Risk factors of lateral lymph node metastasis in cN0 papillary thyroid carcinoma

The Association of Pretreatment Systemic Immune Inflammatory Response Index (SII) and Neutrophil-to-Lymphocyte Ratio (NLR) with Lymph Node Metastasis in Patients with Papillary Thyroid Carcinoma

Objective

Immunoinflammatory response can participate in the development of cancer. To investigate the relationship between pretreatment systemic immune inflammatory response index (SII), systemic inflammatory response index (SIRI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR) and lymph node metastasis in patients with papillary thyroid carcinoma (PTC).

Methods

A retrospective analysis was performed on 547 PTC patients treated in Meizhou People's Hospital from January 2018 to December 2021. Clinicopathological data were collected, including gender, age, Hashimoto's thyroiditis, maximum tumor diameter, extra-membrane infiltration, disease stage, BRAF V600E mutation, pretreatment inflammatory index levels, and lymph node metastasis. The optimal cutoff values of SII, SIRI, NLR, PLR and LMR were calculated by receiver operating characteristic (ROC) curve, and the relationship between inflammatory indexes and other clinicopathological features and lymph node metastasis was analyzed.

Results

There were 303 (55.4%) PTC patients with lymph node metastasis. The levels of SII, SIRI, NLR, and PLR in patients with lymph node metastasis were significantly higher than those in patients without lymph node metastasis, while the levels of LMR were significantly lower than those in patients without lymph node metastasis (all p<0.05). When lymph node metastasis was taken as the endpoint, the critical value of SII was 625.375, the SIRI cutoff value was 0.705, the NLR cutoff value was 1.915 (all area under the ROC curve >0.6). The results of regression logistic analysis showed that age <55 years old (OR: 1.626, 95% CI: 1.009-2.623, p=0.046), maximum tumor diameter >1cm (OR: 2.681, 95% CI: 1.819-3.952, p<0.001), BRAF V600E mutation (OR: 2.709, 95% CI: 1.542-4.759, p=0.001), SII positive (≥625.375/<625.375, OR: 2.663, 95% CI: 1.560-4.546, p<0.001), and NLR positive (≥1.915/<1.915, OR: 1.808, 95% CI: 1.118-2.923, p=0.016) were independent risk factors for lymph node metastasis of PTC.

Conclusion

Age <55 years old, maximum tumor diameter >1cm, BRAF V600E mutation, SII positive, and NLR positive were independent risk factors for lymph node metastasis in PTC.

Risk factors analysis of lateral cervical lymph node metastasis in papillary thyroid carcinoma: a retrospective study of 830 patients

OBJECTIVE

The aim of this study is to investigate the risk factors for lateral cervical lymph node metastasis in papillary thyroid carcinoma (PTC).

METHODS

Clinicopathological data (age, gender, Hashimoto's thyroiditis, preoperative circulating tumor cells (CTCs), multifocal, maximum lesion diameter, invaded capsule, T stage, and lymph node metastasis) of 830 PTC patients diagnosed and treated in Meizhou People's Hospital from June 2021 to April 2023 were collected. The related factors of lateral cervical lymph node metastasis were analyzed.

RESULTS

There were 334 (40.2%), and 103 (12.4%) PTC patients with central lymph node metastasis, and lateral cervical lymph node metastasis, respectively. Compared with patients without lateral cervical lymph node metastasis, PTC patients with lateral cervical lymph node metastasis had a higher proportion of multifocal, maximum lesion diameter > 1 cm, invaded capsule, T3-T4 stage. Regression logistic analysis showed that male (odds ratio (OR): 2.196, 95% confidence interval (CI): 1.279-3.769, p = 0.004), age < 55 years old (OR: 2.057, 95% CI: 1.062-3.988, p = 0.033), multifocal (OR: 2.759, 95% CI: 1.708-4.458, p < 0.001), maximum lesion diameter > 1 cm (OR: 5.408, 95% CI: 3.233-9.046, p < 0.001), T3-T4 stage (OR: 2.396, 95% CI: 1.241-4.626, p = 0.009), and invaded capsule (OR: 2.051, 95% CI: 1.208-3.480, p = 0.008) were associated with lateral cervical lymph node metastasis.

CONCLUSIONS

Male, age < 55 years old, multifocal, maximum lesion diameter > 1 cm, T3-T4 stage, and invaded capsule were independent risk factors for lateral cervical lymph node metastasis in PTC.

Analysis of risk factors for lateral lymph node metastasis in T1 stage papillary thyroid carcinoma: a retrospective cohort study

Background

The occurrence of cervical lymph node metastasis in T1 stage papillary thyroid carcinoma (PTC) is frequently observed. Notably, lateral lymph node metastasis (LLNM) emerges as a critical risk factor adversely affecting prognostic outcomes in PTC. The primary aim of this investigation was to delineate the risk factors associated with LLNM in the initial stages of PTC.

Methods

This retrospective analysis encompassed 3,332 patients diagnosed with T1 stage PTC without evident LLNM at the time of diagnosis. These individuals underwent primary surgical intervention at West China Hospital, Sichuan University between June 2017 and February 2023. The cohort was divided into two groups: patients manifesting LLNM and those without metastasis at the time of surgery. Additionally, T1 stage PTC patients were subdivided into T1a and T1b categories. Factors influencing LLNM were scrutinized through both univariate and multivariate analyses.

Results

The incidence of LLNM was observed in 6.2% of the cohort (206 out of 3,332 patients). Univariate analysis revealed significant correlations between LLNM and male gender (P<0.001), tumor localization in the upper lobe (P<0.001), maximal volume of the primary tumor (P<0.001), largest tumor diameter (P<0.001), multifocality (P<0.001), and bilaterality (P<0.001), with the exception of age (P=0.788) and duration of active surveillance (AS) (P=0.978). Multivariate logistic regression analysis identified male gender (P<0.001), upper lobe tumor location (P<0.001), maximal primary tumor volume (P<0.001), and multifocality (P<0.001) as independent predictors of LLNM. However, age categories (≤55, >55 years), maximum tumor diameter, bilaterality, and surveillance duration did not exhibit a significant impact. Comparative analyses between T1a and T1b subgroups showed congruent univariate results but revealed differences in multivariate outcomes. In the T1a subgroup, gender, tumor location, and multifocality (all P<0.05) were associated with elevated LLNM risk. Conversely, in the T1b subgroup, tumor location, dimensions, and multifocality (all P<0.05) were significant predictors of LLNM risk, whereas gender (P=0.097) exerted a marginal influence.

Conclusions

The investigation highlights several key risk factors for LLNM in T1 stage PTC patients, including gender, upper lobe tumor location, larger tumor size, and multifocality. Conversely, prolonged AS and younger age did not significantly elevate LLNM risk, suggesting the viability of AS as a strategic option in selected cases.

Diagnostic value of contrast-enhanced ultrasonography in the preoperative evaluation of lymph node metastasis in papillary thyroid carcinoma: a single-center retrospective study

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has been recently used for the assessment of cervical lymph node metastasis (LNM) to guide surgical operation in patients with papillary thyroid carcinoma (PTC). However, the specificity and sensitivity of CEUS reported from previous studies are not consistent. The objective of this study was to evaluate the diagnostic value of CEUS for the metastasis of cervical lymph nodes in PTC patients based on data from one regional central hospital.

METHODS

The diagnostic value of CEUS in preoperative LNM of PTC patients was concluded by comparing the results of CEUS on lymph node status with postoperative pathology examination. In addition, this study conducted hierarchical analysis of PTC patients to explore whether tumor size, different lymph node regions, and Hashimoto's thyroiditis influence the assessment of CEUS.

RESULTS

This research study ultimately enrolled 965 PTC patients, including 266 males and 699 females with a mean age of 42.27 ± 11.34 years. A total of 527 patients were considered clinical-node negative, and 438 were clinical-node positive before surgery. The specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of CEUS in the assessment of LNM in PTC patients were 56.00%, 71.00%, 57.06%, 69.76% and 62.59%, respectively. For central and lateral lymph nodes, the accuracy of CEUS in PTC patients was 49.43% and 54.30%, respectively. In addition, it was shown that the accuracy of CEUS in PTC patients with Hashimoto's thyroiditis (HT) slightly decreased to 58.44%, and the accuracy of CEUS in PTC patients with non-HT in turn increased to 64.17%. The accuracy of CEUS in non-papillary thyroid microcarcinoma (PTMC) and PTMC patients was 65.68% and 61.24%, respectively. The accuracy of CEUS in predicting central LNM was significantly different between PTC patients with or without HT (P < 0.001) in this study but not for lateral lymph nodes (P = 0.114).

CONCLUSION

The accuracy of CEUS in the assessment of LNM in PTC is not consistently satisfactory, especially for central lymph nodes, small tumor diameters, or patients with HT. More diagnostic technologies for abnormal lymph nodes should be considered in PTC patients.

CRISPR/Cas9-mediated high-mobility group A2 knockout inhibits cell proliferation and invasion in papillary thyroid carcinoma cells

PURPOSE

Metastasis and recurrence are the prognostic risk factor in patients with thyroid carcinoma. High-mobility group A2 (HMGA2) protein plays a crucial role in papillary thyroid carcinoma (PTC) metastasis. The aim of this study was to investigate the mechanisms underlying the HMGA2 effect on PTC cell proliferation and invasion.

MATERIALS AND METHODS

We used the CRISPR/Cas9 system to perform knockout of the HMGA2 gene in the human PTC cell line TPC-1. The knockout monoclonal cells were screened and verified by PCR analysis and genomic sequencing. Cell proliferation was examined after the knockout of the HMGA2 gene using cell counting kit-8 (CCK-8) assays. Furthermore, cell migration and invasion after the knockout were examined by cell scratch tests. Additionally, the changes in cell cycle and apoptosis after the knockout were detected by flow cytometry.

RESULTS

The results of the PCR analysis and the genomic sequencing confirmed that the human PTC TPC-1 ​cell line with knockout of HMGA2 gene was successfully established. The knockout of the HMGA2 gene significantly reduced the cell proliferation, growth, and invasion. Meanwhile, the knockout of the HMGA2 gene delayed the conversion of the G2/M phase and promoted cell necrosis.

CONCLUSION

The CRISPR/Cas9-mediated HMGA2 knockout in the TPC-1 ​cell line inhibited cell proliferation and invasion, which might be due to the blockage of the cell cycle in the G2/M phase and the promotion of cell necrosis.

Accuracy of papillary thyroid cancer prognostic nomograms: a systematic review

Objective

Current staging and risk-stratification systems for predicting survival or recurrence of patients with differentiated thyroid carcinoma may be ineffective at predicting outcomes in individual patients. In recent years, nomograms have been proposed as an alternative to conventional systems for predicting personalized clinical outcomes. We conducted a systematic review to evaluate the predictive performance of available nomograms for thyroid cancer patients.

Design and methods

PROSPERO registration (CRD42022327028). A systematic search was conducted without time and language restrictions. PICOT questions: population, patients with papillary thyroid cancer; comparator prognostic factor, single-arm studies; outcomes, overall survival, disease-free survival, cancer-specific survival, recurrence, central lymph node metastases, or lateral lymph node metastases; timing, all periods; setting, hospital setting. Risk of bias was assessed through PROBAST tool.

Results

Eighteen studies with a total of 20 prognostic models were included in the systematic review (90,969 papillary thyroid carcinoma patients). Fourteen models were at high risk of bias and four were at unclear risk of bias. The greatest concerns arose in the analysis domain. The accuracy of nomograms for overall survival was assessed in only one study and appeared limited (0.77, 95% CI: 0.75-0.79). The accuracy of nomograms for disease-free survival ranged from 0.65 (95% CI: 0.55-0.75) to 0.92 (95% CI: 0.91-0.95). The C-index for predicting lateral lymph node metastasis ranged from 0.72 to 0.92 (95% CI: 0.86-0.97). For central lymph node metastasis, the C-index of externally validated studies ranged from 0.706 (95% CI: 0.685-0.727) to 0.923 (95% CI: 0.893-0.946).

Conclusions

Our work highlights the extremely high heterogeneity among nomograms and the critical lack of external validation studies that limit the applicability of nomograms in clinical practice. Further studies ideally using commonly adopted risk factors as the backbone to develop nomograms are required.

Significance statement

Nomograms may be appropriate tools to plan treatments and predict personalized clinical outcomes in patients with papillary thyroid cancer. However, the nomograms developed to date are very heterogeneous, and their results seem to be closely related to the specific samples studied to generate the same nomograms. The lack of rigorous external validation procedures and the use of risk factors that sometimes appear to be far from those commonly used in clinical practice, as well as the great heterogeneity of the risk factors considered, limit the ability of nomograms to predict patient outcomes and thus their current introduction in clinical practice.

A nomogram based on the risk factors of cervical lymph node metastasis in papillary thyroid carcinoma coexistent with Hashimoto's thyroiditis

OBJECTIVE

The purpose of this study was to explore the risk factors of cervical lymph node metastasis(LNM) in papillary thyroid carcinoma(PTC) coexistent with Hashimoto's thyroiditis(HT).

METHODS

The clinical data of patients who underwent thyroid operation between November 2016 and January 2020 in our hospital were analyzed retrospectively. The association between sonographic features and the risk factors of cervical LNM in PTC coexistent with HT was analyzed and a nomogram based on the risk factors was built.

RESULTS

Age, US features as calcification, blood flow type, distance between thyroid nodule and fibrous capsule were risk factors of cervical LNM(P < 0.05).Size, SWVmax and SWVmean of thyroid nodule, SWVratio between thyroid nodule and thyroid gland were higher in PTCs with LNM than those without LNM(P < 0.05). The ROC curve showed that the cutoff value of SWVratio for predicting LNM was 1.29 (Sensitivity = 0.806, Specificity = 0.775, AUC = 0.823, P < 0.001). Based on the risk factors above, a relevant nomogram prediction model was established. The model verification showed that the C-index of the modeling set was 0.814, indicating that the nomogram model had good predicted accuracy.

CONCLUSION

Based on the risk factors above, a relevant nomogram prediction model was established. The model verification showed that the C-index of the modeling set was 0.814, indicating that the nomogram model had good predicted accuracy. The nomogram based on the risk factors above had good prediction ability, which could optimize thyroidectomy and cervical lymph node dissection and improving prognosis.

Developing and validating a multivariable machine learning model for the preoperative prediction of lateral lymph node metastasis of papillary thyroid cancer

Background

At present, preoperative diagnosis of lateral cervical lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC) mostly depends on the training and expertise of ultrasound doctors. A machine-learning model for predicting LLNM accurately before PTC surgery may help to determine the scope of surgery and reduce unnecessary surgical trauma.

Methods

The data of patients with primary PTC who underwent thyroidectomy with lateral cervical lymph node surgery at Beijing Tongren Hospital between July 2009 and June 2021 were retrospectively analyzed. All patients had complete ultrasonic examination, clinical data, and definite pathology diagnosis of lymph nodes. LLNM was confirmed by postoperative pathology. The patients were randomly divided into a training set (155 cases) and a test set (98 cases) at a ratio of 6:4. Eleven parameters, including patient demographics, ultrasound results, and tumor-related conditions, were collected, and a prediction model was established using the support vector machine (SVM) algorithm. Several other machine-learning algorithms were also used to establish models for comparison. The accuracy, precision, recall, F1-score, sensitivity, specificity, Cohen's kappa value, and area under the receiver operating characteristic curve (AUC) were used to evaluate model performance.

Results

A total of 87 males and 156 females were included in the study, aged 14-80 years. One hundred and four patients of them had LLNM and 139 did not have LLNM. The pandas Python library was used for the statistical analysis, and the Spearman coefficient was used to analyze the correlation between each parameter and the prediction index. The SVM model performed the best among all the models. Its accuracy, precision, recall, F1-score, sensitivity, specificity, Cohen's kappa value, and AUC were 90.8%, 91.0%, 90.8%, 90.8%, 87.5%, 94.0%, 81.6%, and 91.0%, respectively.

Conclusions

This model can enable surgeons to improve the accuracy of ultrasonography in predicting LLNM without additional examination, thus avoiding missing positive lateral cervical lymph nodes and reducing the sequelae caused by unnecessary lateral neck dissection.

Evaluation of serum B7-H3 expression, ultrasound and clinical characteristics to predict the risk of cervical lymph node metastases in papillary thyroid carcinoma by nomogram

BACKGROUND

Improving the preoperative diagnosis of cervical lymph node metastasis (LNM) will help improve the clinical outcomes of papillary thyroid carcinoma (PTC) patients. B7-H3, as an immune checkpoint of the B7 family, is highly expressed in PTC tissues and related to LNM and prognosis. We aimed to explore the clinical values of serum B7-H3 (sB7-H3) in predicting LNM in PTC by a nomogram prediction model.

METHODS

From September 2019 to May 2021, a total of 344 PTC patients with primary surgery in our hospital were enrolled in this research. Enzyme-linked Immunosorbent Assay (ELISA) was used to detect sB7-H3 from the peripheral blood of PTC patients and normal controls. We created a nomogram prediction model in combination with sB7-H3 expression, clinical and ultrasound characteristics to predict LNM in the early stage.

RESULTS

Gender (p = 0.001), age (p = 0.015), tumor size (p < 0.001), number of tumors (p = 0.021) and sB7-H3 expression (p = 0.003) were independent risk factors for LNM in PTC. All the factors were included in the nomogram. The area under the curve (AUC) was 73.9% (95% CI, 68.12%-79.69%).

CONCLUSION

The nomogram is helpful in assessing the risk of LNM in PTC. sB7-H3 has excellent potential in predicting LNM in patients with PTC as an adjunctive ultrasound tool.

A novel hybrid approach for "Scarless" (at the neck) lateral neck dissection for papillary thyroid carcinoma: A case series and literature review

Lateral neck dissection (LND) is a necessary treatment for thyroid cancer with lateral lymph node metastasis. However, the defect created during open surgery leaves a visible scar on the neck. With advancements in surgical technology, many robotic and endoscopic surgical techniques have been reported as alternatives to open surgery. In this study, we present a case series demonstrating the successful application of a novel hybrid approach for endoscopic LND and a review of different surgical approaches for "scarless" (at the neck) LND. We performed endoscopic LND via a combined chest and transoral approach in 24 patients between January 2021 and March 2022. The surgery was completed successfully in all patients with an average operation time of 298.1 ± 72.9 min. The numbers of positive/retrieved lymph nodes at levels II, III-IV, and VI were 0.7 ± 0.9/8.4 ± 4.1, 3.6 ± 2.7/19.5 ± 6.8, and 4.9 ± 3.9/10.3 ± 4.5, respectively. Complications included transient hypoparathyroidism in 10 patients, transient recurrent laryngeal nerve injury in 1 patient, internal jugular vein (IJN) injury in 1 patient, IJN sacrifice due to cancer invasion in 1 patient, and chyle leak in 1 patient, and no cases of tumor recurrence were observed during follow-up. The present case series indicates that the combined chest and transoral approach is feasible and effective for performing LND. Our review of different approaches for "scarless" (at the neck) LND identified advantages and disadvantages for all techniques. Our novel approach has unique advantages, and thus, it can provide an ideal surgical procedure for specific papillary thyroid carcinoma patients.

Endoscopic thyroidectomy via the combined trans-oral and chest approach for cT1-2N1bM0 papillary thyroid carcinoma

BACKGROUND

Recent years there have been witnessed considerable advances in endoscopic selective lateral neck dissection (LND). However, dissection of lymph nodes at level IV and level VI via the chest approach is inherently challenging. In this study, we used combined trans-oral and chest approach for endoscopic thyroidectomy in patients with cT1-2N1bM0 papillary thyroid carcinoma (PTC).

METHODS

Clinical characteristics and surgical outcomes of ten patients with cT1-2N1bM0 PTC who underwent endoscopic thyroidectomy via combination of trans-oral and chest approach between September 2020 and September 2021 were retrospectively reviewed.

RESULTS

All 10 patients successfully underwent total thyroidectomy and selective LND via chest approach, while central neck dissection (CND) and supplementary dissection of lymph nodes at level IV were performed via the trans-oral approach. The mean number of positive/retrieved level II, III-IV, and VI lymph nodes were 0.6 ± 1.0/9.8 ± 5.0, 4.6 ± 2.8/23.1 ± 4.7, and 4.9 ± 3.4/10.3 ± 4.6, respectively. Four patients developed transient hypoparathyroidism which spontaneously resolved within 1 month. Five patients developed numbness of lateral neck and ear and one patient experienced limb lift restriction. No other complications or tumor recurrence occurred during follow-up.

CONCLUSION

It is feasible to perform total thyroidectomy, CND, and selective LND via combined trans-oral and chest approach, and satisfactory short-term outcomes were observed in this cohort. This approach may offer one more option for cT1-2N1bM0 PTC patients, especially those in whom metastatic lymph nodes at level IV or level VI are detected by preoperative examination.

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.

Value of Echogenic Foci in Diagnosing Papillary Thyroid Carcinoma and Predicting Aggressive Biological Behavior

OBJECTIVES

To assess the diagnostic value of echogenic foci in papillary thyroid carcinoma (PTC) and the relationship between echogenic foci and aggressiveness of PTC.

METHODS

From January 2018 to January 2021, a total of 950 patients diagnosed with thyroid nodules (n = 1113) in our hospital were retrospectively analyzed. Among the 1113 nodules, single PTC in 527 patients confirmed by surgery was studied for their aggressive biological behavior. The patterns of echogenic foci were classified as: no echogenic foci, sparse punctate echogenic foci, focal punctate echogenic foci, diffuse punctate echogenic foci, petal-like punctate echogenic foci, comet-tail artifacts, coarse echogenic foci, peripheral rim (eggshell echogenic foci), and mixed echogenic foci. The clinical and ultrasonographic characteristics were also analyzed. A univariate analysis was performed, and binary logistic regression was performed to screen independent risk factors.

RESULTS

For the differential diagnosis of PTC, age < 50 years, size <1.1 cm, hypoechoic or very hypoechoic, aspect ratio > 1, irregular shape, types II (punctate echogenic foci) and VI (mixed echogenic foci) were independent risk factors. For the aggressive biological behavior of PTC, male sex, age<42 years, size <1.0 cm, types IIb (focal punctate echogenic foci), IIc (diffuse punctate echogenic foci), and VI (mixed echogenic foci) were independent risk factors for predicting cervical lymph node metastasis of PTC.

CONCLUSION

Echogenic foci are useful in diagnosing PTC and predicting aggressiveness of PTC, which contribute to screening invasive PTC and avoiding overdiagnosis and overtreatment.

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.

Qin's seven steps for endoscopic selective lateral neck dissection via the chest approach in patients with papillary thyroid cancer: experience of 35 cases

BACKGROUND

Endoscopic thyroidectomy is widely performed as it does not result in neck scar. However, there is a paucity of reports pertaining to completely endoscopic lateral neck dissection (LND). In this study, we introduce our step-wise approach for performing endoscopic selective LND via the chest-breast approach. We refer to this approach as Qin's seven steps.

METHODS

The Qin's seven steps are: (1) establishment of working space range; (2) dissection of lymph nodes between the SCM and the sternohyoid muscle (level IV) and exposure of omohyoid; (3) dissection of lymph nodes at level IV; (4) dissection of lymph nodes at level III; (5) dissection of lymph nodes at carotid triangle (level III); (6) exposure of accessory nerve and dissection of lymph nodes at level II a; (7) dissection of lymph nodes at level II b. We reviewed the clinical data of 35 patients with papillary thyroid cancer (PTC) who were operated using the Qin's seven steps.

RESULTS

All 35 patients successfully underwent LND; bilateral LND was performed in 5 patients. The mean tumor size was 1.8 ± 1.0 cm; seven patients had multiple lesions. The mean number of retrieved lymph nodes in level II, III and IV were 8.8 ± 5.6, 6.1 ± 4.0 and 9.3 ± 5.1, respectively. As for complications, there were 3 cases of accessory nerve injury and 1 case of hypoglossal nerve injury. Internal jugular vein injury, cervical plexus injury and lymphatic leakage occurred in 2, 7, and 1 patients, respectively.

CONCLUSION

The Qin's seven steps for performing endoscopic selective LND could be safely used in PTC patients with lateral lymph node metastasis. Satisfactory results were achieved in the short-term follow-up period. We recommend the use of Qin's seven steps for PTC patients who are not desirous of neck scar.

[Correlation between conventional ultrasound features and BRAFV600E gene mutation and central lymph node metastasis in thyroid papillary carcinoma]

Objective:To investigate whether central lymph node metastasis（CLNM） in the central region of thyroid papillary carcinoma（PTC） is related to conventional ultrasound features of the primary lesion and BRAFV600E gene mutation. Methods:A total of 300 patients with PTC confirmed by surgical pathology and central lymph node dissection in the First Affiliated Hospital of Jinzhou Medical University from October 2019 to June 2021 were collected. The subjects were divided into the metastatic group and the non-metastatic group according to whether CLNM occurred. The correlation was determined by analyzing the conventional ultrasound characteristics and BRAFV600E gene test results of the two groups of patients. Results:Among 300 PTC patients, 120（40%） had CLNM. Univariate analysis showed that there were statistically significant differences between groups in gender, nodule maximum diameter line, number of lesions, boundaries, morphology, aspect ratio, proximity to the membrane, calcification and BRAFV600E gene mutation（P<0.05）. Logistic multivariate regression analysis showed that gender, maximum diameter line, aspect ratio, proximity to the membrane, microcalcification and BRAFV600E were the risk factors for CLNM in PTC patients（P<0.05）. ROC curve showed that when the maximum diameter was 8.5 mm, the Yooden index was the maximum. Conclusion:When the risk factors of male, maximum diameter ≥8.5 mm, aspect ratio ≥1, microcalcification, proximity to capsule and BRAFV600E（+） appear in PTC patients, high attention should be paid to preventive CLN dissection as soon as possible.

Factors predicting the risk of biochemical incomplete response in well-differentiated thyroid cancer after total thyroidectomy

BACKGROUND

Differentiated thyroid cancer (DTC) is the most common endocrine carcinoma with an overall good prognosis. However, persistent or recurrent disease (P/R disease) and incomplete biochemical response (BIR) are causes of morbidity. Histopathology and TNM stage may not predict P/R disease and BIR in all patients. Various clinical parameters, histopathological features and preablative-stimulated thyroglobulin (presTg) have been proposed to predicts P/R disease. However, there is uncertainty for presTg cutoff and diagnostic accuracy. The study's objective was to predict the BIR before radioiodine ablation from available clinical, histopathological and biochemical parameters.

METHODS

A retrospective, single-center study, including DTC patients, was done. Demography and factors predicting BIR evaluated.

RESULT

In comparison to the patients in remission, patients with BIR were older (P = 0.042), had higher presTg (P < 0.001), and lymph nodes (LN) metastases [central or lateral compartment (P < 0.001)]. Visualization of LN on whole-body scan (P = 0.014), higher TNM stage (P = 0.001) and distance metastasis (P < 0.001) were also associated with BIR. On multivariate analysis, high presTg (P < 0.001) and LN metastases (LNscan and histopathologically proven LN involvement, P < 0.001) were associated with BIR. A presTg level ≥12.30 ng/ml has high sensitivity (90.6%) and specificity (80.6%) to predict the BIR (odds ratio 39.90).

CONCLUSIONS

The presTg and LN involvement are robust markers that predict BIR. A raised presTg level with LN metastases and nonvisualization of the LN on the whole-body scan is a worrying feature for the future BIR. We propose the inclusion of high presTg as a high-risk factor in DTC.

Prediction Model of Pathologic Central Lymph Node Negativity in cN0 Papillary Thyroid Carcinoma

Background

Most patients with papillary thyroid carcinoma (PTC) have an excellent prognosis. Although central lymph node invasion is frequent, management via central lymph node dissection (CLND) remains controversial. The present study retrospectively investigated independent predictors of pathologic central lymph node negativity (pCLN-) and established a prediction model for pCLN- in clinical lymph node negativity (cN0) PTC.

Methods

A total of 2,687 patients underwent thyroid surgery for cN0 PTC from 2013 to 2018 at the First Affiliated Hospital of Chongqing Medical University, and lobectomy plus ipsilateral CLND was the basic surgical extent. Clinicopathological characteristics were reviewed and analyzed. Univariate and multivariate analyses were performed to identify factors related to pCLN-. A prediction model was established based on the results of multivariate analyses.

Results

The pCLN- rate was 51.5% (1,383/2,687). Multivariate analysis revealed that sex, age, thyroid stimulating hormone (TSH), size, location, laterality, unifocality and extrathyroidal extension negativity (ETE-) were independent predictors of pCLN-. The nomogram showed good discriminative ability (C-index: 0.784 and 0.787 in derivation and validation groups, respectively) and was well calibrated. We quantified the clinical usefulness of the nomogram by decision curve analysis. The median length of follow-up was 30 (range 12– 83) months, and 190 cases were lost, with a follow-up rate of 92.9% (2,497/2,687). Of the 2,687 patients included, 21 (0.8%) experienced recurrence.

Conclusion

This nomogram, which integrates available preoperative clinicopathological features and intraoperative frozen biopsy outcomes, is a reliable tool with high accuracy to predict pCLN- in cN0 PTC.

Dynamic Nomogram for Predicting Lateral Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma

OBJECTIVE

To establish a dynamic nomogram based on preoperative clinical data for prediction of lateral lymph node metastasis (LLNM) of papillary thyroid carcinoma.

STUDY DESIGN

Retrospective study.

SETTING

The Sixth Affiliated Hospital of Sun Yat-Sen University.

METHODS

The data of 477 patients from 2 centers formed the training group and validation group and were retrospectively reviewed. Preoperative clinical factors influencing LLNM were identified by univariable and multivariable analysis and were to construct a predictive dynamic nomogram for LLNM. Receiver operating characteristic analysis and calibration curves were used to evaluate the predictive power of the nomogram.

RESULTS

The following were identified as independent risk factors for LLNM: male sex (odds ratio [OR] = 4.6, P = .04), tumor size ≥10.5 mm (OR = 7.9, P = .008), thyroid nodules (OR = 6.1, P = .013), irregular tumor shape (OR = 24.6, P = .001), rich lymph node vascularity (OR = 9.7, P = .004), and lymph node location. The dynamic nomogram constructed with these factors is available at https://zxh1119.shinyapps.io/DynNomapp/. The nomogram showed good performance, with an area under the curve of 0.956 (95% CI, 0.925-0.986), a sensitivity of 0.87, and a specificity of 0.91, if high-risk patients were defined as those with a predicted probability ≥0.3 or total score ≥200. The nomogram performed well in the external validation cohort (area under the curve, 0.915; 95% CI, 0.862-0.967).

CONCLUSIONS

The dynamic nomogram for preoperative prediction of LLNM in papillary thyroid carcinoma can help surgeons identify high-risk patients and develop individualized treatment plans.

Risk Factors for and Prediction Model of Skip Metastasis to Lateral Lymph Nodes in Papillary Thyroid Carcinoma

BACKGROUND

Cervical lymph node metastasis is a prognostic factor of papillary thyroid carcinoma (PTC). Skip metastasis (central lymph node negative and lateral lymph node positive) of PTC is not uncommon. This study aimed to retrospectively investigate the risk factors for skip metastasis in PTC and develop a prediction model for skip metastasis.

METHODS

A total of 745 PTC patients underwent total thyroidectomy and central plus lateral lymph node dissection at the First Affiliated Hospital of Chongqing Medical University from January 2012 to December 2017. Clinicopathological characteristics were collected and analyzed. Univariate and multivariate analyses were performed to detect the risk factors for skip metastasis. A prediction model was established based on the results of multivariate analyses.

RESULTS

The skip metastasis rate was 9.7% (72/745). Age > 55 years (OR 2.63, 95% CI 1.34-5.04, p = 0.004), tumor located in the upper portion (OR 4.15, 95% CI 2.30-7.63, p = 0.001), and unilaterality (OR 2.76, 95% CI 1.14-8.23, p = 0.040) were independent risk factors for skip metastasis. Clinically lymph node-negative (cN0) patients with tumor in the upper portion (24.6%, 43/175) had higher possibility of skip metastasis than those of clinically lateral lymph node-positive (cN1b) patients (5.9%, 10/169) (p = 0.001). The area under the receiver operating characteristic curve of prediction model was 0.734 and 0.740 in derivation group and validation group, respectively. However, skip metastasis was not associated with tumor-free survival rate of PTC patients (p = 0.274).

CONCLUSION

Age > 55 years, tumor located in the upper portion, and unilaterality may increase the risk of skip metastasis. We developed the first prediction model for skip metastasis based on clinicopathological parameters in PTC patients.

Risk Factors for Contralateral Occult Carcinoma in Patients With Unilateral Papillary Thyroid Carcinoma: A Retrospective Study and Meta-Analysis

BACKGROUND

Bilateral lesions are common in papillary thyroid carcinoma (PTC). For patients with unilateral PTC, occult carcinoma that is not detected preoperatively, but pathologically after surgery, might remain in the contralateral lobe. In this situation, inadequate surgical extent could cause relapse and even lead to re-operation. Here, we explore the frequency and investigate the risk factors of contralateral occult PTC in unilateral PTC through a retrospective study conducted by our team and published articles online, respectively.

METHODS

We collected the patients' clinical data in our hospital, whose cancer was determined to be confined to the unilateral lobe by preoperative image examination (N = 204). These patients underwent initially total or near-total thyroidectomy and included their clinical data in the meta-analysis. We searched related literature in the PubMed, Embase, MEDLINE, Cochrane, and Web of Science databases until December 7, 2020, in order to perform a meta-analysis. The relevant articles were examined and the eligible studies were included to assess the association between clinicopathologic factors and contralateral occult PTC.

RESULTS

The meta-analysis included nine studies (involving 4347 patients). Of these, eight studies were from the databases, and one study was our retrospective data. The meta-analysis showed that the prevalence of contralateral occult PTC was 26.6% in all patients. A tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and central lymph node metastasis were significantly associated with contralateral occult PTC. In contrast, sex, age, ETE, capsular invasion, BRAF mutation, Hashimoto thyroiditis, and lateral lymph node metastasis were insignificantly associated with contralateral occult PTC.

CONCLUSION

The meta-analysis identified a tumor size > 1 cm, ipsilateral multifocality, contralateral benign nodule, and CLNM as being significant risk factors for contralateral occult PTC. These findings may guide the extent of surgery in unilateral PTC patients.

Multi-gene assay and clinical characteristics research in papillary thyroid carcinoma

Background

To investigate the significance of multi-gene assay in papillary thyroid carcinoma (PTC) patients in clinical practice.

Methods

From April to December 2019, medical records of 68 patients with PTC after the initial surgery were retrospectively collected and analyzed in terms of the relations between gene mutations and clinicopathological characteristics.

Results

RET/PTC rearrangement was not detected in BRAF V600E mutation patients (P<0.001). Besides, compared with wild-type patients, BRAF V600E mutation was associated with significantly older age (P=0.001) and a higher rate of extrathyroid invasion (P=0.023). Significantly higher BRAF V600E mutation rates were found in clinical lymph node-negative (P=0.041) and non-metastatic lateral lymph nodes (P=0.027) patients as RET/PTC rearrangement was associated with younger age (P=0.001) and the increasing metastatic number of lymph nodes (P=0.020). Compared to other gene mutations, the multivariate analysis showed that larger tumor size [odds ratio (OR), 8.831; 95% CI: 1.971-35.578; P=0.004], the BRAF V600E mutation alone(OR, 10.567; 95% CI: 1.748-63.873; P=0.010) or in combination with one additional gene mutation (OR, 8.654; 95% CI: 1.453-68.603; P=0.041), and Hashimoto's thyroiditis (OR, 0.112; 95% CI: 0.025-0.499; P=0.004) were all independent predictors for the prevalence of ETE.

Conclusions

BRAF V600E mutation was associated with older age and the aggressiveness of PTC but was independent of lymph node metastasis (LNM). RET/PTC rearrangement suggested more LNM in young patients with PTC. BRAF V600E mutation combined with other gene mutations, namely, multi-gene mutations, could indicate a higher aggressiveness in PTC.

Risk Factors for Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Systematic Review and Meta-Analysis

Purpose: To explore the risk factors that may predict the lymph node metastasis potential of these lesions and new prevention strategies in papillary thyroid carcinoma patients. Materials and Methods: In total, 9,369 papillary thyroid carcinoma patients with 37.17% lymph node metastasis were analyzed (Revman 5.3 software) in this study. The PubMed and Embase databases were used for searching works systematically that were published through to January 22, 2020. Results: Several factors were related to the increased risk of lymph node metastasis in patients with papillary thyroid carcinoma: age <45 years (pooled OR = 1.52, 95% CI = 1.14-2.01, p <0.00001); gender = male (pooled OR = 1.68, 95% CI = 1.51-1.87, p <0.00001); multifocality (pooled OR = 2.05, 95% CI = 1.45-2.89, p <0.0001); tumor size ≥1.0 cm (pooled OR = 3.53, 95% CI = 2.62-4.76, p <0.00001); tumor location at the upper pole 1/3 (pooled OR =1.46, 95% CI = 1.04-2.04, p = 0.03); capsular invasion + (pooled OR = 3.48, 95% CI = 1.69-7.54, p = 0.002); and extrathyroidal extension + (pooled OR = 2.03, 95% CI= 1.78-2.31, p <0.00001). However, tumor bilaterality (pooled OR = 0.85, 95% CI = 0.54-1.34, p = 0.49) and Hashimoto's thyroditis (pooled OR = 1.08, 95% CI = 0.79-1.49, p = 0.62) showed no correlation with lymph node metastasis in papillary thyroid carcinoma patients. Conclusion: The systematic review and meta-analysis defined several significant risk factors of lymph node metastasis in papillary thyroid cancer patients: age (<45 years), gender (male), multifocality, tumor size (>1 cm), tumor location (1/3 upper), capsular invasion, and extra thyroidal extension. Bilateral tumors and Hashimoto's thyroiditis were unrelated to lymph node metastasis in patients with papillary thyroid cancer.

Development and validation of web-based nomograms for predicting lateral lymph node metastasis in patients with papillary thyroid carcinoma

Background

The purpose of this study was to evaluate the factors associated with lateral lymph node metastasis (LLNM) in patients with papillary thyroid carcinoma (PTC), and to develop two web-based nomograms that predict the probability of level-II and level-III/IV LLNM in these patients.

Methods

The records of 653 patients with PTC were retrospectively reviewed. Univariate and multivariate analyses were performed to identify risk factors associated with LLNM in 460 patients ("derivation group"). Two models [including and excluding the subregions of central lymph node metastasis (CLNM)] were used to predict the probability of level-II LLNM; the same two models were also used for level-III/IV LLNM. Model performance was assessed using receiver operating characteristic (ROC) analysis and decision curve analysis (DCA) in 193 patients ("validation group"). Two web-based nomograms were established.

Results

Increased tumor size, a tumor in the upper lobe, and prelaryngeal and ipsilateral paratracheal lymph node metastasis (LNM) were significantly associated with level-II LNM (P<0.05). Increased tumor size, a tumor in the upper lobe, and certain subregions of CLNM were associated with level-III/IV LNM (P<0.05). Use of ROC analysis of each model indicated that including subgroups of CLNM led to better model performance than excluding these subgroups. We quantified the benefit of each model by using DCA analysis in the validation group.

Conclusions

Our web-based nomograms provide quantification of risk for LLNM in patients with PTC before and during surgery.

Individualized Prediction Of Metastatic Involvement Of Lymph Nodes Posterior To The Right Recurrent Laryngeal Nerve In Papillary Thyroid Carcinoma

Purpose

We aimed to establish a prediction model based on preoperative clinicopathologic features and intraoperative frozen section examination for precise prediction of metastatic involvement of lymph nodes posterior to the right recurrent laryngeal nerve (LN-prRLN) in patients with papillary thyroid carcinoma (PTC).

Methods

Clinicopathologic data pertaining to patients with PTC who underwent initial thyroid surgery between July 2015 and December 2017 were collected from electronic medical records. Multivariate logistic regression analysis was performed to identify independent predictors of LN-prRLN metastasis for incorporation in the nomogram. The performance of the model was assessed using discriminative ability, calibration, and clinical application.

Results

A total of 592 patients were enrolled in this study. The LN-prRLN metastatic positivity was 19% (95% confidence interval [CI], 15.61–21.89%). On multivariate analysis, ultrasonography-reported LN status, extrathyroid extension, Delphian lymph node metastasis, and number of metastatic pretracheal and paratracheal lymph nodes were independent predictors of LN-prRLN metastasis. The nomogram showed good discriminative ability (C-index: 0.87; [95% CI, 0.84–0.91]; bias-corrected C-index: 0.86 [through bootstrapping validation]) and was well calibrated. The decision curve analysis indicated potential clinical usefulness of the nomogram.

Conclusion

This study demonstrates that the risk of LN-prRLN metastasis in individual patients can be robustly predicted by a nomogram that integrates readily available preoperative clinicopathologic features and intraoperative frozen section examination. The nomogram may facilitate intraoperative decision-making for patients with PTC.

Significance of CEP78 and WDR62 gene expressions in differentiated thyroid carcinoma: Possible predictors of lateral lymph node metastasis

OBJECTIVES

This study aimed at investigating the clinical significance of CEP78 and WDR62 in differentiated thyroid carcinoma (DTC). This study also aimed at finding predictors that help in detecting patients with DTC who have high risk for lateral lymph node metastasis (LNM).

METHODS

Quantitative real-time polymerase chain reaction (RT-qPCR) was performed to examine CEP78, and WDR62 mRNA expressions in 40 tissue specimens of DTC, and 40 goiter tissue specimens. Additionally, we reviewed clinical, ultrasound, laboratory, pathological data of patients to analyze the associations between these characteristics and lateral LNM.

RESULTS

Our results demonstrated that relative CEP78 mRNA levels were significantly decreased in thyroid cancer tissues than goiter tissues (P = 0.002). ROC curve analysis confirmed the diagnostic value of CEP78 mRNA expression, providing an AUC equals to 0.698 (95% confidence intervals (CI), 0.583-0.813; P = 0.002). The relative WDR62 mRNA expression was not statistically different in DTC tissues and goiter tissues (P = 0.686). Furthermore, the DTC patients had been included to examine risk factors for lateral LNM. In multivariate analysis, the significant factors for predicting lateral LNM were low CEP78 mRNA expression (cut off value ≤0.54; P = 0.03; OR = 19.62; 95% CI, 1.3-296.23), central LNM (P = 0.011; OR = 33.6; 95% CI, 2.24-503.6) and calcifications (P = 0.023; OR = 27.187; 95% CI, 1.57-469.5).

CONCLUSIONS

CEP78 can be used as a promising molecular biomarker for differentiation between DTC and goiter tissues, in addition it might serve as a predictor of lateral LNM in DTC along with central LNM and calcifications. Unlike CEP78, WDR62 mRNA expression was not statistically different in DTC and goiter.

Risk factors for skip metastasis and lateral lymph node metastasis of papillary thyroid cancer

BACKGROUND

Lymph node metastases from papillary thyroid cancer is believed to disseminate sequentially, first to the central neck and later to the lateral neck. Skip metastases of papillary thyroid cancer, however, are defined as lateral lymph node metastasis without central lymph node metastasis. The aim of this study was to investigate the risk factors for skip metastases and lateral lymph node metastasis of papillary thyroid cancer.

METHODS

We reviewed 721 papillary thyroid cancer patients undergoing total thyroidectomy with central lymph node dissection and lateral lymph node dissection during 2013 to 2018. Multivariate logistic regression analysis was performed to identify clinicopathologic risk factors for skip metastasis and lateral lymph node metastasis of papillary thyroid cancer.

RESULTS

The rate of skip metastases was 7.4% (42 of 567 patients). Multivariate analysis showed that female sex and papillary thyroid microcarcinoma (≤ 1 cm) were independent risk factors for skip metastases, with odds ratios ([OR], 95% confidence interval [CI]) of 2.29 (1.02-5.16) and 2.84 (1.46-5.16), respectively. Intrathyroidal spread of papillary thyroid cancer and an increased number of central lymph nodes dissected were inversely associated with skip metastases with ORs (95% CI) of 0.13 (0.02-0.99) and 0.88 (0.83-0.94), respectively. In contrast, a greater tumor size, central lymph node metastasis, an increased number of central lymph nodes dissected, and an increased number of lateral lymph nodes dissected were associated with a lateral lymph node metastasis risk of papillary thyroid cancer, with ORs (95% CI) as follow: 1.67 (1.08-2.59), 3.07 (1.71-5.52), 1.25 (1.14-1.37), and 1.07 (1.04-1.10), respectively, by multivariate analysis.

CONCLUSION

Greater tumor size, central lymph node metastasis, and an increased number of both central lymph nodes and lateral lymph nodes dissected were predictors for lateral lymph node metastasis of papillary thyroid cancer. In addition, papillary thyroid microcarcinoma was an independent risk factor for skip metastases. A complete and comprehensive central compartment dissection may decrease the false-positive detection of skip metastases of papillary thyroid cancer.

Comparison of the prevalence of incidental and non-incidental papillary thyroid microcarcinoma during 2008-2016: a single-center experience

Background

The incidence of papillary thyroid microcarcinoma (PTMC) is increasing; however, it is not clear whether this reflects an increase in the incidence of incidental or in that of non-incidentally (presurgically) discovered PTMC (IPTMC vs. NIPTMC). We assessed the incidence of IPTMC and NIPTMC over the past 9 years, to discern whether the increase in PTMC incidence is due to improved diagnostics or to a real increase in the incidence.

Methods

We performed a retrospective chart review of 4327 patients who were consecutively admitted to and surgically treated for thyroid pathology at a single institution. As a main presurgical diagnostic test, all patients underwent ultrasound-guided fine-needle aspiration biopsy (UG-FNAB). The analyzed time frame was divided into three equal periods (I: 2008–2010, II: 2011–2013, III: 2014–2016), and IPTMCs and NIPTMCs were assessed and compared in each period.

Results

We evaluated 393 (9.08%) patients with thyroid malignancy, of which 156 (3.60% of all thyroid tumors [TTs]; 39.69% of all thyroid cancers [TCs]) were diagnosed as PTMC. The prevalence of NIPTMC among all TCs increased from 16.66% in 2008 to 33.75% in 2016, while that of IPTMC decreased from 20.83% in 2008 to 13.75% in 2016. The incidence rates of NIPTMC and IPTMC in period III differed statistically significantly (p < 0.0001). The prevalence rate of NIPTMC in period III was higher than that in period II, yet comparable to that in period I (p = 0.0014; p = 0.2804, respectively).

Conclusions

The prevalence of NIPTMC, rather than that of IPTMC, is escalating; this may be due to better presurgical diagnosis.