Clinical Implication of the Number of Central Lymph Node Metastasis in Papillary Thyroid Carcinoma: Preliminary Report

Killing capacity analysis of tumor-infiltrating cytotoxic lymphocytes and impact on lymph node metastasis in differentiated papillary carcinoma of thyroid with the BRAF V600E mutation

BACKGROUND

Cytotoxic lymphocytes (CLs) express potent toxins, including perforin (P) and granzyme-B (G), which brings about target cell death. The purpose of this study was to evaluate the killing capacity of tumor-infiltrating CLs by means of P and G analysis, and explore the association with lymph node metastasis in papillary carcinoma of thyroid (PTC) without Hashimoto's thyroiditis (HT).

METHODS

Infiltration of lymphocytes in PTC was observed in frozen sections. Both fresh tumor tissues and paracancerous tissues with lymphocyte infiltration were collected and prepared into a single cell suspension. Flow cytometry was used to detect the percentages of CD3+P+, CD3+G+, CD8+P+, and CD8+G+ T lymphocytes (TLs) and CD16-CD56+P+ and CD16-CD56+G+ natural killer (NK) cells. Finally, we investigated differential expression of P and G in NK cells and cytotoxic T lymphocytes (CTLs) in paired tumor tissues (group T, n = 44) and paracancerous tissues (group N, n = 44) from patients with PTC with the BRAF V600E mutation. Furthermore, patients were divided into two groups according to whether cervical central lymph node metastasis (CCLNM) existed: group A (with lymph node metastases, n = 27) and group B (with nonlymph node metastases, n = 17). Patients were also divided into three groups according to the total number of positive CCLNM: group B, group C (with low-level lymph node metastases, less than 5, n = 17) and group D (with high-level lymph node metastases, no less than 5, n = 10).

RESULTS

The percentage of CD3+P+ CTLs was significantly higher in group N than in group T (P < 0.05). The percentage of CD8+G+ CTLs was significantly higher in group T than in group N (P < 0.05). The percentages of CD3+G+, CD16-CD56+P+and CD16-CD56+G+ NK cells showed no significant difference in either group T or group N (P > 0.05). The percentages of CD3+P+ CTLs in group A and group C were significantly higher in the paracancerous tissue than in the tumor tissue (P < 0.05). The percentages of CD8+G+ CTLs in group A and group C were significantly higher in the tumor tissues than in the paracancerous tissues (P < 0.05). The percentage of CD16-CD56+G+ NK cells in group D was significantly higher in the tumor tissues than in the paracancerous tissues (P < 0.05).

CONCLUSIONS

The killing capacity of infiltrating CLs in PTC differed between tumor tissues and paracancerous tissues. In cases with CCLNM, higher expression of CD16-CD56+G+ NK cells in tumor tissues may be associated with a high risk of lymph node metastasis.

Prospective application of a prediction model for lateral lymph node metastasis in papillary thyroid cancer patients with central lymph node metastasis

Objective

This study aimed to develop and apply a prediction model to estimate the probability of lateral lymph node metastasis (LLNM) in patients with cN0 unilateral papillary thyroid carcinoma (PTC) with central lymph node metastasis (CLNM).

Setting

All study data were collected from a single tertiary hospital.

Methods

Univariable and multivariable logistic regression analyses were used to explore independent predictors of LLNM in the derivation and internal validation cohorts, which were used to construct and validate a nomogram. Another 96 patients were included prospectively to evaluate the efficacy of this nomogram.

Results

Maximum tumor diameter greater than 1.0 cm (OR, 2.712; 95% CI, 1.412-5.210), multifocality (OR, 2.758; 95% CI, 1.120-6.789), the number of CLNM ≥3 (OR, 2.579; 95% CI, 1.315-5.789), CLNM ratio ≥0.297 (OR, 2.905; 95% CI, 1.396-6.043), and tumors located in the upper portion (OR 2.846, 95% CI 1.151-7.039) were independent predictors associated with LLNM. The prediction model showed excellent discrimination with an AUC of 0.731 (95% CI, 0.635-0.827). Novel risk stratification for LLNM was constructed based on this nomogram. In the prospective cohort, we stratified these patients into three risk subgroups: low-, moderate-, and high-risk subgroups and we found that the probability of LLNM was positively correlated with the total points from the nomogram.

Conclusion

This nomogram was applied in prospective clinical practice and distinguished PTC patients with a genuinely high risk of LLNM. Surgeons can use our nomogram to tailor the surgical plan and to credibly determine further postoperative therapy.

TRPC5 expression promotes the proliferation and invasion of papillary thyroid carcinoma through the HIF-1α/Twist pathway

OBJECTIVE

This study aimed to investigate the effect of TRPC5 on PTC (papillary thyroid carcinoma) proliferation and invasion.

METHODS

Immunofluorescence and western blot were used to evaluate the expression of TRPC5 in paraffin sections and clinical tissues. Overexpression and silencing of TRPC5 to generate the cells for in vitro experiments. Wound-healing assay, transwell invasion assay, MTT assay, and in vivo tumorigenicity assay were used to determine cell proliferation and cell migration in vitro and in vivo. Real-time PCR was used to test the expression of TRPC5. Western blot was used to test the expression of downstream factors: E-cadherin, Vimentin, MMP-9, MMP-2, TRPC5, ZEB, Snail, and Twist.

RESULTS

The level of TRPC5 protein expression was higher in PTC than in adjacent normal thyroid tissue. TPC-1 cells overexpressing TRPC5 were more proliferative, had longer migration distances, and increased the number of invading cells. TPC-1 cells silenced with TRPC5 had a weaker proliferation capacity, shorter migration distances, and a reduced number of invading cells. Overexpression and silencing of TRPC5 modulated E-cadherin, Vimentin, MMP-9, MMP-2, TRPC5, and Twist, but did not affect ZEB and Snail. The results of tumor formation experiments in nude mice showed that inhibition of TRPC5 expression suppressed the volume and weight of transplanted tumors.

CONCLUSION

TRPC5 induced papillary thyroid cancer metastasis and progression via up-regulated HIF-1α signaling in vivo and in vitro. High TRPC5 expression is a biomarker for lymph node metastasis at its early stages.

Comprehensive analysis of clinicopathologic and sonographic features in thyroid cancer with skip lymph node metastasis: establish and assessment of a prediction nomogram

Lateral Lymph Node Metastasis (LLNM) is common in Papillary Thyroid Carcinoma (PTC) and is associated with a poor prognosis. LLNM without central lymph node metastasis as skip metastasis is not common. We aimed to investigate clinicopathologic and sonographic risk factors for skip metastasis in PTC patients, and to establish a nomogram for predicting the possibility of skip metastasis in order to determine the therapeutic strategy. We retrospectively reviewed the data of 1037 PTC patients who underwent surgery from 2016 to 2020 at a single institution. Univariate and multivariate analyses were used to identify the clinicopathologic and preoperative sonographic risk factors of skip metastasis. A nomogram including the risk factors for predicting skip metastasis was further developed and validated. The incidence of skip metastasis was 10.7%. The univariate and multivariate analyses suggested that gender (p= 0.001), tumor location (p= 0.000), extrathyroidal extension (p= 0.000), and calcification (p= 0.000) were independent risk factors. For papillary thyroid microcarcinoma, tumor location (p= 0.000) and calcification (p= 0.001) were independent risk factors. A nomogram according to the clinicopathologic and sonographic predictors was developed. The receiver operating characteristic curve indicated that AUC was 0.824 and had an excellent consistency. The calibration plot analysis showed a good performance and clinical utility of the model. Decision curve analysis revealed it was clinically useful. A nomogram for predicting the probability of skip metastasis was developed, which exhibited a favorable predictive value and consistency. For the female PTC patient, tumor located at the upper pole is more likely to have skip metastasis. Surgeons and sonographers should pay close attention to the patients who have the risk factors. Evidence level: This article's evidence level is 3. Level 3 evidence is derived from non-randomized, controlled clinical trials. In this study, patients who receive an intervention are compared to a control group. Authors may detect a statistically significant and clinically relevant outcome.

Should multifocality be an indication for prophylactic central neck dissection in papillary thyroid cancer?

Although multifocality is common in patients with papillary thyroid cancer, its effects on lymphatic metastasis and the necessity of central dissection in the presence of multifocality are still controversial. In our clinic, 258 patients who underwent thyroidectomy between 2015 and 2020 and were found to have papillary thyroid cancer in postoperative pathology reports were analyzed. The tumor characteristics contributing to central lymph node metastasis positivity were evaluated. Lymph node metastases were not significantly increased in the presence of multifocality. In cases with bilateral multifocal tumors, compared to cases with unilateral multifocal tumors, capsular invasion (p = 0.02), vascular invasion (p = 0.01) and cervical lymphatic metastasis (p = 0.004) were observed to increase. Bilateral multifocal tumors have more aggressive clinicopathological features than unilateral tumors. We found that the risk of central lymph node metastasis increased significantly in bilateral multifocal tumors in our study. Prophylactic central lymph node dissection may be considered in patients with no preoperative or intraoperative lymph node metastasis but thought to have a multifocal tumor.

Risk Factors of Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma and the Value of Sentinel Lymph Node Biopsy

Objective: The present study aims to investigate the risk factors of central lymph node metastasis (CNM) in papillary thyroid microcarcinoma (PTMC) and evaluate the predictive value of sentinel lymph node biopsy (SLNB) during surgery.

Methods: The clinicopathological data of 179 patients with PTMC staging in cN0 and with SLNB performed were analyzed retrospectively. Positive sentinel lymph node ratio (PSLNR) and additional positive lymph node (APLN) were analyzed in cases with positive SLNB. The efficiency of SLNB was investigated. ROC curves were plotted to evaluate the predictive value of PSLNR for APLN.

Results: Cumulative maximum diameter of tumors (CMD) (P = 0.041) and capsule involvement (CI) (P = 0.014) were independent risk factors for central lymph node metastasis. The SLNB success rate was 97.28%, and the incidence of CNM was 31.28%. The sensitivity, specificity, false positive rate (FPR), false negative rate (FNR), positive predictive value (PPV), and negative predictive value (NPV) of SLNB to evaluate CNM and APLN were 82.14 vs. 61.54%, 100 vs. 80.39%, 0 vs. 19.61%, 17.86 vs. 38.46%, 100 vs. 34.78%, and 92.48 vs. 92.48%, respectively. For cases with positive SLNB, subgroup analysis was performed according to APLN. The PSLNRs of true and false positive groups were 0.4620 ± 0.1744 and 0.2425 ± 0.1355, respectively (P < 0.001). Analyzing the predictive value of PSLNR by the ROC curve, the optimal diagnostic cutoff point was 0.2917 [AUC = 0.861 (95% CI: 0.757, 0.966), P < 0.001], and the sensitivity, specificity, FPR, FNR, PPV, and NPV of PSLNR were 87.50, 73.33, 26.67, 12.50, 63.64, and 91.67%, respectively.

Conclusion: CMD and CI are independent risk factors for central lymph node metastasis in PTMC. SLNB has good predictive value for CNM. For cases with positive SLNB, PSLNR could be used to predict the presence of APLN, which may provide a theoretical basis for intraoperative lymph node dissection.

Ultrasound lymphatic imaging for the diagnosis of metastatic central lymph nodes in papillary thyroid cancer

OBJECTIVES

Up to 40% of papillary thyroid cancer (PTC) patients have lymph node metastasis, a condition that implies persistent, recurrent, or progressive disease. However, the American Joint Committee on Cancer Manual states that there is no reliable examination for adequate lymph node staging. Therefore, our aim is to develop a lymphatic imaging technique using ultrasonography to address this challenge.

METHODS

We consecutively enrolled PTC patients who underwent ultrasound (US) lymphatic imaging via the peritumoral injection of contrast media. Identification of the sentinel lymph nodes and the targeted sentinel lymph nodes was separately based on the lymphatic drainage pathway and the enhancement patterns. Every identified targeted node was assigned a score, according to the features on conventional US and enhancement patterns, and was referred for ultrasound-guided fine-needle aspiration. Cytological and histopathologic results represented the statuses of the targeted lymph nodes and overall central lymph nodes, respectively, which were applied to evaluate the diagnostic performance of US lymphatic imaging.

RESULTS

In total, 100 PTC patients were included. On the basis of the cytological results, the sensitivity (97.1%, 95% confidence interval [CI]: 84.7-99.9%) of detecting positive targeted nodes by US lymphatic imaging significantly increased by 45.5% at a threshold of 4 or higher (p = 0.0001), without loss of specificity (p = 1.0000). The surgical results showed that the metastatic degree was positively correlated with an increase in the score (τ: 0.671, p < 0.001).

CONCLUSION

Ultrasound lymphatic imaging has a high diagnostic performance, and its corresponding scoring system facilitates grading of the nodal burden in the central compartment.

KEY POINTS

• Ultrasound neck lymphatic imaging is an effective contrast-enhanced ultrasound (CEUS) technique (applied after the peritumoral injection of contrast media) for identifying sentinel lymph nodes in the central compartment by tracing the imaged afferent lymphatic vessel. • Lack of enhancement or perfusion defects is the typical enhancement pattern for recognizing the involved central lymph nodes. • Ultrasound lymphatic imaging for identification of positive central lymph nodes before surgery may effectively avoid complications associated with the surgical sentinel node procedure.

Factors Affecting Central Node Metastasis and Metastatic Lymph Node Ratio in Papillary Thyroid Cancer

OBJECTIVE

Despite the growing evidence that metastatic lymph node ratio (MLNR) is a valuable predictor for the prognosis of papillary thyroid carcinoma, it has not yet been fully determined which factors give the ratio predictive value independent of the number of metastatic lymph nodes (MLNs).

STUDY DESIGN

Retrospective cohort study.

SETTING

A comprehensive cancer center.

METHODS

Recurrence and clinicopathologic factors were analyzed in 2409 patients with papillary thyroid carcinoma who underwent total thyroidectomy and central node dissection.

RESULTS

Cutoff values of MLNs ≥2 and MLNR ≥28.2% increased the recurrence risk (hazard ratio [95% CI], 9.97 [4.73-21.0] and 11.4 [5.53-23.3], respectively). Younger age, male sex, multifocality, tumor size, lymphatic and vascular invasion, and gross extrathyroidal extension positively correlated with MLN and MLNR (all P < .05). Meanwhile, lymphocytic thyroiditis negatively correlated with MLNR in female patients (P < .001), by increasing total lymph node yields as compared with papillary thyroid carcinoma without lymphocytic thyroiditis. In multivariate analysis, younger age, tumor size, and lymphatic invasion remained significant in male and female patients for MLN and MLNR; lymphocytic thyroiditis was also significantly correlated with MLNR in female patients.

CONCLUSION

Our study demonstrates that MLN and MLNR are independently observed prognostic markers for tumor recurrence. However, lymphocytic thyroiditis in female patients seems to have lower MLNR by increasing total lymph node yields. In light of their association, a different cutoff for MLNR needs to be applied according to the presence or absence of underlying lymphocytic thyroiditis in the use of MLNR for predicting the recurrence.

LEVEL OF EVIDENCE

4.

Risk Factors and a Prediction Model of Lateral Lymph Node Metastasis in CN0 Papillary Thyroid Carcinoma Patients With 1-2 Central Lymph Node Metastases

BACKGROUND

Papillary thyroid cancer (PTC) in clinically lymph node-negative (cN0) patients is prone toward lymph node metastasis. As a risk factor for tumor persistence and local recurrence, lateral lymph node metastasis (LLNM) is related to the number of central lymph node metastases (CLNMs).

METHODS

We performed LLNM risk stratification based on the number of CLNMs for cN0 PTC patients who underwent thyroidectomy and lymph node dissection between January 2013 and December 2018. A retrospective analysis was applied to the 274 collected patients with 1-2 CLNMs. We examined the clinicopathological characteristics of the patients and constructed a LASSO model.

RESULTS

In the 1-2 CLNM group, tumors >10 mm located in the upper region and nodular goiters were independent risk factors for LLNM. Specifically, tumors >20 mm and located in the upper region contributed to metastasis risk at level II. Hashimoto's thyroiditis reduced this risk (p = 0.045, OR = 0.280). Age ≤ 30 years and calcification (microcalcification within thyroid nodules) correlated with LLNM. The LASSO model divided the population into low- (25.74%) and high-risk (57.25%) groups for LLNM, with an AUC of 0.715.

CONCLUSIONS

For patients with 1-2 CLNMs, young age, calcification, nodular goiter, tumor >10 mm, and tumor in the upper region should alert clinicians to considering a higher occult LLNM burden. Close follow-up and therapy adjustment may be warranted for high-risk patients.

A rare case showing an enlarged level I lymph node as the first symptom due to papillary thyroid microcarcinoma

As the high-pace development of sonography in recent years, the incidence of papillary thyroid carcinoma (PTC) has increased sharply worldwide, especially papillary thyroid microcarcinoma (PTMC). As we all know, PTMC is an indolent tumor, and level I lymph nodes (LNs) at a higher region relatively, so the majority of PTMCs admitted to surgery before the level I LNs metastasis. It is rare to see PTMC with level I LNs metastasis. At best of our known, there is only one Chinese research mentioned it but without a description of it. In this case, we reported a 30-year-old female who developed a recurrent submental cystic mass after being received treatment to remove a certain volume of light-yellow fluid. Pathology verified that mass in the submental area involved by PTMC. We consider that it may relate to age, multifocality, the diameter of PTMC, numbers of central compartment LNs, and "re-metastasis".

Risk model and risk stratification to preoperatively predict central lymph node metastasis in papillary thyroid carcinoma

Background

The central lymph node is the most common involvement for papillary thyroid carcinoma (PTC), which is correlated to recurrence and survival. But it is difficult to accurately evaluate lymph node prior to an operation. This retrospective study was designed to develop a risk model and risk stratification to preoperatively predict central lymph node metastasis (CLNM) in PTC and validate this model.

Methods

A series of 1,714 initial treatment PTC patients were enrolled. Among these patients, 1,001 patients were used to develop a predictive model and establish a stratification scoring system. This was validated through the remaining 713 patients.

Results

The multivariate analysis revealed that CLNM and lateral lymph node metastasis (LLNM) in ultrasound (US), tumor size, gender, capsule invasion in US, microcalcification and age were significant independent predictors for CLNM. The area under the curve (AUC) of the model was 0.778. Furthermore, the cutoff value to predict CLNM was 8 points, and the sensitivity and specificity were 77% and 65%, respectively. In the scoring system for CLNM, a score of ≤8, 8-18 and >18 were defined as low, intermediate and high risk, respectively. The risk of CLNM was approximately 30%, 60% and 80%, corresponding to the stratification. When validated, the model predicted the risk of CLNM with an AUC of 0.811, a sensitivity and specificity of 83% and 63%, respectively.

Conclusions

This study presented a predictive model to preoperatively assess the risk of CLNM in PTC. The predictive model performed well, but needed to be prospectively validated in external center.

Right posterior paratracheal lymph nodes metastasis is one of the predictive factors in right-sided papillary thyroid carcinoma

BACKGROUND

Lymph nodes in the right paratracheal region are separated as anterior and posterior on the basis with right recurrent laryngeal nerve. Dissection of the right posterior paratracheal lymph nodes is sometimes overlooked during a central neck dissection. Therefore, this study was designed to assess the clinicopathologic risk factors and prognostic implication for recurrence related to the presence of right posterior paratracheal lymph nodes metastasis in patient with right-sided papillary thyroid carcinoma.

METHODS

Records from 763 patients with papillary thyroid carcinoma who underwent total thyroidectomy with central neck dissection, including the right posterior paratracheal lymph nodes, between January 2007 and March 2015 were reviewed retrospectively.

RESULTS

Among 763 patients (120 men and 643 women; mean age 49.04 years) with right-sided papillary thyroid carcinoma, 127 exhibited right posterior paratracheal lymph nodes metastases. In multivariate analysis, central-compartment lymph nodes metastases (odds ratio 5.203; 95% confidence interval, 2.864-9.453) and lateral cervical lymph nodes metastases (odds ratio 3.668; 95% confidence interval, 2.375-5.667) were independently correlated with right posterior paratracheal lymph nodes metastases. Twenty-three patients (3.0%) showed loco-regional recurrence. The loco-regional recurrence rate was greater in the groups for males (P = .012), larger tumor size (>10 mm; P = .044), extrathyroidal extention (P = .002), and right posterior paratracheal lymph nodes metastasis (P < .001).

CONCLUSION

Right posterior paratracheal lymph nodes metastases are predictive factors of loco-regional recurrence, and these lymph nodes should be removed completely during a right central neck dissection in patients with right-sided papillary thyroid carcinoma with central or lateral cervical lymph node metastasis.

Individual prediction of lateral neck metastasis risk in patients with unifocal papillary thyroid carcinoma

INTRODUCTION

Much controversy exists over whether to perform lateral neck dissection (LND) on patients with papillary thyroid carcinoma (PTC). This study aimed to build predictive nomograms that could individually estimate lateral neck metastasis (LNM) risk and help determine follow up intensity.

PATIENTS AND METHODS

Unifocal PTC patients who underwent LND between April 2012 and August 2014 were identified. Clinical and pathological variables were retrospectively evaluated using univariate and stepwise multivariate logistic regression analysis. Variables that had statistical significance in final multivariate logistic models were chosen to build nomograms, which were further corrected using the bootstrap resampling method.

RESULTS

In all, 505 PTC patients were eligible for analysis. Among these, 178 patients (35.2%) had lateral neck metastasis. Two nomograms were generated: nomogram (c) and nomogram (c + p). Nomogram (c) incorporated four clinical variables: age, tumor size, tumor site, and extrathyroidal extension (ETE). It had a good discriminative ability, with a C-index of 0.79 (bootstrap-corrected, 0.78). Nomogram (c + p) incorporated two clinical variables and two pathological variables: tumor size, tumor site, extranodal extension (ENE), and number of positive nodes in the central compartment. Nomogram (c + p) showed an excellent discriminative ability, with a C-index of 0.86 (bootstrap-corrected, 0.85).

CONCLUSION

Two predictive nomograms were generated. Nomogram (c) is a clinical model, whereas nomogram (c + p) is a clinicopathological model. Each nomogram incorporates only four variables and can give an accurate estimate of LNM risk in unifocal PTC patients, which may assist clinicians in patient counseling and decision making regarding LND.

The impact of the number of harvested central lymph nodes on the lymph node ratio

OBJECTIVE

The purpose of this study was to analyze the impact of lymph node harvest on the lymph node ratio (LNR).

METHODS

We retrospectively reviewed 106 patients diagnosed preoperatively with PTMC (papillary thyroid microcarcinoma), no evidence of central or lateral neck nodal metastasis, and who underwent a total thyroidectomy and bilateral central lymph node neck dissection (CND).

RESULTS

The median number of retrieved lymph nodes in the central compartments was 7±6.59 (range: 1-42). The mean number of metastatic lymph nodes in the central compartments on pathology was 1.1±1.79 (range: 0-7). The high node volume group (>7) had a significantly higher rate of central lymph node (CLN) metastasis than the low node volume group (≤7) in the final pathologic report (p<0.001). With the linear regression method, the number of CLN metastasis increased as the number of retrieved lymph nodes increased (correlation coefficient=0.286, p=0.003). The multivariate analysis confirmed the number of retrieved lymph nodes in the central compartments was a risk factor for high LNR (p=0.008, odds ratio 3.737). The rates of vocal fold palsy and hypoparathyroidism did not differ according to the number of retrieved lymph nodes.

CONCLUSION

The lymph node ratio in the final pathologic report is larger when a greater number of lymph nodes are retrieved during the central compartment neck dissection.

The LINC01186 suppresses cell proliferation and invasion ability in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy. Long non coding RNAs (lncRNAs) have been involved in regulating tumor progression including PTC. In the present study, we demonstrated that long non coding RNA LINC01186 was significantly downregulated in PTC tissue samples compared with adjacent normal tissue samples in patients. LINC01186 expression was also found to be higher in PTC cells. Lower LINC01186 expression was associated with lymph node metastasis of PTC patients. Functionally, LINC01186 overexpression significantly suppressed cell proliferation, cell colony formation and cell invasion ability in TPC-1 and IHH-4 cells. In addition, we demonstrated that LINC01186 overexpression inhibited large tumor suppressor kinase 1 (LATS1)/YY1 associated protein 1 (YAP) signaling by reducing YAP1 expression, while increasing LATS1 expression in TPC-1 and IHH-4 cells. Collectively, our data suggested that LINC01186 may serve as a potential target for therapy in thyroid carcinoma.

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).

Significance of micrometastases in the calculation of the lymph node ratio for papillary thyroid cancer

Purpose

The lymph node ratio (LNR) is an important prognostic factor in papillary thyroid carcinoma (PTC), but micrometastases in cervical lymph nodes (LNs) are not of great clinical importance. In this study, we analyzed the accuracy of prediction of the prognosis depending on whether micrometastases were included in the number of metastatic LNs when calculating LNR.

Methods

The study included 353 PTC patients who underwent total thyroidectomy with neck LN dissection, and calculated LNR by 2 methods according to whether micrometastases were included in the number of metastatic LNs: Method 1 did not and method 2 did include. To compare the predictive values of LNR by the 2 methods, correlation coefficients and receiver operating characteristic (ROC) curves were analyzed.

Results

Positive correlations were found between LNR and preablation stimulated thyroglobulin (sTg) levels in both methods, but the correlation between method 1 LNR and preablation sTg level was significantly stronger than that for method 2 (Fisher z = 1.7, P = 0.045). The areas under these 2 independent ROC curves were analyzed; the prognostic efficacy of method 1 LNR was more accurate than that of method 2 LNR, and the difference was statistically significant (P = 0.0001).

Conclusion

Regional recurrence of PTC can be predicted more accurately by not including micrometastases in the number of metastatic LNs when calculating LNR.

Practice patterns among thyroid cancer surgeons: implications of performing a prophylactic central neck dissection

Background

Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. It is unclear how identification of lymph node (LN) metastases should impact the decision to treat with radioactive iodine (RAI). The goals of this study were to identify indications for performing pCND and identify factors that predict the use of adjuvant RAI.

Methods

This was a population based cross-sectional analysis. A prospectively collected database identified 594 patients who underwent total thyroidectomy +/− CND. A multivariate model was constructed to identify indications for pCND and predictors of the use of RAI.

Results

425 CNDs were performed of which 224 were prophylactic. Conventional risk factors (age, tumor size, extra-thyroidal extension) were not associated with performing a pCND. The presence of clinically suspicious lymphadenopathy was the only factor associated with performing CND, thus rendering the CND therapeutic. Positive LNs were retrieved in 39 % of pCND’s, upstaging 87 patients. Among all peri-operative predictors of receiving RAI, presence of LN metastases was the strongest predictor [OR = 5.9 (3.7–9.5)], while tumor size was a modest predictor [OR = 1.8 (1.5–2.1)]. Other conventional risk factors did not predict use of adjuvant RAI.

Conclusions

Conventional risk factors were not indications for performing a pCND, implying that the decision was based on individual surgeon preference. Performing pCND upstaged 39 % of patients from cN0 to pN1a, increasing the likelihood of receiving RAI 6-fold. Conventional risk factors were not predictors of receiving adjuvant RAI. This highlights the need for a unified approach to performing a pCND and administering RAI.

Risk factors analyses for lateral lymph node metastases in papillary thyroid carcinomas: a retrospective study of 356 patients

Objective

The aim of this study was to investigate the incidence and risk factors for lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC).

Subjects and methods

356 patients diagnosed with PTC who underwent total thyroidectomy and central lymph node dissection and lateral lymph node dissection between January 2005 and December 2011 were enrolled. The relation between LLNM and clinicopathological features such as gender, age, tumor size, tumor spread, psammoma bodies, tumor multifocality, extrathyroidal extension (ETE), unilateral or bilateral disease, tumor primary location and central lymph node metastases (CLNM) was analyzed.

Results

The rate of LLNM was 75.0%. In the univariate analysis, it was significantly associated with age, tumor size, tumor spread, extrathyroidal extension, primary tumor location and central lymph node metastasis (p < 0.05). In contrast, in the multivariate analysis, it was significantly associated with primary tumor location, central lymph node metastasis (p < 0.05) and tumor size > 1.5 cm with p = 0.05 but was unrelated to the other factors.

Conclusion

Patients with PTC, with the primary tumor located in the upper part of the lobe and positive central compartment lymph node metastasis with a tumor size > 1.5 cm diameter are more likely to have LLNM. Therefore, more meticulous evaluations including the lateral lymph nodes should be performed before surgery.

Metastatic Lymph Node Ratio of Central Neck Compartment Has Predictive Values for Locoregional Recurrence in Papillary Thyroid Microcarcinoma

OBJECTIVES

This study aimed to evaluate the significance of metastatic lymph node ratio (the ratio between the metastatic lymph node and the harvested lymph nodes; MLNR) in the central neck for the prediction of locoregional recurrence in patients with papillary thyroid microcarcinoma.

METHODS

After reviewing medical records of papillary thyroid microcarcinoma patients who received total thyroidectomy with central neck node dissection, 573 consecutive adult patients were enrolled in this study, with a follow-up period of more than 36 months. Regarding the risk of recurrence, multivariate analyses were performed with the following variables; sex, age, multiplicity of the primary tumor, presence of pathological extrathyroidal extension, the level of postoperative stimulated serum thyroglobulin, the number of harvested lymph nodes, the number of lymph node metastasis and MLNR.

RESULTS

The MLNR showed a predictive significance for the locoregional recurrence (P<0.05). Most recurrences were occurred in the lateral neck (n=12, 80%) with a median interval of 20 months. The lowest cutoff value of the MLNR for a meaningful separation of disease recurrence was 0.44 (hazard ratio, 8.86; 95% confidence interval, 1.49 to 52.58; P=0.001).

CONCLUSION

When the MLNR is higher than 0.44, there is an increased risk of locoregional recurrence mostly in the lateral neck. Therefore, MLNR of the central neck in a permanent or frozen biopsy may be helpful in decision making in the extent of thyroidectomy and/or the need for contralateral central neck lymph nodes dissection.

Bilaterality weighs more than unilateral multifocality in predicting prognosis in papillary thyroid cancer

Papillary thyroid cancer (PTC) often presents as multifocal tumor;, however, whether multifocality is associated with poor prognosis remains controversial. The aims of this retrospective study were to identify the characteristics of PTC with multifocal tumors and evaluate the association between the location and prognosis. We reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as three groups: N1 (solitary tumor), N2 (2 or more foci within unilateral lobe of thyroid), and N3 (bilateral tumors, at least one tumor focus for each lobe of thyroid). We analyzed the differences of clinicopathologic features and clinical outcomes among the three groups. Cox regression model was used to assess the relation between the different locations of multifocal tumors and prognosis. Although the differences of clinicopathologic features such as the size of tumor, extrathyroidal extension, and cervical lymph node metastasis were not significant among the three groups, the bilateral-multifocality was proved to be an independent risk factor for neck recurrence (hazard ratio (HR) = 4.052, 95 % confidence interval (CI) 2.070-7.933), distant metastasis (HR = 3.860, 95 % CI 1.507-9.884), and cancer death (HR = 7.252, 95 % 2.189-24.025). In addition, extrathyroidal extension (HR = 2.291, 95 % CI 1.185-4.427) and older age >45 years (HR = 6.721, 95 % CI 2.300-19.637) were also significant predictors for neck recurrence and cancer death, respectively. Therefore, bilateral-multifocality as an indicator for more extensive tumor location could be used to assess the risk of recurrence and mortality in PTC. Given the poor prognosis associated with bilateral-multifocality and other risk factors, aggressive therapy and intensive follow-up were recommended for PTC patients with them.

THERAPY OF ENDOCRINE DISEASE: Central neck dissection: a step forward in the treatment of papillary thyroid cancer

Since its introduction in the '70s and '80s, CND for papillary cancer is here to stay. Compartment VI should always be explored during surgery for papillary thyroid carcinoma (PTC) for obvious lymph node metastases. These can be easily spotted by an experienced surgeon or, eventually, by frozen section. No doubt, obvious nodal disease in the Delphian, paratracheal and subithsmic areas should be dissected in a comprehensive manner (therapeutic central neck dissection), avoiding the selective removal of suspicious nodes. Available evidence for routine prophylactic CND is not completely satisfactory. Our group's opinion, however, is that it reduces or even eliminates the need for repeat surgery in the central neck, better defines the extent (and stage) of the disease and provides a further argument against routine radioiodine ablation. Thus, PTC is becoming more and more a surgical disease that can be cured by optimized surgery alone in the majority of cases. Prophylactic CND, however, involves a higher risk for the parathyroid function and should be skilfully performed, preferably only on the same side as the primary tumour and preserving the cervical portion of the thymus.

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.

Prediction of central lymph node metastasis in 392 patients with cervical lymph node-negative papillary thyroid carcinoma in Eastern China

Central lymph node metastasis (CLNM) is common in papillary thyroid microcarcinoma (PTMC). The aim of the present study was to investigate the risk factors associated with CLNM in clinical lateral cervical lymph node-negative (cN0) PTMC in Eastern China. A total of 392 patients with confirmed PTMC by histological examination who underwent thyroidectomy and central neck lymph node dissection (CND) between May 2011 and October 2012 at the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China) were enrolled. The clinicopathological and ultrasonographic data from the patients were analyzed retrospectively. A scoring system was developed on the basis of independent predictive factors for CLNM. Male gender, age <45 years, maximum tumor diameter >5 mm, lower lobe location, multifocal carcinoma with total tumor diameter >10 mm and extracapsular spread were independent predictive factors for CLNM according to logistic regression analysis. The clinicopathological score was statistically significant, with an index point ≥2 indicating CLNM with 86.2% sensitivity and 70.4% specificity. The findings of the present study indicate that CND may be recommended to be routinely performed when the clinicopathological index point ≥2.

Intraoperative frozen section for the evaluation of extrathyroidal extension in papillary thyroid cancer

BACKGROUND

We investigated extrathyroidal extension (ETE) through frozen biopsy for intraoperative decision making in patients with papillary thyroid cancer (PTC).

METHODS

During the period of the study an operation was performed in 268 patients with PTC and ETE was evaluated using intraoperative frozen biopsies of thyroid tissue.

RESULTS

Extrathyroidal extension was confirmed in 54 patients (20 %) on frozen biopsy. Fifty-three patients among 54 patients showing ETE on frozen biopsy were confirmed on permanent pathologic analysis. Accordingly, frozen biopsy had a sensitivity of 66 %, a specificity of 99 %, a positive predictive value of 98 %, and a negative predictive value of 87 %. Tumor size (OR 4.373; CI 2.257-8.475, p = <0.001) was an independent factor for predicting ETE on frozen biopsy.

CONCLUSIONS

Intraoperative frozen biopsy can be an useful tool in identifying the presence of ETE. It can also help the operator decide the extent of surgery and central neck dissection in patients with PTC.

Clinical risk factors for central lymph node metastasis in papillary thyroid carcinoma: a systematic review and meta-analysis

BACKGROUND

Prophylactic central lymph node dissection (CLND) in clinically node-negative patients remains controversial, and predictive factors for central lymph node metastasis (CLNM) in patients with papillary thyroid carcinoma (PTC) are not well defined. Herein, we conducted a systematic review to quantify the clinicopathologic factors predictive for CLNM in patients with PTC.

METHODS

A systematic search of electronic databases (PubMed, Embase, Cochrane CENTRAL, Scopus and Wanfang Database) for studies published until July 2014 was performed. Cohort, case-control studies and randomized controlled trials that examined clinical risk factors of CLNM were included.

RESULTS

Twenty-five studies (4 prospective and 21 retrospective studies) involving 7,719 patients met final inclusion criteria. From the pooled analyses, male gender (OR 1.93, 95% CI 1.40 to 2.64), tumour multifocality (OR 1.93, 95% CI 1.62 to 2.30), tumour size >0.5 cm (OR 3.48, 95% CI 2.24 to 5.41), capsular invasion (OR 1.91, 95% CI 1.36 to 2.67), extrathyroidal extension (OR 2.42, 95% CI 1.58 to 3.71), lymphovascular invasion (OR 13.29, 95% CI 5.61 to 31.48) and lateral lymph node metastasis (OR 14.33, 95% CI 5.34 to 38.50) were significantly associated with increased risk of CLNM, while age >45 years (OR 0.65, 95% CI 0.51 to 0.83) and lymphocytic thyroiditis (OR 0.70, 95% CI 0.53 to 0.92) resulted in decreased risk of CLNM. Bilaterality and tumour location were not significantly associated with CLNM development (all P > 0.05).

CONCLUSIONS

Our analysis identified several clinicopathologic factors associated with CLNM. These findings may guide the necessity and extent of prophylactic CLND and ultimately improve the outcomes of patients with PTC.

Extent of central neck dissection among thyroid cancer surgeons: Cross-sectional analysis

BACKGROUND

It is unclear if surgeons are performing comprehensive central neck dissections for well-differentiated thyroid cancer. The purpose of this study was to determine mean lymph node retrieval in central neck dissection as well as variability across surgeons and institutions.

METHODS

A prospectively collected database identified 18 surgeons performing 425 central neck dissections, 313 unilateral and 112 bilateral. Demographics, perioperative, and pathologic factors were analyzed.

RESULTS

Mean lymph node yield was 7.4 and 11.9 for unilateral and bilateral central neck dissection, respectively. Although 224 central neck dissections were prophylactic, both total and pathologic lymph node yields were significantly higher in therapeutic central neck dissection. There was a significant variation in lymph node yield across individual surgeons, institutions, and regions. High-volume central neck dissection surgeons have significantly lower lymph node yield compared to low-volume surgeons.

CONCLUSION

Central neck dissection seems to be performed adequately; however, there is a significant variation in lymph node yield. Future initiatives should try to standardize the central neck dissections performed, with emphasis on obtaining a sufficient yield. © 2015 Wiley Periodicals, Inc. Head Neck 38: E328-E332, 2016.

Expression of signal transducer and activator of transcription 3 and its phosphorylated form is significantly upregulated in patients with papillary thyroid cancer

The aim of the present study was to investigate the expression of signal transducer and activator of transcription 3 (STAT3) and phosphorylated STAT3 (pSTAT3) in tissues of papillary thyroid cancer (PTC) in comparison with the expression in adjacent normal tissues. The expression of STAT3, pSTAT3, fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor-C (VEGF-C) was examined in tissues of 42 cases of PTC and the adjacent normal tissues of 20 of the 42 PTC cases using immunohistochemistry and western blotting. The association between the expression levels and the clinicopathological features was analyzed. The expression of STAT3, pSTAT3, FGF2 and VEGF-C in the PTC tissues (76.2, 42.9, 81.0 and 73.8%, respectively) was significantly higher than that in the normal tissues (P<0.05). In the PTC tissues, the expression of STAT3 was linearly correlated with the levels of pSTAT3 and VEGF-C (P<0.05). In conclusion, STAT3 and pSTAT3 are significantly upregulated in PTC tissues, and may potentially be used as markers to screen for PTC with lymph node metastasis.

Papillary thyroid microcarcinomas located at the middle part of the middle third of the thyroid gland correlates with the presence of neck metastasis

BACKGROUND

Papillary thyroid microcarcinomas (PTMCs), located at upper poles of the thyroid, are associated with lateral neck metastasis (LNM) according to previous reports. Controversy remains regarding the correlation between the location of PTMCs and central neck metastasis (CNM).

METHODS

Medical records of 949 patients with PTMCs diagnosed between 2010 and 2013 were reviewed retrospectively. With a subdivision of the middle third of the thyroid gland, correlations between tumor location and CNM/LNM along with other clinicopathologic factors were analyzed by binary logistic regression.

RESULTS

PTMCs located in the middle part of the middle third of the thyroid gland (MPMT) showed the greatest rate of CNM (57.5%) among all locations. PTMCs located at isthmus showed the second greatest rate of CNM (44.3%). In the multivariate analysis, MPMT, tumor size >0.5 cm, young and middle age, male sex, multifocality within the affected lobe, and capsular invasion were correlated with CNM. PTMCs located at upper poles and MPMT showed comparatively high rates of LNM (8.6% and 8.3%). Consistent with previous reports, an upper pole location, MPMT, and a tumor size >0.5 cm greatly correlated with LNM in the multivariate analysis. Eleven patients had skip metastases, which only occurred with upper/lower pole locations and MPMT.

CONCLUSION

PTMCs located in the MPMT correlated with both CNM and LNM. Tumor location along with other clinicopathologic factors such as young and middle age, male sex, and tumor size >0.5 cm could facilitate preoperative stratification and guide operative management for patients with PTMC.

Differentiating the location of cervical lymph node metastasis is very useful for estimating the risk of distant metastases in papillary thyroid carcinoma

OBJECTIVE

A larger primary tumour size, greater numbers of cervical lymph node (LN) metastasis are associated with a higher risk of distant metastases in papillary thyroid carcinoma (PTC). However, the impact of the location of cervical LN metastasis on distant metastasis is controversial. The aim of this study was to evaluate the risk of distant metastases according to the tumour size and LN status in PTC patients, with special consideration of the LN metastasis pattern.

PATIENTS

This retrospective cohort study reviewed 1700 classical PTC patients who underwent initial thyroid surgery at Asan Medical Center between 2000 and 2004.

RESULTS

The cumulative risk of distant metastases was increased with the increase in tumour size and was significantly different according to the location of involved LNs by the tumour node metastasis (TNM) staging. The cumulative risk in pN1b group showed the steepest increasing pattern with the increase in tumour size compared with pN1a and pN0/Nx group. When we analysed the cumulative risk of distant metastases according to the number of involved LNs, patients with more than 20 involved LNs also had the steepest increase in the risk of distant metastases with the increase in tumour size. However, only the location of involved LNs, not the number of involved LNs, was associated with distant metastases in multivariate analysis.

CONCLUSIONS

We confirm that the location of involved LNs categories based on the TNM staging system is more useful than the number of involved LNs categories for estimating the risk of distant metastasis in PTC. Differentiating N1a disease from N1b disease is important for the follow-up and management of patients with PTC.

Ultrasonographic findings relating to lymph node metastasis in single micropapillary thyroid cancer

Background

In thyroid cancer, preoperative ultrasonography (US) is performed to detect the primary tumor and lymph node metastasis (LNM), which are related to prognosis. This study examined the relationships between specific US findings and LNM in micropapillary thyroid cancer (MPTC).

Methods

Data on 220 patients with solitary MPTC who underwent total thyroidectomy and neck dissection between 2008 and 2009 were evaluated retrospectively. We classified the US findings according to the nature, shape, echogenicity, extent, margin, and calcification of the primary tumor and evaluated the correlations between these findings and those of LNM.

Results

Hypoechogenicity (odds ratio = 2.331, P = 0.025) and marked hypoechogenicity (OR = 4.032, P = 0.016) of MPTC were risk factors for central LNM. All of the patients with lateral cervical LNM showed hypoechogenicity or marked hypoechogenicity. Hypoechogenicity (odds ratio = 5.349, P = 0.047) and other types of calcification (odds ratio = 2.495, P = 0.010) were significant risk factors for lateral cervical LNM.

Conclusions

Specific sonographic findings (hypoechogenicity or marked hypoechogenicity, and calcification) suggest LNM.

Impact of prophylactic central neck dissection on oncologic outcomes of papillary thyroid carcinoma: a review

Prophylactic neck dissection (PND) for papillary thyroid carcinoma (PTC) is controversial. Our aim was to assess current levels of evidence (LE) according to the Oxford Centre for Evidence-based Medicine ( http://www.cebm.net/?O=1025 ) regarding the oncologic benefits of PND. Data were analyzed via MEDLINE keywords: PTC, differentiated thyroid carcinoma, PND, central lymph node metastases, central compartment, recurrence-free survival. There was conflicting evidence regarding the rate of reoperation for recurrence, with some studies showing a lower rate after PND with increased recurrence-free survival and a higher rate of undetectable pre- and post-ablation thyroglobulin levels (LE 4), whereas other studies did not show a difference (LE 4). Only one study (LE 4) showed improved disease-specific survival with PND. PND may improve recurrence-free survival, although this is supported by only a low LE. Current recommendations can only be based on low-level evidence.

Tumor location-dependent skip lateral cervical lymph node metastasis in papillary thyroid cancer

BACKGROUND

Lateral cervical lymph node metastasis without central lymph node (CLN) metastasis is not infrequent in papillary thyroid cancer (PTC). This study was designed to investigate the frequency and pattern of skip metastasis in PTC.

METHODS

We reviewed 131 patients who underwent total thyroidectomy with CLN dissection and selective lymph node dissection. Tumor location was classified in 3 areas (upper, middle, and lower third) based on preoperative ultrasonographic findings.

RESULTS

All skip metastases occurred in patients whose tumors had been on the upper part of the thyroid (p < .001). Among 9 patients with skip metastasis, level III lymph nodes (66.7%) were the lymph nodes that were most frequently involved in skip metastasis.

CONCLUSION

Primary tumors in the upper portion of the thyroid are closely linked to skip metastasis. Careful preoperative evaluation of lateral cervical lymph nodes is suggested when a tumor is in the upper portion.

Low-risk papillary thyroid cancer: times are changing

The prevalence of papillary thyroid cancer (PTC), particularly of low-risk PTC (MACIS <6), is rising due to the increasingly use of neck imaging techniques, fine-needle aspiration and whole body PET scans. Observational cohort studies carried out in the last two decades suggest that low-risk PTC are being overtreated due to the current management paradigm being built on studies done in the 70s and 80s that still echo in some influential guidelines. With the progressive adoption of total thyroidectomy and central neck dissection as the mainstay of treatment for PTC, and suppressed basal thyroglobulin and neck ultrasound once a year as the essential tools for follow-up, the use of radioiodine ablation, body scans and stimulated thyroglobulin concentrations has become obsolete for the vast majority of patients with low-risk PTC. Future guidelines on the management of differentiated thyroid cancer should discuss separately three different diseases: low-risk PTC, high-risk PTC and follicular cancer.

Number of central lymph node metastasis for predicting lateral lymph node metastasis in papillary thyroid microcarcinoma

BACKGROUND

The purpose of this study was to present our evaluation of the relationship between the number of positive central lymph nodes and lateral lymph node metastasis in patients with papillary thyroid microcarcinoma (PTMC).

METHODS

Up to 141 patients with PTMC were divided into 3 groups according to different positive central lymph node classifications as follows: group A, no positive central lymph node; group B, 1 positive central lymph node; and group C, 2 or more positive central lymph nodes.

RESULTS

Incidence of lateral lymph node metastasis was 30.5% (43 of 141). It was significantly high in group C compared with groups A and B, although there was no significant difference between groups A and B. Number of positive central lymph node ≥2, underlying Hashimoto thyroiditis, and extrathyroidal extension were the independent predictive factors for lateral lymph node metastasis on multivariate analysis.

CONCLUSION

Lateral lymph node metastasis was mainly observed in patients with ≥2 positive central lymph nodes, which is an independent predictive factor for lateral lymph node metastasis. Therefore, ≥2 positive central lymph nodes may be valuable in predicting lateral lymph node metastasis.

German Association of Endocrine Surgeons practice guideline for the surgical management of malignant thyroid tumors

INTRODUCTION

Over the past years, the incidence of thyroid cancer has surged not only in Germany but also in other countries of the Western hemisphere. This surge was first and foremost due to an increase of prognostically favorable ("low risk") papillary thyroid microcarcinomas, for which limited surgical procedures are often sufficient without loss of oncological benefit. These developments called for an update of the previous practice guideline to detail the surgical treatment options that are available for the various disease entities and tumor stages.

METHODS

The present German Association of Endocrine Surgeons practice guideline was developed on the basis of clinical evidence considering current national and international treatment recommendations through a formal expert consensus process in collaboration with the German Societies of General and Visceral Surgery, Endocrinology, Nuclear Medicine, Pathology, Radiooncology, Oncological Hematology, and a German thyroid cancer patient support organization.

RESULTS

The practice guideline for the surgical management of malignant thyroid tumors includes recommendations regarding preoperative workup; classification of locoregional nodes and terminology of surgical procedures; frequency, clinical, and histopathological features of occult and clinically apparent papillary, follicular, poorly differentiated, undifferentiated, and sporadic and hereditary medullary thyroid cancers, thyroid lymphoma and thyroid metastases from primaries outside the thyroid gland; extent of thyroidectomy; extent of lymph node dissection; aerodigestive tract resection; postoperative follow-up and surgery for recurrence and distant metastases.

CONCLUSION

These evidence-based recommendations for surgical therapy reflect various "treatment corridors" that are best discussed within multidisciplinary teams and the patient considering tumor type, stage, progression, and inherent surgical risk.

The prognostic value of the metastatic lymph node ratio and maximal metastatic tumor size in pathological N1a papillary thyroid carcinoma

OBJECTIVE

The presence of central neck lymph node (LN) metastases (defined as pN1a according to Tumor Node Metastasis classification) in papillary thyroid cancer (PTC) is known as an independent risk factor for recurrence. Extent of LN metastasis and the completeness of removal of metastatic LN must have an impact on prognosis but they are not easy to measure. Moreover, the significance of the size of metastatic tumors in LNs has not been clarified. This study was to evaluate the impact of the extent of LN metastasis and size of metastatic tumors on the recurrence in pathological N1a PTC.

DESIGN

This retrospective observational cohort study enrolled 292 PTC patients who underwent total thyroidectomy with central neck dissection from 1999 to 2005. LN ratio was defined as the number of metastatic LNs divided by the number of removed LNs, which was regarded as variable reflecting both extent of LN metastasis and completeness of resection, and LN size as the maximal diameter of tumor in metastatic LN.

RESULTS

The significant risk factors for recurrence in univariate analysis were large primary tumor size (defined as larger than 2 cm), high LN ratio (defined as higher than 0.4), and presence of macrometastasis (defined as larger than 0.2 cm). Age, sex, clinical node status, and microscopic perithyroidal extension had no effect on recurrence. In multivariate analysis, high LN ratio and presence of macrometastasis were independent risk factors for recurrence.

CONCLUSION

LN ratio and size of metastatic nodes had a significant prognostic value in pathological N1a PTC. We suggest that risk stratification of pathological N1a PTC according to the pattern of LN metastasis such as LN ratio and size would give valuable information to clinicians.

Adequacy of pathology reports of specimens from patients with differentiated thyroid cancer

This study aims to investigate the adequacy of pathology reports of specimens from patients with differentiated thyroid cancer (DTC) operated in our institution. Retrospective analysis of the pathology reports of all patients diagnosed with DTC in our area, from 1 January 2006 through 30 June 2011, was done. Sixty-eight patients were diagnosed with DTC. All reports were descriptive. In all the reports, but one, one or more core data items (according to the Royal College of Pathologists) were missing. Information about 1 and 2 items was lacking in 7.4 and 42.6 % of the reports, respectively. The rest were missing three or more data. Lymphovascular invasion, histology subtype, and completeness of excision were, in this order, the three most frequently omitted data. Sometimes, the information in question was not explicitly expressed but could be extrapolated from the data available. The pathology reports of DTC specimens frequently miss some of the information considered necessary to provide a comprehensive patient care.

Experience and analysis of Delphian lymph node metastasis in patients with papillary thyroid carcinoma

Background

Recently, lymph node metastasis (LNM) has been regarded as an important factor influencing loco-regional recurrence and survival rate in papillary thyroid cancer (PTC) patients. The aims of this study were to investigate the detection rate and metastasis rate of the Delphian lymph node (DLN) and clinical patterns related to regional LNM, and to examine how DLN metastasis affects PTC treatment.

Methods

We reviewed the medical records of 413 patients with pathologically confirmed PTC from among 452 patients who underwent thyroid surgery between January 2010 and October 2010 in the Department of Endocrine Surgery at Kosin University Gospel Hospital in Busan, South Korea.

Results

Multivariate analyses revealed a significantly higher proportion of cases with lymphovascular invasion (56.6% vs. 12.5%, P <0.001), central neck node metastasis (88.6% vs. 34.5%, P <0.001) and lateral neck node metastasis (47.2% vs. 10.2%, P <0.005) among cases with DLN metastasis compared to those without. The negative predictive value (NPV) of DLN metastasis with regard to the presence of contralateral central LNM for cases with a tumor size 1 cm or smaller than 1 cm was found to be 93.3% (127/136).

Conclusion

When DLN metastasis is not detected in papillary thyroid microcarcinomas (PTMC), thyroid lobectomy on the affected side and ipsilateral central neck lymph node dissection should be sufficient. In addition, even in cases where lateral neck LNM is not detected on preoperative examination, if DLN metastasis is detected postoperatively, more careful attention should be paid to the lateral neck nodes during follow-up.

Not the number but the location of lymph nodes matters for recurrence rate and disease-free survival in patients with differentiated thyroid cancer

Background

Several Japanese studies have focused on identifying prognostic factors in patients with positive lymph nodes to predict recurrence rate and disease-free survival (DFS). However, different treatment protocol is followed in Japan compared with the European and American approach. This study was designed to investigate whether the number and/or location of lymph nodes predicts prognosis in patients with DTC treated with total thyroidectomy, lymph node dissection, and postoperative radioactive iodine ablation.

Methods

All 402 patients who were treated at the Department of Nuclear Medicine between 1998 and 2010 for DTC were reviewed. Patients were treated with (near) total thyroidectomy, lymph node dissection on indication, and postoperative I-131 ablation. Median follow-up was 49 (range, 10–240) months. Outcome measures were recurrence rate, disease-free survival, and mean time to recurrence.

Results

Ninety-seven patients had proven lymph node metastases. Recurrence rate was significantly higher in patients with positive lymph nodes in the lateral compartment vs. patients with lymph node metastasis in the central compartment (60 vs. 30%, p = 0.007). Disease-free survival and mean time to recurrence also were significantly shorter (30 vs. 52 months, p = 0.035 and 7 vs. 44 months, p = 0.004, respectively). The number of lymph nodes and extranodal growth were not significantly associated with the outcome measures used.

Conclusions

The location of positive lymph nodes was significantly correlated with the risk of recurrence and a shorter DFS. Hence, the TNM criteria are useful in subdividing patients based on risk of recurrence and DFS.

Optimization of staging of the neck with prophylactic central and lateral neck dissection for papillary thyroid carcinoma

OBJECTIVE

To analyze the yield and rate of node metastases (pN1) for prophylactic central (CND) and lateral neck dissection (LND) for papillary thyroid carcinoma, the risk factors for pN1, and outcomes.

BACKGROUND

Prophylactic CND and LND are not routinely employed. Adjuvant radioiodine treatment may be modulated, however, by surgical staging of the neck.

METHODS

Retrospective study, consecutive patients ultrasonographically classified cN0 treated with prophylactic CND, and lateral LND (levels III and IV). The number of nodes was resected and the incidence of pN1 was recorded.

RESULTS

For 317 patients (254 women, mean age 44 years, mean tumor size 17 mm), the number of lymph nodes was 5 for unilateral CND, 9 for bilateral CND, and 12 for LND. pN1 stage was 42% overall: 23% for unilateral CND, 39% for bilateral CND, and 23% for LND (median number of metastatic nodes = 2 for each). Fifty-five percent of the patients staged pN1 had metastatic nodes in the lateral neck. Ten percent had more than 10 metastatic nodes and/or more than 3 nodes with extra capsular spread. pN1 was correlated with tumor size (P = 0.0025), extrathyroidal tumor extension (P < 0.0001), male sex (P = 0.0006), and age younger than 45 years (P = 0.0003). Permanent hypoparathyroidism and unintentional recurrent nerve paralysis occurred in 2 cases each. Patients staged pN0 received less radioiodine than patients staged pN1 (median 30 vs 100 mCi, P < 0.0001).

CONCLUSIONS

For staging, bilateral prophylactic CND is preferable to unilateral CND. Prophylactic CND with LND optimizes staging providing a basis for a personalized approach for adjuvant radioiodine.