hobnail variant; recent and continuing studies are focused on defining other molecular anomalies that may be useful for prognostic stratification and may provide therapeutic targets.

Metabolic Alterations of Thyroid Cancer as Potential Therapeutic Targets

Thyroid cancer (TC) is the most frequent endocrine tumor with a growing incidence worldwide. Besides the improvement of diagnosis, TC increasing incidence is probably due to environmental factors and lifestyle modifications. The actual diagnostic criteria for TC classification are based on fine needle biopsy (FNAB) and histological examination following thyroidectomy. Since in some cases it is not possible to make a proper diagnosis, classical approach needs to be supported by additional biomarkers. Recently, new emphasis has been given to the altered cellular metabolism of proliferating cancer cells which require high amount of glucose for energy production and macromolecules biosynthesis. Also TC displays alteration of energy metabolism orchestrated by oncogenes activation and tumor suppressors inactivation leading to abnormal proliferation. Furthermore, TC shows significant metabolic heterogeneity within the tumor microenvironment and metabolic coupling between cancer and stromal cells. In this review we focus on the current knowledge of metabolic alterations of TC and speculate that targeting TC metabolism may improve current therapeutic protocols for poorly differentiated TC. Future studies will further deepen the actual understandings of the metabolic phenotype of TC cells and will give the chance to provide novel prognostic biomarkers and therapeutic targets in tumors with a more aggressive behavior.

Population-Based Assessment of Complications Following Surgery for Thyroid Cancer

CONTEXT

As thyroid cancer incidence rises, more patients undergo thyroid surgery. Although postoperative complication rates have been reported in single institution studies, population-based data are limited.

OBJECTIVE

To determine thyroid cancer surgery complication rates and identify at-risk populations.

DESIGN/SETTING/PATIENTS

Using the Surveillance, Epidemiology, and End Results-Medicare database, we evaluated general complications within 30 days and thyroid surgery-specific complications within 1 year in 27,912 patients who underwent surgery for differentiated or medullary thyroid cancer between 1998 and 2011. Multivariable analyses of patient characteristics associated with postoperative complications were performed.

MAIN OUTCOME MEASURES

General and thyroid surgery-specific complications.

RESULTS

Overall, 1820 (6.5%) patients developed general postoperative complications and 3427 (12.3%) developed thyroid surgery-specific complications. In multivariable analyses, general and thyroid surgery-specific complications were significantly higher in patients >65 years [odds ratio (OR), 2.61; 95% confidence interval (CI), 2.31 to 2.95; OR, 3.12; 95% CI, 2.85 to 3.42], those with a Charlson/Deyo comorbidity score of 1 (OR, 2.40; 95% CI, 1.66 to 3.49; OR, 1.88; 95% CI, 1.53 to 2.31) and ≥2 (OR, 7.05; 95% CI, 5.33 to 9.56; OR, 3.62; 95% CI, 3.11 to 4.25), and those with regional (OR, 1.18; 95% CI, 1.03 to 1.35; OR, 1.31; 95% CI, 1.19 to 1.45) or distant disease (OR, 2.83; 95% CI, 2.30 to 3.47; OR, 1.85; 95% CI, 1.54 to 2.21), respectively.

CONCLUSIONS

The rates of thyroid cancer surgery complications are higher than predicted, and patients with older age, more comorbidities, and advanced disease are at greatest risk. Efforts to reduce complications are needed.

Elevated Concentrations of SERPINE2/Protease Nexin-1 and Secretory Leukocyte Protease Inhibitor in the Serum of Patients with Papillary Thyroid Cancer

Introduction. SERPINE2 and secretory leukocyte protease inhibitor (SLPI) are proteins with anticoagulant properties which could promote solid tumor growth. However, their role in the pathogenesis of thyroid cancer has not been determined. Materials and Methods. The aim of this study was to assess serum SERPINE2 and SLPI concentrations in a group of 36 patients with papillary thyroid cancer (PTC) and a group of 19 subjects with multinodular nontoxic goiter (MNG). The control group (CG) consisted of 20 healthy volunteers. Blood samples were collected one day before surgery. Serum SERPINE2 and SLPI concentrations were measured using specific ELISA methods. Results. Significantly higher concentrations of SERPINE2 and SLPI were found in patients with PTC as compared with MNG and controls. Positive correlation was found between SERPINE2 and SLPI concentrations in PTC patients. The levels of SERPINE2 and SLPI did not differ significantly between MNG and healthy controls. Conclusions. Our results indicate that SERPINE2 and SLPI play a significant role in the development of papillary thyroid cancer and imply that the evaluation of serum concentrations of both anticoagulant molecules may be considered as additional marker for the differentiation of malignancies during the preoperative diagnosis of patients with thyroid gland tumors.