Recurrence of papillary thyroid cancer after optimized surgery

MiR-374a/b-5p Suppresses Cell Growth in Papillary Thyroid Carcinoma Through Blocking Exosomal ANXA1-Induced Macrophage M2 Polarization

Papillary thyroid carcinoma (PTC), comprising 85% of all thyroid cancers, is an epithelial malignancy. The potential for malignant transformation in normal cells by thyroid cancer cells via exosomal Annexin A1 (ANXA1) delivery is investigated in this study. Our aim is to determine the impact of PTC cells on macrophage polarization through exosomal ANXA1 secretion and its implications for tumor progression. Exosomes in PTC cells were examined using transmission electron microscopy, exosome labeling, and nanoparticle tracking analysis. Real-time quantitative polymerase chain reaction was employed to quantify gene expression levels. Protein levels were determined through Western blot analysis. The interplay between genes was assessed using luciferase reporter and RNA pull-down assays. Functional experiments were conducted to investigate PTC cell proliferation and apoptosis. Our findings reveal that ANXA1 promotes PTC cell proliferation and inhibits apoptosis. Exosomes derived from PTC cells were found to promote macrophage M2 polarization. ANXA1 stimulates M2 polarization through the activation of the PI3K/AKT pathway. MicroRNA-374a-5p (miR-374a-5p) and microRNA-374b-5p (miR-374b-5p) were identified as inhibitors of ANXA1 expression and PI3K/AKT pathway activity, thereby inhibiting macrophage M2 polarization. Furthermore, miR-374a-5p and miR-374b-5p were observed to suppress PTC cell proliferation through their regulatory action on ANXA1. Our study suggests that miR-374a/b-5p inhibits PTC cell growth by blocking the macrophage M2 polarization induced by exosomal ANXA1.

Restratification of intermediate risk factors on the recurrence of papillary thyroid carcinoma: a retrospective cohort study

BACKGROUND

Data regarding the long-term recurrence in patients with intermediate-risk papillary thyroid carcinoma (PTC) are limited. The aim of this study was to assess the impact of primary tumor-related risk factors and lymph node (LN)-only risk factors on recurrence-free survival (RFS) in patients with intermediate-risk PTC.

MATERIALS AND METHODS

Patients with PTC who received initial treatment at our institution between 2010 and 2016 were retrospectively reviewed. A total of 799 intermediate-risk PTC patients were included and further categorized into subgroups according to the different categories of intermediate-risk factors. The RFS rates of these subgroups were investigated and compared.

RESULTS

Structural recurrence developed in 11 patients (1.4%) of the whole cohort during a median follow-up duration of 96 months. There were no significant differences in RFS between the primary tumor-only risk group and the LN-only risk group, while the combined group of primary tumor risk factors and LN risk factor (metastatic LNs >5) was associated with a worse RFS rate. In the matched-pair analysis, no significant difference in RFS was found between patients who underwent thyroid lobectomy and those who underwent total thyroidectomy (6-year RFS: 99.6 vs. 98.8%, P =0.316) during a median follow-up duration of 100 months.

CONCLUSIONS

Intermediate-risk PTC patients who underwent thyroid lobectomy had a comparable RFS to those who underwent total thyroidectomy. The combination of primary tumor risk factors and LN risk factor (metastatic LNs >5) may be a useful tool for predicting the risk of long-term structural recurrence in patients with intermediate-risk PTC.

Biological functions and therapeutic potential of CKS2 in human cancer

The incidence of cancer is increasing worldwide and is the most common cause of death. Identification of novel cancer diagnostic and prognostic biomarkers is important for developing cancer treatment strategies and reducing mortality. Cyclin-dependent kinase subunit 2 (CKS2) is involved in cell cycle and proliferation processes, and based on these processes, CKS2 was identified as a cancer gene. CKS2 is expressed in a variety of tissues in the human body, but its abnormal expression is associated with cancer in a variety of systems. CKS2 is generally elevated in cancer, plays a role in almost all aspects of cancer biology (such as cell proliferation, invasion, metastasis, and drug resistance) through multiple mechanisms regulating certain important genes, and is associated with clinicopathological features of patients. In addition, CKS2 expression patterns are closely related to cancer type, stage and other clinical variables. Therefore, CKS2 is considered as a tool for cancer diagnosis and prognosis and may be a promising tumor biomarker and therapeutic target. This article reviews the biological function, mechanism of action and potential clinical significance of CKS2 in cancer, in order to provide a new theoretical basis for clinical molecular diagnosis, molecular targeted therapy and scientific research of cancer.

Case Report: Two cases of recurrences at the suprasternal space and lymph nodes between the sternocleidomastoid and sternohyoid muscles in papillary thyroid carcinoma

Recently, lymph node metastasis to the suprasternal space (SSLN) and lymph nodes between the sternocleidomastoid and sternohyoid muscles (LNSS) have received attention. This article reports two cases of SSLN and LNSS recurrence and emphasizes the need for a thorough evaluation and consideration of the possibility of recurrence in this region. The clinical significance of the prophylactic dissection of SSLN and LNSS remains unclear, and further studies are required to determine its value. Regular follow-up checks of suspicious lymph nodes at SSLN and LNSS, as well as the central and lateral compartments, are recommended after thyroidectomy to detect recurrences and ensure appropriate management.

Total thyroidectomy versus unilateral lobectomy for unilateral multifocal papillary thyroid carcinoma: systematic review and meta‑analysis

The optimal surgical procedure(s) for unilateral multifocal papillary thyroid carcinomas is currently controversial. As such, the present study aimed to compare the efficacies of total thyroidectomy and lobectomy in patients with unilateral multifocal papillary thyroid carcinoma. A literature search of the PubMed/Medline, Embase, Web of Science, Cochrane Library, Wan Fang, and Zhi Wang databases for relevant studies, published from inception to October 31, 2022, was performed. Two researchers independently extracted data from the included studies. Lymph node metastasis, vocal fold paralysis, parathyroid injury, postoperative recurrence, and disease-free survival were evaluated. The meta-analysis included 7 studies comprising 1540 patients, of whom 496 and 1044 underwent lobectomy and total thyroidectomy, respectively. Compared with lobectomy, total thyroidectomy resulted in more vocal cord paralysis (odds ratio [OR] 0.35 [95% confidence interval (CI) 0.13 to 0.96]; P = 0.04) and parathyroid injury (OR 0.11 [95% CI 0.03-0.39]; P = 0.001) but with better disease-free survival (OR 0.21 [95% CI 0.09-0.49]; P = 0.000), although vocal cord paralysis and parathyroid injury, in large part, resolved within 1 year after surgery. In addition, there was no difference in postoperative lymph nodes metastasis (OR 0.74 [95% CI 0.13-4.21]; P = 0.737) and postoperative recurrence (OR 2.37 [95% CI 0.42-13.38]; P = 0.33). Excluding studies that deviated from the general trend, total thyroidectomy was beneficial in reducing recurrence. Compared with lobectomy, total thyroidectomy was beneficial in reducing recurrence and disease-free survival and may be considered a more optimal approach for unilateral multifocal papillary thyroid carcinoma.

Papillary Thyroid Carcinoma Presenting with Chronic Cough and Hemoptysis in Primary Care: A Case Report

BACKGROUND The article discusses an unusual case of papillary thyroid carcinoma in which chronic cough and hemoptysis were the predominant symptoms. While the more common causes of hemoptysis are pulmonary in origin, extrapulmonary etiologies have been reported, including thyroid carcinoma. The clinical presentation of thyroid malignancy in this case mimics many other common disorders, such as pulmonary tuberculosis, bronchogenic carcinoma, bronchiectasis, and chronic obstructive pulmonary disease. Hence, making it challenging to suspect early when patients present to primary care. CASE REPORT A 54-year-old woman presented with a chronic cough and hemoptysis in our Primary Care Medicine Clinic. While initial assessments in the primary care medicine clinic yielded no remarkable findings, a subsequent high-resolution computed tomography scan of the thorax uncovered a thyroid lesion. Subsequent evaluation in the hospital setting included an ultrasound examination, revealing multiple thyroid nodules, and fine needle aspiration that confirmed papillary thyroid carcinoma. She underwent total thyroidectomy with central and left lateral neck dissection, complicated by left vocal cord palsy. She received 2 cycles of periodic radioactive iodine therapy and injection laryngoplasty postoperatively. There was no evidence of iodin avid disease and recurrence of hemoptysis after surgery. CONCLUSIONS This case report emphasizes the significance of considering papillary thyroid carcinoma when assessing hemoptysis in the primary care setting, as early detection and treatment of it would result in a better outcome.

Transoral endoscopic and robotic thyroidectomy for thyroid cancer: the mid-term oncological outcome

BACKGROUND

Traditional open thyroidectomy is the surgical standard for thyroid cancer; however, it inevitably leaves a visible scar on the neck and affects the patient's quality of life. Therefore, to avoid making a neck incision, the transoral endoscopic thyroidectomy vestibular approach (TOETVA) and transoral robotic thyroidectomy (TORT) have been developed recently, and the surgical outcomes of these techniques are as favorable as open surgery for benign disease. Additionally, positive short-term surgical outcomes have also been achieved in a few patients with thyroid cancer. However, no data on the mid-to-long-term recurrence and survival rates of transoral thyroidectomy in thyroid cancer are available. Therefore, in this study, we analyzed the surgical outcomes and mid-term oncological results of the TOETVA and TORT in patients with thyroid cancer.

METHODS

We reviewed patients who had received TOETVA or TORT between July 2017 and November 2021 and followed up on their oncological outcomes until December 2022. Perioperative surgical and mid-term oncological outcomes were analyzed.

RESULTS

The 115 patients underwent 122 operations (57 TOETVAs and 65 TORTs), including seven complete thyroidectomies for differentiated thyroid cancer (DTC), Stage I-II, including T1-T3, N0-N1a, and initial low- to high-risk groups. There was no conversion from transoral to open surgery. TORT required a longer operating time (median [interquartile range]) than TOETVA (lobectomy: 279 [250, 318] vs. 196 [173, 253] min, p < 0.001; bilateral total thyroidectomy: 375 [309, 433] vs. 279 [238, 312] min, p < 0.001); however, no difference was found between the two groups regarding perioperative complications. Complete thyroidectomy with a second transoral approach was safe. TOETVA and TORT achieved favorable oncological outcomes with 100% survival and 98.2% acceptable response (excellent and indeterminate response) during a mean 37.88 ± 12.42 months mid-term follow-up.

CONCLUSIONS

Transoral endoscopic and robotic thyroidectomy was safe and achieved favorable mid-term oncological outcomes in a selected cohort of patients with early-stage DTC.

Risk factors and predictive model for recurrence in papillary thyroid carcinoma: a single-center retrospective cohort study based on 955 cases

Background

The 2015 American Thyroid Association guidelines proposed recurrence risk stratification of differentiated thyroid carcinoma, including papillary thyroid carcinoma (PTC), but this stratification excluded non-initial treatment patients with worse outcomes. This study aimed to explore the potential risk factors for recurrence in PTC and develop a predictive model for both initial and non-initial treatment of patients with PTC.

Methods

A total of 955 patients were included in this study. Differences between the recurrence (-) and recurrence (+) groups were compared. The 955 patients were randomized into two groups: the training group (671 cases) and the validation group (284 cases). All variables were selected using the LASSO regression analysis. A nomogram was developed based on the results of the univariate and multivariate logistic regression analyses. The nomogram performance was evaluated using discrimination and calibration.

Results

Patients aged ≥55 years, extranodal extension (ENE), metastatic LN ratio (LNR) >0.5, and non-initial treatment were identified as potential risk factors for recurrence through LASSO regression and univariate and multivariate analyses. The receiver operating characteristic curve (ROC curve) showed high efficiency, with an area under the ROC curve (AUC) of 0.819 (95% confidence interval [CI], 0.729-0.909) and 0.818 (95% CI, 0.670-0.909) in the training and validation groups, respectively. The calibration curve indicated that the nomogram had a good consistency.

Conclusion

In patients with PTC, age ≥55 years, ENE, LNR >0.5, and non-initial treatment are potential risk factors for recurrence. The predictive model of recurrence was confirmed to be a practical and convenient tool for clinicians to accurately predict PTC recurrence.

Mining Prognostic Biomarkers of Thyroid Cancer Patients Based on the Immune-Related Genes and Development of a Reliable Prognostic Risk Model

PURPOSE

Tumor immunity serves an essential role in the occurrence and development of thyroid cancer (THCA). The aim of this study is to establish an immune-related prognostic model for THCA patients by using immune-related genes (IRGs).

METHODS

Wilcox test was used to screen the differentially expressed immune-related genes (DEIRGs) in THCA and normal tissues, then the DEIRGs related to prognosis were identified using univariate Cox regression analysis. According to The Cancer Genome Atlas (TCGA) cohort, we developed a least absolute shrinkage and selection operator (LASSO) regression prognostic model and performed validation analyses regard to the predictive value of the model in internal (TCGA) and external (International Cancer Genome Consortium) cohorts respectively. Finally, we analyzed the correlation among the prognostic model, clinical variables, and immune cell infiltration.

RESULTS

Eighty-two of 2,498 IRGs were differentially expressed between THCA and normal tissues, and 18 of them were related to prognosis. LASSO Cox regression analysis identified seven DEIRGs with the greatest prognostic value to construct the prognostic model. The risk model showed high predictive value for the survival of THCA in two independent cohorts. The risk score according to the risk model was positively associated with poor survival and the infiltration levels of immune cells, it can evaluate the prognosis of THCA patients independent of any other clinicopathologic feature. The prognostic value and genetic alternations of seven risk genes were evaluated separately.

CONCLUSION

Our study established and verified a dependable prognostic model associated with immune for THCA, both the identified IRGs and immune-related risk model were clinically significant, which is conducive to promoting individualized immunotherapy against THCA.

Accuracy of papillary thyroid cancer prognostic nomograms: a systematic review

Objective

Current staging and risk-stratification systems for predicting survival or recurrence of patients with differentiated thyroid carcinoma may be ineffective at predicting outcomes in individual patients. In recent years, nomograms have been proposed as an alternative to conventional systems for predicting personalized clinical outcomes. We conducted a systematic review to evaluate the predictive performance of available nomograms for thyroid cancer patients.

Design and methods

PROSPERO registration (CRD42022327028). A systematic search was conducted without time and language restrictions. PICOT questions: population, patients with papillary thyroid cancer; comparator prognostic factor, single-arm studies; outcomes, overall survival, disease-free survival, cancer-specific survival, recurrence, central lymph node metastases, or lateral lymph node metastases; timing, all periods; setting, hospital setting. Risk of bias was assessed through PROBAST tool.

Results

Eighteen studies with a total of 20 prognostic models were included in the systematic review (90,969 papillary thyroid carcinoma patients). Fourteen models were at high risk of bias and four were at unclear risk of bias. The greatest concerns arose in the analysis domain. The accuracy of nomograms for overall survival was assessed in only one study and appeared limited (0.77, 95% CI: 0.75-0.79). The accuracy of nomograms for disease-free survival ranged from 0.65 (95% CI: 0.55-0.75) to 0.92 (95% CI: 0.91-0.95). The C-index for predicting lateral lymph node metastasis ranged from 0.72 to 0.92 (95% CI: 0.86-0.97). For central lymph node metastasis, the C-index of externally validated studies ranged from 0.706 (95% CI: 0.685-0.727) to 0.923 (95% CI: 0.893-0.946).

Conclusions

Our work highlights the extremely high heterogeneity among nomograms and the critical lack of external validation studies that limit the applicability of nomograms in clinical practice. Further studies ideally using commonly adopted risk factors as the backbone to develop nomograms are required.

Significance statement

Nomograms may be appropriate tools to plan treatments and predict personalized clinical outcomes in patients with papillary thyroid cancer. However, the nomograms developed to date are very heterogeneous, and their results seem to be closely related to the specific samples studied to generate the same nomograms. The lack of rigorous external validation procedures and the use of risk factors that sometimes appear to be far from those commonly used in clinical practice, as well as the great heterogeneity of the risk factors considered, limit the ability of nomograms to predict patient outcomes and thus their current introduction in clinical practice.

Thyroglobulin expression, Ki-67 index, and lymph node ratio in the prognostic assessment of papillary thyroid cancer

The clinical significance of thyroglobulin (Tg) expression in papillary thyroid cancer (PTC) has not been systematically explored in relation to the Ki-67 index, lymph node ratio (LNR), or other conventional prognostic predictors. In this retrospective study of 327 patients with PTC, we investigated the immunohistochemical expression of Tg in both primary tumors and their matching lymph node metastases in relation to the Ki-67 index, LNR, and clinical data. Tumoral Tg immunoreactivity was inversely correlated to the Ki-67 index and tumor recurrence. The Ki-67 index was higher in lymph node metastases (mean 4%) than in the primary tumors (mean 3%). Reduced Tg expression, estimated as 0-25% Tg positive tumor cells, was more common in lymph node metastases compared to primary tumors. In addition to advanced metastatic burden (defined as N1b stage and LNR ≥ 21%), low Tg expression (0-25% positive tumor cells) in lymph node metastases had a significant prognostic impact with shorter recurrence-free survival. These findings support the potential value of histopathological assessment of Tg expression and Ki-67 index in lymph node metastases as complementary predictors to anticipate the prognosis of PTC patients better.

A miRNA-Based Prognostic Model to Trace Thyroid Cancer Recurrence

Simple Summary

Some thyroid tumors elected for surveillance remain indolent, while others progress. The mechanism responsible for this difference is poorly understood, making it challenging to devise patient surveillance plans. Early prediction is important for tailoring treatment and follow-up in high-risk patients. The aim of our study was to identify predictive markers for progression. We leveraged a highly sensitive test that accurately predicts which thyroid nodules are more likely to develop lymph node metastasis, thereby improving care and outcomes for cancer patients.

Abstract

Papillary thyroid carcinomas (PTCs) account for most endocrine tumors; however, screening and diagnosing the recurrence of PTC remains a clinical challenge. Using microRNA sequencing (miR-seq) to explore miRNA expression profiles in PTC tissues and adjacent normal tissues, we aimed to determine which miRNAs may be associated with PTC recurrence and metastasis. Public databases such as TCGA and GEO were utilized for data sourcing and external validation, respectively, and miR-seq results were validated using quantitative real-time PCR (qRT-PCR). We found miR-145 to be significantly downregulated in tumor tissues and blood. Deregulation was significantly related to clinicopathological features of PTC patients including tumor size, lymph node metastasis, TNM stage, and recurrence. In silico data analysis showed that miR-145 can negatively regulate multiple genes in the TC signaling pathway and was associated with cell apoptosis, proliferation, stem cell differentiation, angiogenesis, and metastasis. Taken together, the current study suggests that miR-145 may be a biomarker for PTC recurrence. Further mechanistic studies are required to uncover its cellular roles in this regard.

Evolution of intra-tumoral heterogeneity across different pathological stages in papillary thyroid carcinoma

BACKGROUND

Intra-tumor heterogeneity (ITH) results from the continuous accumulation of mutations during disease progression, thus impacting patients' clinical outcome. How the ITH evolves across papillary thyroid carcinoma (PTC) different tumor stages is lacking.

METHODS

We used the whole-exome sequencing data from The Cancer Genome Atlas Thyroid Cancer (TCGA-THCA) cohort to track the ITH and assessed its relationship with clinical features through different stages of the PTC progression. We further assayed the expression levels of the specific genes in papillary thyroid cancer cell lines compared to an immortalized normal thyroid epithelial cell line by qRT-PCR.

RESULTS

We revealed the timing of mutational processes and the dynamics of the temporal acquisition of somatic events during the lifetime of the PTC. ITH significantly influences the PTC patient's survival rate and, as genetic heterogeneity increases, the prognosis gets worse in advanced tumor stages. ITH also affects the mutational architecture of each clinical stage which is subject to periodic fluctuations. Different mutational processes may cooperate to shape a stage-specific mutational spectrum during the progression from early to advanced tumor stages. Moreover, different evolutionary paths characterize PTC progression across pathological stages due to both mutations recurrently occurring in all stages in hotspot positions and distinct codon changes dominating in different stages. A different expression level of specific genes also exists in different thyroid cancer cell lines.

CONCLUSIONS

Our findings suggest ITH as a potential unfavorable prognostic factor in PTC and highlight the dynamic changes in different clinical stages of PTC, providing some clues for the precision medicine and suggesting different diagnostic decisions depending on the clinical stages of patients. Finally, complete clear guidelines to define risk stratification of PTC patients are lacking; thus, this work could contribute to defining patients who need more aggressive treatments and, in turn, could reduce the social burden of this cancer.

Predictive Significance of Two MMP-9 Promoter Polymorphisms and Acetylated c-Jun Transcription Factor for Papillary Thyroid Carcinoma Advancement

Papillary thyroid carcinoma represents a challenge from a prognostic standpoint. Molecular alterations responsible for PTC advancement include MMP-9 genetic promoter polymorphisms that bind transcription factors with varying degrees of affinity and, hence, constitute a predisposition for MMP-9 expression. We examined how two promoter polymorphisms (the -1562 C/T transition and -131 (CA)n tandem repeats) as well as levels of the c-Jun transcription factor and its modified form acetylated at Lys271 influence MMP-9 expression and PTC progression. A significant proportion of PTC samples were heterozygous for the (CA)n tandem repeat number, had a transcription-promoting T allele at -1562, and expressed high levels of c-Jun, acetylated c-Jun, and MMP-9 protein. The T allele at the -1562 position accompanied the elevated MMP-9 protein expression, while high acetylated c-Jun levels accompanied the high MMP-9 protein levels on mRNA. The -1562 C/T transition, MMP-9, and acetylated c-Jun were associated with the presence of extra-thyroid invasion and degree of tumor infiltration, while the T allele and acetylated c-Jun also correlated with tumor stage. We conclude that the -1562 MMP-9 polymorphism and levels of acetylated c-Jun affect PTC progression via modulation of MMP-9 levels. Genotyping the MMP-9 at -1562 and estimating the levels of MMP-9 and acetylated c-Jun in PTC may prove beneficial in identifying high-risk patients.

Long-term follow-up ultrasonography surveillance in a large cohort of patients with papillary thyroid carcinoma

OBJECTIVE

This study aimed to investigate the predictive factors as well as the time and age course of recurrence/persistence in a large cohort of postoperative patients with papillary thyroid carcinoma (PTC) based on the long-term ultrasonography (US) follow-up data.

METHODS

Between January 2007 and December 2016, 3106 patients underwent surgery for PTC and at least two postoperative US follow-up examination over more than three years. Tumor recurrence/persistence was confirmed based on the follow-up US data and histopathological results. Univariate and multivariate analyses were performed to evaluate the predictive factors of tumor recurrence/persistence. Kaplan-Meier survival analysis was used to evaluate the recurrence-/persistence-free survival curve based on the US results.

RESULTS

A total of 321(10.3%) patients developed tumor recurrence/persistence during 54.3 months of mean follow-up (range 36-135 months), including 268(83.5%) cases of lymph node recurrence/persistence, 37 (11.5%) cases of non-lymph node recurrence/persistence, and 16(5%) cases of both types. Recurrence/persistence was observed using US examination at a mean interval of 23.6 ± 21.6 months (range 1-135 months) after surgery and peak incidence was observed 1-2 years after initial treatment. Younger (20-30 years old) and older (70-80 years old) patients had a higher proportion of tumor recurrence/persistence. Multifocality, advanced T and advanced N stages were independent risk factors of tumor recurrence/persistence.

CONCLUSION

Tumor recurrence/persistence of PTC usually occurs during the early postoperative period. For patients with multifocal cancer, advanced T and N stage, the US surveillance examination should be cautiously performed, especially in younger and older patients.

APOBEC SBS13 Mutational Signature-A Novel Predictor of Radioactive Iodine Refractory Papillary Thyroid Carcinoma

Standard surgery followed by radioactive iodine (131I, RAI) therapy are not curative for 5−20% of papillary thyroid carcinoma (PTC) patients with RAI refractory disease. Early predictors indicating therapeutic response to RAI therapy in PTC are yet to be elucidated. Whole-exome sequencing was performed (at median depth 198x) on 66 RAI-refractory and 92 RAI-avid PTCs with patient-matched germline. RAI-refractory tumors were significantly associated with distinct aggressive clinicopathological features, including positive surgical margins (p = 0.016) and the presence of lymph node metastases at primary diagnosis (p = 0.012); higher nonsilent tumor mutation burden (p = 0.011); TERT promoter (TERTp) mutation (p < 0.0001); and the enrichment of the APOBEC-related single-base substitution (SBS) COSMIC mutational signatures 2 (p = 0.030) and 13 (p < 0.001). Notably, SBS13 (odds ratio [OR] 30.4, 95% confidence intervals [CI] 1.43−647.22) and TERTp mutation (OR 41.3, 95% CI 4.35−391.60) were revealed to be independent predictors of RAI refractoriness in PTC (p = 0.029 and 0.001, respectively). Although SBS13 and TERTp mutations alone highly predicted RAI refractoriness, when combined, they significantly increased the likelihood of predicting RAI refractoriness in PTC. This study highlights the APOBEC SBS13 mutational signature as a novel independent predictor of RAI refractoriness in a distinct subgroup of PTC.

125I Seed Brachytherapy for Refractory Loco-Regional Recurrence of Non-Anaplastic Thyroid Cancer

Purpose

The purpose of this research was to evaluate the feasibility and efficacy of ¹²⁵I seed brachytherapy as salvage treatment for recurrence from non-anaplastic thyroid cancer refractory to other modalities.

Methods

Between June 2006 and September 2019, fifteen patients with recurrent non-anaplastic thyroid cancer were treated with ¹²⁵I seed brachytherapy. ¹²⁵I seeds were implanted into the tumor under the guidance of CT and/or ultrasound images with the median prescription dose of 120 Gy (range, 100-140 Gy). The median seed number was 80 (range 10-214). Clinical efficacy was evaluated with Response Evaluation Criteria in Solid Tumors.

Findings

Fifteen patients were selected, eleven of whom had papillary carcinoma, two suffered from follicular carcinoma, and two were diagnosed with medullary carcinoma. These patients had twenty-four nodes in total. After they received salvage surgery and/or radioactive iodine (RAI) therapy, local recurrence was detected in all of them. No less than one node was observed in everyone’s cervical or supraclavicular areas, and four patients had lung metastatic. The median follow-up period lasted 48 months (range, 5-93 months). All patients did not develop locoregional recurrence after experiencing ¹²⁵I seed brachytherapy. Only three of them formed new metastases in nontarget regional nodes after brachytherapy, and additional brachytherapy can solve all regional failure problems. No significant adverse events were observed in any patient.

Implications

For the chosen patients, 125I seed brachytherapy is feasible for treating refractory local recurrence from non-anaplastic thyroid cancer. Further studies are required to determine the role of 125I seed brachytherapy in the treatment of thyroid cancer.

ASSOCIATION BETWEEN HASHIMOTO'S THYROIDITIS AND PAPILLARY THYROID CANCER: A SINGLE CENTER EXPERIENCE

PURPOSE

To investigate the association between papillary thyroid cancer (PTC) and Hashimoto's thyroiditis (HT).

DESIGN

This study is a retrospective study that conducted during 7 consecutive years with a median 119.5 months follow-up.

SUBJECTS AND METHOD

Patients who underwent thyroidectomy in Dokuz Eylül University Hospital during 7 consecutive years were included. Patients' demographics, biochemical, radiological, and pathological results were retrospectively assessed.

RESULTS

Four hundred sixty nine patients were evaluated. Among 469 patients who underwent thyroidectomy, 132 (28.1%) were malignant, while 182 patients were diagnosed with HT (38.8%). PTC was ranked first at 92.4% (n: 122). The prevalence of HT was 54.9% in patients with PTC and 33.1% in patients without PTC diagnosis (p<0.001). Younger age and the presence of HT were independently associated with PTC. The presence of HT was associated with increased risk of development of PTC (OR: 2.2, %95 CI: 1.4-3.5, p<0.001) but not with TNM stage or recurrence. Lymph node metastasis at presentation was the strongest predictor of recurrence (OR: 13.9, CI: 3.5-54.6, p<0.001).

CONCLUSIONS

HT was an independent risk factor for development of PTC. According to our findings, HT patients (particularly with nodular HT) should be observed carefully and thyroid fine needle aspiration biopsy (TFNAB) should be encouraged if necessary.

Serum TSH levels are associated with postoperative recurrence and lymph node metastasis of papillary thyroid carcinoma

OBJECTIVE

To explore the relationship between thyroid-stimulating hormone (TSH) levels in the serum and postoperative recurrence and lymph node metastasis (LNM) in papillary thyroid cancer (PTC) patients after surgery.

METHODS

We selected 272 patients diagnosed with PTC from June 2011 to July 2014. The clinical and pathological data of 272 PTC patients were collected at the First Affiliated Hospital of Wenzhou Medical University and analysed retrospectively. All PTC patients were tested for the BRAF^V600E gene mutation before surgery by fine-needle aspiration (FNA) cytology, and TSH levels in the serum were determined one month after surgery. The optimal cut-off value of thyroid-stimulating hormone (TSH) for predicting the recurrence or metastasis of PTC after surgery was determined by the establishment of a receiver operating characteristic (ROC) curve. Kaplan-Meier and Cox regression analyses were used to evaluate the correlation between the optimal cut-off value of TSH and disease-free survival rate and prognosis.

RESULTS

Of 272 patients, only 182 (73 BRAF^V600E+, 109 BRAF^V600E-) met the final study criteria. Among them, 60 cases had recurrence or metastasis, and 122 cases were controls. The optimal cut-off value of TSH for the prediction of recurrence or metastasis of PTC after surgery was 2.615 mlU/L. In our study, a high TSH level (> 2.615 mlU/L) was correlated with the BRAF^V600E mutation, multifocality, lymph node metastasis, recurrence, and metastasis. In all 182 patients, those with high TSH levels had worse disease-free survival. This result was more obvious in the 73 BRAF^V600E+ patients. The univariate analysis showed that lymph node metastasis, multifocality, lymph node dissection, tumour size, sex, BRAF^V600E mutation, and a high postoperative TSH level were all significantly correlated with recurrence or metastasis in PTC patients (all P < 0.05). In addition, the Cox multivariate analysis showed that lymph node metastasis, BRAF^V600E mutation, and high postoperative TSH levels were independent risk factors for PTC recurrence or metastasis (all P < 0.05).

CONCLUSION

PTC patients with high TSH levels (> 2.615 mlU/L) have worse disease-free survival, which is more obvious in the BRAF^V600E+ population.

Is Postoperative Adjuvant Radioactive Iodine Ablation Therapy Always Necessary for Intermediate-Risk Papillary Thyroid Cancer Patients With Central Neck Metastasis?

BACKGROUND

Papillary thyroid cancer (PTC) is commonly associated with neck lymph node metastasis (LNM), and recurrence does occur after radioactive iodine (RAI) ablation therapy. This study aimed to analyze the effectiveness of RAI ablation with regard to disease recurrence in intermediate-risk PTC patients with neck LNM. In addition, the study identified possible predisposing risk factors that might benefit from RAI ablation and analyzed common RAI therapy complications among these patients.

METHODS

A retrospective analysis of 349 intermediate-risk PTC patients with neck LNM who underwent thyroidectomy with neck dissection was performed. The oncologic results and clinicopathologic characteristics of these patients together with the incidence of postoperative RAI therapy complications were evaluated.

RESULTS

Of the 349 patients, disease recurrence after treatment occurred for 27 patients (8%) during a mean follow-up period of 58.7 months (range 7-133 months). The recurrence-free survival curve of the patients who received postoperative RAI therapy (n = 208) did not differ significantly from that of the patients who did not receive it (n = 141) (P = 0.567). Nine patients without adjuvant RAI therapy (6%, 9/141) had recurrence. The recurrence rate for the central LNM patients without RAI therapy was only 2% (2/106). Both of these patients with recurrence had pathologic extranodal spread (ENS) and a high number (> 5) of metastatic central LNs. Postoperative RAI-related complications were observed in 24 patients (12%).

CONCLUSIONS

Postoperative RAI is not necessary for intermediate-risk papillary thyroid cancer patients with central LNM, especially for patients with negative ENS and low number (< 5) of metastatic lymph nodes.

[Local recurrence of iodine refractory thyroid cancers. Surgical therapy options for larynx and trachea infiltration]

AIM

 Local recurrence of thyroid carcinomas can result in tumor infiltration in the lower region of the larynx. Since these tumors typically no longer store iodine, treatment options are greatly limited. The present study describes our experience with laryngo-tracheal resection of such cases of local recurrence.

MATERIALS AND METHODS

 From July 2019 to November 2020, we treated five patients with malignant infiltration of the trachea and larynx due to local recurrence of a thyroid carcinoma. We performed laryngo-tracheal resection with end-to-end anastomosis in four patients and frontolateral partial laryngectomy in one patient.

RESULTS

 The median length of hospital stay was 6 days (5-14). An R0 resection was performed in two patients. Problems with the anastomosis or bilateral recurrent laryngeal nerve paralysis was not seen in any of the patients. One patient had to be reintubated on the second postoperative day due to lung failure. He was able to be extubated after five days.

CONCLUSION

 High tracheal resection with partial resection of the larynx was able to be performed with minimal risk. Although radical resections are rare, they expand oncological treatment options in the case of local recurrence of thyroid carcinomas that are iodine-refractory. High tracheal resection could be part of the oncological treatment spectrum in the case of local recurrence of thyroid carcinomas that no longer store iodine.

HYOU1 facilitates proliferation, invasion and glycolysis of papillary thyroid cancer via stabilizing LDHB mRNA

HYOU1 is upregulated in many kinds of cancer cells, and its high expression is associated with tumour invasiveness and poor prognosis. However, the role of HYOU1 in papillary thyroid cancer (PTC) development and progression remains to be elucidated. Here, we reported that HYOU1 was highly expressed in human PTC and associated with poor prognosis. HYOU1 silencing suppressed the proliferation, migration and invasion of PTC cells. Mechanistic analyses showed that HYOU1 silencing promoted oxidative phosphorylation while inhibited aerobic glycolysis via downregulating LDHB at the posttranscriptional level. We further confirmed that the 3'UTR of LDHB mRNA is the indirect target of HYOU1 silencing and HYOU1 silencing increased miR‐375‐3p levels. While LDHB overexpression significantly suppressed the inhibitory effects of HYOU1 silencing on aerobic glycolysis, proliferation, migration and invasion in PTC cells. Taken together, our findings suggest that HYOU1 promotes glycolysis and malignant progression in PTC cells via upregulating LDHB expression, providing a potential target for developing novel anticancer agents.

Machine learning-based prediction model using clinico-pathologic factors for papillary thyroid carcinoma recurrence

This study analyzed the prognostic significance of clinico-pathologic factors, including the number of metastatic lymph nodes (LNs) and lymph node ratio (LNR), in patients with papillary thyroid carcinoma (PTC), and attempted to construct a disease recurrence prediction model using machine learning techniques. We retrospectively analyzed clinico-pathologic data from 1040 patients diagnosed with PTC between 2003 and 2009. We analyzed clinico-pathologic factors related to recurrence through logistic regression analysis. Among the factors that we included, only sex and tumor size were significantly correlated with disease recurrence. Parameters such as age, sex, tumor size, tumor multiplicity, ETE, ENE, pT, pN, ipsilateral central LN metastasis, contralateral central LNs metastasis, number of metastatic LNs, and LNR were input for construction of a machine learning prediction model. The performance of five machine learning models related to recurrence prediction was compared based on accuracy. The Decision Tree model showed the best accuracy at 95%, and the lightGBM and stacking model together showed 93% accuracy. Among those factors mentioned above, LNR and contralateral LN metastasis were used as important features in all machine learning prediction models. We confirmed that all machine learning prediction models showed an accuracy of 90% or more for predicting disease recurrence in PTC. LNR and contralateral LN metastasis were used as important features for constructing a robust machine learning prediction model. In the future, we have a plan to perform large-scale multicenter clinical studies to improve the performance of our prediction models and verify their clinical effectiveness.

Prognostic Value and Function of KLF5 in Papillary Thyroid Cancer

Simple Summary

This study was conducted to investigate the clinical significance and prognostic value of KLF5 in a large cohort of Middle Eastern PTC patients and explore its functional role and mechanism in PTC cell lines in vitro and in vivo. We found KLF5 over-expression in PTC patient cases and this was significantly associated with aggressive clinico-pathological parameters and worse outcome. We also found a significant association between KLF5 and HIF-1α in PTC patients and cell lines. Functionally, KLF5 promoted cell growth, stemness, invasion, migration, and angiogenesis, while its inhibition reverses its action in PTC cell lines. Finally, the depletion of KLF5 regressed PTC tumor growth in nude mice. These data suggest that KLF5 may potentially be a suitable therapeutic target in PTC, and pharmacological inhibition of KLF5 might be a viable therapeutic option for the treatment of patients with an aggressive subtype of PTC.

Abstract

The Krüppel-like factor 5 (KLF5), a zinc-finger transcriptional factor, is highly expressed in several solid tumors, but its role in PTC remains unclear. We investigated the expression of KLF5 protein in a large cohort of PTC patient samples and explored its functional role and mechanism in PTC cell lines in vitro and in vivo. KLF5 overexpression was observed in 65.1% of all PTC cases and it was significantly associated with aggressive clinico-pathological parameters and poor outcome. Given the significant association between KLF5 and HIF-1α overexpression in PTC patients, we investigated the functional correlation between KLF5 and HIF-1α in PTC cells. Indeed, the analysis revealed the co-immunoprecipitation of KLF5 with HIF-1α in PTC cells. We also identified KLF5-binding sites in the HIF-1α promoter that specifically bound to KLF5 protein. Mechanistically, KLF5 promoted PTC cell growth, invasion, migration, and angiogenesis, while KLF5 downregulation via specific inhibitor or siRNA reverses its action in vitro. Importantly, the silencing of KLF5 decreases the self-renewal ability of spheroids generated from PTC cells. In addition, the depletion of KLF5 reduces PTC xenograft growth in vivo. These findings suggest KLF5 can be a possible new molecular therapeutic target for a subset of PTC.

Association Between Age and Nodal Metastasis in Papillary Thyroid Carcinoma

OBJECTIVE

To determine the relationship between age and rate of lymph node metastasis, nodal burden of disease, as well as rate of lateral neck disease in papillary thyroid cancer, especially in patients aged <30 years.

STUDY DESIGN

Population-based cross-sectional study.

SETTING

Population-based cancer database.

METHODS

Data were extracted from the SEER 18 database (Surveillance, Epidemiology, and End Results) of the National Cancer Institute. The study cohort included 59,330 patients diagnosed with papillary thyroid cancer between 1988 and 2015. Patients aged 0 to 10 years, 11 to 20 years, and 21 to 30 years old were compared with those >30 years. All analyses were adjusted for sex, race, and T classification.

RESULTS

The overall rate of lymph node metastasis was 26.11%, which increased with decreasing age. Adjusted odds ratios of lymph node metastasis were 7.19 (95% CI, 3.76-13.75) for the 0- to 10-year-old group, 3.45 (95% CI, 3.08-3.87) for the 11- to 20-year-old group, and 2.28 (95% CI, 2.15-2.41) for the 21- to 30-year-old group, relative to the group >30 years old. Decreased age was also associated with increased total positive nodes, increased lymph node ratio, and increased risk of lateral neck disease.

CONCLUSION

Pediatric and early young adult patients with papillary thyroid carcinoma have a greater risk of lymph node metastasis, greater burden of nodal disease, and a greater risk of lateral neck metastases.

LncRNA XIST Promotes Migration and Invasion of Papillary Thyroid Cancer Cell by Modulating MiR-101-3p/CLDN1 Axis

Papillary thyroid carcinoma (PTC) is the most common endocrine malignancy in the worlds. Long non-coding RNA X-inactive specific transcript (XIST) was found to upregulate in PTC tissues and cell lines. However, the molecular mechanism underlying PTC metastasis and whether XIST plays regulatory role in PTC are still largely unknown. qRT-PCR was performed to detect the expression of lncRNA XIST and mRNAs. Western blotting was carried out to detect CLDN1, MMP2, and MMP9. Transwell assay was used to detect migration and invasion. Starbase bioinformatics prediction and luciferase assay were used to validate the relationship of miR-101-3p and XIST or CLDN1. LncRNA XIST was upregulated in PTC tissues and cells. XIST knockdown suppressed migration and invasion of PTC cells. XIST could directly bind with miR-101-3p. Overexpression of miR-101-3p suppressed migration and invasion of PTC cells. CLDN1 was the target of miR-101-3p, and overexpression of CLDN1 can reverse the inhibition of cell migration and invasion by miR-101-3p, What's more, miR-101-3p inhibition and CLDN1 overexpression can reverse the affection of sh-XIST on migration and invasion of PTC cells inhibition. XIST promotes migration and invasion of papillary thyroid cancer cell via directly regulating miR-101-3p/CLDN1 axis, which is a novel mechanistic of XIST in the regulation of PTC.

Long non-coding RNA AGAP2-AS1 increases the invasiveness of papillary thyroid cancer

Papillary thyroid cancer (PTC) is considered a low hazard endocrine system cancer, but a considerable number of patients have poor prognosis because of lymph node metastasis and invasion of surrounding tissues. In this study, we analyzed the expression and function of the long non-coding RNA (lncRNA) AGAP2-AS1 in PTC. We found that AGAP2-AS1 expression was significantly higher in human PTC tissues than adjacent noncancerous tissues (n=110; p<0.01) and correlated with lymph node metastasis (p=0.01) and tumor-node-metastasis stage (p=0.006). AGAP2-AS1 downregulation decreased migration and invasion by PTC cells, and reduced expression of matrix metalloproteinase-2 (MMP2). AGAP2-AS1 upregulated MMP2 expression by competitively binding to microRNA-425-5p. In addition, miR-424-5p expression was decreased in PTC tissues and correlates negatively with the AGAP2-AS1 levels. These results demonstrate that AGAP2-AS1 expression is significantly elevated in PTC tissues and that, by binding to miRNA-425-5p, it upregulates the MMP2 expression, thereby increasing the invasiveness and migration capacity of PTC cells.

Prognostic values of m6A RNA methylation regulators in differentiated Thyroid Carcinoma

N6-methyladenosine (m6A) is the most prevalent modification of RNA in mammals. m6A RNA methylation levels are dynamically regulated by m6A RNA methylation regulators. While increasing evidence has suggested that m6A RNA methylation is vital in the initiation and progression of human carcinoma, little is known about the expression and effect of m6A RNA methylation regulators in differentiated thyroid carcinoma (DTC). Herein, we demonstrate that most of the thirteen main m6A RNA methylation regulators are differentially expressed in DTC tissues and normal thyroid tissues. Based on consensus clustering of m6A RNA methylation regulators, DTC cases were divided into two subgroups (TC1 and TC2). Compared with the TC1 subgroup, the TC2 subgroup was associated with a poorer prognosis, older age, higher T grade, higher N grade and higher TNM stage. The results indicated that alteration of m6A RNA methylation regulators was closely related to DTC. We further established a risk signature of four m6A RNA methylation regulators that could evaluate prognosis and clinicopathological features in DTC. Finally, the results of the TCGA analysis were verified by other cohorts from Gene Expression Omnibus (GEO) database. In conclusion, m6A RNA methylation regulators play a crucial part in the progression of DTC and are potentially useful for evaluating the prognosis and providing potential novel insights into treatment strategies.

Risk Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

Purpose: To explore the risk factors that may predict the lymph node metastasis potential of these lesions and new prevention strategies in papillary thyroid carcinoma patients. Materials and Methods: In total, 9,369 papillary thyroid carcinoma patients with 37.17% lymph node metastasis were analyzed (Revman 5.3 software) in this study. The PubMed and Embase databases were used for searching works systematically that were published through to January 22, 2020. Results: Several factors were related to the increased risk of lymph node metastasis in patients with papillary thyroid carcinoma: age <45 years (pooled OR = 1.52, 95% CI = 1.14-2.01, p <0.00001); gender = male (pooled OR = 1.68, 95% CI = 1.51-1.87, p <0.00001); multifocality (pooled OR = 2.05, 95% CI = 1.45-2.89, p <0.0001); tumor size ≥1.0 cm (pooled OR = 3.53, 95% CI = 2.62-4.76, p <0.00001); tumor location at the upper pole 1/3 (pooled OR =1.46, 95% CI = 1.04-2.04, p = 0.03); capsular invasion + (pooled OR = 3.48, 95% CI = 1.69-7.54, p = 0.002); and extrathyroidal extension + (pooled OR = 2.03, 95% CI= 1.78-2.31, p <0.00001). However, tumor bilaterality (pooled OR = 0.85, 95% CI = 0.54-1.34, p = 0.49) and Hashimoto's thyroditis (pooled OR = 1.08, 95% CI = 0.79-1.49, p = 0.62) showed no correlation with lymph node metastasis in papillary thyroid carcinoma patients. Conclusion: The systematic review and meta-analysis defined several significant risk factors of lymph node metastasis in papillary thyroid cancer patients: age (<45 years), gender (male), multifocality, tumor size (>1 cm), tumor location (1/3 upper), capsular invasion, and extra thyroidal extension. Bilateral tumors and Hashimoto's thyroiditis were unrelated to lymph node metastasis in patients with papillary thyroid cancer.

Distinguishing Recurrent Thyroid Cancer from Residual Nonmalignant Thyroid Tissue Using Multiphasic Multidetector CT

BACKGROUND AND PURPOSE

During thyroidectomy incomplete resection of the thyroid gland may occur. This complicates the imaging surveillance of these patients as residual thyroid needs to be distinguished from local recurrence. Therefore, the purpose of this study was to determine if multiphasic multi-detector computed tomography (4D-MDCT) can differentiate residual nonmalignant thyroid tissue and recurrent thyroid carcinoma after thyroidectomy.

MATERIALS AND METHODS

In this retrospective study, Hounsfield unit values on multiphasic multidetector CT in precontrast, arterial (25 seconds), venous (55 seconds), and delayed (85 seconds) phases were compared in 29 lesions of recurrent thyroid cancer, 29 with normal thyroid, and 29 with diseased thyroid (thyroiditis/multinodular thyroid). The comparison of Hounsfield unit values among lesion types by phase was performed using ANOVA. The performance of Hounsfield unit values to predict recurrence was evaluated by logistic regression and receiver operating characteristic analysis.

RESULTS

All 3 tissue types had near-parallel enhancement characteristics, with a wash-in-washout pattern. Statistically different Hounsfield unit density was noted between the recurrence (lowest Hounsfield unit), diseased (intermediate Hounsfield unit), and normal (highest Hounsfield unit) thyroid groups throughout all 4 phases (P < .001 for each group and in each phase). Dichotomized recurrence-versus-diseased/normal thyroid tissue with univariate logistic regression analysis demonstrated that the area under the receiver operating characteristic curve for differentiating benign from malignant thyroid for the various phases of enhancement was greatest in the precontrast phase at 0.983 (95% CI, 0.954-1), with a cutoff value of ≤62 (sensitivity/specificity, 0.966/0.983) followed by the arterial phase.

CONCLUSIONS

Recurrent thyroid carcinoma can be distinguished from residual nonmalignant thyroid tissue using multiphasic multidetector CT with high accuracy. The maximum information for discrimination is in the precontrast images, then the arterial phase. An optimal clinical protocol could be built from any number of phases but should include a precontrast phase.

Total tumor diameter: the neglected value in papillary thyroid microcarcinoma

BACKGROUND

Tumor multifocality is not uncommon in papillary thyroid carcinoma (PTC), especially in micro-PTC. However, assessing the size of the largest tumor may underestimate effect of additional foci. We aimed to investigate the effect of total tumor diameter (TTD) on clinicopathological features of micro-PTC.

METHODS

Data from 442 patients who underwent thyroidectomy with cervical lymph node dissection for PTC were retrospectively analyzed. Patients were classified into subgroups according to multifocality and TTD. The relationships of clinicopathological features among these groups were analyzed.

RESULTS

Multifocality was observed in 119 patients (26.9%). TTD > 1 cm and presence of extrathyroidal extension (ETE) were significantly higher in multifocal tumors compared to unifocal tumor (P < 0.001, P = 0.016, respectively). When comparing multifocal micro-PTC with TTD > 1 cm to those with unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm, the proportions of cases with ETE, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) were significantly higher (all P < 0.05). There was no significant difference in terms of these parameters between multifocal micro-PTC with TTD > 1 cm and macro-PTC or multifocal macro-PTC. The risk of CLNM was 2.056 (P = 0.044) times higher in multifocal micro-PTC with TTD > 1 cm than in unifocal micro-PTC.

CONCLUSION

For multifocal micro-PTC, TTD can better assess the aggressiveness of the tumor. Multifocal micro-PTC with TTD > 1 cm was more aggressive than unifocal micro-PTC or multifocal micro-PTC with TTD ≤ 1 cm.

Evolution and Impact of Subclonal Mutations in Papillary Thyroid Cancer

Unlike many cancers, the pattern of tumor evolution in papillary thyroid cancer (PTC) and its potential role in relapse have not been elucidated. In this study, multi-region whole-exome sequencing (WES) was performed on early-stage PTC tumors (n = 257 tumor regions) from 79 individuals, including 17 who had developed relapse, to understand the temporal and spatial framework within which subclonal mutations catalyze tumor evolution and its potential clinical relevance. Paired primary-relapse tumor tissues were also available for a subset of individuals. The resulting catalog of variants was analyzed to explore evolutionary histories, define clonal and subclonal events, and assess the relationship between intra-tumor heterogeneity and relapse-free survival. The multi-region WES approach was key in correctly classifying subclonal mutations, 40% of which would have otherwise been erroneously considered clonal. We observed both linear and branching evolution patterns in our PTC cohort. A higher burden of subclonal mutations was significantly associated with increased risk of relapse. We conclude that relapse in PTC, while generally rare, does not follow a predictable evolutionary path and that subclonal mutation burden may serve as a prognostic factor. Larger studies utilizing multi-region sequencing in relapsed PTC case subjects with matching primary tissues are needed to confirm these observations.

Upregulation of sphingosine kinase 1 is associated with recurrence and poor prognosis in papillary thyroid carcinoma

Sphingosine kinase 1 (SPHK1), an ATP-dependent protein, has previously been demonstrated to be upregulated in several types of human cancer and to play an important role in tumor development and progression. However, the role of SPHK1 in predicting long-term prognosis in patients with papillary thyroid carcinoma (PTC) remains unclear. The purpose of the present study was to assess the significance of SPHK1 expression and its associations with clinicopathological characteristics and prognostic outcome in patients with PTC. Immunohistochemistry staining was retrospectively performed to investigate the expression levels of SPHK1 in 92 PTC tumors. Statistical analyses revealed that high levels of SPHK1 expression were associated with tumor size, lymph node metastasis and the Tumor-Node-Metastasis stage. The disease-free survival (DFS) time of patients that exhibited high levels of SPHK1 expression was shorter, whereas patients with lower levels of SPHK1 expression survived longer. Furthermore, multivariate analysis suggested that upregulated SPHK1 was an independent prognostic factor for predicting DFS of patients with PTC. The results of the Cell Counting Kit-8 and invasion assays demonstrated that SPHK1 overexpression significantly enhanced the proliferation and invasion of a PTC cell line, consistent with clinical findings. The results from the present study provide evidence that elevated expression levels of SPHK1 may be involved in the development and progression of PTC, indicating that this protein may act as a potential prognostic marker for patients with this disease.

Risk of Recurrence in Differentiated Thyroid Cancer: A Population-Based Comparison of the 7th and 8th Editions of the American Joint Committee on Cancer Staging Systems

BACKGROUND

Differentiated thyroid cancer (DTC) survival is excellent, making recurrence a more clinically relevant prognosticator. We hypothesized that the new American Joint Committee on Cancer (AJCC) 8th edition improves on the utility of the 7th edition in predicting the risk of recurrence in DTC.

METHODS

A population-based retrospective review compared the risk of recurrence in patients with DTC according to the AJCC 7th and 8th editions using the Surveillance, Epidemiology, and End Results-based Kentucky Cancer Registry from 2004 to 2012.

RESULTS

A total of 3248 patients with DTC were considered disease-free after treatment. Twenty percent of patients were downstaged from the 7th edition to the 8th edition. Most patients had stage I disease (80% in the 7th edition and 94% in the 8th edition). A total of 110 (3%) patients recurred after a median of 27 months. The risk of recurrence was significantly associated with stage for both editions (p < 0.001). In the 7th edition, there was poor differentiation between lower stages and better differentiation between higher stages (stage II hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.39-2.11; stage III HR 3.72, 95% CI 2.29-6.07; stage IV HR 11.66, 95% CI 7.10-19.15; all compared with stage I). The 8th edition better differentiated lower stages (stage II HR 4.06, 95% CI 2.38-6.93; stage III HR 13.07, 95% CI 5.30-32.22; stage IV 11.88, 95% CI 3.76-37.59; all compared with stage I).

CONCLUSIONS

The AJCC 8th edition better differentiates the risk of DTC recurrence for early stages of disease compared with the 7th edition. However, limitations remain, emphasizing the importance of adjunctive strategies to estimate the risk of recurrence.

Recurrent Papillary Thyroid Carcinoma to the Cervical Lymph Nodes: Outcomes of Compartment-Oriented Lymph Node Resection

INTRODUCTION

Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications.

PATIENTS AND METHODS

All patients who underwent LND for recurrent papillary thyroid carcinoma between 2000 and 2015 were included. Demography, the extent of the initial surgery, usage of ¹³¹I, the pattern of recurrence, diagnosis, details of the surgical reintervention, histological findings, surgical morbidity, and clinical and biochemical outcomes were analyzed.

RESULTS

There were 11 (12.7%) males and 75 (87.2%) females with a mean age of 42.8 ± 14.6 years. Seventy-seven patients had undergone total thyroidectomy and in 67 (77.9%) some type of LN resection. In 76 (88.3%), ¹³¹I was administered after the initial surgery. We localized suspicious lymph nodes by US in all patients, and metastases were documented before surgery by FNA in 63. Seven (8.13%) patients underwent central LND, 63 (73.2%) lateral LND and 16 (18.6%) both, central and lateral LND. Major complications occurred in 6 patients (6.9%). Sixty-two (72.0%) patients received ¹³¹I after surgery. A second surgical re-exploration was performed in 30 (34.8%) patients, and 7 patients required 3 or more additional LND. In a mean follow-up of 59.4 ± 39 months, 51 (59.3%) patients are clinically, radiologically and biochemically free of disease.

CONCLUSIONS

In this series, compartment-oriented lymph node resection of recurrent papillary thyroid carcinoma leads to a final clinical and biochemical disease-free status of 59.3% with 6.9% of major complications.

Molecular Network-Based Identification of Circular RNA-Associated ceRNA Network in Papillary Thyroid Cancer

Circular RNAs (circRNAs) have displayed dysregulated expression in several types of cancer. Nevertheless, their function and underlying mechanisms in papillary thyroid cancer (PTC) remains largely unknown. This study aimed to describe the regulatory mechanisms in PTC. The expression profile of circRNA was download from the Gene Expression Omnibus (GEO) database. The mRNA and miRNA data of PTC was downloaded from The Cancer Genome Atlas (TCGA) database. The circRNA-miRNA-mRNA network by Cytoscape. The interactions between proteins were analyzed using the STRING database and hubgenes were identified using MCODE plugin. Then, we conducted a circRNA-miRNA-hubgenes regulatory module. Gene Ontology (GO) and Kyoto Encyclopedia of Gene and Genomes (KEGG) pathway analysis were conducted using R packages "Clusterprofile". We identified 14 differential expression circRNAs (DEcircRNA), 3106 differential expression mRNAs (DEmRNA), 142 differential expression miRNAs (DEmiRNA) and in PTC. Twelve circRNAs, 33 miRNAs, and 356 mRNAs were identified to construct the ceRNA network of PTC. PPI network and module analysis identified 5 hubgenes. Then, a circRNA-miRNA-hubgene subnetwork was constructed based on the 2 DEcircRNAs, 3 DEmiRNAs, and 4 DEmRNAs. GO and KEGG pathway analysis indicated DEmRNAs might be associated with PTC onset and progression. These ceRNAs are critical in the pathogenesis of PTC and may serve as future therapeutic biomarkers.

Functional analysis and clinical significance of the isocitrate dehydrogenase 2 gene in papillary thyroid carcinoma

Objective: Mitochondrial NADP+-dependent isocitrate dehydrogenase 2 (IDH2) is a major producer of mitochondrial NADPH. IDH2-related research has focused on its mutation mechanism and its clinical significance, but the role of wild-type IDH2 in carcinoma remains controversial. Altered IDH2 levels have been identified in several types of carcinomas. However, the significance and expression of IDH2 in thyroid cancer remains unknown.

Methods: We examined the expression of IDH2 in thyroid cancer and adjacent normal tissues using quantitative real-time PCR (qRT-PCR), immunohistochemical (IHC) staining analyses, and western blot analysis with frozen tissues. The relationship between IDH2 and the clinicopathological features of thyroid cancer was analyzed by IHC. Subsequently, we investigated the function of wild-type IDH2 in thyroid cancer cells in vitro.

Results: We found that the mRNA expression and protein levels of IDH2 were higher in tumor than in adjacent tissues, when evaluated by qRT-PCR, western blot, and IHC analyses. Tumor size, T stage, lymph node metastasis, and TNM stage showed significant differences between the IDH2 high expression and low expression groups. Multiple logistic regression analyses indicated that tumor size and IDH2 expression were significantly correlated with the occurrence of neck LNM. Furthermore, CCK8 levels, colony formation, and invasive cell number were decreased in the sh-IDH2 groups. The upregulation of IDH2 in thyroid cancer cells showed opposite effects.

Conclusion: Our results indicated that IDH2 may play an important role in the development of thyroid cancer. IDH2 can be used as a potential biomarker for diagnosis and prognosis and may be a potential therapeutic target for thyroid cancer.

Radioguided occult lesion localization in patients with recurrent thyroid cancer

PURPOSE

Well planned re-surgery is critical for recurrent/persistent thyroid cancer (TC). We aimed to investigate the clinical outcome of radioguided-occult lesion localization (ROLL) guided surgery in patients with recurrent/persistent TC.

METHODS

This study includes 29 patients [F/M: 22/7, median age 43 ± 12 years (18-58)] with a diagnosis of TC (22 papillary, 2 follicular and 5 medullary). Before surgery, all patients underwent ultrasonography (USG) guided mapping and intra-lesional radioactivity injection. Surgery was performed based on the excision of radioactivity injected lesions by a gamma probe and non-injected tumor foci via USG-neck map. Researchers determined surgical success by post-operative tumor markers and neck-USG.

RESULTS

Among 29 patients, 60 metastatic lesions were identified by USG [median size 10 ± 6.3 mm (range 5-30)]. Neck-USG performed after surgery provided no evidence of disease (NED) in %97 (28/29) of TC patients. In the follow-up, stimulated thyroglobulin (Tg) levels were less than 1 ng/ml in 79%(19/24) of DTC patients and suppressed Tg < 0.2 ng/ml was noted in 92% (22/24).In patients with DTC with an incomplete structural response, we dramatically changed the American Thyroid Association (ATA) response category and achieved an excellent response in 92% (22/24) of patients. Among patients with MTC, 5/5 patients had normal USG and calcitonin levels were reduced by 60-80% in 4/5 and > 80% in1/5 patients.

CONCLUSIONS

In this study we have shown that, ROLL-guided surgery yielded NED rate of %97 (28/29) and increased excellent response rates according to ATA guidelines. Further studies with larger patient groups and longer follow-up should be performed to confirm the efficacy of this surgery.

Gold Nanoparticles Suppressed Proliferation, Migration, and Invasion in Papillary Thyroid Carcinoma Cells via Downregulation of CCT3

Emerging evidences have demonstrated that gold nanoparticles (AuNPs) have been used for cancer treatment. The aim of this study was to investigate the effects and molecular mechanisms of AuNPs on papillary thyroid carcinoma (PTC) cells (BCPAP and TPC-1). Characterizations of AuNPs were detected by UV-Vis spectra, transmission electron microscopy (TEM), and dynamic light scattering (DLS). Cell proliferation and apoptosis, migration, and invasion of PTC cells were evaluated by MTT, flow cytometry, wound healing, and transwell assays, respectively. Furthermore, qRT-PCR and western blot assays were performed to assess the protein expressions related to apoptosis and migration including caspase-3, caspase-9, Bax, Bcl-2, MMP-2, and MMP-9. The study revealed that AuNPs significantly suppressed cell viability, migration, and invasion and remarkably induced apoptosis of BCPAP and TPC-1 cells compared with the control group. Moreover, AuNPs negatively regulated the expression of CCT3 and silencing of CCT3 obviously promoted the proliferation, migration, and invasion inhibition and apoptosis induction of PTC cells combined with AuNPs. Collectively, these results highlighted the potential application of AuNPs in PTC target therapy.

A local drug delivery system based on visible light-cured glycol chitosan and doxorubicin⋅hydrochloride for thyroid cancer treatment in vitro and in vivo

Systemic drug delivery systems (SDDSs) for thyroid cancer treatment are associated with serious side effects including nausea, anorexia, and hair loss as a result of damage to normal tissues. In this study, we investigated the feasibility of a local DDS (LDDS) based on visible light-cured glycol chitosan (GC) hydrogel and doxorubicin⋅hydrochloride (DOX⋅HCl), called GC10/DOX, on thyroid cancer treatment in vivo. Visible light irradiation increased the storage modulus and swelling ratio of the GC10/DOX hydrogel precursor. The release of DOX⋅HCl from GC10/DOX exhibited two unique patterns comprising an initial burst within 18 hours, followed by a controlled and sustained release thereafter. In vitro cell viability testing showed that GC10/DOX had a greater antitumor effect than free DOX⋅HCl and GC10 hydrogel controls. In vivo, local injection of GC10/DOX near tumor tissue led to a superior antitumor effect compared with controls consisting of free DOX⋅HCl intravenously injected to the tail vein of thyroid cancer-bearing mouse and GC10 hydrogel subcutaneously injected near the tumor. Altogether, our results suggest that GC10/DOX may have clinical potential for thyroid cancer treatment.

Analysis of Survival and of Time Until Recurrence of Disease of Patients With Papillary Thyroid Carcinoma-Multivariant Analysis

BACKGROUND

We examined survival and time until recurrence of disease by multivariant analysis in patients treated for papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

In the period from January 2003 to January 2018, we analyzed 102 patients with PTC in Public Health Institution-Hospital "Sveti Vracevi" in Bijeljina. Survival and time until recurrence of the disease were analyzed using patients' general data and factors based on preoperative, intraoperative and postoperative examinations. Many prognostic factors were analyzed together; the AGES prognostic score, consisting of age, grade, extent and size, and the AMES prognostic score, consisting of age, metastases, extent and size.

RESULTS

We analyzed 102 patients with PTC. Out of these 87 patients had AGES p.s ≤ 3.99 and 15 patients had AGES p.s> 4. The survival of patients was affected by the presence of distant metastases at the time of diagnosis p = 0.00109 and age p = 0.0436. Recurrence of the disease was recorded in 14 patients. Most patients had recurrence of the disease in the first 5 years after initial surgery. Analyzing the time until recurrence, we concluded that, statistically speaking, AGES p.s> 4 affect recurrence of the disease p = 0.0355 in a significant way, while distant metastases affect it in a very significant way (p = 0.008).

CONCLUSIONS

Prognostic factors of papillary thyroid carcinoma can be divided into 4 categories, patients' general data and factors based on preoperative, intraoperative and postoperative examinations.

Young age increases the risk of lymph node positivity in papillary thyroid cancer patients: a SEER data-based study

Introduction

Currently in papillary thyroid cancer (PTC), the correlation between lymph node positivity (LN+) and patient's age at diagnosis is still inconclusive. The aim of this study was to investigate whether younger PTC patients had higher LN+ rates.

Patients and methods

From the 1998-2013 Surveillance, Epidemiology, and End Results database, we analyzed PTC patients with at least 1 LN examined. The patients were divided into 5 groups by age separately for each T stage: ≤30; 31-40; 41-50; 51-60; >60 years.

Results

A total of 46,077 PTC patients were identified, including 8,386 (18.2%) patients aged ≤30 years, 10,971 (23.8%) patients aged 31-40 years, 11,646 (25.3%) patients aged 41-50 years, 8,596 (18.7%) patients aged 51-60 years, and 6,478 (14.1%) patients aged >60 years. In each T stage, LN+ rates were inversely associated with age at diagnosis, which was validated by multivariate logistic regression analysis (p<0.001). In addition, the subset of patients 30 or younger had the highest lymph node ratio compared with other subsets (p<0.001).

Conclusion

We identified that younger PTC patients have an increased predisposition for LN+ regardless of T stage. This finding could help surgeons to select the optimal treatment for younger PTC patients.

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%.

Overexpression of G Protein-Coupled Receptor Kinase 6 (GRK6) Is Associated with Progression and Poor Prognosis of Papillary Thyroid Carcinoma

Background

Approximately 20% of patients with papillary thyroid carcinoma (PTC) will develop cancer recurrence, but no clinically available biomarker has been identified. Our study aimed to evaluate the prognostic value of G protein-coupled receptor kinase 6 (GRK6) in PTCs.

Material/Methods

We retrospectively enrolled 108 PTC patients in this study, and explored the expression of GRK6 in resected tumor samples by RT-qPCR and immunohistochemistry (IHC). The clinical data were interpreted by chi-square test, univariate analysis, and multivariate analysis. To investigate the functional mechanisms of GRK6 in regulating PTC progression, we also performed overexpression and silencing experiments in TPC-1 cells, a cell line generated from PTC tissues.

Results

RT-qPCR results showed a higher level of GRK6-mRNA in PTCs than in adjacent thyroid tissues. IHC revealed a distinct protein expression pattern of GRK6 among PTCs. Accordingly, we classified patients into low-GRK6 and high-GRK6 groups. The chi-square test showed that a higher GRK6 was associated with larger tumor size (P=0.045) and advanced TNM stage (P=0.001). Kaplan-Meier survival curve and log rank test demonstrated that higher GRK6 predicted poor disease-free survival (DFS) in PTC patients (P=0.002). Furthermore, Cox regression analysis confirmed that GRK6 was an independent prognostic factor for a higher recurrence risk of PTCs (P=0.047). MTT assay and Transwell assay demonstrated that GRK6 overexpression can significantly enhance tumor proliferation and invasion, which was consistent with clinical findings.

Conclusions

Our data show the oncogenic effects of GRK6 in promoting PTC progression.

Utility of routine ultrasonography follow-up after total thyroidectomy in patients with papillary thyroid carcinoma: a single-center study

BACKGROUND

This study aimed to assess the appropriate number of sessions and interval of routine follow-up ultrasonography (US) in patients who underwent total thyroidectomy for papillary thyroid carcinoma (PTC).

METHODS

Between January 2008 and December 2009, 569 patients underwent total thyroidectomy for PTC. Of the 569 patients, 44 were excluded from the study because of no US follow-up data for the neck (n = 43) or owing to indeterminate tumor recurrence/persistence (n = 1). The follow-up US for all the patients was performed by a single radiologist. Based on the cytohistopathological results, tumor recurrence/persistence was determined.

RESULTS

In the 525 patients, the mean interval to the last follow-up US was 54.7 months, and the mean number of follow-up US sessions was 4.4. Of the 525 patients, 31 (5.9%) showed nodal (n = 30) and non-nodal (n = 1) tumor recurrence/persistence. Patient age and N stage were independently associated with tumor recurrence/persistence. Among patients showing tumor recurrence/persistence after total thyroidectomy, the time at first detection of suspicious US findings on follow-up US was ≤8 months in 2 patients, between 10 and 23 months in 21, and ≥ 25 months in 8. In a receiver operating characteristic curve analysis, the number of sessions and interval of the provided follow-up US were inappropriate for the detection of tumor recurrence/persistence.

CONCLUSIONS

For the detection of tumor recurrence/persistence after total thyroidectomy in PTC patients, routine US follow-up with a 1- or 2-year interval may be excessive.

Lung Recurrence of Papillary Thyroid Cancer Diagnosed With Antithyroglobulin Antibodies After 10 Years From Initial Treatment

Introduction: Papillary thyroid cancer (PTC) is the most common endocrine malignancy. More than 98% of patients achieve an excellent response with no evidence of clinical, biochemical, or structural disease after initial treatment. In these patients structural recurrence is rare, more frequently diagnosed in the first 5 years from initial treatment and almost invariably localized in neck lymph nodes. Patient: We report the case of a woman affected by PTC who presented with rapidly rising anti-thyroglobulin antibodies (TgAb) level after 10 years from clinical, morphological and biochemical remission. Diagnosis and Treatment: In 2003, a 56 year old patient was treated with total thyroidectomy and radioiodine remnant ablation (RRA) for a PTC (2 cm) with minimal extrathyroidal extension (T3N1aM0 according to the 6th AJCC TNM staging system) associated with diffuse lymphocytic thyroiditis. In 2004 the patient was free of disease defined as undetectable Tg after recombinant human TSH administration in the absence of TgAb and structural disease. Since February 2012 the appearance and progressive increase of TgAb titer was observed and in 2014 a ¹⁸FDG-PET scan documented three hypermetabolic lesions suggestive of lung micrometastases. The lung lesions were cytologically confirmed as PTC metastases. Both the primary tissue and the lung metastasis were positive for BRAF V600E mutation. The patient was treated with 131-radioiodine that showed radioiodine avid lung lesions that lose the ability to take up iodine at the following treatment. The patient is still alive and the lung lesions are growing slowly. Conclusions: Structural recurrence in patients that demonstrated an excellent response after initial treatment for PTC is extremely rare, and distant metastases exceptional but possible. This case is peculiar because recurrence was early identified after 10 years from initial treatment for the presence of detectable TgAb in a patient that had an histological diagnosis of lymphocytic thyroiditis but with an atypical clinical presentation (normal thyroid at neck ultrasound and undetectable TgAb and anti-thyroid peroxidase antibodies). For this reason TgAb should be tested with Tg in patients with a history of lymphocytic thyroiditis, either histological or humoral, also when TgAb is in the normal range and not suggestive of autoimmune thyroiditis.

Number of Metastatic Lymph Nodes and Ratio of Metastatic Lymph Nodes to Total Number of Retrieved Lymph Nodes Are Risk Factors for Recurrence in Patients With Clinically Node Negative Papillary Thyroid Carcinoma

OBJECTIVES

The number of metastatic lymph nodes (LNs) and the ratio between the number of metastatic LNs and the total number of retrieved LNs (the LN ratio [LNR]) have been proposed as risk factors for recurrence of papillary thyroid carcinoma (PTC). However, the significance of the number of LNs and the LNR in patients with clinically node negative PTC has not been clearly determined. The purpose of this study is to evaluate their significance.

METHODS

We retrospectively analyzed 382 patients with PTC who had undergone total thyroidectomy with prophylactic central neck dissection (CND) between January 2000 and December 2010. We excluded patients with lobectomy, concurrent lateral compartment neck dissection, a follow-up period less than at least 2 years, number of harvested central LNs less than or equal to one, clinically positive LN, distant metastasis, recurrent cancer or other types of malignancy. The correlations between recurrence and various clinicopathologic characteristics including tumor size, extrathyroidal extension (ETE), stage, number of metastatic central LNs, and the LNR were investigated.

RESULTS

After a mean follow-up period of 82.2±26.4 months, recurrence occurred in 14 patients (3.7%). Tumor size ≥20 mm, maximal ETE, presence of central LN metastasis, number of metastatic LNs ≥2, and LNR ≥0.31 correlated with recurrence in the univariate analysis. However, tumor size ≥20 mm, maximal ETE, number of metastatic LNs ≥2, and LNR ≥0.31 were significantly associated with recurrence in the multivariate analysis (hazard ratio=6.61, 7.17, 3.43, and 11.23, respectively).

CONCLUSION

The LNR and the number of metastatic LNs are independent prognostic risk factors for recurrence in patients with clinically node negative PTC, and these factors can be used to guide postoperative adjuvant therapy and follow-up strategy after prophylactic CND.

Twisted Gastrulation BMP Signaling Modulator 1 Regulates Papillary Thyroid Cancer Cell Motility and Proliferation

Bone morphogenetic proteins (BMPs) are growth factors that have important functions in cell proliferation, migration and differentiation. To date, BMP pathway activation has been found in multiple human tumors and is associated with enhanced malignant tumor growth and metastasis. BMP activity is tightly regulated by a family of soluble extracellular secreted BMP modulators. Twisted gastrulation BMP signaling modulator 1 (TWSG1) is a direct BMP regulator that is required for the full signaling activity of BMPs. However, the functions and mechanisms of TWSG1 in papillary thyroid cancer (PTC) metastasis have not been reported. TWSG1 expression was detected in 44 PTC tissues with lymph node metastasis (LNM) and 56 PTC tissues without LNM using quantitative real-time polymerase chain reaction (qRT-PCR). Gain- and loss-of-function approaches were used to assess the biological function of TWSG1 in PTC cells. Matrigel assays demonstrated the effect of tumor cell-derived TWSG1 on endothelial cell function. Our results showed that TWSG1 expression was significantly enhanced in PTC with LNM compared to that in PTC without LNM. TWSG1 knockdown inhibited migration, invasion and proliferation of PTC cells. Additionally, TWSG1 suppression impaired the tumor cell-induced endothelial cell sprout formation. We found that TWSG1 signaling may be transduced by the BMP target transcription factor inhibitor of DNA binding 1 (Id1) and matrix metalloproteinases (MMPs) 2 and 9. In conclusion, TWSG1 was highly expressed in metastasized PTC; tumor growth, migration and invasion were dependent on TWSG1, and it may be a new diagnostic and therapeutic target for PTC.

Downregulation of serum miR-26a predicts poor clinical outcome of papillary thyroid carcinoma

Deregulation of miRNAs has been demonstrated to play an important role in the initiation and development of many types of cancers including papillary thyroid carcinoma (PTC). Currently the role of miR-26a and its potential clinical significance for PTC remains unknown. Eighty-four PTC patients and forty healthy controls were enrolled in this study. Quantitative real-time PCR (qRT-PCR) was performed to determine the expression level of serum miR-26a in all the participants. The association between serum miR-26a expression level and clinical outcome of PTC was investigated. Serum miR-26a expression level was reduced in PTC patients compared with the healthy controls (P<0.01) and significantly increased after receiving treatments (P<0.01). Serum miR-26a expression level was associated with lymph node metastasis (P=0.0173) and TNM stage (P=0.0022). In addition, PTC with lower serum miR-26a expression had poorer overall (P=0.029) and disease free survival rates (P=0.0004). Moreover, serum miR-26a expression was an independent risk factor for PTC (P<0.05). Collectively, down-regulation of serum miR-26a is associated with poor prognosis in PTC and it might be a promising biomarker for this malignancy.

Nomograms predicting disease-specific regional recurrence and distant recurrence of papillary thyroid carcinoma following partial or total thyroidectomy

The study aimed to establish effective nomograms for prediction of tumor regional recurrence and distant recurrence of papillary thyroid carcinoma (PTC) patients after partial or total thyroidectomy.These nomograms were based on a retrospective study on 1034 patients who underwent partial or total thyroidectomy for PTC. The predictive accuracy and discriminative ability of the nomograms were evaluated by the concordance index (C-index) and calibration curve. In addition, a validation cohort was included at the same institution.Multivariate analysis demonstrated that family history, maximal tumor diameter, capsular invasion, and lymph node staging were independent risk factors for regional recurrence-free survival; and family history, histological variants, capsular invasion, perineuronal invasion, and vascular invasion were independent risk factors for distant recurrence-free survival. They were selected into the 2 nomograms, respectively, and the C-index for regional recurrence-free survival and distant recurrence-free survival prediction were 0.72 and 0.83, respectively. In the validation cohort, the 2 nomograms displayed a C-index of 0.72 and 0.89, respectively.The nomograms developed in this study demonstrated their discrimination capability for predicting 3 and 5-year regional recurrence and distant recurrence after partial or total thyroidectomy, and can be used to identify high-risk patients.