A prospective randomized controlled trial to assess the efficacy and safety of prophylactic central compartment lymph node dissection in papillary thyroid carcinoma

Risk factors of transient and permanent hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis

BACKGROUND

Postoperative hypoparathyroidism (hypoPT) is a common complication following thyroid surgery. However, current research findings on the risk factors for post-thyroid surgery hypoPT are not entirely consistent, and the same risk factors may have different impacts on transient and permanent hypoPT. Therefore, there is a need for a comprehensive study to summarize and explore the risk factors for both transient and permanent hypoPT after thyroid surgery.

MATERIALS AND METHODS

Two databases (PubMed and Embase) were searched from inception to 2024. The Newcastle-Ottawa Scale was used to rate study quality. Pooled odds ratios were used to calculate the relationship of each risk factor with transient and permanent hypoPT. Subgroup analyses were conducted for hypoPT with different definition-time (6 or 12 months). Publication bias was assessed using Begg's test and Egger's test.

RESULTS

A total of 19 risk factors from the 93 studies were included in the analysis. Among them, sex and parathyroid autotransplantation were the most frequently reported risk factors. Meta-analysis demonstrated that sex (female vs. male), cN stage, central neck dissection, lateral neck dissection, extent of central neck dissection (bilateral vs. unilateral), surgery [total thyroidectomy (TT) vs. lobectomy], surgery type (TT vs. sub-TT), incidental parathyroidectomy, and pathology (cancer vs. benign) were significantly associated with transient and permanent hypoPT. Preoperative calcium and parathyroid autotransplantation were only identified as risk factors for transient hypoPT, while preoperative PTH was a protective factor. Additionally, node metastasis and parathyroid in specimen were associated with permanent hypoPT.

CONCLUSION

The highest risk of hypoPT occurs in female thyroid cancer patients with lymph node metastasis undergoing TT combined with neck dissection. The key to preventing postoperative hypoPT lies in the selection of surgical approach and intraoperative protection.

Patterns of cervical lymph node involvement in mono-focal papillary thyroid carcinoma patients with different capsular status: A multi-center analysis

OBJECTIVE

The characteristics of cervical lymph node involvement in papillary thyroid carcinoma (PTC) patients with different degree of capsular invasion remains unclear, especially for those with mono-focal lesion who have traditionally been considered as low neck metastasis risk subgroup.

STUDY DESIGN

Retrospective cohort study.

SETTING

Three academic teaching hospital.

METHODS

A total of 1276 mono-focal PTC patients were retrospectively analyzed.

RESULTS

Mono-focal PTC patients with extrathyroidal extension (ETE) showed significantly higher central lymph node metastasis (CLNM) rate than those without. For patients with no gross ETE (gETE), those with minimal ETE (mETE) also showed more commonly CLNM than those with encapsulated lesions. However, the lateral lymph node metastasis (LLNM) rates of patients with mETE and encapsulated tumors were comparable, both lower than that of patients with gETE. Age ≥40, male, and MTD ≥0.5 cm were identified as independent risk factors of CLNM for those with encapsulated tumors and were enrolled for creating a prediction model. In terms of LLNM, only MTD ≥1.0 cm was confirmed as independent risk factors of LLNM for patients with positive gETE.

CONCLUSIONS

The presence and degree of ETE may have different effects on the risk of central and lateral lymph node metastasis. gETE demonstrates a strong correlation with both CLNM and LLNM while mETE is only associated with CLNM in mono-focal PTC patients. A comprehensive model is established in the aim of predicting neck involvement according to the capsular status and the corresponding stratified risk factors, which may aid clinical decision-making for the management of neck regions.

Disease-free survival and response to therapy of clinically node- negative Papillary Thyroid Cancer treated without central neck dissection: Retrospective study of 321 patients

BACKGROUND AND OBJECTIVE

Nodal metastases in the central compartment are frequent in papillary thyroid cancer (PTC). However, they are mostly micrometastases with no impact on survival and their relevance on the risk of locoregional relapse is controversial. There is no consensus regarding optimal management of the central neck in patients with PTC cN0. In our center, we do not perform prophylactic central neck dissection (pCND). The objective of this study is to review our long-term results and compare them with the most recent literature.

PATIENTS AND METHODS

Retrospective review of patients with PTC who underwent total thyroidectomy (TT) without CND between 2005 and 2017. Primary result was disease-free survival in the neck (DFS).

RESULTS

321 patients were identified, mostly T1-T2 tumors (94.1%). Median follow-up was 90 months. DFS in the central compartment was excellent (96.1% at 10 year's follow-up). 19 patients had cervical recurrence, of which 15 underwent salvage surgery. On their last visit, including salvage surgery when appropriate, 77% of patients had excellent response, 18.7% had indeterminate response, 3.1% had biochemically incomplete response and 1.2% had morphologically incomplete response. Recurrent laryngeal nerve (RLN) paralysis after TT was transient in 4.7% of patients and permanent in 0.9% of patients. There were no RLN paralysis after salvage surgery. Permanent hypoparathyroidism occurred in 3.4% of patients. Only one patient had hypoparathyroidism after salvage surgery and it was permanent.

CONCLUSIONS

Based on long-term results and low rate of complications associated with salvage surgery in our experience, we consider routine pCND is not justified.

Impact of age on central lymph nodes involvement in papillary thyroid cancer

BACKGROUND

Total thyroidectomy is the main line of treatment for papillary thyroid cancer. Central lymph node dissection (CLND) is still debatable. In this study, we aimed to correlate the central lymph node status with the age of patients.

METHODS

This is a retrospective study including patients with papillary thyroid cancer (PTC) who underwent total thyroidectomy and CLND at a tertiary cancer center during the period from January 2012 to September 2022. Patients were subdivided into 3groups: patients younger than 20 years old, patients between 20 and 40 years old, and patients older than 40 years old. Correlation between central lymph node status, lateral lymph node status, and harvest count with each other and between age groups was done.

RESULTS

315 patients were included. The younger the age group the higher the possibility of harboring positive central nodes, however, the positivity of lateral nodes was similar. Neither central nodal harvest nor positive central node count significantly differed between groups. The lateral nodal harvest was significantly higher in the < 20 years group with no affection to the number of positive nodes retrieved. The younger the age group the longer the disease-free survival (DFS).

CONCLUSION

We can conclude that patients younger than twenty years had a higher probability of harboring malignancy in central nodes and higher lateral node harvest on dissection. In contrast, they do have a lower incidence of recurrence.

Long-term impact of prophylactic central neck dissection in non-invasive classic papillary thyroid carcinoma

BACKGROUND

The utilization of prophylactic central neck dissection (pCND) in cases of non-invasive clinical node-negative (cN0) papillary thyroid carcinoma (PTC) remains a topic of debate, with a dearth of long-term evidence.

MATERIALS AND METHODS

We retrospectively reviewed 1181 cN0 PTC patients from 1997 to 2011. Of these, 641 underwent pCND (pCND + group) and 540 did not (pCND-group). Propensity score matching (PSM) was used to identify similar patients. Event-free survival and long-term complications including permanent hyperparathyroidism and permanent recurrent laryngeal nerve (RLN) paralysis were analyzed after PSM.

RESULTS

The pCND + group had more aggressive characteristics. In the matched cohort after PSM, the 5-year, 10-year, and 15-year EFS rates were 98.9 %, 98.2 %, and 97.1 % for the pCND + group, and 97.7 %, 97.1 %, and 97.1 % for the pCND-group, respectively. There was no statistically significant difference in EFS rates between the two groups (Log Rank P = 0.38). There was no statistically significant difference in the incidence of permanent hyperparathyroidism (3.3 % vs. 1.5 %, P = 0.08) and permanent RLN paralysis (1.7 % vs. 0.9 %, P = 0.13) between the pCND+ and pCND- groups.

CONCLUSION

Our study, with a median follow-up duration of 107 months, indicates that pCND does not lead to a significant reduction in nodal recurrence among non-invasive cN0 PTC patients.

Nomogram to predict the risk of biochemical recurrence and structural recurrence in patients with stage cN1 papillary thyroid carcinoma

INTRODUCTION

Although papillary thyroid carcinoma (PTC) is thought to be the least aggressive thyroid cancer, it has a significant recurrence rate. Therefore, we aimed to develop a nomogram to estimate the probability of biochemical recurrence (BIR) and structural recurrence (STR) in patients with stage cN1 PTC.

METHODS

We studied the relationship between the characteristics of patients with stage N1a PTC and the risk of recurrence by analysing the data of 617 inpatients (training cohort) and 102 outpatients (validation cohort) in our hospital. We used the least absolute shrinkage and selection operator regression model to identify prognostic indicators to construct nomograms to predict the risk of BIR and STR.

RESULTS

There were 94 (15.24%) BIR cases in the training cohort and 36 (35.29%) in the validation cohort. There were 31 (5.02%) STR cases in the training cohort and 23 (22.55%) cases in the validation cohort. The variables included in the BIR nomogram were sex, age at diagnosis, tumour size, extrathyroidal infiltration, and lymph node ratio (LNR). While the variables included in the STR nomogram were tumour size, extrathyroidal infiltration, BRAF state, metastatic lymph nodes, and LNR. Both the prediction models demonstrated good discrimination ability. The results showed the calibration curve of the nomogram was near the optimum diagonal line, and the decision curve analysis showed a noticeably better benefit.

CONCLUSION

The LNR may be a valid prognostic indicator for patients with stage cN1 PTC. The nomograms could help clinicians identify high-risk patients and choose the best postsurgical therapy and monitoring.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Sentinel node mapping in thyroid cancer: an overview

In this paper we describe the current status of sentinel node mapping (SNM) in thyroid tumors and its potential perspectives. SNM in thyroid cancer has been tested since the end of the twentieth century, mainly in papillary thyroid cancer (PTC) and in medullary thyroid cancer (MTC). In PTC, it has been employed to find occult lymph node metastases in the central compartment of the neck as an alternative or indication for prophylactic dissection, by several methods. All of them have proven effective in spotting sentinel nodes, but the results have been somewhat diminished by uncertainty about the clinical significance of occult metastases in differentiated thyroid cancer. SNM in MTC has also been used to find occult lymph node metastases in the lateral compartments of the neck, also with excellent results hindered by a similar doubt about the real clinical significance of MTC micrometastases. Well designed, adequately sized randomized controlled trials are lacking, so SNM in thyroid tumors remains an interesting yet experimental methodology. New technology is emerging that could facilitate such studies, which could add solid information about the clinical significance of occult neck metastases in thyroid cancer.

Scope of prophylactic lymph node dissection in the surgical treatment of differentiated thyroid cancer. Recommendations of the AFCE (Association francophone de chirurgie endocrinienne) with the SFE (Société française d'endocrinologie) and the SFMN (Société française de médecine nucléaire)

Prophylactic lymph node dissection is considered only for papillary cancers. It is not indicated for vesicular cancers or oncocytic cancers, nor should it entail a secondary surgical intervention in the event of an incidental discovery of papillary cancer on a thyroidectomy specimen. Prophylactic lymph node dissection means a cervical lymph node dissection in the absence of any pre- or intraoperative evidence (biological, cytological, histological, clinical or ultrasound) of lymph node metastases. There is currently no evidence in the literature that prophylactic central dissection improves overall survival, which is similar for N0 and NX patients. Yet although prophylactic lymph node dissection is not justified by overall survival, it does seem to reduce the risk of locoregional recurrence in the case of micro-N1, and it allows occult metastases to be detected and a tumour to be reclassified. This enables patients at risk of recurrence to be more surely identified and therapeutic strategy and follow-up adapted accordingly. Prophylactic homolateral central lymph node dissection is warranted for papillary cancers with largest ultrasound diameter 4cm and above and/or with intraoperative macroscopic evidence of perithyroid tissue invasion. The benefits and risks of lymph node dissection must be assessed and discussed on a case-by-case basis. Only a central lymph node dissection homolateral to the tumour is recommended, except for bilateral or isthmic cancers, for which a prophylactic bilateral central lymph node dissection may be considered. This bilateral lymph node dissection incurs an increased risk of complications (parathyroids, recurrent laryngeal nerve). Prophylactic lateral lymph node dissection is not recommended.

ESTIMation of the ABiLity of prophylactic central compartment neck dissection to modify outcomes in low-risk differentiated thyroid cancer: a prospective randomized trial

BACKGROUND

Prophylactic central neck dissection in clinically low-risk cT1bT2N0 papillary thyroid carcinoma is controversial, due to a large number of conflicting retrospective studies, some showing an advantage in terms of locoregional recurrence, others showing no advantage. These previous studies all show high rates of excellent response. We aim to demonstrate the non-inferiority of thyroidectomy alone as compared to total thyroidectomy with prophylactic central neck dissection in conjunction with adjuvant RAI 30 mCi with rTSH stimulation in terms of excellent response at 1 year.

TRIAL DESIGN AND METHODS

Prospective randomized open multicenter phase III trial including patients with 11-40-mm papillary thyroid carcinoma (Bethesda VI) or suspicious cytology (Bethesda V) confirmed malignant on intra-operative frozen section analysis, with no suspicious lymph nodes on a specialized preoperative ultrasound examination. Patients will be randomized 1:1 into two groups: the reference group total thyroidectomy with bilateral prophylactic central neck dissection, and the comparator group total thyroidectomy alone. All patients will receive an ablative dose of 30mCi of radioactive iodine (RAI) within 4 months of surgery. The primary outcome is to compare the rate of excellent response at 1 year after surgery between the groups, as defined by an unstimulated serum thyroglobulin (Tg) level ≤ 0.2 ng/mL with no anti-Tg antibodies, an normal neck ultrasound and no ectopic uptake on the post-RAI scintiscan. Non-inferiority will be demonstrated if the rate of patients with excellent response at 1 year after randomization does not differ by more than 5%. Setting the significance level at 0.025 (one-sided) and a power of 80% requires a sample size of 598 patients (299 per group). Secondary outcomes are to compare Tg levels at 8 +/- 2 postoperative weeks, before RAI ablation, the rate of excellent response at 3 and 5 years, the rate of other responses at 1, 3, and 5 years (biochemical incomplete, indeterminate, and structurally incomplete responses), complications, quality of life, and cost-utility.

DISCUSSION (POTENTIAL IMPLICATIONS)

If non-inferiority is demonstrated with this high-level evidence, prophylactic neck dissection will have been shown to not be necessary in clinically low-risk papillary thyroid carcinoma.

TRIAL REGISTRATION

NCT03570021. June 26,2018.

Central node dissection in papillary thyroid carcinoma in the era of near-infrared fluorescence

The most common site of lymph node metastases in papillary thyroid carcinoma is the central compartment of the neck (level VI). In many patients, nodal metastases in this area are not clinically apparent, neither on preoperative imaging nor during surgery. Prophylactic surgical clearance of the level VI in the absence of clinically suspicious lymph nodes (cN0) is still under debate. It has been suggested to reduce local recurrence and improve disease-specific survival. Moreover, it helps to accurately diagnose the lymph node involvement and provides important staging information useful for tailoring of the radioactive iodine regimen and estimating the risk of recurrence. Yet, many studies have shown no benefit to the long-term outcome. Arguments against the prophylactic central lymph node dissection (CLND) cite minimal oncologic benefit and concomitant higher operative morbidity, with hypoparathyroidism being the most common complication. Recently, near-infrared fluorescence imaging has emerged as a novel tool to identify and preserve parathyroid glands during thyroid surgery. We provide an overview of the current scientific landscape of fluorescence imaging in thyroid surgery, of the controversies around the prophylactic CLND, and of fluorescence imaging applications in CLND. To date, only three studies evaluated fluorescence imaging in patients undergoing thyroidectomy and prophylactic or therapeutic CLND for thyroid cancer. The results suggest that fluorescence imaging has the potential to minimise the risk of hypoparathyroidism associated with CLND, while allowing to exploit all its potential benefits. With further development, fluorescence imaging techniques might shift the paradigm to recommend more frequently prophylactic CLND.

A Nod to the Nodes: An Overview of the Role of Central Neck Dissection in the Management of Papillary Thyroid Carcinoma

Lymph node metastasis in thyroid cancer is common and associated with an increased risk of locoregional recurrence (LRR). Although therapeutic central neck dissection is well established, prophylactic central node dissection (pCND) for microscopic occult nodal involvement is controversial and recommendations are based on low-level evidence. The potential benefits of pCND such as reducing LRR and re-operation, refining staging, and improving surveillance are enthusiastically debated and the decision to perform pCND must be weighed up against the increased risks of complications.

An integrated nomogram combining deep learning, clinical characteristics and ultrasound features for predicting central lymph node metastasis in papillary thyroid cancer: A multicenter study

OBJECTIVE

Central lymph node metastasis (CLNM) is a predictor of poor prognosis for papillary thyroid carcinoma (PTC) patients. The options for surgeon operation or follow-up depend on the state of CLNM while accurate prediction is a challenge for radiologists. The present study aimed to develop and validate an effective preoperative nomogram combining deep learning, clinical characteristics and ultrasound features for predicting CLNM.

MATERIALS AND METHODS

In this study, 3359 PTC patients who had undergone total thyroidectomy or thyroid lobectomy from two medical centers were enrolled. The patients were divided into three datasets for training, internal validation and external validation. We constructed an integrated nomogram combining deep learning, clinical characteristics and ultrasound features using multivariable logistic regression to predict CLNM in PTC patients.

RESULTS

Multivariate analysis indicated that the AI model-predicted value, multiple, position, microcalcification, abutment/perimeter ratio and US-reported LN status were independent risk factors predicting CLNM. The area under the curve (AUC) for the nomogram to predict CLNM was 0.812 (95% CI, 0.794-0.830) in the training cohort, 0.809 (95% CI, 0.780-0.837) in the internal validation cohort and 0.829(95%CI, 0.785-0.872) in the external validation cohort. Based on the analysis of the decision curve, our integrated nomogram was superior to other models in terms of clinical predictive ability.

CONCLUSION

Our proposed thyroid cancer lymph node metastasis nomogram shows favorable predictive value to assist surgeons in making appropriate surgical decisions in PTC treatment.

Advances in Endocrine Surgery

Recent changes in the landscape of endocrine surgery include a shift from total thyroidectomy for almost all patients with papillary thyroid cancer to the incorporation of thyroid lobectomy for well-selected patients with low-risk disease; minimally invasive parathyroidectomy with, and potentially without, intraoperative parathyroid hormone monitoring for patients with well-localized primary hyperparathyroidism; improvement in the management of parathyroid cancer with the incorporation of immune checkpoint blockade and/or targeted therapies; and the incorporation of minimally invasive techniques in the management of patients with benign tumors and selected secondary malignancies of the adrenal gland.

Advancements in Thyroidectomy: A Mini Review

Demand for minimally invasive surgery has driven the development of new gadgets and surgical techniques. Yet, questions about safety and skeptical views on new technology have prevented proliferation of new modes of surgery. This skepticism is perhaps due to unfamiliarity of new fields. Likewise, there are currently various remote-access techniques available for thyroid surgeons that only few regions in the world have adapted. This review will explore the history of minimally invasive techniques in thyroid surgery and introduce new technology to be implemented.

Is thyroglobulin detection in fine-needle aspirates useful for the diagnosis of central neck metastatic papillary thyroid cancer?

Objective

The central neck lymph node (LN) status is important for the treatment strategy of papillary thyroid cancer (PTC), while the diagnosis is difficult. This study aims to evaluate the diagnostic value of fine-needle aspiration (FNA) and its washout thyroglobulin (FNA-Tg) detection in central neck LN metastasis.

Methods

Central neck LNs with FNA cytology (FNA-C) and FNA-Tg measurements from a tertiary hospital were included. Tg levels were correlated with histopathological or follow-up results. The diagnostic performance of FNA-C, FNA-Tg, and combining FNA-C and FNA-Tg for detecting LN metastasis was assessed.

Results

A total of 132 LNs in the central neck from 129 patients were studied. The median FNA-Tg concentration of 74 metastatic LNs was 552.5 ng/mL, whereas, in 58 benign LNs, the median Tg concentration was 0.1 ng/mL (P < 0.001). Receiver operating characteristic analysis (area under the curve, 0.861) was used, and a cutoff value of 14.6 ng/mL was obtained. There was no significant increase in the diagnostic accuracy when FNA-Tg was used or combined with FNA-C, compared with FNA-C alone. The size, location of LNs, the presence of the ipsilateral thyroid gland, and Hashimoto's thyroiditis did not affect the incidence of misdiagnosis.

Conclusions

FNA-C is the gold standard for evaluating central neck metastasis in PTC patients. Measurement of Tg levels in FNA washout does not improve the diagnostic accuracy any further.

Impact of Lymph Node Dissection on Postoperative Complications of Total Thyroidectomy in Patients with Thyroid Carcinoma

Background: Lymph node dissection (LND) in primary treatment of differentiated thyroid carcinoma is controversial. The aim of our retrospective study was to analyse the risk factors of post-thyroidectomy complications and to assess the morbidity of lymph node dissection, especially in the central neck compartment, since prophylactic central lymph node dissection has not been proven to bring an overall survival benefit. Methods: We performed a retrospective analysis of postoperative complications from 1547 consecutive patients with differentiated thyroid carcinoma in an academic department of endocrine surgery over a period of 10 years. Results: A total of 535 patients underwent lymph node dissection, whereas the other 1012 did not. The rate of postoperative hypoparathyroidism was higher in patients with LND (17.6% vs. 11.4%, p = 0.001). No significant difference in the rate of permanent hypoparathyroidism (2.4% vs. 1.3%, p = 0.096) was observed between these two groups. A multivariate analysis was performed. Female gender, ipsilateral and bilateral central LND (CLND), parathyroid autotransplantation, and the presence of the parathyroid gland on the resected thyroid were associated with transient hypoparathyroidism. Bilateral CLND and the presence of the parathyroid gland on specimen were associated with permanent hypoparathyroidism. The rate of transient recurrent laryngeal nerve (RLN) injury (15.3% vs. 5.4%, p < 0.001) and permanent RLN injury (6.5% vs. 0.9%, p < 0.001) were higher in the LND group. In multivariate analysis, ipsilateral and bilateral lateral LND (LLND) were the main predictive factors of transient and permanent RLN injury. Bilateral RLN injury (2.6% vs. 0.4%, p < 0.001), chyle leakage (2.4% vs. 0%, p < 0.001), other nerve injuries (2.2% vs. 0%, p < 0.001), and abscess (2.4% vs. 0.5%, p = 0.001) were higher in the patients with LND. Conclusions: The surgical technique and the extent of lymph node dissection during surgery for thyroid carcinoma increase postoperative morbidity. A wider knowledge of lymph-node-dissection-related complications associated with thyroid surgery could help surgeons to carefully evaluate the surgical and medical therapeutic options.

Evaluate the immune-related eRNA models and signature score to predict the response to immunotherapy in thyroid carcinoma

BACKGROUND

The functional alterations of eRNAs have been reported to be correlated with tumorigenesis. However, the roles of eRNAs in thyroid cancer (THCA) remain still unclear. This study aimed to construct an immune-related eRNA prognostic signature that could effectively predict the survival and prognosis for THCA.

METHODS

The Weighted Gene Co-Expression Network Analysis (WGCNA) was performed to identify THCA-specific immune-related hub genes and immune-related eRNAs were obtained using Pearson correlation analysis. Univariate and least absolute shrinkage and selection operator (LASSO) Cox regression were conducted to construct an immune-related eRNA prognostic signature in training cohort, and the predictive capability was verified in test cohort and entire cohort. Kaplan-Meier analysis, principal component analysis (PCA), receiver operating characteristic (ROC) curves, and nomogram were used to validate the risk signature. Furthermore, CIBERSORT, ESTIMATE and ssGSEA were analyzed to explore the tumor immune microenvironment (TIME) of the risk signature, and the response of potential immunotherapeutic were also discussed.

RESULTS

A total of 125 immune-related eRNAs were obtained and 16 immune-related eRNAs were significantly correlated with overall survival (OS). A 9-immune-related eRNA prognostic signature was constructed, and the risk score was identified as an independent predictor. High-risk groups were associated with a poorer OS. Immune microenvironment analysis indicated that low risk score was correlated with higher immuneScore, high immune cell infiltration, and the better response of immunotherapy. Additionally, we also detected 9 immune-related eRNA expression levels in sixty-two matched tumorous and non-tumorous tissues using qRT-PCR analysis.

CONCLUSION

Our immune-related eRNA risk signature that was an independent prognostic factor was strongly correlated with the immune microenvironment and may be promising for the clinical prediction of prognosis and immunotherapeutic responses in THCA patients.

Effect of a Polyglycolic Acid Mesh Sheet (Neoveil™) in Thyroid Cancer Surgery: A Prospective Randomized Controlled Trial

Simple Summary

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Surgery for PTC involves resection of the thyroid gland and lymph node dissection around thyroid. Lymph node dissection is associated with an increased amount of fluid from the dissection area and chyle leakage due to thoracic duct injury. A polyglycolic acid mesh sheet (Neoveil™) has been proven to prevent postoperative fluid leakage in other surgeries. So, we aim to evaluate whether Neoveil™ can reduce postoperative drainage and chyle leakage in surgery for PTC. With the use of Neoveil™, the amount of drainage significantly decreased on the postoperative 2nd day and postoperative total drainage amount was lower. Triglyceride level was lower in the Neoveil™ group but was not statistically significant. No adverse effect from the Neoveil™ was observed during 9 months follow up. Our study suggests that Neoveil™ can be applied to reduce postoperative drainage in thyroid surgery for PTC.

Abstract

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Surgery for PTC involves resection of the thyroid gland and central lymph node dissection. Central lymph node dissection is associated with an increased amount of fluid from the dissection area and chyle leakage due to thoracic duct injury. There are few studies that deal with reducing fluid drainage and preventing chyle leakage after thyroid surgery with central lymph node dissection. A polyglycolic acid mesh sheet (Neoveil™) has been demonstrated to prevent postoperative fluid leakage in other surgeries. This study aims to evaluate whether a polyglycolic acid mesh sheet can reduce postoperative drainage and chyle leakage in papillary thyroid cancer surgery, and this study was designed as a prospective, open-label, randomized controlled trial in a single university hospital. The patients were randomly assigned to having only fibrin glue used in the central node dissection area (control group) or to having a polyglycolic acid mesh sheet applied after fibrin glue (treatment group). A total of 330 patients were enrolled, of which 5 patients were excluded. A total of 161 patients were included in the treatment group, and 164 patients were included in the control group. The primary outcome was the drainage amount from the Jackson-Pratt drain, and the secondary outcome was the triglyceride level in the drained fluid on the 1st and 2nd postoperative days. The drainage amount was significantly lower in the treatment group on the 2nd postoperative day (60.9 ± 34.9 mL vs. 72.3 ± 38.0 mL, p = 0.005). The sum of drainage amount during the whole postoperative days (1st and 2nd days) was also significantly lower in the treatment group (142.7 ± 71.0 mL vs. 162.5 ± 71.5 mL, p = 0.013). The postoperative triglyceride levels were lower in the treatment group but were not statistically significant (92.1 ± 60.1 mg/dL vs. 81.3 ± 58.7 mg/dL on postoperative day 1, p = 0.104 and 67.6 ± 99.2 mg/dL vs. 53.6 ± 80.4 mg/dL on postoperative day 2, p = 0.162). No adverse effects were observed in the treatment groups during the postoperative 9-month follow-up. Our study suggests that polyglycolic acid mesh sheets can be safely applied to reduce postoperative drainage amount in thyroidectomy patients who need lymph node dissection.

A Narrative Review of Preventive Central Lymph Node Dissection in Patients With Papillary Thyroid Cancer - A Necessity or an Excess

Objective

This review article summarises the latest evidence for preventive central lymph node dissection in patients with papillary thyroid cancer taking into account the possible complications and risk of recurrence.

Background

Papillary thyroid cancer is the most frequent histological variant of malignant neoplasms of the thyroid gland. It accounts for about 80-85% of all cases of thyroid cancer. Despite good postoperative results and an excellent survival rate in comparison with many other malignant diseases, tumor metastases to the cervical lymph nodes are frequent. Most researchers agree that the presence of obvious metastases in the lymph nodes requires careful lymph node dissection. It was suggested to perform preventive routine lymphadenectomy in all patients with malignant thyroid diseases referred to surgery.

Methods

It was performed the literature review using the “papillary thyroid cancer”, “central lymph node dissection”, “hypocalcemia”, “recurrent laryngeal nerve paresis”, “metastasis”, “cancer recurrence” along with the MESH terms. The reference list of the articles was carefully reviewed as a potential source of information. The search was based on Medline, Scopus, Google Scholar, eLibrary engines. Selected publications were analyzed and their synthesis was used to write the review and analyse the role of preventive central lymph node dissection in patients with papillary thyroid cancer.

Conclusions

The necessity of preventive central lymph node dissection in patients with differentiated papillary thyroid carcinoma is still controversial. There is much evidence that it increases the frequency of transient hypocalcemia. Due to the fact that this complication is temporary, its significance in clinical practice is debatable. It can also be assumed that an extant of surgery in the neck area is associated with an increased risk of recurrent laryngeal nerve injury. However, most studies indicate that this injury is associated more with thyroidectomy itself than with lymph node dissection. Recurrent laryngeal nerve dysfunction is also a temporary complication in the vast majority of cases. At the same time, a large amount of data shows that central lymph node dissection reduces the risk of thyroid cancer recurrence in two times.

Real-World Evidence on the Sensitivity of Preoperative Ultrasound in Evaluating Central Lymph Node Metastasis of Papillary Thyroid Carcinoma

INTRODUCTION

Guidelines for prophylactic dissection in clinical central negative node (cN0) of papillary thyroid carcinoma vary among different countries due to the uncertainty on the benefit of dissection. The Chinese guidelines recommend prophylactic central compartment lymph node dissection (pCLND) under professional technology. Preoperative ultrasound (US) evaluation of central lymph node determines the surgical strategy used. Sensitivity differs significantly when US is conducted by different physicians even in diverse hospitals. In this study, the aim was to explore why the Chinese guidelines were different from the America Thyroid Association (ATA) guidelines through the real-world evidence on the preoperative diagnosis of cN0.

METHODS

Preoperative US and surgical pathology data for 1,015 patients with PTC attending 13 Grade-A tertiary hospitals in 2017 were collected. A retrospective analysis using US assessment of CLNM was the conducted to explore the benefits of this approach in China. US physicians in our hospital were trained on scanning the thyroid gland and its regional lymph nodes in normalization. Data of 1,776 patients were collected under the same condition from 2012 to 2017, whose ultrasonography was performed by diverse physicians and doctors. Further, data of 339 patients evaluated by the same sonographer and operated by the same surgical team was collected between 2015 and 2017. In this set of data, US combined CT versus US alone was compared. Patients were grouped into metastasis group and non-metastasis group based on postoperative pathological diagnosis of CLNM. Diagnostic efficacy of US was evaluated.

RESULTS

A total of 925 patients who underwent preoperative ultrasonography in central lymph node, including 825 cases who underwent thyroidectomy and central lymph node dissection were included in this study. The sensitivity of ultrasonography in detecting CLNM was 23.18%, with occult metastasis rate of 40.8%. Data for 1,776 patients comprising paired ultrasonic report and pathological report were collected in our hospital, whose physicians underwent standardized training. The sensitivity was 37.58%. Furthermore, specialized evaluation showed high sensitivity in US/CT (84.58%) than US (58.21%) alone.

CONCLUSION

Although the sensitivity of US could be enhanced by standardized training and combination with CT, the prevalence of low sensitivity of US in real-world multicenter data and the high occult metastasis rate indicated that the Chinese guidelines were based on the current conditions.

Ultrasonic Characteristics Improve Prediction of Central Lymph Node Metastasis in cN0 Unifocal Papillary Thyroid Cancer

BACKGROUND

Prediction of central lymph node metastasis (CLNM) is vital for clinical decision-making processes in clinically N0 (cN0) unifocal papillary thyroid carcinoma (PTC), but the sensitivity of preoperative detection of CLNM is limited. The aim of the present study was to determine whether there are ultrasonic (US) characteristics associated with CLNM.

METHODS

In total, 1657 PTC patients (514 men and 1143 women) were enrolled in the present study between January 2018 and May 2021. The patients met the following inclusion criteria based on preoperative detection: suspected nodule confirmed as PTC by biopsy; the nodule was unifocal and less than 4 cm in diameter; no prior neck radiation exposure; no extrathyroidal extension; and no CLNM or distant metastases on imaging. All the enrolled patients underwent total thyroidectomy with prophylactic central lymph node dissection (CLND). A postoperative pathological diagnosis was made.

RESULTS

CLNM was found in 58.4% of male patients and 36.9% of female patients. In univariate analysis, size, adjacent anterior capsule, distance to the lower pole and color Doppler flow imaging (CDFI) were considered risk factors for the male and female groups (p < 0.05). In multivariate analyses, size, adjacent anterior capsule, distance to the lower pole and CDFI were independent risk factors for male patients. For females, the independent risk factors included size, adjacent anterior capsule, distance to the lower pole and CDFI.

CONCLUSION

In the present cohort, US imaging characteristics, including size, adjacent anterior capsule, distance to the lower pole and CDFI, were identified to be potentially beneficial in preoperative clinical decision-making processes for cN0 unifocal PTC patients.

Lymph Node Dissection for Papillary Thyroid Carcinoma

Cervical lymph node metastasis is frequent in patients with papillary thyroid carcinoma. In addition to the extent of thyroidectomy, the need as well as the extent of concomitant lymphadenectomy has been a subject of controversy and debate. The central compartment is the most frequent site of metastasis followed by the lateral compartment although skip metastasis in the lateral compartment can occur. Papillary thyroid carcinoma can also present with cervical lymph node metastasis, while the primary tumor remains clinically undetectable. Surgical removal of clinically involved nodal metastasis should be mandatory to prevent recurrence and improve disease prognosis. However, despite a low accuracy of preoperative imaging for microscopic disease and the frequent microscopic metastasis to the central compartment, routine prophylactic neck dissection has not been shown to have any relevance to prevent recurrence or improve disease cure. Routine or prophylactic central compartment dissection is generally not recommended unless in the presence of high-risk tumors. The potential benefit of reducing central compartment recurrence or avoiding high-risk reoperation probably outweighs the risk of inducing surgical complication including hypoparathyroidism during routine central neck dissection. Therapeutic lateral neck dissection is performed for clinically involved nodes detected by preoperative imaging confirmed by needle biopsy, while prophylactic lateral neck dissection is contraindicated. The extent of neck dissection has been de-escalated, and compartmental nodal dissection aiming at preservation of function is performed to achieve a complete surgical resection. Postoperative adjuvant radioiodine is frequently administered for patients with positive nodal metastasis (intermediate-risk group) to avoid future recurrence. Routine central neck dissection may also upstage patients with microscopic nodal metastases and increase the use of postoperative adjuvant radioiodine.

The effectiveness and safety of prophylactic central neck dissection in clinically node-negative papillary thyroid carcinoma patients: A meta-analysis

OBJECTIVE

This meta-analysis was performed to evaluate the effectiveness and safety of prophylactic central neck dissection (PCND) in patients with clinically node-negative (cN0) papillary thyroid carcinoma.

MATERIALS AND METHODS

A meta-analysis of the literature was performed using the key words "papillary thyroid carcinomas" and "lymph node ecisions" for searches of electronic databases. Complications such as transient hypocalcemia, permanent hypocalcemia, transient and permanent hypoparathyroidism, transient and permanent vocal cord paralysis, transient recurrent and permanent recurrent laryngeal nerve injury, and local recurrence were pooled by meta-analysis. Stata17.0 was used to carry out the meta-analysis.

RESULTS

Data were extracted from 15 studies. In the present review, the group of patients who had total thyroidectomy (TT) with PCND had a lower local recurrence than the group with TT alone (OR 0.22, 95% CI 0.10-0.45, P = 0.000), whereas the incidence of permanent hypocalcemia (OR 4.24, 95% CI 1.05-17.22, P = 0.043) and transient hypoparathyroidism (OR 2.14, 95% CI 1.34-3.42, P =0.001) were higher. No significant differences were recorded in the incidence of other complications: transient hypocalcemia (OR 2.24, 95% CI 0.77-6.51, P = 0.138), permanent hypoparathyroidism (OR 1.70, 95% CI 0.89-3.27, P = 0.111), transient vocal cord paralysis (OR 1.48, 95% CI 0.78-2.83, P = 0.231), permanent vocal cord paralysis (OR 1.44, 95% CI 0.53-3.94, P = 0.477), transient recurrent laryngeal nerve injury (OR 1.47, 95% CI 0.93-2.32, P = 0.102) and permanent recurrent laryngeal nerve injury (OR 1.24, 95% CI 0.56-2.74, P = 0.587) between the two groups.

CONCLUSION

Compared with TT alone, TT with PCND was more effective in reducing local recurrence without increasing the risk of recurrent laryngeal nerve, thyroid and vocal cord, except for hypocalcemia and transient hypoparathyroidism. Therefore, we believe that TT with PCND should be recommended for patients with cN0 PTC.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD4202 2355078.

Prophylactic Central Neck Dissection for Clinically Node-Negative Papillary Thyroid Carcinoma

OBJECTIVE

We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) that scrutinized the oncological benefits and postsurgical complications of total thyroidectomy (TT) plus prophylactic central neck dissection (pCND) versus TT alone among clinically node-negative (cN0) papillary thyroid cancer (PTC) patients.

METHODS

We screened five databases from inception to September 4, 2021 and evaluated the risk of bias of the eligible studies. We pooled dichotomous outcomes using the risk ratio (RR) with 95% confidence interval (CI).

RESULTS

Overall, we included 5 RCTs with low risk of bias comprising 795 patients (TT plus pCND = 410 and TT alone = 385). With regard to efficacy endpoint, the rate of structural loco-regional recurrence did not significantly differ between both groups (n = 4 RCTs, RR = 0.49, 95% CI [0.19, 1.27], P = .14). With regard to safety endpoints, the rates of hypoparathyroidism (n = 5 RCTs, RR = 1.48, 95% CI [0.73, 2.97], P = .27), recurrent laryngeal nerve injury (n = 5 RCTs, RR = 1.34, 95% CI [0.59, 3.03], P = .48), and bleeding (n = 3 RCTs, RR = 1.75, 95% CI [0.42, 7.26], P = .44) did not significantly differ between both groups.

CONCLUSION

For cN0 PTC patients, there was no significant difference between TT plus pCND and TT alone with regard to the rate of structural loco-regional recurrence or frequency of postsurgical complications. Adaptation of pCND in cN0 PTC patients should be contemplated by taking into consideration the clinical oncological benefits and rate of postsurgical adverse events.

LEVEL OF EVIDENCE

1 Laryngoscope, 2021.