Ultrasonographically and anatomopathologically detectable node metastases in the lateral compartment as indicators of worse relapse-free survival in patients with papillary thyroid carcinoma

Risk factors associated with preferential lateral lymph node metastasis in papillary thyroid carcinoma

BACKGROUND

Lateral lymph node metastasis (LLNM) is common in patients with papillary thyroid cancer (PTC), usually occurring after central lymph node metastasis (CLNM). However, some patients experience LLNM without first developing CLNM. This study aimed to identify the risk factors for developing LLNM without CLNM.

METHODS

We retrospectively reviewed 421 patients diagnosed with PTC who underwent lobectomy or total thyroidectomy with central and ipsilateral lateral lymph node dissection. We collected clinicopathological data and used univariate and multivariate logistic regression analyses to determine the risk factors associated with LLNM without CLNM.

RESULTS

The LLNM without CLNM frequency was 18.3% (77/421). Univariate analyses demonstrated that age over 55 years, primary tumor in the upper portion of the thyroid, the number of central lymph node (CLN) and LLNM, primary tumor size, and the summed size of multi-foci tumors smaller than 1 cm were significantly associated with LLNM without CLNM (p < 0.05). Multivariate analysis revealed that LLNM without CLNM was more likely to occur in patients aged ≥55 years (odds ratio [OR], 2.309; 95% confidence interval [CI], 1.133-4.704; p = 0.021), and primary tumor in the upper portion of the thyroid (OR, 0.524; 95% CI, 0.295-0.934; p = 0.028).

CONCLUSION

The lymph node metastasis pattern in patients with PTC is not constant. Therefore, surgeons should evaluate the lateral lymph nodes, especially in patients older than 55 years or when the primary tumor is in the upper portion of the thyroid.

Risk factors for recurrent disease in small papillary thyroid cancers - a Swedish register-based study

AIMS

To study the correlation between clinicopathological risk factors and the risk for intervention-requiring cancer recurrence in patients with small papillary thyroid cancers (sPTCs).

MATERIALS AND METHODS

Records for 397 patients with sPTC (T1 ≤ 20mm) were obtained from the Scandinavian Quality Register for Thyroid, Parathyroid and Adrenal Surgery (SQRTPA) between 2010 and 2016. Follow-up time was at least 5 years. Data regarding intervention-requiring cancer recurrence were obtained from patient medical records and analysed regarding lymph node (LN) status (N0, N1a and N1b) and recurrence.

RESULTS

Age was significantly lower in the N1a and N1b groups compared to N0 (45 vs. 40.5 vs. 49 years, respectively; p = 0.002). Tumour size was smaller in the N1a group compared to N1b group (9 vs. 11.8 mm; p <0.01). The mean number of metastatic LNs at initial surgery was higher in the N1b compared to N1a group (6.6 vs. 3; p = 0.001), and in the recurrent compared to the non-recurrent group (7 versus 3.9; p <0.01). The recurrence rate was higher in the N1b group than the N1a and N0 groups (25% vs. 2.4% vs. 1.4%, respectively; p = 0.001).

CONCLUSIONS

Lymph node stage N1b at diagnosis, and having five or more metastatic nodes, are strong risk factors for cancer recurrence and decreased disease-free survival in sPTC. The management of patients with sPTC should include thorough lymph node mapping for optimal treatment and individual risk stratification.

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.

A LASSO-based model to predict central lymph node metastasis in preoperative patients with cN0 papillary thyroid cancer

Introduction

Central lymph node metastasis (CLNM) is common in papillary thyroid carcinoma (PTC). Prophylactic central lymph node dissection (PCLND) in clinically negative central compartment lymph node (cN0) PTC patients is still controversial. How to predict CLNM before the operation is very important for surgical decision making.

Methods

In this article, we retrospectively enrolled 243 cN0 PTC patients and gathered data including clinical characteristics, ultrasound (US) characteristics, pathological results of fine-needle aspiration (FNA), thyroid function, eight gene mutations, and immunoenzymatic results. Least absolute shrinkage and selection operator (LASSO) analysis was used for data dimensionality reduction and feature analysis.

Results

According to the results, the important predictors of CLNM were identified. Multivariable logistic regression analysis was used to establish a new nomogram prediction model. The receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA) curve were used to evaluate the performance of the new prediction model.

Discussion

The new nomogram prediction model was a reasonable and reliable model for predicting CLNM in cN0 PTC patients, but further validation is warranted.

A novel hybrid approach for "Scarless" (at the neck) lateral neck dissection for papillary thyroid carcinoma: A case series and literature review

Lateral neck dissection (LND) is a necessary treatment for thyroid cancer with lateral lymph node metastasis. However, the defect created during open surgery leaves a visible scar on the neck. With advancements in surgical technology, many robotic and endoscopic surgical techniques have been reported as alternatives to open surgery. In this study, we present a case series demonstrating the successful application of a novel hybrid approach for endoscopic LND and a review of different surgical approaches for "scarless" (at the neck) LND. We performed endoscopic LND via a combined chest and transoral approach in 24 patients between January 2021 and March 2022. The surgery was completed successfully in all patients with an average operation time of 298.1 ± 72.9 min. The numbers of positive/retrieved lymph nodes at levels II, III-IV, and VI were 0.7 ± 0.9/8.4 ± 4.1, 3.6 ± 2.7/19.5 ± 6.8, and 4.9 ± 3.9/10.3 ± 4.5, respectively. Complications included transient hypoparathyroidism in 10 patients, transient recurrent laryngeal nerve injury in 1 patient, internal jugular vein (IJN) injury in 1 patient, IJN sacrifice due to cancer invasion in 1 patient, and chyle leak in 1 patient, and no cases of tumor recurrence were observed during follow-up. The present case series indicates that the combined chest and transoral approach is feasible and effective for performing LND. Our review of different approaches for "scarless" (at the neck) LND identified advantages and disadvantages for all techniques. Our novel approach has unique advantages, and thus, it can provide an ideal surgical procedure for specific papillary thyroid carcinoma patients.

Endoscopic thyroidectomy via the combined trans-oral and chest approach for cT1-2N1bM0 papillary thyroid carcinoma

BACKGROUND

Recent years there have been witnessed considerable advances in endoscopic selective lateral neck dissection (LND). However, dissection of lymph nodes at level IV and level VI via the chest approach is inherently challenging. In this study, we used combined trans-oral and chest approach for endoscopic thyroidectomy in patients with cT1-2N1bM0 papillary thyroid carcinoma (PTC).

METHODS

Clinical characteristics and surgical outcomes of ten patients with cT1-2N1bM0 PTC who underwent endoscopic thyroidectomy via combination of trans-oral and chest approach between September 2020 and September 2021 were retrospectively reviewed.

RESULTS

All 10 patients successfully underwent total thyroidectomy and selective LND via chest approach, while central neck dissection (CND) and supplementary dissection of lymph nodes at level IV were performed via the trans-oral approach. The mean number of positive/retrieved level II, III-IV, and VI lymph nodes were 0.6 ± 1.0/9.8 ± 5.0, 4.6 ± 2.8/23.1 ± 4.7, and 4.9 ± 3.4/10.3 ± 4.6, respectively. Four patients developed transient hypoparathyroidism which spontaneously resolved within 1 month. Five patients developed numbness of lateral neck and ear and one patient experienced limb lift restriction. No other complications or tumor recurrence occurred during follow-up.

CONCLUSION

It is feasible to perform total thyroidectomy, CND, and selective LND via combined trans-oral and chest approach, and satisfactory short-term outcomes were observed in this cohort. This approach may offer one more option for cT1-2N1bM0 PTC patients, especially those in whom metastatic lymph nodes at level IV or level VI are detected by preoperative examination.

Outcomes of Papillary Thyroid Microcarcinoma Presenting with Palpable Lateral Lymphadenopathy

Purpose: Papillary thyroid microcarcinoma (PTMC) is typically indolent in nature, allowing management with active surveillance protocols. Occasionally, a more aggressive phenotype can present and may lead to poor outcomes such as patients presenting with clinically significant lateral lymphadenopathy (cN1b). Prior analysis of the outcomes of this cohort is largely from papillary thyroid cancer (PTC) (>1 cm) or from institutions where use of radioactive iodine (RAI) is limited. Hence, we aim to describe the outcomes of patients with PTMC who presented with palpable cN1b disease, treated with total thyroidectomy and RAI. Methodology: We performed a retrospective cohort study. Outcomes of patients with PTMC who presented with palpable lateral lymph node (LN) metastases (microPTC cN1b) treated between 1997 and 2020 at Royal North Shore Hospital were compared with two control groups' outcomes: patients with clinically detected PTMC without evidence of involved LNs (microPTC cN0) and with larger PTC (>10 mm) who presented with palpable lateral lymphadenopathy (larger PTC cN1b). We assessed clinicopathological variables, postoperative risk stratification, rates of disease recurrence, reoperative surgery, and structural disease-free survival (DFS). Results: In total, 1534 PTMCs were diagnosed following thyroid surgery in the study period; of these, 157 (10%) were clinically detected microPTC cN0 and 26 microPTC cN1b (1.7%). There were 138 patients in the larger PTC cN1b control group. All cN1b patients were treated with total thyroidectomy and adjuvant RAI. Mean size of the largest LN deposit was similar between the microPTC cN1b and larger PTC cN1b groups (23 vs. 27 mm, p = 0.11). Patients with microPTC cN1b were more likely to have biochemical or structural persistence or recurrence compared with microPTC cN0 (19%, 5/26 vs. 3.8%, 6/157, p = 0.002) but less likely than larger PTC cN1b patients (19%, 5/26 vs. 42%, 58/138, p = 0.04). All patients in the microPTC cN1b group who had an excellent response to initial therapy (85%, 22/26) were disease free at last follow-up. The rate of reoperation was similar for the microPTC cN1b and microPTC cN0 groups (4%, 1/26 vs. 2%, 3/157, p = 0.461) and significantly lower than the larger PTC cN1b group (4%, 1/26 vs. 26%, 36/138, p = 0.002). Five-year DFS estimates were significantly better for microPTC cN1b patients than for larger PTC cN1b patients (94% vs. 59%, p = 0.001). Conclusions: MicroPTC cN1b patients treated with thyroidectomy and adjuvant RAI have inferior clinical outcomes compared with microPTC cN0 patients but have better outcomes than their larger PTC cN1b counterparts with respect to disease persistence and recurrence. Response to initial therapy provides valuable prognostication in microPTC cN1b patients: if these patients had an excellent response to initial treatment, they achieved long-term DFS in this series.

Qin's seven steps for endoscopic selective lateral neck dissection via the chest approach in patients with papillary thyroid cancer: experience of 35 cases

BACKGROUND

Endoscopic thyroidectomy is widely performed as it does not result in neck scar. However, there is a paucity of reports pertaining to completely endoscopic lateral neck dissection (LND). In this study, we introduce our step-wise approach for performing endoscopic selective LND via the chest-breast approach. We refer to this approach as Qin's seven steps.

METHODS

The Qin's seven steps are: (1) establishment of working space range; (2) dissection of lymph nodes between the SCM and the sternohyoid muscle (level IV) and exposure of omohyoid; (3) dissection of lymph nodes at level IV; (4) dissection of lymph nodes at level III; (5) dissection of lymph nodes at carotid triangle (level III); (6) exposure of accessory nerve and dissection of lymph nodes at level II a; (7) dissection of lymph nodes at level II b. We reviewed the clinical data of 35 patients with papillary thyroid cancer (PTC) who were operated using the Qin's seven steps.

RESULTS

All 35 patients successfully underwent LND; bilateral LND was performed in 5 patients. The mean tumor size was 1.8 ± 1.0 cm; seven patients had multiple lesions. The mean number of retrieved lymph nodes in level II, III and IV were 8.8 ± 5.6, 6.1 ± 4.0 and 9.3 ± 5.1, respectively. As for complications, there were 3 cases of accessory nerve injury and 1 case of hypoglossal nerve injury. Internal jugular vein injury, cervical plexus injury and lymphatic leakage occurred in 2, 7, and 1 patients, respectively.

CONCLUSION

The Qin's seven steps for performing endoscopic selective LND could be safely used in PTC patients with lateral lymph node metastasis. Satisfactory results were achieved in the short-term follow-up period. We recommend the use of Qin's seven steps for PTC patients who are not desirous of neck scar.

Diagnostic Accuracy of Ultrasound for the Evaluation of Lateral Compartment Lymph Nodes in Papillary Thyroid Carcinoma

AIMS

To evaluate the diagnostic accuracy of ultrasound (US) assessing the lateral compartment lymph node metastasis in patients with primary papillary thyroid carcinoma (PTC), and to demonstrate the incidence and patterns of the lateral lymph node metastasis.

METHODS

We retrospectively reviewed 198 patients with primary PTC who underwent thyroidectomy in addition to modified lateral neck dissections (MLND) involving level II to level V due to clinically positive lateral neck disease. A skilled and experienced single operator performed all US examinations. Surgical pathology results were accepted as the reference method and sensitivity, specificity, and diagnostic accuracy of US in detecting metastatic lymph nodes established using level-by-level analysis.

RESULTS

In the study cohort, 10.1% of the patients had lateral compartment lymph node metastases without any central compartment involvement. For the lateral compartment, 48.5% had level II, 74.7% had level III, 64.6% had level IV, and 29.3% of the patients had level V metastasis. None of the patients had isolated level V metastasis. The sensitivity, specificity, and diagnostic accuracy of US in identifying lateral lymph compartment metastasis ranged from 87% to 91.4%, 92% to 98.6% 92.4% to 96%, respectively. However, the sensitivity (74.7%) and diagnostic accuracy (76.2%) of US significantly decreased for the central compartment while specificity (90%) remained similar.

CONCLUSION

US performed by a skilled operator has an excellent diagnostic accuracy for the evaluation of lateral cervical lymph nodes in primary PTC; thus, might enable precise tailoring of the management strategies. Moreover, the high incidence of level V involvement favors MLND over selective approaches.

Radiomics in Differentiated Thyroid Cancer and Nodules: Explorations, Application, and Limitations

Radiomics is an emerging technique that allows the quantitative extraction of high-throughput features from single or multiple medical images, which cannot be observed directly with the naked eye, and then applies to machine learning approaches to construct classification or prediction models. This method makes it possible to evaluate tumor status and to differentiate malignant from benign tumors or nodules in a more objective manner. To date, the classification and prediction value of radiomics in DTC patients have been inconsistent. Herein, we summarize the available literature on the classification and prediction performance of radiomics-based DTC in various imaging techniques. More specifically, we reviewed the recent literature to discuss the capacity of radiomics to predict lymph node (LN) metastasis, distant metastasis, tumor extrathyroidal extension, disease-free survival, and B-Raf proto-oncogene serine/threonine kinase (BRAF) mutation and differentiate malignant from benign nodules. This review discusses the application and limitations of the radiomics process, and explores its ability to improve clinical decision-making with the hope of emphasizing its utility for DTC patients.

Correlation between sonographic features and pathological findings of cervical lymph node metastasis of differentiated thyroid carcinoma

Background

The aim of this study is to evaluate the relationship between the sonographic features and pathological findings of cervical lymph node metastasis of differentiated thyroid carcinoma (DTC).

Methods

A total of 49 patients who had thyroid surgery and lateral or central cervical lymph node dissection from October to December 2019 in our hospital were selected. All the lymph nodes included in the dissection were examined by intraoperative ultrasound and were divided into 5 groups according to the sonographic characteristics (A: overall hyperechoic group; B: hypoechoic with punctate hyperechoic group; C: mass hyperechoic group; D: cystic degeneration group; E: hypoechoic group without punctate hyperecho). All samples were sent to the Pathology Department according to the area of origin and classified and numbered for comparative analysis of the microscopic pathology and the sonogram.

Results

A total of 120 suspicious metastatic lymph nodes were finally screened out by intraoperative ultrasound. The sonographic signs of these suspicious metastatic lymph nodes in the lateral and central regions of the neck were significantly different from the normal lymph nodes. Besides, the indicators including sensitivity, specificity, accuracy, positive predictive value and negative predictive value of intraoperative ultrasound for detecting lateral and central lymph nodes were 89.04% vs. 82.98%, 93.83% vs. 80.00%, 90.97% vs. 81.10%, 92.86% vs. 70.91%, and 90.48% vs. 88.89%, respectively. The pathological features of metastatic lymph nodes were shown as follows: group A, diffuse distribution of follicular structure; group C, focal distribution of follicular structure; group B and E, atypical follicular epithelial cells with or without papillary structure. Necrosis and liquefaction were observed in group D.

Conclusions

The relationship between sonographic features and follicular structure of metastatic lymph nodes are firmly related. A correct understanding of these features is practical to improve the diagnostic rate of conventional ultrasonography and reduce the incidences of misdiagnosis.

Risk Factors and Prediction Model for Lateral Lymph Node Metastasis of Papillary Thyroid Carcinoma in Children and Adolescents

Purpose

Papillary thyroid carcinoma (PTC) in children and adolescents is prone to lateral lymph node metastasis (LNM), which is a high-risk factor for recurrence. However, few studies focused on identifying risk factors and establishing prediction models for lateral LNM of PTC in children and adolescents.

Patients and Methods

We retrospectively reviewed consecutive cases of children and adolescents with PTC undergoing thyroidectomy and cervical lymph node dissection between January 2009 and December 2019. The demographics and clinicopathologic features were collected and analyzed.

Results

A total of 102 children and adolescents with PTC were enrolled in our study; 51 of whom had lateral LNM (50%). After adjusting for other risk factors, the independent risk factors for lateral LNM were multifocality (odds ratio [OR]: 6.04; 95% confidence interval [CI]: 1.653–22.092; p=0.007), tumor size (OR: 1.752; 95% CI: 1.043–2.945; p=0.034), and the number of central LNM (OR: 1.23; 95% CI: 1.028–1.472; p=0.023). The formula of the combined predictor is: Multifocality + 0.31 × Tumor size + 0.115 × Number of central LNM. The area under the receiver operating characteristic curve of multifocality, tumor size, number of central LNM, and the combined predictor was 0.706, 0.762, 0.748, and 0.855, respectively. When the value of the combined predictor was ≥2.2744, lateral LNM could be predicted. The sensitivity and specificity of the predicted value were 82.4% and 74.5%, respectively.

Conclusion

The independent risk factors for lateral LNM in children and adolescents with PTC were multifocality, tumor size, and the number of central LNM. The prediction model can better predict the presence of lateral LNM.

Prophylactic central lymph node dissection informs the decision of radioactive iodine ablation in papillary thyroid cancer

BACKGROUND

Prophylactic central lymph node dissection (CLND) in papillary thyroid cancer (PTC) is controversial. We aimed to investigate if prophylactic CLND aids risk stratification and contributes to the decision for postoperative RAI ablation.

METHODS

Patients undergoing thyroidectomy for PTC and prophylactic CLND were identified from an endocrine surgical unit database. Pathology reports where reviewed for number and size of lymph nodes and patients stratified by risk according to the ATA guidelines.

RESULTS

426 patients were identified with PTC ≤4 cm and prophylactic CLND. 96 patients (23%) had central lymph node metastasis (CLNM) that qualified them for the intermediate risk group. In 17 patients (4%), the CLNM data led to upgrading independently of other histopathological characteristics. Correcting for multiple variables, CLNM was an independent factor contributing to RAI treatment.

CONCLUSION

Prophylactic CLND provides information to aid the selection of RAI ablation independent of primary cancer histology for risk stratification in 4% of patients. This benefit should be carefully balanced with the risk of CLND and patient treatment choice when deciding on management of PTC ≤4 cm.

Prophylactic Central Lymph Node Dissection Improves Disease-Free Survival in Patients with Intermediate and High Risk Differentiated Thyroid Carcinoma: A Retrospective Analysis on 399 Patients

The role of prophylactic central lymph node dissection (pCLND) in the treatment of differentiated thyroid cancer (DTC) is controversial and still a matter of debate. The primary outcome of our study was to assess whether pCLND is effective in reducing the incidence of recurrent disease, and the secondary goal was to estimate the incidence of postoperative complications in patients who underwent pCLND and to evaluate the prognostic value of occult node metastases. In this retrospective study, we included patients with preoperative diagnosis of DTC and clinically uninvolved lymph nodes (cN0). The patients were divided into two groups, depending on the surgical approach: total thyroidectomy alone (TT group) or total thyroidectomy and pCLND (pCLND group). Three hundred and ninety-nine patients were included in this study, 320 (80.2%) in the TT group and 79 (19.8%) in the pCLND group. There were no significant differences in morbidity among the two groups. Histopathological evaluation demonstrated a similar distribution of aggressive features, especially regarding multicentricity, extrathyroidal extension, and angioinvasivity between the two groups. Occult lymph node metastases were found in 20 (25.3%) patients in the pCLND group. Prophylactic CLND was effective in improving disease-free survival in patients with intermediate and high risk of disease recurrence (p = 0.0392); occult lymph node metastases resulted as a significant negative prognostic factor (p < 0.001).

Clinicopathologic factors and preoperative ultrasonographic characteristics for predicting central lymph node metastasis in papillary thyroid microcarcinoma: a single center retrospective study

Introduction

The treatment of papillary thyroid microcarcinoma remains controversial. Central lymph node metastasis is common in papillary thyroid microcarcinoma and it is an important consideration in treatment strategy selection.

Objective

The aim of this study was to investigate clinicopathologic risk factors and thyroid nodule sonographic characteristics for central lymph node metastasis in papillary thyroid microcarcinoma.

Methods

We retrospectively reviewed the data of 599 papillary thyroid microcarcinoma patients who underwent surgery from 2005 to 2017 at a single institution. Univariate and multivariate analyses were used to identify the clinicopathologic factors and preoperative sonographic features of central lymph node metastasis. A receiver-operating characteristic, ROC curve analysis, was performed to identify the efficacy of ultrasonographic features in predicting central lymph node metastasis. A nomogram based on the risk factors was established to predict central lymph node metastasis.

Results

The incidence of central lymph node metastasis was 22.4%. The univariate and multivariate analyses suggested that gender, age, multifocality, extrathyroidal invasion, and lateral lymph node metastasis were independent risk factors for central lymph node metastasis. The univariate and multivariate analyses revealed that nodular shape, margin, and calcification were independently associated with central lymph node metastasis. The ROC curve analysis revealed that the combination of shape, margin and calcification had excellent accuracy in predicting central lymph node metastasis. The nomogram was developed based on the identified risk factors for predicting central lymph node metastasis, and the calibration plot analysis indicated the good performance and clinical utility of the nomogram.

Conclusions

Central lymph node metastasis is associated with male gender, younger age (<45 years), extrathyroidal invasion, multifocality and lateral lymph node metastasis in papillary thyroid microcarcinoma patients. The ultrasongraphic features, such as irregular shape, ill-defined margin and calcification, may improve the efficacy of predicting central lymph node metastasis. Surgeons and radiologists should pay close attention to the patients who have these risk factors. The nomogram may help guide surgical decision making in papillary thyroid microcarcinoma.

Development and validation of web-based nomograms for predicting lateral lymph node metastasis in patients with papillary thyroid carcinoma

Background

The purpose of this study was to evaluate the factors associated with lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC), and to develop two web-based nomograms that predict the probability of level-II and level-III/IV LLNM in these patients.

Methods

The records of 653 patients with PTC were retrospectively reviewed. Univariate and multivariate analyses were performed to identify risk factors associated with LLNM in 460 patients ("derivation group"). Two models [including and excluding the subregions of central lymph node metastasis (CLNM)] were used to predict the probability of level-II LLNM; the same two models were also used for level-III/IV LLNM. Model performance was assessed using receiver operating characteristic (ROC) analysis and decision curve analysis (DCA) in 193 patients ("validation group"). Two web-based nomograms were established.

Results

Increased tumor size, a tumor in the upper lobe, and prelaryngeal and ipsilateral paratracheal lymph node metastasis (LNM) were significantly associated with level-II LNM (P<0.05). Increased tumor size, a tumor in the upper lobe, and certain subregions of CLNM were associated with level-III/IV LNM (P<0.05). Use of ROC analysis of each model indicated that including subgroups of CLNM led to better model performance than excluding these subgroups. We quantified the benefit of each model by using DCA analysis in the validation group.

Conclusions

Our web-based nomograms provide quantification of risk for LLNM in patients with PTC before and during surgery.

The Impact of Arterial Phase on the Detection of Cervical Lymph Node Metastasis From Papillary Thyroid Carcinoma: A Quantitative Evaluation on Multiphasic Computed Tomography

OBJECTIVE

The purpose of this study was to assess the diagnostic performance of multiphasic computed tomography (CT) in the discrimination of metastatic lymph nodes (LNs) of papillary thyroid cancer by using quantitative parameters.

METHODS

This study enrolled 272 pathologically proven metastatic and benign LNs. Multiphasic CT was utilized by using nonenhanced, arterial (25-second delay), and venous (80-second delay) phases. Mean tissue attenuation values (MAVs) of metastatic and benign LNs were measured, and normalized MAV (common carotid artery and paraspinal muscle) and wash-in and wash-out percentages were also calculated.

RESULTS

The arterial phase showed the highest diagnostic performance in differentiation (area under the curve ± standard error, 0.97 ± 0.02; 95% confidence interval, 0.94-1.0; P < 0.001). Cutoff values for MAVs, normalized MAVs, and wash-in and wash-out percentages to predict metastatic LNs were calculated as 109 HU, 0.33, 1.93, 122.5, and -5.6 (sensitivity: 93.4%, 93.3%, 90.4%, 94.1%, and 97.8%, and specificity: 99.3%, 90.4%, 98.5%, 92.6%, and 99.3%, respectively).

CONCLUSIONS

Early-phase enhanced CT and the use of quantitative parameters derived from multiphasic CT improve the detection of cervical lymph node metastasis from papillary thyroid cancer.

Radiomics signature for prediction of lateral lymph node metastasis in conventional papillary thyroid carcinoma

Purpose

Preoperative neck ultrasound (US) for lateral cervical lymph nodes is recommended for all patients undergoing thyroidectomy for thyroid malignancy, but it is operator dependent. We aimed to develop a radiomics signature using US images of the primary tumor to preoperatively predict lateral lymph node metastasis (LNM) in patients with conventional papillary thyroid carcinoma (cPTC).

Methods

Four hundred consecutive cPTC patients from January 2004 to February 2006 were enrolled as the training cohort, and 368 consecutive cPTC patients from March 2006 to February 2007 served as the validation cohort. A radiomics signature, which consisted of 14 selected features, was generated by the least absolute shrinkage and selection operator (LASSO) regression model in the training cohort. The discriminating performance of the radiomics signature was assessed in the validation cohort with the area under the receiver operating characteristic curve (AUC).

Results

The radiomics signature was significantly associated with lateral cervical lymph node status (p < 0.001). The AUC of its performance in discriminating metastatic and non-metastatic lateral cervical lymph nodes was 0.710 (95% CI: 0.649–0.770) in the training cohort and was 0.621 (95% CI: 0.560–0.682) in the validation cohort.

Conclusions

The present study showed that US radiomic features of the primary tumor were associated with lateral cervical lymph node status. Although their discriminatory performance was slightly lower in the validation cohort, our study shows that US radiomic features of the primary tumor alone have the potential to predict lateral LNM.

Machine Learning Algorithms for the Prediction of Central Lymph Node Metastasis in Patients With Papillary Thyroid Cancer

BACKGROUND

Central lymph node metastasis (CLNM) occurs frequently in patients with papillary thyroid cancer (PTC), but performing prophylactic central lymph node dissection is still controversial. There are no reliable models for predicting CLNM. This study aimed to develop predictive models for CLNM by machine learning (ML) algorithms.

METHODS

Patients with PTC who underwent initial thyroid resection at our hospital between January 2018 and December 2019 were enrolled. A total of 22 variables, including clinical characteristics and ultrasonography (US) features, were used for conventional univariate and multivariate analysis and to construct ML-based models. A 5-fold cross validation strategy was used for validation and a feature selection approach was applied to identify risk factors.

RESULTS

The areas under the receiver operating characteristic curve (AUC) of 7 models ranged from 0.680 to 0.731. All models performed significantly better than US (AUC=0.623) in predicting CLNM (P<0.05). In decision curve, most of the models also performed better than US. The gradient boosting decision tree model with 7 variables was identified as the best model because of its best performance in both ROC (AUC=0.731) and decision curves. Based on multivariate analysis and feature selection, young age, male sex, low serum thyroid peroxidase antibody and US features such as suspected lymph nodes, microcalcification and tumor size > 1.1 cm were the most contributing predictors for CLNM.

CONCLUSIONS

It is feasible to develop predictive models of CLNM in PTC patients by incorporating clinical characteristics and US features. The ML algorithm may be a useful tool for the prediction of lymph node metastasis in thyroid cancer.

Genomic and Transcriptomic Characterization of Papillary Microcarcinomas With Lateral Neck Lymph Node Metastases

CONTEXT

Most papillary microcarcinomas (PMCs) are indolent and subclinical. However, as many as 10% can present with clinically significant nodal metastases.

OBJECTIVE AND DESIGN

Characterization of the genomic and transcriptomic landscape of PMCs presenting with or without clinically important lymph node metastases.

SUBJECTS AND SAMPLES

Formalin-fixed paraffin-embedded PMC samples from 40 patients with lateral neck nodal metastases (pN1b) and 71 patients with PMC with documented absence of nodal disease (pN0).

OUTCOME MEASURES

To interrogate DNA alterations in 410 genes commonly mutated in cancer and test for differential gene expression using a custom NanoString panel of 248 genes selected primarily based on their association with tumor size and nodal disease in the papillary thyroid cancer TCGA project.

RESULTS

The genomic landscapes of PMC with or without pN1b were similar. Mutations in TERT promoter (3%) and TP53 (1%) were exclusive to N1b cases. Transcriptomic analysis revealed differential expression of 43 genes in PMCs with pN1b compared with pN0. A random forest machine learning-based molecular classifier developed to predict regional lymph node metastasis demonstrated a negative predictive value of 0.98 and a positive predictive value of 0.72 at a prevalence of 10% pN1b disease.

CONCLUSIONS

The genomic landscape of tumors with pN1b and pN0 disease was similar, whereas 43 genes selected primarily by mining the TCGA RNAseq data were differentially expressed. This bioinformatics-driven approach to the development of a custom transcriptomic assay provides a basis for a molecular classifier for pN1b risk stratification in PMC.

Preoperative Ultrasonographic Staging of Papillary Thyroid Carcinoma With the Eighth American Joint Committee on Cancer Tumor-Node-Metastasis Staging System

OBJECTIVE

The purpose of this study was to evaluate the performance of preoperative ultrasonography (US) in the staging of papillary thyroid carcinoma (PTC) according to the eighth AJCC TNM classification system, to determine the effect of the preoperative US staging in the management of PTC.

PATIENTS AND METHODS

Preoperative US was performed by 2 highly trained sonographers in 665 consecutive patients with PTC, and the T and N categories were determined preoperatively. The accuracy of preoperative US in clinical staging was evaluated based on the histopathological specimens according to the eighth AJCC TNM classification. Further analysis was performed to identify the high-risk factors of N1b stage.

RESULTS

Overall accuracy of preoperative US for T stage was 92.5% (615/665). The accuracy of sonographic evaluation for T was high except for the T4a. Overall accuracy of preoperative US for N stage was 59% (426/655). The accuracies of sonographic evaluation for N0, N1a, and N1b were 81.8% (274/335), 33.3% (70/250), and 87.5% (70/80), respectively. Of 250 N1a patients, 164 (65.6%) were underestimated by US. Univariate and multivariate analyses showed that larger tumor diameter, multifocality, and higher T stage significantly increase the risk of N1b stage (P < 0.01).

CONCLUSIONS

Preoperative US was useful for the evaluation in staging of PTC, but some limitations still existed. For higher-risk patients of N1b (larger tumor size, multifocality, and higher T stage), preoperative US examination for lateral neck region should be further emphasized, and prophylactic lateral nodal dissection should be determined based on both preoperative imaging results and intraoperative evaluation.

MKL1 overexpression predicts poor prognosis in patients with papillary thyroid cancer and promotes nodal metastasis

Papillary thyroid cancer (PTC), the most common thyroid malignancy, has a strong propensity for cervical lymph node metastasis (LNM), which increases the risk of locoregional recurrence and decreases survival probability in some high-risk groups. Hence, there is a pressing requirement for a reliable biomarker to predict LNM in thyroid cancer. In the present study, MKL1 (also known as MRTFA) expression was significantly increased in PTC patients with LNM compared with those without. Further receiver operating characteristic (ROC) analysis showed that MKL1 expression had a diagnostic value in the differentiation of LNM in PTC. Furthermore, Kaplan-Meier analysis revealed that high MKL1 expression was associated with significantly decreased survival in PTC. Additionally, our study indicated that MKL1 promoted the migration and invasion of PTC cells. MKL1 interacted with and recruited Smad3 to the promoter of MMP2 to activate MMP2 transcription upon treatment with TGF-β. Moreover, there was significant correlation between expression of TGF-β, MKL1 and MMP2 in our clinical cohort of specimens from individuals with PTC. Our results suggest that the detection of MKL1 expression could be used to predict cervical LNM and inform post-operative follow-up in individuals with PTC.

Original tumour suppressor gene polycystic kidney and hepatic disease 1-like 1 is associated with thyroid cancer cell progression

In recent decades, thyroid cancer (TC) has become one of the most common endocrine malignancies. Next-generation sequencing of paired TC and adjacent healthy thyroid tissues demonstrated that polycystic kidney and hepatic disease 1-like 1 (PKHD1L1) may serve as a tumour suppressor gene in thyroid cancer. However, the function of PKHD1L1 in thyroid cancer is still unknown. To validate the results of whole-transcriptome resequencing, the expression levels of PKHD1L1 were evaluated in 58 pairs of papillary thyroid cancer (PTC) tissue samples and three thyroid cancer cell lines. In addition, The Cancer Genome Atlas (TCGA) data were used to analyse the relationship between PKHD1L1 and patient clinicopathological features. Cell Counting Kit-8, colony formation, migration and invasion assays were performed to assess the effects of PKHD1L1 knockdown in three TC cell lines. PKHD1L1 expression was significantly lower in thyroid carcinoma compared with that in matched normal tissue, and this result was consistent with that in TCGA cohort. TCGA data demonstrated that PKHD1L1 downregulation was associated with a number of aggressive clinicopathological features, such as histological type, lymph node metastasis (LNM), distant metastasis, tumour size and clinical stage. Logistic regression analysis of data from patients with PTC revealed that PKHD1L1 expression, histological type, age and tumour size were independent high-risk factors for LNM. The PKHD1L1 biological function was investigated in the three TC cell lines: TPC-1, KTC1 and BCPAP. A loss of function experiment demonstrated that PKHD1L1 knockdown promoted cell proliferation, colony formation and cell invasion in TC cell lines. In conclusion, PKHD1L1 may be a tumour suppressor gene associated with PC, and may be a potential therapeutic target in the future.

Deciphering novel biomarkers of lymph node metastasis of thyroid papillary microcarcinoma using proteomic analysis of ultrasound-guided fine-needle aspiration biopsy samples

Thyroid papillary microcarcinoma is now a common clinical problem. Cervical lymph node metastasis is the main metastasis mode of PTMC. However, before operation, it is still difficult to determine exactly whether PTMC patient is suffering with cervical lymph node metastasis. To resolve this dilemma, for better selection of optimum treatment plans, it is necessary to investigate the overall changes in proteomes of PTMC, and evaluate the potential of biomarkers to predict lymph node metastasis. Tandem mass tags combined with multidimensional liquid chromatography and mass spectrometry analyses were used aiming to screen the proteomic profiles of fine-needle aspiration biopsy samples. Quantitative proteomic analysis, significant pathway and functional categories were investigated. In total, 3391 proteins of the 3793 protein groups identified were quantified. Bioinformatics analysis indicated that differentially expressed proteins were involved in multiple biological functions, metastasis-related pathways. Moreover, IFN-stimulated gene 15 proteins were found to be well distinguished between patients with lymph node metastatic and patients with nonmetastatic PTMC. Knocking down ISG15 with shRNA inhibited the xenografted tumor growth. This study provided a reference proteome map for lymph node metastatic PTMC. ISG15 probably is a prognosis marker of thyroid papillary microcarcinoma patients with lymph node metastasis. SIGNIFICANCE: Nowadays, thyroid cancer has become a widespread epidemic. The rate of thyroid cancer incidence has been faster than any other cancers, reported by the American Cancer Society. Papillary thyroid microcarcinoma (PTMC) is a subset of PTC defined as PTC measuring≤1 cm in size, which comprises nearly one-half of all the cases of PTCs. Actually, the rapidly increasing global incidence of PTC is mainly attributed to the corresponding increase in the diagnosis of PTMC. Scholars have figuratively compared the increase of PTMC to the "tsunami". The treatment scheme for PTMC is still not uniform, and the controversy is mainly focused on the necessity of surgery treatment. PTMCs often have an indolent course in the absence of evidence of metastatic cervical lymph nodes, distant metastases and extrathyroidal extension. Therefore, it is important for us to reliably differentiate the small number of PTMC patients developing significant metastases progression from the larger population of patients that harbor indolent PTMCs. The present study aimed to investigate the overall changes in proteomes of PTMC, and evaluate the potential of biomarkers to predict lymph node metastasis. Tandem mass tags (TMT) combined with multidimensional liquid chromatography and mass spectrometry analyses were used aiming to screen the proteomic profiles of fine-needle aspiration biopsy (FNAB) samples. Quantitative proteomic analysis, significant pathway and functional categories were investigated. Our results showed that some differential expression proteins were likely to be important resources for finding new diagnostic biomarkers.

Meta-analysis of ultrasound for cervical lymph nodes in papillary thyroid cancer: Diagnosis of central and lateral compartment nodal metastases

PURPOSE

To evaluate the performance of preoperative ultrasound in the diagnosis of cervical lymph nodes metastases (CLNM) of papillary thyroid cancer (PTC) and its value in assisting cervical lymph node dissection (CLND).

METHODS

PubMed, EMBASE and Cochrane Library databases were searched to identify relevant studies up to Sep. 2017. Overall sensitivity, specificity, and diagnostic odds ratio (DOR) were used to assess the diagnostic efficacy of ultrasound in detecting central and lateral CLNM of PTC.

RESULTS

Nineteen studies comprising 4014 patients were included in the meta-analysis. The pooled sensitivity, specificity, DOR and area under curve (AUC) of ultrasound in detecting central CLNM were 0.33 (95% confidence interval (95% CI): 0.31-0.35), 0.93 (95% CI: 0.92-0.94), 5.63 (95% CI: 3.50-9.04), and 0.69, respectively; and lateral CLNM were 0.70 (95% CI: 0.68-0.72), 0.84 (95% CI: 0.82-0.85), 18.7 (95% CI: 10.3-33.9) and 0.88, respectively. We found that the rate of central CLNM of PTC was 48.0%, and 36.2% of the dissected lymph nodes were metastatic, meanwhile, the rate of lateral CLNM of PTC was 59.2%, and 46.6% of the dissected lymph nodes were metastatic in the meta-analysis.

CONCLUSIONS

Preoperative ultrasound demonstrates poor sensitivity in the diagnosis of central CLNM, and good diagnostic efficacy for lateral CLNM of PTC. Prophylactic central CLND is recommended to PTC patients due to the high incidence of central CLNM and low diagnostic efficacy of ultrasound.

Predictive Factors of Skip Metastasis in Papillary Thyroid Cancer

Background

Skip metastasis is defined as metastasis incident to the lateral compartment without involvement of the central compartment, and is generally unpredictable in papillary thyroid cancer (PTC). The present study aimed to investigate the frequency and predictor value of skip metastasis in PTC patients.

Material/Methods

A total of 355 patients diagnosed with thyroid cancer who had received a prior complete thyroidectomy with bilateral central neck and ipsilateral lateral neck lymph node dissection were enrolled in this study. The clinicopathological and ultrasound features were analyzed. A univariate and multivariate analysis were performed to identify the risk factors of skip metastasis.

Results

The frequency of skip metastasis was 12.4% (44/355). The PTC patients with skip metastasis exhibited fewer lymph node metastasis, which was more commonly detected in tumor size ≤1 cm (OR 9.354; p=0.001; 95% confidence interval (CI) 1.865–26.735), tumors located in upper pole (OR 3.822; p<0.001; 95% CI 1.935–7.549), without a well-defined margin (OR 2.528; p=0.016; CI 1.191–5.367), and extrathyroidal extension (OR 2.406; p=0.013; CI 1.691–4.367).

Conclusions

Skip metastasis was common in PTC. The PTC patients with a tumor size ≤1.0 cm, located in the upper pole, without a well-defined margin and extrathyroidal extension should be carefully evaluated for skip metastasis.

Lateral lymph node metastasis in papillary thyroid carcinoma: A systematic review and meta-analysis for prevalence, risk factors, and location

BACKGROUND

Lymph node metastasis (LNM) is frequent in papillary thyroid carcinoma (PTC) and is associated with a poor prognosis. Unlike central LNM (CLNM), there are few studies focusing on LLNM. We aimed to investigate the prevalence and the risk factors for LLNM, with its most prevalent sites.

METHODS

We performed a comprehensive literature search using the PubMed and EMBASE databases for relevant studies published prior to November 2016 that examined the risk factors for LLNM.

RESULTS

Twenty-three studies, including 18,741 patients, were included. The prevalence of LLNM was 20.9% in all patients. CLNM (pooled OR = 7.84, 95% CI = 6.13-10.02, p < .0001), extrathyroidal extension (pooled OR = 3.22, 95% CI = 2.21-4.70, p < .0001), tumor multifocality (pooled OR = 2.19, 95% CI = 1.67-2.89, p < .0001), male sex (pooled OR = 1.72, 95% CI = 1.50-1.98, p < .0001), upper pole location (pooled OR = 2.96, 95% CI = 1.93-4.53, p < .0001), tumor size ≥1.0 cm (pooled OR = 2.49, 95% CI = 1.71-3.61, p < .0001), lymphovascular invasion (pooled OR = 3.96, 95% CI = 2.61-6.03, p < .0001) and tumor bilaterality (pooled OR = 1.31, 95% CI = 1.12-1.53, p = .0006) were significantly associated with LLNM. Most frequently affected areas were levels III and IV.

CONCLUSIONS

The prevalence of LLNM was high although the prognostic impact is unknown. The significant risk factors for LLNM were not much different from known risk factors for CLNM.

CUNR scoring system for the prediction of lateral lymph node metastasis in papillary thyroid carcinoma

Objective

Our present study aimed to evaluate and compare the number and rate of central lymph node metastases (LNMs) for the prediction of lateral LNM (LLNM) in papillary thyroid carcinoma (PTC) and to develop a scoring system.

Results

Capsule invasion, tumor location in the upper portion of the thyroid, an ipsilateral central compartment LNM number ≥3, and an ipsilateral central compartment LNM rate of ≥56% were identified as significant independent predictors of ipsilateral lateral LNM in PTC. The predictive ability of an ipsilateral central compartment LNM rate ≥56% (area under the curve (AUC) = 0.802) was better than that of an ipsilateral central compartment LNM number ≥3 (AUC = 0.755). The ROC curves identified the best index point (CUNR) to distinguish the presence or absence of ipsilateral LLNM as 11, which has a high sensitivity (0.860) and a low false-negative rate (0.100, 1-Specificity). These findings were supported by the validation cohort.

Conclusions

Patients with a CUNR index point equal to or greater than 11 and ipsilateral lateral lymph node dissection should be considered for a diagnosis of LLNM.

Patients and Methods

A total of 1,281 PTC patients were included and divided into two groups: those with a presence of LLNM (n = 222) and those with an absence of LLNM (n = 1059). Univariate and multivariate analyses were performed to detect the risk factors for LLNM, and receiver operating characteristic (ROC) curves were used to detect the best cutoff values of these predictors. Additionally, a scoring system for the odds ratio (OR) of independent factors was developed and validated in an independent cohort of PTC patients (n = 560).

Importance of surgeon-performed ultrasound in the preoperative nodal assessment of patients with potential thyroid malignancy

INTRODUCTION

A comprehensive cervical ultrasound evaluation is essential in the operative planning of patients with thyroid disease. Reliance on radiographic reports alone may result in incomplete operative management as pathologic lymph nodes are often not palpable and evaluation of the lateral neck is not routine. This study examined the role of surgeon-performed ultrasound in the evaluation of patients who underwent lateral neck dissection for thyroid cancer.

METHODS

We conducted a retrospective review of a prospectively maintained database of patients who underwent therapeutic lymph node dissection for thyroid cancer between 2001 and 2016 at our tertiary referral center. All patients had surgeon-performed ultrasound preoperatively by 1 of 7 endocrine surgeons. These findings were compared with prereferral imaging studies to determine the value of surgeon-performed ultrasound to their overall treatment.

RESULTS

Of 92 patients who underwent thyroidectomy with lateral neck dissection, 97% had prereferral imaging of the neck (ultrasonography, computed tomography, positron emission tomography). Of these patients, nodal disease was suggested by computed tomography scanning in 70.8% and by ultrasonography in 54%. Of all patients, 45% had positive lateral neck nodes detected only on surgeon-performed ultrasound despite prior neck imaging. Nodal disease was identified in 50% of patients with only 1 study and 50% of patients with greater than 1 study before surgeon-performed ultrasound. Of patients with nodes detected by surgeon-performed ultrasound, only 67% had a prereferral diagnosis of thyroid cancer.

CONCLUSIONS

Our data demonstrate that reliance on standard preoperative imaging alone would have led to an incorrect initial operation in 45% of our patients. Awareness of the limitations of prereferral imaging is important for surgeons treating patients with thyroid and parathyroid disease. Surgeon-performed ultrasound is a useful tool in the diagnosis and accurate staging of patients.

Persistent and recurrent disease in patients with papillary thyroid carcinoma with clinically apparent (cN1), but not extensive, lymph node involvement and without other factors for poor prognosis

OBJECTIVE

Lymph node metastases (LNM) are frequent in patients with papillary thyroid cancer (PTC). The risk of persistent disease (PD) and tumor recurrence (TR) is increased when factors for poor prognosis other than LNM exist, when LNM are numerous, large, detected by preoperative ultrasonography (US), or exhibit extranodal extension. This study evaluated the risk of PD and TR in patients with LNM not exhibiting these characteristics.

SUBJECTS AND METHODS

Eighty-six patients with 5 or fewer LNM detected during intraoperative inspection, but not by preoperative US, who had no other factors for poor prognosis [tumors > 4 cm, extensive extrathyroid invasion, vascular invasion, aggressive histological subtype, distant metastases, incomplete tumor resection], were studied. All patients underwent total thyroidectomy followed by radioiodine ablation. PD was defined as metastases on initial post-therapy whole-body scans (RxWBS) or detected by imaging methods up to 12 months after ablation. TR was defined as structural disease diagnosed more than one year after ablation in patients without PD.

RESULTS

PD was diagnosed in 3/86 patients (3.5%). TR was observed in 2/83 patients (2.5%) after 62 months of follow-up. There was no case of death due to the disease. A correlation was observed between pre-ablation Tg and PD or TR [1/48 (2%) with Tg ≤ 2 ng/mL versus 2/22 (9%) with Tg > 2 ≤ 10 ng/mL versus 2/7 (28.5%) with Tg ≥ 10 ng/ml)]. It is noteworthy that 38 patients had up to 3 positive LN and pre-ablation Tg ≤ 2 ng/ml, and none of them had PD or TR.

CONCLUSIONS

The frequency of PD and TR was low in patients with PTC with 5 or fewer LNM and without other factors for poor prognosis. Low postoperative stimulated Tg was predictive of the absence of PD and TR in these patients.

The diagnostic and prognostic values of Ki-67/MIB-1 expression in thyroid cancer: a meta-analysis with 6,051 cases

Background

Growing evidence has demonstrated that Ki-67/MIB-1 has an effect on the clinical progression and prognosis in cancers. However, the diagnostic and prognostic values of Ki-67/MIB-1 in thyroid cancer remain unclear.

Materials and methods

The meta-analysis was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were retrieved from PubMed, EBSCO, EMBASE, ISI Web of Science, China National Knowledge Infrastructure, WanFang and Chinese VIP databases. MetaDiSc and STATA12.0 were used to analyze the meta-analysis. Fixed-effect analysis and random-effect analysis were applied to pool the relative ratio based on heterogeneity in this meta-analysis.

Results

In the meta-analysis, 51 eligible studies were included. The pooled sensitivity of Ki-67/MIB-1 was 0.61 (95% confidence interval [CI]: 0.59–0.63) and specificity was 0.75 (95% CI: 0.74–0.77) in thyroid cancer. The pooled positive likelihood ratio was 3.19 (95% CI: 2.30–4.42) and negative likelihood ratio was 0.43 (95% CI: 0.35–0.54). In the diagnosis of thyroid cancer, the pooled diagnostic odds ratio of Ki-67/MIB-1 was 8.54 (95% CI: 5.03–14.49). The area under the symmetric receiver operating characteristic curve was 0.804 (standard error =0.031). Our results showed that there were statistical associations between Ki-67/MIB-1 and age (odds ratio [OR] =1.71, 95% CI: 1.14–2.57, P=0.010), tumor size (OR =1.86, 95% CI: 1.17–2.96, P=0.008), lymph node metastasis (OR =2.49, 95% CI: 1.42–4.39, P=0.002), metastasis status (OR =6.96, 95% CI: 2.46–19.69, P<0.001), tumor node metastasis stage (OR =6.56, 95% CI: 3.80–11.34, P<0.001) and extrathyroid extension (OR =1.91, 95% CI: 1.27–2.87, P=0.002). Furthermore, thyroid cancer patients with a high level of Ki-67/MIB-1 had a worse disease-free survival as compared to patients with a low level of Ki-67/MIB-1 (hazard ratio =5.19, 95% CI: 3.18–8.46, P<0.001). Also, Ki-67/MIB-1 was found to be associated with increased risk of mortality (hazard ratio =3.56, 95% CI: 1.17–10.83, P=0.025).

Conclusion

Our results demonstrated that Ki-67/MIB-1 might act as a potential factor in diagnosing thyroid cancer in Chinese. Also, the meta-analysis indicated that Ki-67/MIB-1 might have an effect on prognosis in non-Chinese thyroid cancer patients.

Fibronectin 1 promotes migration and invasion of papillary thyroid cancer and predicts papillary thyroid cancer lymph node metastasis

Lymph node metastasis (LNM) is common in papillary thyroid cancer (PTC), and is an indicator of recurrence. The detailed molecular mechanism of LNM in PTC has not been well described. This study aimed to investigate the role of fibronectin 1 in PTC LNM and its clinical relevance. The expression of fibronectin 1 was confirmed in PTC tissues and cell lines. A correlation analysis was conducted and a receiver-operating characteristic curve obtained. The effect of fibronectin 1 on the proliferation of PTC cell lines was performed using a colony-formation assay and Cell Counting Kit 8. Cell-cycle analysis was performed with a flow-cytometry assay. Migration and invasion ability were evaluated by transwell and wound-healing assays. Fibronectin 1 was overexpressed in metastasized PTC. Overexpressed fibronectin 1 was positively correlated with PTC LNM. Receiver-operating characteristic analysis showed that the diagnostic accuracy of fibronectin 1 was 81.1%, with sensitivity of 80% and specificity of 82%. Overexpression of fibronectin 1 promoted proliferation, migration, and invasion in PTC. Fibronectin 1 plays a critical role in PTC metastasis by modulating the proliferation, migration, and invasion ability of PTC cells, and it is a valuable diagnostic biomarker for predicting PTC LNM.

NONHSAT076754 aids ultrasonography in predicting lymph node metastasis and promotes migration and invasion of papillary thyroid cancer cells

Lymph node metastasis (LNM) is the primary challenge in papillary thyroid cancer (PTC). Recurrent cancerous lymph nodes require repeated surgeries, which increases the risk for surgical complications. Thus, the evaluation of LNM before surgery is important. Ultrasonography is the most convenient way to examine cervical LNM, but the sensitivity of ultrasonography in the identification of LNM in cases of PTC is extremely low. A series of lncRNAs (long noncoding RNAs) have been reported as candidate biomarkers in a variety of tumors. This study detected the lncRNA NONHSAT076754 in PTC and analyzed the correlation of NONHSAT076754 with the clinicopathological and ultrasonographic characteristics of patients with PTC. The value of NONHSAT076754 as an auxiliary diagnostic biomarker for use along with ultrasonography in the differentiation of LNM in PTC was assessed. Additionally, the biological function of NONHSAT076754 in PTC cells was demonstrated. Our study indicated that NONHSAT076754 promotes migration and invasiveness of PTC and serves as a valuable auxiliary biomarker that can be used along with ultrasonography in the prediction of cervical LNM.

Papillary thyroid microcarcinoma: time to shift from surgery to active surveillance?

The incidence of differentiated thyroid cancer is increasing greatly in high-income countries. Roughly 50% of this increase is attributable to the identification of intrathyroidal papillary thyroid microcarcinomas. Since mortality associated with these tumours remains low and stable, the increasing diagnosis has led to concerns about overdiagnosis and overtreatment. Management of papillary thyroid microcarcinomas should take into account the reported absence of mortality when diagnosed in the absence of lymph node metastases and distant metastases, as shown even in recent studies promoting active surveillance; a low recurrence rate of 1-5%; and the risk of permanent complications from surgery that cannot be decreased to less than 1-3%, even in high-volume tertiary care centres with experienced surgeons. On the basis of these data, active surveillance with curative intent, in which active treatment is delayed until the cancer shows signs of significant progression to avoid side-effects of treatment, should be considered in properly selected patients.

ENDOCRINE TUMOURS: Imaging in the follow-up of differentiated thyroid cancer: current evidence and future perspectives for a risk-adapted approach

The clinical and epidemiological profiles of differentiated thyroid cancers (DTCs) have changed in the last three decades. Today's DTCs are more likely to be small, localized, asymptomatic papillary forms. Current practice is, though, moving toward more conservative approaches (e.g. lobectomy instead of total thyroidectomy, selective use of radioiodine). This evolution has been paralleled and partly driven by rapid technological advances in the field of diagnostic imaging. The challenge of contemporary DTCs follow-up is to tailor a risk-of-recurrence-based management, taking into account the dynamic nature of these risks, which evolve over time, spontaneously and in response to treatments. This review provides a closer look at the evolving evidence-based views on the use and utility of imaging technology in the post-treatment staging and the short- and long-term surveillance of patients with DTCs. The studies considered range from cervical US with Doppler flow analysis to an expanding palette of increasingly sophisticated second-line studies (cross-sectional, functional, combined-modality approaches), which can be used to detect disease that has spread beyond the neck and, in some cases, shed light on its probable outcome.

Recurrence Incidence in Differentiated Thyroid Cancers and the Importance of Diagnostic Iodine-131 Scintigraphy in Clinical Follow-up

Objective:

Differentiated thyroid cancers (DTC) are tumors with good prognosis. However, local recurrence or distant metastasis can be observed. In our study, we aimed to investigate the incidence of recurrence and the importance of diagnostic iodine-131 whole body scan (WBS) in clinical follow-up in patients with DTC.

Methods:

The clinical data of 217 patients with DTC who were followed-up more than 3 years were reviewed retrospectively. The incidence of recurrence was investigated in a group of patients who had radioactive iodine (RAI) treatment and showed no sign of residual thyroid tissue or metastasis with diagnostic WBS that was performed at 6-12 months after therapy and had a thyroglobulin (Tg) level lower than 2 ng/dl.

Results:

At the time of diagnosis, ten cases had thyroid capsule invasion, 25 cases had extra-thyroid soft tissue invasion, 11 patients showed lymph node metastasis and four patients had distant organ metastasis. One hundred forty-five patients had RAI treatment at ablation dose (75-100 mCi), whereas 35 patients had RAI treatment at metastasis dose (150-200 mCi). Thirty-seven patients with papillary microcarcinoma did not receive RAI treatment. In 12 (%7.5) of the 160 patients who were considered as “successful ablation”, a recurrence was identified. Recurrence was detected by diagnostic WBS in all cases and stimulated Tg level was <2 ng/dL with the exception of the two cases who had distant metastasis.

Conclusion:

Identification of pathological findings with WBS in patients who developed local recurrence in the absence of elevated Tg highlights the importance of diagnostic WBS in clinical follow-up.

Cervical lymph node thyroglobulin measurement in washout of fine-needle aspirates for diagnosis of papillary thyroid cancer metastases

BACKGROUND

Patients with papillary thyroid cancer (PTC) and enlarged cervical lymph nodes (CLNs) are usually assessed by fine-needle aspiration biopsy cytology (FNAB-C). Thyroglobulin (Tg) is frequently detected in washout of fine-needle aspirates (FNA) of these lymph nodes. The aim of this study was to evaluate the accuracy of the measurement of FNAB-Tg in the washout of FNAB in combination with FNAB-C to detect CLN metastases in PTC.

METHODS

We retrospectively evaluated 163 surgically proven CLNs. Ultrasound-guided FNAB-C and FNAB-Tg measurements were performed and the ultrasound features were evaluated.

RESULTS

The sensitivity, specificity and accuracy of FNAB-C, FNAB-Tg and FNAB-C/FNAB-Tg in diagnosis of metastatic CLNs were 85.7, 87.8 and 71.6%, were 80.5, 87 and 82.8% and were 97.1, 96.3 and 95.7%, respectively. The diagnostic sensitivity, specificity and accuracy of FNAB-C/FNAB-Tg for metastatic CLNs was significantly higher than that of FNAB-C or FNAB-Tg alone (p < 0.01).

CONCLUSION

Combined US-guided FNAB-C and FNAB-Tg can improve the accuracy for diagnosis of metastatic CLNs in patients with PTC.

Nodal metastases in thyroid cancer: prognostic implications and management

The significance of cervical lymph node metastases in differentiated thyroid cancer has been controversial and continues to evolve. Current staging systems consider nodal metastases to confer a poorer prognosis, particularly in older patients. Increasingly, the literature suggests that characteristics of the metastatic lymph nodes such as size and number are also prognostic. There is a growing trend toward less aggressive treatment of low-volume nodal disease. The aim of this review is to summarize the current literature and discuss prognostic and management implications of lymph node metastases in differentiated thyroid cancer.

A scoring system is an effective tool for predicting central lymph node metastasis in papillary thyroid microcarcinoma: a case-control study

Background

The purpose of this study was to evaluate the clinicopathologic and ultrasonographic (US) characteristics and establish an effective scoring system for predicting central lymph node metastasis (CLNM) in papillary thyroid microcarcinoma (PTMC).

Methods

A total of 498 patients with PTMC who underwent total thyroidectomy or lobectomy with therapeutic central lymph node dissection (CLND) were enrolled. Univariate and multivariate analyses were performed to find the independent predictors for CLNM based on clinicopathological and US characteristics. Using the standardized regression coefficient, a 10-point score system was constructed in line with these independent predictors. Then, the scoring system was evaluated for the diagnostic value in predicting CLNM.

Results

Tumor location (the lower polo), tumor size (>5 mm), extrathyroidal extension, margin (no well-defined), display of enlarged lymph node, and contact of >25 % with the adjacent capsule were independent predictors for CLNM. Verifying the scoring system, a cutoff value of 5 points was found to be the best prediction for CLNM, the sensitivity and specificity were 64.7 and 80.5 %, respectively, and the positive and negative predictive values were 77.3 and 69.0 %, respectively.

Conclusions

The points ≤ 5 could be considered as a low risk for CLNM, and the points > 5 could be identified as a high risk for CLNM. More advanced diagnostic approaches and prophylactic CLND are needed for patients with the points > 5.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Protection and Dissection of Recurrent Laryngeal Nerve in Salvage Thyroid Cancer Surgery to Patients with Insufficient Primary Operation Extent and Suspicious Residual Tumor

Some thyroid cancer patients undergone insufficient tumor removal in the primary surgery in China . our aim is to evaluate the impact of dissection of the recurrent laryngeal nerve during a salvage thyroid cancer operation in these patients to prevent nerve injury. Clinical data of 49 enrolled patients who received a salvage thyroid operation were retrospectively reviewed. Primary pathology was thyroid papillary cancer. The initial procedure performed included nodulectomy (20 patients), partial thyroidectomy (19 patients) and subtotal thyroidectomy (10 patients). The effect of dissection and protection of the recurrent laryngeal nerve and the mechanism of nerve injury were studied. The cervical courses of the recurrent laryngeal nerves were successfully dissected in all cases. Nerves were adherent to or involved by scars in 22 cases. Three were ligated near the place where the nerve entered the larynx, while another three were cut near the intersection of inferior thyroid artery with the recurrent laryngeal nerve. Light hoarseness occurred to four patients without a preoperative voice change. In conclusion, accurate primary diagnosis allows for a sufficient primary operation to be performed, avoiding insufficient tumor removal that requires a secondary surgery. The most important cause of nerve damage resulted from not identifying the recurrent laryngeal nerve during first surgery , and meticulous dissection during salvage surgery was the most efficient method to avoid nerve damage.

Downregulation of long noncoding RNA NONHSAT037832 in papillary thyroid carcinoma and its clinical significance

Long noncoding RNA (lncRNA) is a kind of RNA that is longer than 200 nucleotides with limited or no protein-coding potential. Studies have proved that lncRNAs play important regulatory roles in gene expression and contribute to oncogenesis and cancer metastasis. However, the expression level of lncRNAs and their clinicopathologic significance in papillary thyroid carcinoma (PTC) have not been well studied. In this study, we investigated the expression level of a novel lncRNA NONHSAT037832 in PTC and paired noncancerous thyroid tissues as well as some cell lines by quantitative real-time polymerase chain reaction. The association between the expression level of NONHSAT037832 and clinicopathologic characteristics of patients with PTC was further analyzed. Three receiver operating characteristic curves (ROCs) were established to evaluate the diagnostic value of NONHSAT037832. The results suggested that the expression level of NONHSAT037832 was significantly decreased in PTC compared with paired noncancerous tissues (P < 0.01). And, NONHSAT037832 was also significantly downregulated in two PTC cell lines (K1 and IHH-4) compared to normal thyroid follicular epithelial cell line Nthy-ori 3-1 (P < 0.01). Downregulated NONHSAT037832 was significantly associated with lymph node metastasis (P = 0.015) and tumor size (P = 0.032). The ROCs revealed that NONHSAT037832 had a high diagnostic value for differentiating between PTC and noncancerous diseases as well as identifying PTC with lymph node metastasis and larger tumors (≥3 cm). The area under curve was up to 0.897 (95%CI = 0.852-0.942, P = 0.000), 0.641 (95%CI = 0.519-0.762, P = 0.033), and 0.702 (95%CI = 0.567-0.827, P = 0.008), respectively. This study indicated that NONHSAT037832 might serve as a potential biomarker of PTC.

Post-PET ultrasound improves specificity of 18F-FDG-PET for recurrent differentiated thyroid cancer while maintaining sensitivity

Background

Positron emission tomography (PET) using fluor-18-deoxyglucose (18F-FDG) with or without computed tomography (CT) is generally accepted as the most sensitive imaging modality for diagnosing recurrent differentiated thyroid cancer (DTC) in patients with negative whole body scintigraphy with iodine-131 (I-131).

Purpose

To assess the potential incremental value of ultrasound (US) over 18F-FDG-PET-CT.

Material and Methods

Fifty-one consecutive patients with suspected recurrent DTC were prospectively evaluated using the following multimodal imaging protocol: (i) US before PET (pre-US) with or without fine needle biopsy (FNB) of suspicious lesions; (ii) single photon emission computed tomography (≥3 GBq I-131) with co-registered CT (SPECT-CT); (iii) 18F-FDG-PET with co-registered contrast-enhanced CT of the neck; (iv) US in correlation with the other imaging modalities (post-US). Postoperative histology, FNB, and long-term follow-up (median, 2.8 years) were taken as composite gold standard.

Results

Fifty-eight malignant lesions were identified in 34 patients. Forty lesions were located in the neck or upper mediastinum. On receiver operating characteristics (ROC) analysis, 18F-FDG-PET had a limited lesion-based specificity of 59% at a set sensitivity of 90%. Pre-US had poor sensitivity and specificity of 52% and 53%, respectively, increasing to 85% and 94% on post-US, with knowledge of the PET/CT findings (P < 0.05 vs. PET and pre-US). Multimodal imaging changed therapy in 15 out of 51 patients (30%).

Conclusion

In patients with suspected recurrent DTC, supplemental targeted US in addition to 18F-FDG-PET-CT increases specificity while maintainin sensitivity, as non-malignant FDG uptake in cervical lesions can be confirmed.

The Clinical Relevance of Psammoma Body and Hashimoto Thyroiditis in Papillary Thyroid Carcinoma: A Large Case-control Study

This study aims to investigate the impact of psammoma body (PB) on papillary thyroid carcinoma (PTC), and evaluate the association among PB, Hashimoto thyroiditis (HT), and other clinicopathologic characteristics in PTC patients.We conducted a retrospective case-control study involving 1052 PTC patients who underwent total thyroidectomy or lobectomy with lymph node dissection.Psammoma body was observed in 324 out of 1052 PTC (30.8%) patients. Ultrasonographic (US) calcification (P < 0.001), multifocality of the tumor (P = 0.047), lymph node metastasis (LNM) (P < 0.001), HT (P < 0.001), and Primary tumor (T), Regional lymph nodes (N), Distant metastasis (M) staging (P = 0.001) were significantly related to the presence of PB. The presence of PB was significantly associated with US microcalcification (P < 0.001). In the subgroup with HT, compared with the patients without PB, the patients with PB exhibited a higher frequency of central LNM (54.7% vs 32.1%; P < 0.001) and US microcalcification (94.7% vs 38.8%; P < 0.001), as well as smaller tumors (0.9 ± 0.6 vs 1.3 ± 0.9 cm; P < 0.001). In the subgroup without HT, the patients with PB displayed a higher incidence of lateral LNM (25.8% vs 14.6%; P < 0.001), US microcalcification (87.3% vs 52.5%; P < 0.001), and extrathyroidal extension (47.2% vs 34.8%; P = 0.001), as well as larger tumors (1.3 ± 0.9 vs 1.0 ± 0.8 cm; P < 0.001) than without PB. Moreover, in the subgroup with PB, the PTC patients with HT showed a higher LNM (77.9% vs 57.2%; P < 0.001) and a lower frequency of extrathyroidal extension (20.0% vs 47.2%; P < 0.001) than without HT.Psammoma body is a useful predictor of aggressive tumor behavior in PTC patients. HT with PB shows more aggressive behaviors than non-HT with PB in PTC patients.

A Meta-analysis of Central Lymph Node Metastasis for Predicting Lateral Involvement in Papillary Thyroid Carcinoma

OBJECTIVE

Whether central lymph node metastasis is a reliable indicator of lateral lymph node metastasis in papillary thyroid carcinoma remains obscure. To investigate the value of central lymph node metastasis for predicting lateral compartment involvement, we performed a meta-analysis of published studies.

DATA SOURCES

A systematic literature search of PubMed, EMBASE, and Chinese National Knowledge Infrastructure databases was completed, and the reference lists of the identified articles and prior relevant reviews were examined.

REVIEW METHODS

Two reviewers extracted data and assessed the quality of eligible studies independently. Odds ratios and 95% confidence intervals were pooled through a random effects meta-analysis model.

RESULTS

Twenty-one studies were eligible and further analyzed in this meta-analysis. The risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group (odds ratio = 7.64, 95% confidence interval: 5.59-10.44), with moderate heterogeneity across studies (P = .007, I(2) = 48.6%). Subgroup analyses and sensitivity analysis suggested that the results were consistent and credible. However, Begg's funnel plot and Egger linear regression test revealed a likelihood of publication bias (P = .000).

CONCLUSION

This meta-analysis suggests that central lymph node metastasis is valuable for predicting lateral compartment involvement in patients with papillary thyroid carcinoma. For those patients with central lymph node metastasis, additional attention should be paid to the lateral neck, as the risk of lateral lymph node metastasis was significantly higher in the central lymph node-positive group than in the negative group. Further studies regarding appropriate management for patients with high risk of lateral involvement are needed.

Metastatic lymph node status in the central compartment of papillary thyroid carcinoma: A prognostic factor of locoregional recurrence

BACKGROUND

The purpose of this study was to present our focus on the lymph node status in the central compartment and evaluate the relevant factors and disease recurrence.

METHODS

Between January 2004 and December 2009, 1040 patients were diagnosed with papillary thyroid carcinoma (PTC) and underwent surgery.

RESULTS

The number of metastatic lymph nodes was a significant predictor for recurrence conferring a hazard ratio of 1.36 (confidence interval = 1.103-1.680; p = .004). The receiver operating characteristic (ROC) curve was calculated to determine the cutoff number of lymph nodes that predicted recurrence with the highest sensitivity and specificity (area under the ROC curve, 0.794; SE, 0.077; p = .001). The sensitivity/specificity of >3 metastatic lymph nodes for predicting recurrence was 63.6%/77.0%, respectively.

CONCLUSION

The number of metastatic lymph nodes in the central compartment was a statistical significant predictive factor associated with disease recurrence. Further study is required to confirm the relationship between the number of lymph nodes and disease recurrence. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1172-E1176, 2016.