Central lymph node dissection in patients with papillary thyroid cancer: a population level analysis of 14,257 cases

Design and implementation of a national quality registry of thyroid cancer in Iran: study protocol

Purpose

Thyroid cancer is recognized as the predominant form of endocrine cancer. The likelihood of cancer recurrence and the development of distant metastases varies depending on the cancer's pathology and stage. Iran currently lacks country-specific data on thyroid cancer, which can potentially result in clinicians deviating from the optimal treatment. The primary objectives of establishing such a registry are to determine the incidence, identify risk factors, and evaluate treatment outcomes for thyroid cancer within the Iranian population. Ultimately, the overarching goal of this protocol study is to reduce mortality and morbidity rates among thyroid cancer patients by implementing appropriate interventions based on the findings derived from this registration system.

Methods

The study will enroll all individuals aged 18 years and older who have received a diagnosis of primary thyroid carcinoma based on pathology criteria. Data will be collected from various thyroid clinic centers. The participating centers include the Endocrinology Clinic at Shariati Hospital, the Thyroid Clinic in the Nuclear Medicine Center at Shariati Hospital, as well as pathology and nuclear medicine centers in Kerman and Bushehr. Patient records comprise information on outpatient visits to the clinic.

Conclusion

The registry aims to enhance treatment approaches and follow-up protocols while serving as a foundation for conducting clinical, epidemiological, and basic science studies based on robust evidence-based data.

Single-cell and bulk RNA sequencing reveal heterogeneity and diagnostic markers in papillary thyroid carcinoma lymph-node metastasis

PURPOSE

Papillary thyroid carcinoma (PTC) is characterized by lymph-node metastasis (LNM), which affects recurrence and prognosis. This study analyzed PTC LNM by single-cell RNA sequencing (scRNA-seq) data and bulk RNA sequencing (RNA-seq) to find diagnostic markers and therapeutic targets.

METHODS

ScRNA-seq data were clustered and malignant cells were identified. Differentially expressed genes (DEGs) were identified in malignant cells of scRNA-seq and bulk RNA-seq, respectively. PTC LNM diagnostic model was constructed based on intersecting DEGs using glmnet package. Next, PTC samples from 66 patients were used to validate the two most significant genes in the diagnostic model, S100A2 and type 2 deiodinase (DIO2) by quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and immunohistochemical (IHC). Further, the inhibitory effect of DIO2 on PTC cells was verified by cell biology behavior, western blot, cell cycle analysis, 5-ethynyl-2'-deoxyuridine (EdU) assay, and xenograft tumors.

RESULTS

Heterogeneity of PTC LNM was demonstrated by Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analysis. A total of 19 differential genes were used to construct the diagnostic model. S100A2 and DIO2 differ significantly at the RNA (p < 0.01) and protein level in LNM patient tissues (p < 0.001). And differed in PTC tissues with different pathologic typing (p < 0.001). Further, EdU (p < 0.001) and cell biology behavior revealed that PTC cells overexpressed DIO2 had reduced proliferative capacity. Cell cycle proteins were reduced and cells are more likely to be stuck in G2/M phase (p < 0.001).

CONCLUSIONS

This study explored the heterogeneity of PTC LNM using scRNA-seq. By combining with bulk RNA-seq data, diagnostic markers were explored and the model was established. Clinical diagnostic efficacy of S100A2 and DIO2 was validated and the treatment potential of DIO2 was discovered.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Frozen section analysis of central lymph nodes in papillary thyroid cancer: the significance in determining the extent of surgery

BACKGROUND

The indolent feature of papillary thyroid cancer (PTC) has recently led to an increase in less aggressive treatment options instead of total thyroidectomy (TT). We aimed to investigate the clinical significance of elective central compartment neck dissection (CCND) with intraoperative frozen analyses of the central lymph nodes (LNs) to determine the surgical extent of unilateral clinically node-negative PTC.

METHODS

We retrospectively reviewed the medical records of 290 patients with unilateral clinically node-negative PTC who underwent surgery and performed frozen analyses of the central LNs from 2020 to 2021 using our own nodal criteria with cut-off size 5 mm. The patients were divided and investigated according to the surgical extent and the National Comprehensive Cancer Network (NCCN) guidelines; diagnostic accuracy of the frozen analyses was estimated.

RESULTS

TT was performed in 16.2% of patients. The TT group had more metastatic nodes with a larger size, higher LN ratio (LNR), and more extranodal extension. The analyses based on the NCCN guidelines showed similar findings, but more completion TT was required compared with our criteria. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the frozen analyses were 94.6%, 100%, 100%, and 96.1%, respectively.

CONCLUSIONS

Elective CCND with intraoperative frozen analyses is a highly reliable procedure that detects occult nodal metastasis in unilateral node-negative PTC patients. Our nodal criteria yielded significant aggressive nodal characteristics in the TT group while yielding less TTs compared with the NCCN guidelines. The concept and clinical significance of small-volume nodal metastasis in PTC should be further investigated.

Lymphatic Vessel Invasion in Routine Pathology Reports of Papillary Thyroid Cancer

Purpose

It is not mandatory to report lymphatic vessel invasion in pathology reports of papillary thyroid cancer (PTC) according to the current Union for International Cancer Control (UICC) TNM (tumor, nodes, and metastases) classification. However, there is some evidence for its correlation with lymph node metastasis (LNM) and prognosis. The aim of this study was to explore the clinical implication of lymphatic vessel invasion documentation of PTC because pathology reports play a pivotal role in postsurgical clinical decision-making in endocrine tumor boards.

Methods

Patients undergoing postoperative radioiodine treatment for PTC at the University Hospital of Cologne, Germany between December 2015 and March 2020 were identified. Pathology reports were screened for documentation of lymphatic vessel invasion. Demographics and clinicopathologic data of patients documented, including lymphatic vessel invasion and lymph nodal involvement were analyzed.

Results

A total of 578 patients were identified and included. Lymphatic vessel invasion was reported in pathology reports of 366 (63.3%) and omitted in 112 (36.7%) patients. Positive lymphatic vessel invasion (L1) was diagnosed in 67 (18.3%) of 366 patients and was documented as absent (L0) in 299 (81.7%) patients. Lymph nodal (N) status was positive (N+) in 126 (45.6%) and negative (N0) in 150 (54.3%) of these patients. In 54 (80.6%) L1 cases N+ status and in 137 (65.6%) L0 cases N0 status was diagnosed. In 13 (19.4%) cases with L1 status, there were no LNMs (L1 N0). In total, 72 (34.4%) patients had LNM despite L0 status (L0 N+). The sensitivity and specificity of LVI reporting for LNM were 0.42 and 0.91, respectively.

Conclusion

In routine pathology reports of PTC used for indication to postoperative radioiodine treatment by a German endocrine tumor board, lymphatic vessel invasion was found to be reported inconsistently and mostly as L0. L1 diagnoses, however, reliably correlated with reported LNM and might, thus, be relevant for clinical decision-making. For this reason, we advocate for standardized pathologic reassessment of lymphatic vessel invasion, in particular for cases where lymph nodes are not included in the pathologic specimen and if L0 is documented.

An Update of the Appropriate Treatment Strategies in Anaplastic Thyroid Cancer: A Population-Based Study of 735 Patients

BACKGROUND

Anaplastic thyroid cancer (ATC) responds poorly to conventional therapies and requires a multidisciplinary approach to manage. The aim of the current study is to explore whether aggressive treatment is beneficial, especially the appropriate extent of surgery in ATC.

METHODS

Patients diagnosed with ATC from 2004 to 2014 were identified from the Surveillance, Epidemiology, and End Results (SEER) database and included in our study.

RESULTS

A total of 735 ATC patients were identified. The two-year overall survival (OS) rates for stage IVA, IVB, and IVC patients were 36.5%, 15.6%, and 1.4%, respectively. By directly comparing eight treatment modalities, we found that surgery + radiotherapy (RT) ± chemotherapy was the most effective treatment strategy. surgery + chemotherapy and RT + chemotherapy had comparable results (hazard ratio (HR) = 1.461, 95% confidential interval (CI): 0.843-2.531, P = 0.177). Multivariate Cox regression analysis also showed increased mortality risk in patients with increased age (HR = 1.022, P < 0.001), tumor extension to adjacent structures (HR = 1.649, P = 0.013), and distant metastasis (HR = 2.041, P < 0.001), while surgery + RT (HR = 0.600, P = 0.004) and chemotherapy (HR = 0.692, P = 0.010) were independently associated with improved OS. Further analysis revealed that patients undergoing total/near-total thyroidectomy (TT) had superior OS to those receiving less than TT (P < 0.001). In subgroup analysis, the benefit of TT remained significant in patients with tumors larger than 4.0 cm (HR = 0.776, 95% CI: 0.469-0.887, P = 0.007), with adjacent structure extension (HR = 0.642, 95% CI: 0.472-0.877, P = 0.005), including trachea and major vessels, but not in patients with early phase local disease such as tumor ≤ 4.0 cm or tumor within the thyroid or with minimal extrathyroidal extension. Patients with very locally advanced disease or distant metastasis could not benefit from TT as well.

CONCLUSIONS

In operable cases, surgery + RT ± chemotherapy was the optimal treatment modality. Otherwise, RT + chemotherapy was the appropriate strategy. However, TT was not beneficial for very early stage or metastatic ATC.

Central Lymph Node Status has Significant Prognostic Value in the Clinically Node-Negative Tall-Cell Variant of Papillary Thyroid Cancer Regardless of T-Staging and Radioactive Iodine Administration: First Evidence From a Population-Based Study

BACKGROUND

The prognostic value of central lymph node (CLN) status in papillary thyroid cancer (PTC) remains controversial. This study aimed to provide the first evidence on this issue for the aggressive tall-cell variant (TCV) subtype.

METHODS

The study identified TCV patients from the Surveillance, Epidemiology, and End Results database. The Kaplan-Meier method, log-rank test, and multivariate Cox regression models were used for analysis.

RESULTS

Of the 744 patients included, 404 were recorded as N0, which were pathologically or only clinically confirmed. Overall survival (OS) and cancer-specific survival (CSS) did not differ significantly between the N0 and pN1a patients (p > 0.05). To investigate the reason, the N0 patients were subdivided according to the number of examined lymph nodes (ELN). The patients with a N0 diagnosis confirmed by two or more ELNs (N0-e2+) showed significantly better outcomes than the pN1a patients and their N0 counterparts without ELN (N0-e0) (p < 0.05), whereas the N0-e0 and pN1a groups demonstrated comparable outcomes in both the log-rank and multivariate analyses (p > 0.05). Moreover, the subgroup analyses showed that even among the patients with early T-staging (T1-T2) or receipt of radioactive iodine (RAI) therapy, the N0-e0 patients still demonstrated compromised OS compared with the N0-e2+ group (p < 0.05).

CONCLUSION

The cN0 patients without ELN (N0-e0) had outcomes similar to those of the pN1a patients, but showed a poorer OS than the N0-e2+ group regardless of T-staging and RAI administration, suggesting that occult CLN metastases might act as a negative prognosticator in cN0 TCV. Therefore, prophylactic central neck dissection might be considered for biopsy-proven cN0 TCV patients. Prospective studies are expected to further validate our conclusions.

Preferential Use of Total Thyroidectomy without Prophylactic Central Lymph Node Dissection for Early-Stage Papillary Thyroid Cancer: Oncologic Outcomes in an Integrated Health Plan

CONTEXT

The oncologic benefit of prophylactic central lymph node dissection (pCLND) in node-negative papillary thyroid cancer has been debated.

OBJECTIVE

To determine the use of pCLND in an integrated health care system and to evaluate recurrence in the cohort.

DESIGN

Retrospective cohort study of patients with clinically node-negative papillary thyroid cancer who underwent total thyroidectomy with or without pCLND in Kaiser Permanente Southern California Region hospitals between January 1996 and December 2008. Chart review of all patients was performed to collect demographic data, tumor features, stage, and recurrences.

MAIN OUTCOME MEASURES

Proportion undergoing pCLND and recurrence rate of papillary thyroid cancer.

RESULTS

There were 864 patients identified (mean age, 46.1 years). Almost all patients had total thyroidectomy alone, and 34 (3.9%) underwent pCLND. The TNM (tumor, node, metastasis) stages for the 2 groups were not significantly different (p = 0.18). Overall recurrence was 24 (2.8%). There were 23 (2.8%) recurrences in the no-pCLND group and 1 (2.9%) recurrence in the pCLND group (p = 0.95). The rate of recurrence in the central neck compartment in those without pCLND was 1.1% and 0% in the pCLND group (p = 0.54). The recurrence rate in the lateral neck compartment in the no-pCLND group was 2.2%, and this rate was 2.9% in the pCLND group (p = 0.76). The no-pCLND group had a recurrence-free survival rate of 96.4% at 10 years vs 96.8% in the pCLND patients (p = 0.80).

CONCLUSION

Presently, routine pCLND is difficult to advocate in our medical system.

Predictive Value of Estimated Tumor Volume Measured by Ultrasonography for Occult Central Lymph Node Metastasis in Papillary Thyroid Carcinoma

The clinical and prognostic value of tumor volume in various solid tumors has been investigated. However, there have been few studies on the clinical impact of tumor volume in papillary thyroid carcinoma (PTC). This study was performed to investigate the predictive value of estimated tumor volume measured by ultrasonography for occult central neck metastasis (OCNM) of PTC. A total of 264 patients with clinically node-negative PTC on ultrasonography and computed tomography who underwent total thyroidectomy in conjunction with at least ipsilateral prophylactic central neck dissection were enrolled in this study. Tumor volume was derived with the formula used to calculate ellipsoids from two orthogonal scans during 2-D ultrasonography at initial aspiration biopsy. We retrospectively evaluated demographic characteristics, pre-operative ultrasonographic features (tumor size, volume and multifocality) and pathologic results. The OCNM rate was 35.6%; estimated tumor volume was used to predict OCNM (p = 0.035). At 0.385 mL, sensitivity and specificity were 51.1% and 66.5%, and the area under the curve for OCNM detection was 0.610. In multivariate analysis, tumor volume, but not size, was an independent predictive factor for OCNM (odds ratio = 1.83, p = 0.029). The other factors were extrathyroidal extension (odds ratio = 2.39, p = 0.004) and male gender (odds ratio = 3.90, p < 0.001). The estimated tumor volume of PTC measured by ultrasonography could be a pre-operative predictor of OCNM.

Recurrence of papillary thyroid carcinoma with lateral cervical node metastases: Predictive factors and operative management

BACKGROUND

Lateral neck lymph node (LN) metastases (N1b) have been identified as independent risk factors of recurrence in patients with papillary thyroid carcinoma (PTC).

OBJECTIVE

This study aimed to determine the predictive factors of recurrence in N1b PTC patients and to clarify the postoperative event patterns.

METHODS

All patients who underwent operation for N1b PTC between 1978 and 2012 were reviewed. The median follow-up period was 6.5 years.

RESULTS

In total, 344 N1b patients were included. Twenty-four patients (7%) were lost to long-term follow-up. Among the remaining 320 patients, the mean (± SD) follow-up time was 8.9 ± 8.8 years (median, 6.5; range, 2-36.4). Eighty-two patients (26%) presented with lymph node recurrence (LR). Multivariate analyses showed that LN metastases with extracapsular extension and the LN ratio (ratio between the number of N1 and number of resected LN) in the lateral compartment were independent predictors of recurrent disease. The median time to reoperation was 19 months (range, 3-173), with 79% of reoperations occurring within 2 years after the initial thyroidectomy. Reoperations for LR (75 patients) were performed in 76% of the patients with a focused minimal access approach or selective LN dissection. After curative reoperative surgery for recurrence, complications occurred in 6 patients (8%), including a 1% permanent complication rate.

CONCLUSION

Extranodal extension of LN metastases and the LN ratio in the lateral compartment are prognostic factors for recurrence. In most cases, reoperation for LR can be performed with a focused minimal access approach, with a low morbidity rate.

Patterns of structural recurrence in papillary thyroid cancer

BACKGROUND

Papillary thyroid carcinoma (PTC) is uncommonly associated with tumor-related mortality, although local recurrence can be a frequent and difficult problem. This study was conducted to clarify the pattern of structural locoregional recurrence in PTC.

MATERIAL AND METHOD

A retrospective cohort study of patients undergoing surgical intervention for PTC was undertaken. Data were collected from a comprehensive thyroid cancer database maintained within a single tertiary referral center. The primary outcome measure was cancer recurrence requiring surgical intervention. Secondary outcome measures were site of recurrence, time to recurrence, and risk factors for recurrence.

RESULTS

In the period 1980-2013, 1,183 patients with PTC were included in the study. The overall rate of structural recurrence requiring reoperative surgery was 7.9 %. The median time to reoperation was 31 months. Younger age, male gender, large primary tumor diameter, and number of positive lymph nodes at initial presentation were all significantly associated with disease recurrence. The lateral compartments (levels I, II, III, IV, V) were involved almost twice as frequently as the central compartment (level VI) (67 vs 32 %, P < 0.01). The distribution of recurrences was level I (1 %), level II (12 %), level III (18 %), level IV (18 %), level V (17 %), level VI (32 %), level VII (2 %).

CONCLUSIONS

In a center with a liberal approach to central compartment lymph node dissection for PTC, the lateral neck compartment is the most common site of structural recurrence requiring reoperative surgery.

Differentiated thyroid cancer-personalized therapies to prevent overtreatment

The concept of individualized therapy is rapidly gaining recognition in the management of patients with differentiated thyroid cancer (DTC). This Review provides an overview of the most important elements of this paradigm shift in DTC management and discusses the implications for clinical practice. In the majority of patients with DTC who have an inherently good prognosis, the extent of surgery, the dosage of (131)I therapy and the use of levothyroxine therapy are all aspects suitable for individualization, on the basis of both the stage of disease and the response to treatment. In individuals with advanced disease, newer imaging techniques, advances in (131)I therapy and the use of targeted molecular therapies (such as multitargeted kinase inhibitors) have provided new options for the personalized care of patients, for whom until recently no effective therapies were available. Individualized therapies could reduce adverse effects, including the sometimes debilitating hypothyroidism that used to be required before initiation of (131)I treatment, and major salivary gland damage, a common and unpleasant side effect of (131)I therapy. Highly individualized interdisciplinary treatment of patients with DTC might lead to improved outcomes with reduced severity and frequency of complications and adverse effects. However, in spite of ongoing research, personalized therapies remain in their infancy.

The pros and cons of prophylactic central neck dissection in papillary thyroid carcinoma

Prophylactic central neck dissection (pCND) for management of papillary thyroid carcinoma (PTC) is controversial. Compared to many malignancies, PTC has a high overall survival but local recurrence due to lymph node metastases continue to present management challenges. Unlike lateral cervical nodal metastasis metastasis, central neck nodal metastasis are unable to be reliably detected clinically or radiologically at pre-operative assessment. Residual disease (recurrent or persistent) typically requires re-operative surgery in the central compartment, which carries a heightened risk of significant morbidity. These nodal groups can be accessed during the index thyroidectomy for PTC. Thus, pCND offers potential to reduce the rates of recurrence and the need for re-operative surgery in the central neck. This benefit needs to be balanced with the potential morbidity risk from pCND itself at the index resection. This review will discuss the advantages and disadvantages of pCND with regard to long-term outcomes and potential morbidity. The rationale of pCND will be discussed, along with the indications for ipsilateral and contralateral pCND, the role of re-operative surgery for recurrence and the use of selective versus routine pCND. Strategies to select higher risk patients for pCND with the use of molecular markers will be addressed, along with a discussion of quality of life (QoL) research in PTC.