Cervical lymph node dissection in papillary thyroid cancer: Current trends, persisting controversies, and unclarified uncertainties

Does the extent of neck surgery based on preoperative calcitonin level influence survival in medullary thyroid carcinoma: a retrospective tertiary centre experience

INTRODUCTION

Medullary thyroid carcinoma (MTC) is a rare thyroid cancer arising from the calcitonin-secreting parafollicular cells. Previous studies suggested a preoperative calcitonin level >200ng/l is an indication for prophylactic lateral neck dissection (LND) to remove micrometastases and improve survival outcomes.

METHODS

This retrospective single-centre study assessed the efficacy of preoperative calcitonin levels as a marker for determining need for prophylactic LND in MTC. Data were obtained on demographics, preoperative calcitonin levels, size and laterality of index tumour, type of neck dissection (central neck dissection (CND), LND), nodes removed, levels with involved nodes, number of nodes histologically involved, mortality, adjuvant therapy and locoregional recurrence.

RESULTS

A total of 33 patients were identified from St George's University Hospitals NHS Foundation Trust between 1 January 2001 and 19 August 2021; 8 were excluded for data quality issues. Of the 18 classified with a high preoperative calcitonin level (>200ng/l), 10 (56%) had a LND and 8 (44%) had a CND. In the low-calcitonin group, three (43%) patients had a CND only and four (57%) had a LND. There was no difference in absolute or disease-free survival between the low and high groups (p=0.960, p=0.817), or between those who had a CND and LND in the high-calcitonin group (p=0.607, hazard ratio (HR) 0.55; p=0.129, HR 8.78).

CONCLUSION

There was no statistically significant difference in outcomes between high and low calcitonin groups. A selective approach to performing LND in MTC patients based on clinical and imaging findings suggesting disease presence in the lateral neck should be explored further.

Diagnostic role of FNA cytology in the evaluation of cervical lymph nodes in thyroid cancers: Combined evaluation of thyroglobulin in eluate from FNA cytology

BACKGROUND

The presurgical evaluation of cervical lymph nodes (CLNs) in the management of thyroid malignant lesions is crucial for the extent of surgery or detection of metastases. In these last decades, fine-needle aspiration cytology (FNAC) has been shown to have a central role in the detection of nodal thyroid metastases. It is adopted for the possibility of confirming suspected metastases either in the presurgical phase or in the follow-up of patients after thyroidectomy. However, FNAC from CLNs can be challenging, especially in cystic lesions. In this regard, the combination of FNAC with thyroglobulin measurement in the eluate from FNAC (Tg-FNAC) seems to increase the sensitivity of FNAC in the detection of CLN metastases. The role of FNAC and Tg-FNAC was investigated in this series.

METHODS

One hundred fifty-three prospective cytological samples of CLNs were studied along with surgical follow-up in the period between 2020 and 2022. Immunocytochemistry (ICC) was performed on liquid-based cytology-stored material.

RESULTS

One hundred fifty-nine enlarged CLNs included 19 central lymph nodes and 140 CLNs. Forty-two thyroidal CLN metastases and 117 reactive lymph nodes were found. Thirty-one CLN dissections were performed in patients with a previous diagnosis of thyroid carcinoma (mostly papillary thyroid carcinoma [PTC]), whereas 128 CLNs with a concomitant suspicious and/or malignant thyroid nodule were found. There was one false-positive case among all the malignant histologically confirmed cases, and two of 117 reactive CLNs (1.7%) had a diagnosis of metastatic PTC. Markedly high Tg-FNAC was found in all metastatic CLNs, including 11 cystic metastatic CLNs detected by Tg-FNAC with a negative FNAC. ICC (including Tg, CK-19, and LCA) recognized nine cases with low Tg-FNAC and scant suspicious thyrocytes. Tg-FNAC plus FNAC diagnosed 94.2% of malignancies.

CONCLUSIONS

FNAC represents a valid method for the evaluation of CLNs, especially combined with ICC. Tg-FNAC is an additional method with a useful role in FNAC.

Sentinel lymph node mapping: current applications and future perspectives in thyroid carcinoma

Sentinel lymph node (SLN) mapping is a standard, minimally-invasive diagnostic method in the surgical treatment of many solid tumors, as for example melanoma and breast cancer, for detecting the presence of regional nodal metastases. A negative SLN accurately indicates the absence of metastases in the other regional lymph nodes (LN), thus avoiding unnecessary lymph nodal dissection. Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma (TC) with cervical LN metastases at diagnosis in 20-90%, and nodal involvement correlates with local persistence/recurrence. The SLN in PTC is an intraoperative method for staging preoperative N0 patients and for detecting metastatic LNs "in and outside" the cervical LN central compartment; it represents an alternative method to prophylactic central neck node dissection. In this review we summarize different methods and results of the use of SLN in TC. The SLN identification techniques currently used include the selective vital-dye (VD) method, 99mTc-nanocolloid planar lymphoscintigraphy with intraoperative use of a hand-held gamma probe (LS), the combination LS + VD, and the combination LS and preoperative SPECT-CT (LS + SPECT/CT). The application of the SLN procedure in TC has been described in many studies, however, the techniques are heterogeneous, and the role of SLN in TC, with indications, results, advantages and limits, is still debated.

Study to Evaluate the Pattern of Nodal Distribution in Papillary Thyroid Cancer

Among the thyroid cancers, papillary thyroid cancer (PTC) is the most common with lymphatic metastasis. It has the propensity to spread to the level II-VI lymph nodes in a predictable manner. We evaluated the pattern of nodal distribution at different levels of neck in papillary thyroid cancer in this Observational Prospective study. Total 41 patients of PTC (Papillary thyroid cancer) were included in the study. 36 out of them were diagnosed as PTC by FNAC and underwent total thyroidectomy and central neck dissection, while 5 patients were histologically confirmed cases of PTC on previous hemithyroidectomy and underwent completion thyroidectomy and central neck dissection .Patients with T3/T4 stage or N1 underwent lateral neck dissection also. Clinicopathological factors such as age, sex, tumor stage, nodal metastasis and extracapsular invasion, were evaluated. Lymph node metastasis was noted in 21 patients (51.2%) and all these patients had central (level VI) lymph node involvement. Among 21 patients, pathological ipsilateral lateral neck metastasis was noted in 6 patients (28.57%) at level II, 10 patients (47.62%) at level III and 8 patients (38.10%) at level IV. Only 5 patients (23.81%) had metastasis at level V. Extracapsular invasion was observed in 10 (24.4%) patients. We concluded that patients with PTC show higher rates of metastasis at central neck (level VI) and are not easily detected on clinical examination or by USG due to low sensitivity but are sensitive and specific for lateral neck nodes in late stages . Thus, ipsilateral selective neck dissection should be considered with total thyroidectomy and central neck dissection in presence of clinically or radiologically evident lateral lymph nodes (preoperatively) and in T3, T4 stage (late stages) tumors.

Radiomics Analysis of Gray-Scale Ultrasonographic Images of Papillary Thyroid Carcinoma > 1 cm: Potential Biomarker for the Prediction of Lymph Node Metastasis

Purpose

This study aimed to investigate radiomics analysis of ultrasonographic images to develop a potential biomarker for predicting lymph node metastasis in papillary thyroid carcinoma (PTC) patients.

Materials and Methods

This study included 431 PTC patients from August 2013 to May 2014 and classified them into the training and validation sets. A total of 730 radiomics features, including texture matrices of gray-level co-occurrence matrix and gray-level run-length matrix and single-level discrete two-dimensional wavelet transform and other functions, were obtained. The least absolute shrinkage and selection operator method was used for selecting the most predictive features in the training data set.

Results

Lymph node metastasis was associated with the radiomics score (p < 0.001). It was also associated with other clinical variables such as young age (p = 0.007) and large tumor size (p = 0.007). The area under the receiver operating characteristic curve was 0.687 (95% confidence interval: 0.616-0.759) for the training set and 0.650 (95% confidence interval: 0.575-0.726) for the validation set.

Conclusion

This study showed the potential of ultrasonography-based radiomics to predict cervical lymph node metastasis in patients with PTC; thus, ultrasonography-based radiomics can act as a biomarker for PTC.

Nomogram Model Based on Iodine Nutrition and Clinical Characteristics of Papillary Thyroid Carcinoma to Predict Lateral Lymph Node Metastasis

OBJECTIVE

Preoperative evaluation of lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC) has been one of the major clinical challenges. This study aims to develop and validate iodine nutrition-related nomogram models to predict lateral cervical lymph node metastasis in patients with PTC.

METHODS

This is a retrospective study. Urinary iodine concentration (UIC) and serum iodine concentration (SIC) were measured in 187 LLNM patients and 289 non-LLNM (NLLNM) patients. All patients were randomized 3:1 into the training cohort (n = 355) and the validation cohort (n = 121). Using logistic regression analysis, we analyzed the influence of iodine nutrition-related factors and clinicopathological characteristics on LLNM in PTC patients. Lasso regression method was used to screen risk factors and construct a nomogram for predicting LLNM. The receiver operating characteristic curve (ROC curve), calibration curve, and decision curve analysis (DCA) of the nomogram models were carried out for the training and validation cohorts.

RESULTS

Gender, SIC, smoking history, drinking history, family history of PTC, multifocality, bilateral or unilateral tumors, TSH, Tg, and tumor size were included in the nomogram model predicting LLNM, with an area under the curve (AUC) of .795. The nomogram model showed good calibration and clinical benefit in both the training and validation cohorts.

CONCLUSION

The nomogram model based on iodine nutrition and other clinicopathological features is effective for predicting the lateral lymph node metastasis in PTC patients.

Detection of thyroglobulin in fine-needle aspiration for diagnosis of metastatic lateral cervical lymph nodes in papillary thyroid carcinoma: A retrospective study

Objective

We analysed the diagnostic performance of thyroglobulin in fine-needle aspiration (FNA-Tg) in the suspicious lateral cervical lymph nodes (CLNs) in patients with papillary thyroid cancer (PTC), proposed the best cutoff value and discussed the factors that may affect the diagnostic value of FNA-Tg.

Methods

In the present study, a retrospective analysis of 403 patients with PTC with 448 suspected lateral CLNs metastasis from October 2019 to May 2021 was performed. The cutoff value according to the receiver operating characteristic (ROC) curve was determined, and the Wilcoxon rank-sum test was used to evaluate the correlation between FNA-Tg and factors.

Results

According to the ROC curve, the cutoff value of FNA-Tg was 3.69 ng/ml (sensitivity, 92.48%; specificity, 75.00%). Patients who underwent total thyroidectomy were excluded. Compared with US and FNAC, the diagnostic performance of FNA-Tg was the greatest, especially for small CLNs (diameter ≤ 1 cm), cystic CLNs, and patients with Hashimoto’s thyroiditis (HT). Moreover, FNA-Tg levels were correlated with the presence of HT (p = 0.003), the anti-thyroglobulin antibody (Tg-Ab) (p < 0.001), the ratio of metastatic lateral CLNs (p = 0.004) and Tg assay kits (p < 0.001).

Conclusions

FNA-Tg measurement is sensitive enough for diagnosing lateral CLN metastases from PTC, but its diagnostic value is compromised by a number of factors.

Application of Carbon Nanoparticle Tracers in the Lateral Neck Lymph Nodes of CN1bx Patients with Papillary Thyroid Carcinoma

This study aimed to investigate the applicability of carbon nanoparticle tracers in the lateral neck lymph nodes of CN1bx patients with papillary thyroid carcinoma surgery. 73 patients with papillary thyroid carcinoma at our hospital between January 2019 to December 2019 were suspected metastasis in the lateral neck lymph node before surgical treatment. During the operation, carbon nanoparticle tracers were used as black staining tracers for the lateral neck lymph nodes to detect metastasis in each Compartment of the neck. The lateral Compartment is defined as level ll-V The black-stained lymph nodes, dyed by Carbon nanoparticle tracers, and non-dyed lymph nodes were compared. Post-surgery paraffin pathology was adopted as the gold standard to calculate the predictive performance of the carbon nanoparticle tracers in detecting lymph node biopsy metastasis. 59 of the patients (80.8%) had lateral neck metastasis. The black-stained lymph nodes, dyed by Carbon nanoparticle tracers, in Compartment IV exhibited the highest proportions in the case number submitted for detection and in lymph nodes metastasis, followed by Compartment III. The metastasis rate of the dyed lymph nodes in areas III and IV was significantly higher than that of non-dyed lymph nodes (P < 0.05). The sensitivity and accuracy of the dyed lymph node biopsy in Compartments III-IV were 90% and 93.2%, respectively. This predictive performance was similar to that Compartments ll-V combined. In conclusion, when carbon nanoparticle tracers are used for lymph node biopsy, high sensitivity and accuracy are obtained in lateral neck compartments III-IV, making these compartments ideal for lymph node biopsy.

Five genes involved in circular RNA-associated competitive endogenous RNA network correlates with metastasis in papillary thyroid carcinoma

This study aimed to identify potential circular RNA (circRNA), microRNA (miRNA) and mRNA biomarkers as well as their underlying regulatory mechanisms in papillary thyroid carcinoma (PTC). Three microarray datasets from the Gene Expression Omnibus database as well as expression data and clinical phenotype from The Cancer Genome Atlas (TCGA) were downloaded, followed by differential expression, functional enrichment, protein-protein interaction (PPI), and module analyses. The support vector machine (SVM)-recursive feature elimination (RFE) algorithm was used to screen the key circRNAs. Finally, the mRNA-miRNA-circRNA regulatory network and competitive endogenous RNA (ceRNA) network were constructed. The prognostic value and clinical correlations of key mRNAs were investigated using TCGA dataset, and their expression was validated using the UALCAN database. A total of 1039 mRNAs, 18 miRNAs and 137 circRNAs were differentially expressed in patients with PTC. A total of 37 key circRNAs were obtained using the SVM-RFE algorithm, whereas 46 key mRNAs were obtained from significant modules in the PPI network. A total of 11 circRNA-miRNA pairs and 40 miRNA-mRNA pairs were predicted. Based on these interaction pairs, 46 circRNA-miRNA-mRNA regulatory pairs were integrated, of which 8 regulatory pairs in line with the ceRNA hypothesis were obtained, including two circRNAs (circ_0004053 and circ_0028198), three miRNAs (miR-199a-5p, miR-199b-5p, and miR-7-5p), and five mRNAs, namely APOA2, CCL20, LPAR5, MFGE8, and TIMP1. Survival analysis showed that LPAR5 expression was associated with patient survival. APOA2 expression showed significant differences between metastatic and non-metastatic tumors, whereas CCL20, LPAR5, MFGE8 and TIMP1 showed significant differences between metastatic and non-metastatic lymph nodes. Overall, we identified several potential targets and regulatory mechanisms involved in PTC. APOA2, CCL20, LPAR5, MFGE8, and TIMP1 may be correlated with PTC metastasis.

High Iodine Nutrition May Be a Risk Factor for Cervical Lymph Node Metastasis in Papillary Thyroid Cancer Patients

PURPOSE

The aim of this study was to retrospectively identify the effect of iodine on the papillary thyroid cancer (PTC) process and investigate the risk clinicopathologic characteristics of cervical lymph node metastasis (CLNM) for achieving a better preventive strategy of PTC.

METHODS

Totally 187 patients with CLNM and 279 without CLNM (NCLNM) were enrolled, and their urinary iodine concentration (UIC) and serum iodine concentration (SIC) were measured. Logistic regressions were used to reveal the effects of iodine nutrition on the CLNM status of PTC.

RESULTS

The levels of thyroid-stimulating hormone (TSH) and thyroglobulin (TG) were higher in the CLNM group than in the NCLNM group. UIC and SIC were positively correlated, and both of them were correlated with TSH, free thyroxine, and TG. The proportions of UIC >300 μg/L and of SIC >90 μg/L were higher in the CLNM than in the NCLNM. Logistic analysis showed that SIC >90 μg/L was an independent predictor for CLNM in PTC. Additionally, age ≥45, female, TG, multifocality, and diameter of cancer invasion >1 cm also affected CLNM status in PTC, and their logistic regression model showed a certain diagnostic accuracy (area under the receiver-operating characteristic curve = 0.72).

CONCLUSIONS

Relatively high iodine nutrition seemed to be a significant risk factor for the occurrence of CLNM in PTC and may promote lymphatic metastasis in PTC.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Occult contralateral central neck metastasis in papillary thyroid carcinoma with preoperatively documented ipsilateral lateral neck metastasis

BACKGROUND

This study was conducted to evaluate risk factors and long-term prognosis of contralateral central neck metastasis (CCNM) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We present clinical evidence to aid in surgical decision-making regarding the extent of central neck dissection (CND), focusing on separation between ipsilateral and contralateral sides.

METHODS

A total of 379 PTC patients who underwent total thyroidectomy and concomitant bilateral central neck dissection with ipsilateral lateral neck dissection (LND) at a single institution was retrospectively included between January 1997 and December 2015.

RESULTS

The median follow-up time was 83.2 months, the mean age was 44.3 years, and the mean tumor size was 1.5 cm. Among the study sample, 266 patients were female (70.2%) and 113 (29.8%) were male. Of 379 patients, CCNM was present in 34.6%. In multivariate analysis, male sex (adjusted OR = 2.46, p = 0.002), bilaterality (adjusted OR = 2.58, p = 0.004), number of metastatic ipsilateral central lymph nodes (adjusted OR = 1.15, p = 0.002), number of metastatic lateral lymph nodes (adjusted OR = 1.48, p < 0.001), and three-level metastasis (adjusted OR = 2.46, p = 0.012) were identified as risk factors of CCNM. Overall recurrence occurred in 6.0% and 11.5% of patients in the CCNM (-) group and CCNM (+) group, respectively. In addition, contralateral recurrence was observed in 1.2% patients and 0.8% patients in the CCNM (-) group and CCNM (+) group, respectively. However, CCNM did not significantly increase risk of recurrence (adjusted HR = 1.01, p = 0.981).

CONCLUSIONS

Although the probability of pathological CCNM is not negligible, CCNM was not associated with higher risk of recurrence. This study suggest that central neck dissection may be limited to the ipsilateral side, and the result regarding prognosis of CCNM may help to avoid bilateral CND so that it could have potential to minimize unnecessary surgery-related complications such as recurrent laryngeal nerve(RLN) injury or hypoparathyroidism.

Lymph node metastasis between the sternocleidomastoid and sternohyoid muscle in papillary thyroid carcinoma patients: A prospective study at multiple centers

BACKGROUND

The lymph nodes between the sternocleidomastoid and sternohyoid muscle (LNSS) are not explicitly mentioned in the 2015 American Thyroid Association and 2008 American Head and Neck Society (AHNS) guidelines, but they are easily overlooked in papillary thyroid carcinoma (PTC). We prospectively evaluated the clinical significance of the LNSS in papillary thyroid carcinoma (PTC) patients.

METHOD

In five medical centers, two hundred and thirty-four PTC patients with lateral neck metastasis who underwent 264 neck dissection were enrolled in this study. LNSS was resected and used as a specimen to investigate the relationship of LNSS with several clinicopathological parameters.

RESULT

Of the 264 lateral neck dissections, the average lymph node metastasis rate of LNSS was 23.48%, significantly second only to that in level III (p<0.05). Univariate and multivariate analyses showed that a patient age over 45 years (OR 2.155, 95% CI 1.191 to 3.898, p = 0.011), with a tumor located in the inferior lobe of the thyroid (OR 1.517, 95% CI 1.113 to 2.068, p = 0.008), and LN metastasis at levels IIb (OR 2.298, 95% CI 1.121 to 4.712, p = 0.020) and level III (OR 2.408, 95% CI 1.222 to 4.745, p = 0.011) were independent risk factors for LNSS lymphatic metastasis.

CONCLUSION

The LNSS has a high metastatic rate and is easily overlooked. Additional attention should be paid to LNSS, especially in patients over 45 years old and with PTC located in the thyroid's inferior lobe.

Surgical Outcomes and Efficacy of Isthmusectomy in Single Isthmic Papillary Thyroid Carcinoma: A Preliminary Retrospective Study

BACKGROUND AND OBJECTIVES

The optimal extent of surgery needed for isthmic papillary thyroid carcinoma (PTC) is not well-defined, although total thyroidectomy is usually recommended. This study aimed to evaluate the efficacy of isthmusectomy in the surgical treatment of isthmic PTC. Materials and Methods: We retrospectively studied 121 patients who underwent thyroidectomy with or without central neck dissection (CND) for single isthmic PTC from January 2003 to June 2019. We excluded patients who were clinically suspected to have clinically positive cervical lymph node metastasis and gross extrathyroidal extension or to have cancers at sites other than the thyroid isthmus. Patients were divided into three groups according to the extent of thyroidectomy-total thyroidectomy, lobectomy with isthmusectomy (the lobectomy group), and isthmusectomy. Clinical and pathologic characteristics, surgical outcomes, recurrence rate, and survival were analyzed. Results: Of 121 isthmic PTC patients, 28 were men and 93 were women. Total thyroidectomy, lobectomy with isthmusectomy, and isthmusectomy were performed in 70 (57.8%), 40 (33.1%), and 11 (9.1%) patients, respectively. Prophylactic CND was performed in 104 (86%) patients. In a subgroup analysis, patients who underwent total thyroidectomy showed higher postoperative hypoparathyroidism (p < 0.001) than those who underwent lobectomy and isthmusectomy. However, there were no differences in the recurrence rate or survival between the three groups. Conclusion: Thyroid isthmusectomy may be effective in the surgical treatment of small single isthmic PTC. Further studies are necessary to verify this result.

Lymph node metastasis around the entrance point to recurrent laryngeal nerve in papillary thyroid carcinoma

There are few reports on the lymph nodes of entrance point to recurrent laryngeal nerve (LN-epRLN) in patients with papillary thyroid carcinoma (PTC). Thus, we investigated the clinical significance of LN-epRLN and implications it may have. An observational analysis of 878 consecutive patients with PTC who underwent thyroidectomy from April 2016 to March 2017 was conducted. We explored the surrounding tissue of laryngeal entry point, during routine central lymph node dissection (CLND). The lymph node specimens were sent separately for routine histopathological examination. Thereafter, complications and follow-ups were recorded. LN-epRLNs were found in 73 of the 878 patients, with the metastatic rate of 3.76%. Univariate and multivariate analysis showed central lymph node metastases can serve as independent predictors for LN-epRLN metastasis. In summary, we confirmed the significance of LN-epRLN in metastasis and recurrence, which required precise anatomy and thorough CLND. In PTC patients, especially in suspicious presence of central cervical lymph node metastasis, attention should be given to excising the nodal tissue at the laryngeal entry point.

The sentinel lymph node biopsy technique in papillary thyroid carcinoma: The issue of false-negative findings

BACKGROUND

The management of papillary thyroid carcinoma (PTC) is changed after introduction of sentinel lymph node biopsy (SNB) technique for nodal staging. Some debate still surrounds the accuracy of this procedure in terms of wide heterogeneity of sentinel lymph node detection and false-negative findings.

AIM

to identify the key issues which make it difficult the usefulness of SNB in PTC.

METHODS

A comprehensive computer literature search of meta-analyses published in PubMed/MEDLINE and Cochrane library database until June 30, 2019 was conducted. We used a search algorithm based on this combination of terms: (i) "thyroid neoplasm" or "thyroid cancer" or "thyroid carcinoma" or "thyroid malignancy" or "meta-analysis" or "systematic review") AND (ii) "sentinel lymph node biopsy".

RESULTS

Comparing 4 written meta-analyses published in the literature, the diagnostic performance of SNB technique in PTC has been summarized. Relatively high false-negative rates (FNR) were reported for each SNB methods: vital-dye (VD: 12.7%; 7%; 0-38%), 99mTc-nanocolloid planar lymphoscintigraphy with the use of intraoperative hand-held gamma probes (LS: 11.3%; 16%; 0-40%), combined LS with VD (LS+VD: 0%; 0-17%), LS with the additional contribution of preoperative SPECT/CT (7-8%).

CONCLUSION

Evidence-based data about the diagnostic performance of SNB in PTC are increasing. The nuclear medicine community should reach a consensus on the operational definition of the SLN to better guide the surgeon in identifying the lymph nodes most likely contain metastatic cells. Standardization of SLN identification, removal and analysis are required.

Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review

Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.

Which papillary thyroid microcarcinoma should be treated as "true cancer" and which as "precancer"?

BACKGROUND

Papillary thyroid microcarcinoma (PTMC) generally is a cancer with excellent prognosis, but the term "cancer" sounds severe and harsh, which can elicit emotional and physical responses from patients. To eliminate the word "cancer," the term noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) was introduced. However, not all PTMCs can be classified as NIFTP. Sometimes, very aggressive PTMC cases might be observed. Some authors suggest that one of the risk factors for poor prognosis is lymph node metastasis. The aim of the study was to evaluate some clinicopathological features of PTMC as the risk factors for lymph node metastasis.

MATERIAL AND METHODS

We performed a retrospective chart review and selected 177 patients with PTMC. To analyze the cases with potentially aggressive behavior, we enrolled PTMC patients with lymph node metastases (pN1, central, and/or lateral) and evaluated some of their clinicopathological features.

RESULTS

The logistic regression analysis results demonstrated significantly higher rates of multifocal or bilateral tumor occurrence in the PTMC patients with pN1 than in the patients with pN0 (P < 0.0001 for both). In addition, the occurrence of thyroid tumors with sizes above 0.5 cm was a significant risk factor for lymph node metastasis (P < 0.0001). The results of the ROC analyses showed that the presence of multifocal or bilateral tumors and tumor sizes above 0.5 cm were significant predictors of lymph node metastasis (P < 0.0001 for all).

CONCLUSIONS

Multifocal and bilateral PTMC tumors with diameters above 0.5 cm should be treated aggressively as "true cancer" and might benefit from lymph node dissection. Unifocal PTMC tumors with diameters equal to or below 0.5 cm may be treated less aggressively.

CYFRA 21-1 in Lymph Node Fine Needle Aspiration Washout Improves Diagnostic Accuracy for Metastatic Lymph Nodes of Differentiated Thyroid Cancer

Fine needle aspiration cytology (FNAC) and washout thyroglobulin (Tg) measurements are the standard for evaluating a metastatic lymph node (LN) in thyroid cancer. However, patients rarely benefit from these procedures due to false results. This study aims to identify a reliable biomarker that significantly improves the diagnosis of metastatic LNs, in addition to FNAC and washout Tg. This study analyzed 130 LNs that were suspected to have metastases on thyroid ultrasonography, from June 2016 to December 2017. All subjects underwent FNAC, washout Tg measurements and a new biomarker, washout Cytokeratin fragment 21-1 (CYFRA 21-1) measurement. The final LN outcomes were confirmed by surgical histology, repeat FNAC, or follow-up image. The diagnostic values of the presence of washout CYFRA 21-1 for diagnosing metastatic LNs were evaluated according to final LN outcomes. Among the 130 LNs, 42 were metastatic lesions and 88 were benign. The washout CYFRA 21-1 levels were significantly higher in metastatic LNs than in benign LNs. In contrast to the findings of washout Tg, washout CYFRA 21-1 showed little overlap between benign and malignant LNs, and its diagnostic cutoff values were not affected by surgery. The combinations of FNAC and washout CYFRA 21-1 showed higher sensitivity (91.9%), specificity (96.5%), negative predictive value (98.8%), and diagnostic accuracy (94.2%) than FNAC with washout Tg. The combination of FNAC, washout Tg, and washout CYFRA 21-1 showed the best sensitivity (98.8%). When washout CYFRA 21-1 was applied to the discordant results that were observed between FNAC and washout Tg, 20 of 22 LNs were correctly diagnosed. Washout CYFRA 21-1 measurements in thyroid LNs provide a diagnostic modality.

Patterns of Lymph Node Metastasis in Differentiated Thyroid Cancer; Clinical Implications with Particular Emphasis on the Emerging Role of Compartment-Oriented Lymph Node Dissection

Recent advances in modern imaging allow an accurate identification of involved or suspicious lymph nodes within the nodal compartments of the neck. Careful ultrasonographic lymphatic mapping of the neck by an experienced radiologist allows a targeted, compartment-oriented (or selective) lymph node dissection to be performed instead of the more extensive modified radical lymph node dissection. Compartment-oriented lymph node dissection necessitates the close cooperation of an experienced radiologist with a particular interest in thyroid and neck ultrasonography. There is emerging evidence that this more conservative strategy allows local control of the disease while at the same time morbidity is minimized and a better cosmetic result is achieved. Further investigation is needed to establish the precise role of this interesting surgical approach.

Sentinel Lymph Node Biopsy in Small Papillary Thyroid Cancer: A Meta-analysis

PURPOSE

The aim of this study was to compare reported results on available techniques for sentinel lymph node detection rate (SDR) in papillary thyroid cancer (PTC).

METHODS

The MEDLINE database was searched via a PubMed interface to identify original articles regarding sentinel lymph node biopsy (SNB) in thyroid cancer. Studies were stratified according to the sentinel lymph node (SLN) detection technique: vital-dye (VD), Tc-nanocolloid planar lymphoscintigraphy with the use of intraoperative hand-held gamma probes (LS), both Tc-nanocolloid planar lymphoscintigraphy with intraoperative use of hand-held gamma probe and VD (LS + VD), Tc-nanocolloid planar lymphoscintigraphy with the additional contribution of preoperative SPECT/CT, and intraoperative use of hand-held gamma probe (LS-SPECT/CT). Pooled SDR values were presented with a 95% confidence interval (CI) for each SLN detection techniques. A Z-test was used to compare pooled SDR estimates. False-negative rates were summarized for each method.

RESULTS

Forty-five studies were included. Overall SDRs for the VD, LS, LS + VD, and LS-SPECT/CT techniques were 83% (95% CI, 77%-88%; I = 78%), 96% (95% CI, 90%-98%; I = 68%), 87% (95% CI, 65%-96%; I = 75%), and 93% (95% CI, 86%-97%; I = 0%), respectively. False-negative rates were 0% to 38%, 0% to 40%, 0% to 17%, and 7% to 8%, respectively.

CONCLUSIONS

In patients with PTC, Tc-nanocolloids offer a higher SDR than that of the VD technique. The addition of SPECT/CT improved identification of metastatic SLNs outside the central neck compartment.

Carbon nanoparticle lymph node tracer improves the outcomes of surgical treatment in papillary thyroid cancer

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy which is generally accompanied by lymph node metastasis.

OBJECTIVE

Our study evaluated whether carbon nanoparticle lymph node tracer can improve the outcomes of surgical treatment in papillary thyroid cancer (PTC).

METHODS

Ninety-two patients were selected and underwent total thyroidectomy and lymph node resection. Our study placed 45 individuals into the treatment group (carbon nanoparticle group) and 47 cohorts in the control group (no carbon nanoparticle group).

RESULTS

Carbon nanoparticle application remarkably improved lymph nodes detection rate in patients (4.7 ± 3.0; P< 0.05) compared to those in control groups (3.5 ± 2.3). The rate of parathyroid accidental resection in the carbon nanoparticle group significantly decreased (6.67%) compared to the control group (21.28%). Incidents of hypoparathyroidism and hypocalcaemia significantly decreased among the carbon nanoparticle cohorts.

CONCLUSIONS

Our study definitively showed that carbon nanoparticles can be used to effectively treat lymphatic carcinoma. Our study presented clinical evidences for potential application of carbon nanoparticle in improving the management of PTC patients.

Sentinel lymph node biopsy in small papillary thyroid cancer. A review on novel surgical techniques

PURPOSE

Sentinel lymph node biopsy (SNB) in patients with papillary thyroid carcinoma (PTC) and negative for clinically neck lymph node metastatic involvement (N0) has emerged as a promising minimally invasive procedure to detect metastatic nodes.

METHODS

The MEDLINE database was searched via the PubMed interface on 10 January 2018 for the MeSH headings "sentinel lymph node biopsy" and "thyroid carcinoma".

RESULTS

Vital blue dye, radioisotope, and the combination of both techniques are used in PTC patients. These methods and the emerging role of SPECT/CT are discussed in this review. The sentinel lymph node (SLN) identification rates ranged from 0 to 100% for blue dye, 83 to 100% for radioisotopes, and 66 to 100% for the combination of both techniques, respectively.

CONCLUSIONS

SNB based on radioisotope technique with the use of intraoperative gamma-probe is an accurate and safe method that allows the highest SLN detection rate. There is sufficient evidence to propagate the increasing use of SNB procedure that has the potential to avoid prophylactic lymph node surgery in patients clinically N0.

Molecular imaging of platelet-derived growth factor receptor-alpha (PDGFRα) in papillary thyroid cancer using immuno-PET

INTRODUCTION

Receptor tyrosine kinase (RTK) platelet-derived growth factor receptor-alpha (PDGFRα) was recently identified as a molecular switch for dedifferentiation in thyroid cancer that predicts resistance to therapy as well as recurrence of disease in papillary thyroid cancer. Here we describe the radiolabeling and functional characterization of an imaging probe based on a PDGFRα-specific monoclonal antibody (mAb) for immuno-PET imaging of PDGFRα in papillary thyroid cancer.

METHODS

Antibody D13C6 (Cell Signaling) was decorated with chelator NOTA using bioconjugation reaction with 2-(p-NCS-Bz)-NOTA. Radiolabeling was carried out using 40 μg of antibody-NOTA conjugate with 143-223 MBq of [⁶⁴Cu]CuCl₂ in 0.25 M NaOAc (pH 5.5) at 30 °C for 1 h. The reaction mixture was purified with size-exclusion chromatography (PD-10 column). PDGFRα and mock transfected B-CPAP thyroid cancer cells lines for validation of ⁶⁴Cu-labeled immuno-conjugates were generated using LVX-Tet-On technology. PET imaging was performed in NSG mice bearing bilaterally-induced PDGFRα (+/-) B-CPAP tumors.

RESULTS

Bioconjugation of NOTA chelator to monoclonal antibody D13C6 resulted in 2.8 ± 1.3 chelator molecules per antibody as determined by radiometric titration with ⁶⁴Cu. [⁶⁴Cu]Cu-NOTA-D13C6 was isolated in high radiochemical purity (>98%) and good radiochemical yields (19-61%). The specific activity was 0.9-5.1 MBq/μg. Cellular uptake studies revealed a specific radiotracer uptake in PDGFRα expressing cells compared to control cells. PET imaging resulted in SUV_mean values of ~5.5 for PDGFRα (+) and ~2 for PDGFRα (-) tumors, after 48 h p.i.. After 1 h, radiotracer uptake was also observed in the bone marrow (SUV_mean ~5) and spleen (SUV_mean ~8.5).

CONCLUSION

Radiolabeled antibody [⁶⁴Cu]Cu-NOTA-D13C6 represents a novel and promising radiotracer for immuno-PET imaging of PDGFRα in metastatic papillary thyroid cancer.

ADVANCES IN KNOWLEDGE AND IMPLICATIONS FOR PATIENT CARE

The presented work has the potential to allow physicians to identify papillary thyroid cancer patients at risk of metastases by using the novel immuno-PET imaging assay based on PDGFRα-targeting antibody [⁶⁴Cu]Cu-NOTA-D13C6.

Accuracy of preoperative MRI to assess lateral neck metastases in papillary thyroid carcinoma

Primary treatment of papillary thyroid carcinoma (PTC) with lateral lymph node metastasis is surgery, but the extent of lateral neck dissection remains undefined. Preoperative imaging is used to guide the extent of surgery, although its sensitivity and specificity for defining the number and level of affected lymph nodes on the lateral neck is relatively modest. Our aim was to assess the role of preoperative magnetic resonance imaging (MRI) in predicting the requisite levels of neck dissection in patients with regionally metastatic PTC, with a focus on Levels II and V. All patients with PTC and lateral neck metastasis who had undergone neck dissection at the Department of Otorhinolaryngology—Head and Neck Surgery, Helsinki University Hospital, Helsinki, Finland from 2013 to 2016 and had a preoperative MRI available were retrospectively reviewed. A head and neck radiologist re-evaluated all MRIs, and the imaging findings were compared with histopathology after neck dissection. In the cohort of 39 patients, preoperative MRI showed concordance with histopathology for Levels II and V as follows: sensitivity of 94 and 67%, specificity of 20 and 91%, positive predictive value of 56 and 75%, and negative predictive value of 75 and 87%, respectively. In PTC, MRI demonstrated fairly high specificity and negative predictive value for Level V metastasis, and future studies are needed to verify our results to omit prophylactic dissection of this level. Routine dissection of Level II in patients with regionally metastatic PTC needs to be considered, as MRI showed low specificity.

Radioguided sentinel lymph node biopsy in patients with papillary thyroid carcinoma

BACKGROUND

The ATA guidelines do not recommend prophylactic central compartment neck dissection in patients with T1-T2 papillary thyroid carcinoma (PTC) with no clinical evidence of lymph node metastasis, however patients' staging is recommended. Lymph node metastasis may be present also in small PTC, but preoperative ultrasound identifies suspicious cervical lymphadenopathy in 20-30% of patients. The role of sentinel lymph node biopsy (SLNB) remain open to debate. It has been shown that the identification rate of SLN in PTC patients is improved using a radiotracer compared to a dye technique. The aim of this systematic review was to evaluate the role of radioguided SLNB (rSLNB) in the treatment of PTC patients.

METHODS

A systematic search was performed in the PubMed and Embase database to identify all original articles regarding the application of rSLNB in PTC patients. The primary outcome was false negative rate (FNR) of the rSLNB; the secondary outcomes were SLN intraoperative identification rate (IIR), site of lymph node metastasis, and persistent disease during follow up.

RESULTS

Twelve studies were included. Most of PTC patients were T1-T2. The overall SLN IIR, SLN metastatic rate, and FNR were 92.1%, 33.6%, and 25.4%, respectively. Overall, lymph node metastasis were found in the central compartment (23.0%) and in the lateral compartments (10.6%). The persistent disease in patients who underwent SLNB associated to lymph node dissection (LND) in the same compartment of the SLN regardless of the SLN status was 0.6%.

CONCLUSIONS

In all PTC patients, also in T1-T2 stage, due to the high FNR the SLNB performed alone should be abandoned and converted into a technique to guide the lymphadenectomy in a specific neck compartment (i.e., central or lateral) based on the radioactivity, regardless of the SLN status, for better lymph node staging and selection of patients for postoperative radioiodine ablation.

Tumor size interpretation for predicting cervical lymph node metastasis using a differentiated thyroid cancer risk model

Lymph node metastasis (LNM) is common in differentiated thyroid cancer (DTC), but management of clinically negative DTC is controversial. This study evaluated primary tumor size as a predictor of LNM. Multivariate logistic regression analysis was used for DTC patients who were treated with surgery between 2002 and 2012 in the Surveillance, Epidemiology, and End Results (SEER) database, to determine the association of tumor size at 10 mm increments with LNM. A predictive model was then developed to estimate the risk of LNM in DTC, using tumor size and other clinicopathological characteristics identified from the multivariate analysis. We identified 80,565 eligible patients with DTC in the SEER database. Final histology confirmed 9,896 (12.3%) cases affected with N1a disease and 8,194 (10.2%) cases with N1b disease. After the patients were classified into subgroups by tumor size, we found that the percentages of male sex, white race, follicular histology, gross extrathyroidal extension, lateral lymph node metastasis, and distant metastasis gradually increased with size. In multivariate analysis, tumor size was a significant independent prognostic factor for LNM; in particular, the odds ratio for lateral lymph node metastasis continued to increase by size relative to a 1–10 mm baseline. The coefficient for tumor size in the LNM predictive model waŝ0.20, indicating extra change in log(odds ratio) for LNM as 0.2 per unit increment in size relative to baseline. In conclusion, larger tumors are likely to have aggressive features and metastasize to a cervical compartment. Multistratification by size could provide more precise estimates of the likelihood of LNM before surgery.

LGR5 is associated with tumor aggressiveness in papillary thyroid cancer

PURPOSE

Leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5) is a cancer stem cell marker and a down-stream target in Wnt/β-catenin signaling. In human papillary thyroid cancer (PTC), over activation of Wnt/β-catenin has been associated with tumor aggressiveness.

PATIENTS AND METHODS

Using established human cell lines (TPC-1, KTC-1, Nthy-ori-3–1), we report LGR5 and R-spondin (RSPO1–3) overexpression in PTC and manipulate LGR5 and Wnt/β-catenin signaling via both pharmacologic and genetic interventions. We test the association of LGR5 tumor expression with markers of PTC aggressiveness using a Discovery Cohort (n = 26 patients) and a Validation Cohort (n = 157 patients). Lastly, we explore the association between LGR5 and the BRAFV600E mutation (n = 33 patients).

RESULTS

Our results reveal that LGR5 and its ligand, RSPO, are overexpressed in human PTC, whereby Wnt/β-catenin signaling regulates LGR5 expression and promotes cellular migration. In two separate cohorts of patients, LGR5 and RSPO2 were associated with markers of tumor aggressiveness including: lymph node metastases, vascular invasion, increased tumor size, aggressive histology, advanced AJCC TNM stage, microscopic extra thyroidal extension, capsular invasion, and macroscopic invasion. As a biomarker, LGR5 positivity predicts lymph node metastasis with 95.5% sensitivity (95% CI 88.8%-98.7%) and 61% specificity (95% CI: 48.4%–72.4%) and has a negative predictive value (NPV) of 91.3% (95% CI 79.2%–97.5%) for lymph node metastatic disease. In human PTC, LGR5 is also strongly associated with the BRAFV600E mutation (p = 0.005).

CONCLUSION

We conclude that overexpression of LGR5 is associated with markers of tumor aggressiveness in human PTC. LGR5 may serve as a future potential biomarker for patient risk stratification and loco regional metastases in PTC.

The relevance of preoperative ultrasound cervical mapping in patients with thyroid cancer

BACKGROUND

Cervical lymph node involvement in thyroid cancer is associated with locoregional recurrence and decreased disease-free survival. Preoperative lymph node mapping helps in planning surgery for neck dissection and improves patient outcomes. We sought to perform a qualitative and quantitative analysis of ultrasound mapping for thyroid cancer and evaluate the clinical importance of this exam in terms of identifying the group of patients who would benefit most from subsequent surgical dissection.

METHODS

We retrospectively reviewed the cases of 263 patients who underwent thyroid surgery between 2009 and 2013. We calculated the positive predictive values (PPVs) of ultrasound mapping of both the lateral and central compartments together and the lateral or central compartment individually. A quantitative analysis was performed by comparing the number of positive lymph nodes at ultrasound imaging with histopathologic evaluation.

RESULTS

A total of 136 cases of thyroid cancer in 120 patients met the inclusion criteria for ultrasound mapping analysis. The PPVs (and 95% confidence intervals) were 83.82 (0.76-0.89) for the lateral and central compartments, 85.39% (0.76-0.91) for the lateral compartment, and 80.48% (0.7-0.87) for the central compartment. When comparing the positive lymph nodes at ultrasound imaging with histopathologic evaluation, the result was χ(2) = 10.33 (p = 0.006).

CONCLUSION

This single-institution study indicated that preoperative ultrasound mapping is an accurate imaging procedure for predicting lymphatic spread in differentiated and medullary thyroid cancer. Ultrasound mapping can be used as an efficient tool for surgical planning and prognosis determination, as well as for identifying the group of patients who would benefit most from subsequent surgical intervention.

Robotic thyroidectomy and cervical neck dissection for thyroid cancer

A robotic approach for thyroid surgery was developed to overcome the limitations of endoscopic thyroidectomy and provide many technical advantages. This approach facilitates the surgeon's control through a magnified three-dimensional view, decreased tremor, and freedom of motion with articulated instruments. Robotic thyroidectomy is safe and technically feasible in patients with well-differentiated, low-risk thyroid cancer. Furthermore, robotic thyroidectomy may become a good surgical alternative option for patients with more advanced thyroid cancer. Our modified bilateral axillo-breast approach (BABA) for central and lateral cervical neck lymph node (LN) dissection has yielded excellent surgical outcomes as an open procedure. The incorporation of robotics in thyroid cancer surgery will continue to evolve, and the surgical indications for robotic thyroidectomy will continue to expand. Further analyses that include long-term outcomes and randomized comparative trials remain important.

Thoracic duct lesions in thyroid surgery: An update on diagnosis, treatment and prevention based on a cohort study

INTRODUCTION

Thoracic duct fistula at the cervical level is a severe but rare complication following thyroid surgery, particularly associated to lateral dissection of the neck and to mediastinal goiter.

METHODS

we retrospectively analyzed chylous fistulas observed in a cohort of 13.224 patients underwent surgery for thyroid disease since 1986 to 2014, in the Unit of Endocrine Surgery, S. Maria University Hospital, Terni, Italy.

RESULTS

We observed 20 cases of chylous fistula. Thirteen patients underwent primary surgery in our institution while the remaining 7 cases had been referred to our Department from other hospitals for an already diagnosed lymphatic leak. Surgical procedures carried out included total thyroidectomy for mediastinal goiter in 4 patients, total thyroidectomy for cancer in 2 patients, unilateral functional lymphadenectomy in 11 patients and bilateral in 3. Intraoperative repair was carried out in 4 cases. Of the remaining 16 cases, 4 of the 6 fistulas with low flow leakage healed in about 30 days of conservative treatment, 2 cases instead required surgical repair. All 10 patients with "high-flow" fistula underwent surgery. Despite surgery was performed later, postoperative course in patients with late surgical repair is similar to what observed in those patients with early surgical repair. Both groups underwent cervical drainage removal in post-operative day 4.

CONCLUSION

Healing of a cervical chylous fistula can be achieved by conservative medical therapy (nutritional and pharmacological) but in case of therapeutic failure with rapid decrease of general condition, the surgical approach is necessary. In our experience, duct ligation after unsuccessful conservative treatment, is the only resolutive treatment.

Lymph node status of lateral neck compartment in patients with N1b papillary thyroid carcinoma

Conclusion Loco-regional recurrence-free survival was significantly decreased in the papillary thyroid cancer patients with > 6 metastatic lymph nodes and a lymph node ratio > 0.22. Also, the risk of lung metastasis was significantly increased in cases with bilateral neck node metastases. Objective This study focused on the metastatic lymph node status of the lateral neck compartment to understand its prognostic significance for loco-regional recurrence and distant metastasis. Methods Between January 2004 and December 2009, 1040 patients were diagnosed with papillary thyroid cancer and underwent treatment. Results In a multivariate analysis, sex, the number of metastatic lymph nodes, and the lymph node ratio was significantly associated with loco-regional recurrence. The sensitivity/specificity of > 6 metastatic lymph nodes for predicting recurrence was 64.0%/69.7%. The 5-year loco-regional recurrence-free survival of patients with 0-6 metastatic lymph nodes and > 6 metastatic lymph nodes were 93.4% and 79.2%, respectively. The 5-year loco-regional recurrence-free survival of patients with a lymph node ratio ≤ 0.22 and a lymph node ratio > 0.22 were 97.1% and 78.8%, respectively. In the multivariate analysis, only bilateral neck node metastases were significantly associated with lung metastasis.

Association Between Genetic Polymorphisms in the Promoter Regions of Let-7 and Risk of Papillary Thyroid Carcinoma: A Case-Control Study

The aim of this study was to investigate the association between 2 polymorphisms (ie, rs10877887 and rs13293512) in the promoter regions of let-7 and the risk of papillary thyroid carcinoma (PTC).A case-control study of 618 PTC patients and 562 controls was conducted. The rs10877887 polymorphism was genotyped by using polymerase chain reaction-restriction fragment length polymorphism and the rs13293512 polymorphism was genotyped by using a TaqMan Genotyping Assay. The results were confirmed by DNA sequencing.The rs10877887 polymorphism had reduced risks of PTC in heterozygous comparison, dominant model, and overdominant model (TC vs TT: adjusted odds ratio [OR] = 0.73, 95% confidence interval [95% CI] = 0.58-0.94, P = 0.01; TC/CC vs TT: adjusted OR = 0.79, 95% CI = 0.63-1.00, P = 0.047; TC vs TT/CC: adjusted OR = 0.73, 95% CI = 0.57-0.92, P = 0.007, respectively). Stratified analyses showed that PTC patients carrying the rs10877887 CC genotype were more likely to have multiple tumors (adjusted OR = 1.71, 95% CI = 1.03-2.86, P = 0.04), and PTC patients carrying the rs13293512 TC + CC or CC were more likely to develop N0 status (TC/CC vs TT: adjusted OR = 0.64, 95% CI = 0.43-0.94, P = 0.02; CC vs

TC/TT

adjusted OR = 0.50, 95% CI = 0.33-0.77, P = 0.001, respectively).Our study suggests that the rs10877887 polymorphism may be associated with the risk of PTC and the rs13293512 polymorphism may correlate to lymph node metastasis in PTC.

Cervical lymph node metastasis in differentiated thyroid carcinoma: does it have an impact on disease-related morbid events?

PURPOSE

The aim of the study was to evaluate the prognostic impact of cervical lymph node (CLN) metastasis in well-differentiated thyroid cancer (WDTC).

PATIENTS AND METHODS

A cohort of 164 patients who underwent thyroidectomy for WDTC in the last 12 years was studied. Patients were classified into those with CLN metastasis (group 1) and those without (group 2), with 82 patients in each group. Morbid events (recurrence and death) and prognostic risk factors were analyzed.

RESULTS

The mean age of the whole group was 41.3±14.2 years, with 52.4% being at least 45 years old; 69.6% of the patients were female (P=0.02), with a female to male ratio of 2.3 : 1. Near-total thyroidectomy and radioactive iodine-131 therapy were performed in all 81.1% of patients in whom papillary cancer was found. Morbid events were found in 22/164 (13.4%) patients (17 recurrences and five deaths). All recurrences occurred in patients with the papillary subtype, whereas 4/5 deaths occurred in those with follicular thyroid cancer. Morbid events were found in 14/82 (17.1%) and 8/82 (9.6%) patients in group 1 and group 2, respectively (P=0.1). Comparison of morbid events between group 1 and group 2 showed statistically significant differences with respect to tumor size of 1 cm or more, multifocality, and positivity of the follow-up diagnostic tools at 6-12 months. Kaplan-Meier analysis revealed no significant difference between the two groups (P=0.4) over a mean follow-up period of 125.1±14.6 months. Multivariate Cox analysis showed that development of remote deposits, lymph node metastasis five or more nodes, extracapsular nodal invasion in at least three nodes, and positivity of the follow-up diagnostic tools at 6 months were the significant prognostic factors of morbid events.

CONCLUSION

Our study revealed the impact of CLN metastasis on the occurrence of morbid events in WDTC patients (especially in those with the papillary subtype) with node metastasis five or more, extracapsular nodal invasion in at least three nodes, and positivity of follow-up diagnostic tools at 6 months. Hence, these patients should be optimally managed and more closely monitored.

Surgical morbidity of cervical lymphadenectomy for thyroid cancer: A retrospective cohort study over 25 years

INTRODUCTION

Prognosis of thyroid cancer is strictly related to loco-regional metastases. Cervical lymphadenectomy has a specific oncologic role but may lead to significant increase of morbidity. Aim of the study is the analysis of surgical morbidity in cervical lymphadenectomy for thyroid cancer.

METHODS

We retrospectively analyzed 1.765 thyroid cancers operated over a period of 25 years at S. Maria University Hospital, Terni, University of Perugia, Italy. Type of lymphadenectomy, histology and complications were analysed.

RESULTS

A prevalence of differentiated and medullary cancers was observed (respectively 88% and 7.2%). Central lymphadenectomy was carried out in 425 patients, lateral modified and radical lymphadenectomy respectively in 651 and 17 cases. Following central neck dissection we observed: bilateral and unilateral temporary recurrent nerves palsy respectively of 0.7% and 3.5%, unilateral permanent palsy in 1.6% of cases, temporary and permanent hypoparathyroidism respectively in 17.6% and 4.4%. After lateral neck dissection we observed: intra and post-operative haemorrhage respectively in 2% and 0.29%, respiratory distress in 0.29%, lesions of facial nerve in 0.44%, of vagus in 0.14%, of phrenic nerve in 0.14%, of hypoglossal nerve in 0.29%, of the accessory nerve, transient in 1.34% and permanent in 0.29%, permanent lesion of cervical plexus in 0.29%, salivary fistula in 0.14% and chylous fistula in 1.04% of patients. Student's t test was used to compare groups when appliable.

CONCLUSION

Central and lateral cervical lymph node dissection are associated to severe morbidity. Correct indication, surgical expertise, high volume of patients and early multidisciplinary management of complications is the key of an acceptable balance between oncologic benefits and surgical morbidity.

Utility of sentinel lymph node biopsy for thyroid cancer: a comprehensive review

Sentinel lymph node biopsy (SLNB) is a minimally invasive lymphatic mapping technique, used to identify lymph node micrometastases and stage multiple cancer types. Despite the performance of SLNB for thyroid cancer having been under study since 1998, its role has remained controversial. The objective of this review is to summarize current research reporting on SLNB for thyroid cancer, focusing on recent studies of its application to differentiated thyroid cancer. The technique and potential benefits of SLNB are reviewed with regards to its ability to identify lymph node metastases, aid in cancer prognostication, and direct surgical and medical treatment.

Should central lymph node dissection be considered for all papillary thyroid microcarcinoma?

BACKGROUND

Central lymph node dissection (CLND) in patients with papillary thyroid microcarcinoma (PTMC) is still controversial. The aim of this study was to examine the risk factors and the incidence of central lymph node metastases (CLNMs) in patients with PTMC who underwent thyroidectomy and CLND.

PATIENTS AND METHODS

Between 2002 and 2013, 613 patients were enrolled who underwent thyroidectomy with routine CLND for PTMC at the Korea University Medical Center, Ansan Hospital and risk factors and the incidence of CLNM were analyzed. In addition, we also evaluated the complications after thyroidectomy with CLND.

RESULTS

Out of 613 patients, 239 (39.0%) were found to have CLNM. Male sex (p = 0.012), tumor size ≥ 0.5 cm (p = 0.001), capsular invasion or extrathyroidal extension (p = 0.029), and multifocality (p = 0.004) were independent risk factors for CLNM. Among the 69 patients who had PTMC without these risk factors, CLNM was identified in 12 (17.4%). In this study group, two (0.3%) had permanent recurrent laryngeal nerve injury, two (0.3%) had persistent hypocalcemia, and two (0.3%) developed postoperative hemorrhage.

CONCLUSION

CLNM in PTMC is highly prevalent in male sex, tumor size ≥ 0.5 cm, extrathyroidal extension, and multifocality. Even in PTMC patients without these risk factors, the incidence of CLNM is rather higher than expected, and the complication rate of thyroidectomy with CLND is acceptable. Thus, CLND should be considered in all patients with PTMC.

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.

Radio-guided selective compartment neck dissection improves staging in papillary thyroid carcinoma: a prospective study on 345 patients with a 3-year follow-up

BACKGROUND

Prospective uncontrolled study to investigate in papillary thyroid carcinoma (PTC) patients: (1) Distribution of lymph node metastases within the neck compartments, (2) factors predicting lymph nodes metastases, and (3) disease recurrence after thyroidectomy associated with radio-guided selective compartment neck dissection (RSCND).

METHODS

We studied 345 consecutive PTC patients operated on between February 2004 and October 2011 at the S. Anna University Hospital, Ferrara (Italy). Patients with cervical lymph node metastases on preoperative ultrasonography and fine needle aspiration cytology were excluded. All patients underwent total thyroidectomy associated with SLN identification followed by RSCND in the SLN compartment, without SLN frozen section.

RESULTS

In patients with lymph node metastases, metastatic nodes were not in the central neck compartment in 22.6% of the cases. The presence of infiltrating or multifocal PTC was a predicting factor for lymph nodes metastases. The median follow-up was 35.5 months. RSCND was associated with a false-negative rate of 1.1%, a persistent disease rate of 0.6%, and a recurrent disease rate of 0.9%. The permanent dysphonia rate was 1.3%.

CONCLUSION

RSCND associated with total thyroidectomy may improve: (1) the locoregional lymph node staging, and (2) the identification of the site of lymphatic drainage within the neck compartments. Thus, considering the high false-negative rate of sentinel lymph node biopsy (SLNB), a radio-guided technique in PTC patients may guide the lymphadenectomy (ie, RSCND) to increase the metastatic yield and improve staging of the disease rather than avoid prophylactic lymphadenectomy (ie, SLNB).

The effect of neck dissection on quality of life in patients with differentiated thyroid cancer

Cervical lymph node metastases are very common in patients with differentiated thyroid cancer (DTC). The overall long term survival rate in patients with DTC is higher than 90%, with variations in subsets of groups. Despite that DTC has an excellent prognosis, lymphatic spread is associated with increased risk of loco-regional recurrence, which significantly impairs quality-of-life (QOL) and can alter prognosis of the patient. As a result, a rapid shift in patient care from a focus on overall survival to a focus on recurrence-free survival has recently noted. The appropriate lymph node dissection is of great importance in order to achieve this goal. This surgical strategy will prevent disease recurrence, which may require an additional and more morbid surgery. Traditionally, the main outcome measure in oncology patients has been survival, based on tumor control, but recently it has been increasingly recognized that the diagnosis and management of cancer can have a major effect on every aspect of the QOL of a patient. The aims of cancer treatment became not only to increase survival but also to preserve QOL, and measuring these changes has been considered to be of paramount importance.

The effect of surgeon experience on the detection of metastatic lymph nodes in the central compartment and the pathologic features of clinically unapparent metastatic lymph nodes: what are we missing when we don't perform a prophylactic dissection of central compartment lymph nodes in papillary thyroid cancer?

BACKGROUND

Prophylactic central neck dissection (PCND) for papillary thyroid cancer (PTC) is controversial. Recent publications suggest that the number and size of nodes and the presence of extranodal extension (ENE) are important features for risk stratification of lymph node metastases. We analyzed these features in clinically unapparent nodes that would not otherwise be removed. We also investigated the impact of surgeon experience on the ability to detect metastatic lymph nodes intraoperatively.

METHODS

Forty-seven patients with well-differentiated PTC, with no preoperative evidence of central metastases, were included in this study. Intraoperatively, clinically apparent disease was determined by inspection and palpation by the senior surgeon and a fellow/senior resident, and recorded in a blinded fashion. Rate of occult metastases based on intraoperative evaluation were tabulated for each group of surgeons. Histopathologic features of occult nodes were analyzed to determine what clinicians would be missing by foregoing a PCND, and how that would have impacted the patient management.

RESULTS

The rate of occult metastases, based on senior surgeon assessment, was 26%, and did not differ significantly from fellow/senior resident assessment. The level of agreement between these two surgeon groups was moderate (k=0.665). Analysis of the false negative cases revealed that the size of the largest undetected node ranged from 0.1 to 1.3 cm; 36% of patients with occult metastases demonstrated five or more positive nodes, and 27% showed ENE.

DISCUSSION

Clinical assessment based on intraoperative inspection and palpation had poor sensitivity and specificity in identifying metastatic central nodes, regardless of the level of experience of the surgeon. There was moderate agreement between surgeons of different experience levels. Sensitivity improved significantly with larger size of positive nodes, but not with the presence of multiple positive nodes or presence of ENE. In foregoing PCND in this patient population, our results suggest that treating clinicians miss potentially virulent disease with a large number of occult positive central nodes and occult nodes with ENE. This is the first report to address the pathologic features of clinically nonevident central nodes showing a high incidence of clinically relevant, adverse histologic features, as well as the impact of surgeon experience in performing the important intraoperative determination of whether there are clinically evident nodes that require removal.