Clinical implications of Delphian lymph node metastasis in papillary thyroid carcinoma

Meta-analysis of the effect and clinical significance of Delphian lymph node metastasis in papillary thyroid cancer

Objective

To investigate the effect and clinical significance of Delphian lymph nodes (DLN) on the factors influencing papillary thyroid cancer (PTC) to provide individualized guidance for the surgical treatment of thyroid cancer.

Methods

Relevant studies from PubMed, Web of Science, the Cochrane Library, Embase, and China National Knowledge Infrastructure databases were searched until February 13, 2023. Stringent selection parameters were used to obtain included data and homogeneous articles. Analyses were performed using Revman 5.4 and SPSS software. A P-value of < 0.05 was considered statistically significant.

Results

Five studies were finally included in this study. The results revealed a higher risk of DLN metastasis (DLNM) in patients with tumor size >1cm, multifocality, and extrathyroidal extension (ETE) of the thyroid. The risk of central lymph node metastasis (CLNM) was 11.25 times higher in DLN-positive patients with PTC than in DLN-negative (OR = 11.25, 95% CI: 8.64-14.64, P < 0.05) patients. The risk of LLNM was 5.57 times higher in DLN-positive patients with PTC than in DLN-negative (OR = 5.57, 95% CI: 4.57-6.78, P < 0.001) patients. The risk of postoperative recurrence in DLN-positive patients with PTC was 3.49 times higher (OR = 3.49, 95% CI: 1.91-6.38, P < 0.001) than in DLN-negative patients with PTC.

Conclusion

Patients with tumor size >1 cm in diameter, multifocality, and ETE have an increased risk for DLN development. DLN-positive patients with central and lateral cervical lymph node metastasis and postoperative recurrence are at higher risk than DLN-negative patients.

Prelaryngeal and/or pretracheal lymph node metastasis could help to identify papillary thyroid carcinoma with intermediate risk from unilateral lobe cT1-2N0 papillary thyroid carcinoma

Objective

The study aims to explore the possibility of prelaryngeal and/or pretracheal lymph node metastasis in identifying papillary thyroid carcinoma with more than 5 metastatic central lymph nodes from unilateral lobe cT1-2N0 papillary thyroid carcinoma.

Methods

A retrospective analysis was conducted on patients who underwent the initial thyroid surgery for unilateral lobe cT1-2N0 PTC in a single tertiary center between July 2018 to December 2022. Multivariable binary logistic regression analysis was used to identify risk factors for unilateral lobe cT1-2N0 papillary thyroid carcinoma with more than 5 metastatic central lymph nodes.

Results

A total of 737 patients were included in the study and 399 patients were confirmed to suffer from occult central lymph node metastasis. The larger size of the largest diameter of tumor (> 1cm; OR = 3.3, 95%CI 1.6 - 6.83; p = 0.001), pretracheal lymph node metastasis (OR = 5.91, 95%CI 2.73 - 12.77; p < 0.001), prelaryngeal lymph node metastasis (OR = 3.74, 95%CI 1.73 - 8.1; p = 0.001), ipsilateral paratracheal lymph node metastasis (OR = 12.22, 95%CI 3.43 - 43.48; p < 0.001), and contralateral paratracheal lymph node metastasis (OR = 7.68, 95%CI 3.86 - 15.3; p < 0.001) were confirmed to be risk factors for unilateral lobe cT1-2N0 PTC with more than 5 metastatic central lymph nodes. When more than two metastatic prelaryngeal and/or pretracheal lymph nodes occurred, the incidence of more than 5 metastatic central lymph nodes was 71.2%.

Conclusion

Prelaryngeal and/or pretracheal lymph node metastasis could help to identify papillary thyroid carcinoma with more than 5 metastatic central lymph nodes from unilateral lobe cT1-2N0 papillary thyroid carcinoma. When more than two metastatic pretracheal and/or prelaryngeal lymph nodes occurred, total thyroidectomy and ipsilateral central lymph node dissection should be performed and contralateral paratracheal lymph node dissection might be also necessary.

Relationship between pretracheal and/or prelaryngeal lymph node metastasis and paratracheal and lateral lymph node metastasis of papillary thyroid carcinoma: A meta-analysis

Objective

We conducted a meta-analysis to study the relationship between pretracheal and/or prelaryngeal lymph node metastasis and paratracheal and lateral lymph node metastasis in papillary thyroid carcinoma.

Method

A systematic literature search was conducted using PubMed, Embase, and the Cochrane Library electronic databases for studies published up to February 2022. The reference lists of retrieved articles were also reviewed. Two authors independently assessed the methodological quality and extracted the data. A random-effects model was used to calculate the overall pooled relative risk. Publication bias in these studies was evaluated using Egger’s test and Begg’s test.

Results

Twenty-five independent studies involving 10,525 patients were included in the meta-analysis. The pooled relative risk for ipsilateral and contralateral paratracheal lymph node metastasis was 3.01 (95% confidence interval [CI]: 1.66, 5.45) and 5.68 (95% CI: 2.50, 12.88), respectively, in patients with pretracheal lymph node metastasis. Among patients with prelaryngeal lymph node metastasis, the pooled relative risk for ipsilateral paratracheal and/or pretracheal contralateral paratracheal, and lateral lymph node metastasis was 2.02 (95% CI: 1.90, 2.14), 2.22 (95% CI: 1.34, 3.67), and 3.85 (95% CI: 2.89, 5.14), respectively.

Conclusion

Pretracheal lymph node metastasis and prelaryngeal lymph node metastasis were significantly associated with an increased likelihood of both ipsilateral lymph node metastasis and contralateral paratracheal lymph node metastasis in papillary thyroid carcinoma. Prelaryngeal lymph node metastasis was positively correlated with the incidence of lateral lymph node metastasis.

Analysis of the Clinical Value of Delphian Lymph Node Metastasis in Papillary Thyroid Carcinoma

Purpose

Delphian lymph node (DLN) is often involved in metastasis of malignant head and neck tumors. This study evaluates the predictive utility of the DLN and the clinicopathological factors related to DLN metastasis in individuals suffering from papillary thyroid carcinoma (PTC). Patients and Methods. A retrospective analysis was made on 969 PTC patients enrolled from 2017 to 2021. Among these patients, 522 PTC patients are DLN positive and 447 are negative. Comparisons of clinicopathological characteristics between the DLN-positive and DLN-negative patients were made.

Results

The DLN was detected in 53.9% (522/969) cases, and DLN metastasis occurred in 20.3% (106/522) cases. The independent predictors of DLN metastasis (DLNM) include tumor size >1 cm, tumor located in the upper third thyroid or isthmus, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM). DLN-positive individuals exhibited a higher incidence and the number of CLNM, contralateral CLNM (CCLNM), and LLNM as compared to DLN-negative patients. Whether it is cN0 or cN+, the CLNM incidence was increased among DLN-positive patients as compared to that of DLN-negative patients.

Conclusions

Positive DLN indicated an increased rate and number of metastases in the cervical lymph nodes. Intraoperative rapid freezing is recommended to assess the status of the DLN, and careful assessment of cervical lymph nodes is warranted when the DLN is involved to implement an appropriate surgical approach.

Relationship between subgroups of central and lateral lymph node metastasis in clinically node-negative papillary thyroid carcinoma

BACKGROUND

Lymph node metastasis (LNM) of papillary thyroid carcinoma (PTC) has a certain regularity and occurs first to the central lymph node and then to the lateral lymph node. The pathway of PTC LNM can guide surgical prophylactic lymph node dissection (LND) for clinical surgeons.

AIM

To investigate the relationship between subgroups of central LNM and lateral LNM in unilateral clinically node-negative PTC (cN0-PTC).

METHODS

Data were collected for 1089 PTC patients who underwent surgical treatment at the Department of Endocrine and Breast Surgery of the First Hospital of Chongqing Medical University from January 2016 to December 2017. A total of 388 unilateral cN0-PTC patients met the inclusion criteria and were enrolled in this study. The clinical and pathological data for these 388 patients who underwent total thyroidectomy + central LND + lateral LND were retrospectively analyzed. The relationship between the central LNM and lateral LNM subgroups was investigated.

RESULTS

The coincidence rate of cN0-PTC was only 30.0%.Optimal scaling regression analysis showed that sex (57.1% vs 42.9%, P = 0.026), primary tumor size (68.8% vs 31.2%, P = 0.008), tumor location (59.7% vs 40.3%, P = 0.007), extrathyroid extension (ETE) (50.6% vs 49.9%, P = 0.046), and prelaryngeal LNM (57.1% vs 42.9%, P = 0.004) were significantly associated with ipsilateral level-II LNM. Their importance levels were 0.122, 0.213, 0.172, 0.110, and 0.227, respectively. Primary tumor size (74.6% vs 30.2%, P = 0.016), pretracheal LNM (67.5% vs 32.5%, P < 0.001), and paratracheal LNM (71.4% vs 28.6%, P < 0.001) were significantly associated with ipsilateral level-III LNM. Their importance levels were 0.120, 0.408, and 0.351, respectively. Primary tumor size (72.1% vs 27.9%, P = 0.003), ETE (70.4% vs 29.6%, P = 0.016), pretracheal LNM (68.3% vs 31.7%, P=0.001), and paratracheal LNM (80.8% vs 19.2%, P < 0.001) were significantly associated with ipsilateral level-IV LNM. Their importance levels were 0.164, 0.146, 0.216, and 0.472, respectively.

CONCLUSION

The LNM pathway of thyroid cancer has a certain regularity. For unilateral cN0-PTC patients with a tumor diameter > 2 cm and pretracheal or ipsilateral paratracheal LNM, LND at ipsilateral level III and level IV must be considered. When there is a tumor in the upper third of the thyroid with prelaryngeal LNM, LND at level II, level III and level IV must be considered.

Nomograms Combining Ultrasonic Features With Clinical and Pathological Features for Estimation of Delphian Lymph Node Metastasis Risk in Papillary Thyroid Carcinoma

Background

This work explores the clinical significance of Delphian lymph nodes (DLN) in thyroid papillary carcinoma (PTC). At the same time, a nomogram is constructed based on clinical, pathological, and ultrasonic (US) features to evaluate the possibility of DLN metastasis (DLNM) in PTC patients. This is the first study to predict DLNM using US characteristics.

Methods

A total of 485 patients, surgically diagnosed with PTC between February 2017 and June 2021, all of whom underwent thyroidectomy, were included in the study. Using the clinical, pathological, and US information of patients, the related factors of DLNM were retrospectively analyzed. The risk factors associated with DLNM were identified through univariate and multivariate analyses. According to clinical + pathology, clinical + US, and clinical + US + pathology, the predictive nomogram for DLNM was established and validated.

Results

Of the 485 patients with DLN, 98 (20.2%) exhibited DLNM. The DLNM positive group had higher positive rates of central lymph node metastasis (CLNM), lateral lymph node metastasis (LLNM), and T3b–T4b thyroid tumors than the negative rates. The number of CLNM and LLNM lymph nodes in the DLNM+ group was higher as compared to that in the DLNM- group. Multivariate analysis demonstrated that the common independent risk factors of the three prediction models were male, bilaterality, and located in the isthmus. Age ≥45 years, located in the lower pole, and nodural goiter were protective factors. In addition, the independent risk factors were classified as follows: (I) P-extrathyroidal extension (ETE) and CLNM based on clinical + pathological characteristics; (II) US-ETE and US-CLNM based on clinical + US characteristics; and (III) US-ETE and CLNM based on clinical +US + pathological features. Better diagnostic efficacy was reported with clinical + pathology + US diagnostic model than that of clinical + pathology diagnostic model (AUC 0.872 vs. 0.821, p = 0.039). However, there was no significant difference between clinical + pathology + US diagnostic model and clinical + US diagnostic model (AUC 0.872 vs. 0.821, p = 0.724).

Conclusions

This study found that DLNM may be a sign that PTC is more invasive and has extensive lymph node metastasis. By exploring the clinical, pathology, and US characteristics of PTC progression to DLNM, three prediction nomograms, established according to different combinations of features, can be used in different situations to evaluate the transfer risk of DLN.

Male Gender Is Associated with Lymph Node Metastasis but Not with Recurrence in Papillary Thyroid Carcinoma

BACKGROUND

The incidence of papillary thyroid carcinoma (PTC) is higher in females than in males, but it remains unclear whether gender is associated with the aggressiveness of this disease. We aimed to clarify the influence of gender on the risk of developing lymph node metastasis (LNM) and on the prognosis of PTC patients. Study Design. Retrospective cohort study. Setting. Academic tertiary care center.

METHODS

Clinical data of PTC patients who were admitted to the Department of Endocrine and Breast Surgery, the First Affiliated Hospital of Chongqing Medical University, between January 2013 and December 2018 were retrospectively reviewed. The differences in clinical features and outcomes between female and male patients were compared. Univariate and multivariate logistic regression analyses were conducted to assess the impact of gender on LNM. Kaplan-Meier curves were used to estimate recurrence-free survival (RFS).

RESULTS

A total of consecutive 2536 patients were enrolled in this study. Males accounted for 25.2% (639 cases) of all patients. Central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) rates were 52.5% (1346/2536) and 22.0% (558/2536), respectively. Male presented with higher LNM rates than female patients (65.7% vs. 51.2%; P < 0.001). Male gender was independently associated with LNM (OR = 1.93, 95% CI: 1.59-2.35; P < 0.001). After full adjustment, male gender still remained significantly associated with CLNM in all subgroups; however, subgroup analyses indicated no significant relationship between gender and LLNM. In addition, after a median follow-up period of 30 months, no significant difference was found in RFS between female and male patients (P=0.15).

CONCLUSIONS

This observational cohort study revealed that male gender was significantly associated with CLNM; whereas, LLNM was not different between female and male PTC patients in southwestern China. Moreover, currently, there is insufficient evidence to justify that male gender is an independent prognostic factor for recurrence.

Application of Machine Learning Algorithms to Predict Central Lymph Node Metastasis in T1-T2, Non-invasive, and Clinically Node Negative Papillary Thyroid Carcinoma

Purpose: While there are no clear indications of whether central lymph node dissection is necessary in patients with T1-T2, non-invasive, clinically uninvolved central neck lymph nodes papillary thyroid carcinoma (PTC), this study seeks to develop and validate models for predicting the risk of central lymph node metastasis (CLNM) in these patients based on machine learning algorithms.

Methods: This is a retrospective study comprising 1,271 patients with T1-T2 stage, non-invasive, and clinically node negative (cN0) PTC who underwent surgery at the Department of Endocrine and Breast Surgery of The First Affiliated Hospital of Chongqing Medical University from February 1, 2016, to December 31, 2018. We applied six machine learning (ML) algorithms, including Logistic Regression (LR), Gradient Boosting Machine (GBM), Extreme Gradient Boosting (XGBoost), Random Forest (RF), Decision Tree (DT), and Neural Network (NNET), coupled with preoperative clinical characteristics and intraoperative information to develop prediction models for CLNM. Among all the samples, 70% were randomly selected to train the models while the remaining 30% were used for validation. Indices like the area under the receiver operating characteristic (AUROC), sensitivity, specificity, and accuracy were calculated to test the models' performance.

Results: The results showed that ~51.3% (652 out of 1,271) of the patients had pN1 disease. In multivariate logistic regression analyses, gender, tumor size and location, multifocality, age, and Delphian lymph node status were all independent predictors of CLNM. In predicting CLNM, six ML algorithms posted AUROC of 0.70–0.75, with the extreme gradient boosting (XGBoost) model standing out, registering 0.75. Thus, we employed the best-performing ML algorithm model and uploaded the results to a self-made online risk calculator to estimate an individual's probability of CLNM (https://jin63.shinyapps.io/ML_CLNM/).

Conclusions: With the incorporation of preoperative and intraoperative risk factors, ML algorithms can achieve acceptable prediction of CLNM with Xgboost model performing the best. Our online risk calculator based on ML algorithm may help determine the optimal extent of initial surgical treatment for patients with T1-T2 stage, non-invasive, and clinically node negative PTC.