Clinical and Pathologic Predictors of Lymph Node Metastasis and Recurrence in Papillary Thyroid Microcarcinoma

Development and validation of a clinical predictive model for high-volume lymph node metastasis of papillary thyroid carcinoma

The central lymph node metastasis (CLNM) status in the cervical region serves as a pivotal determinant for the extent of surgical intervention and prognosis in papillary thyroid carcinoma (PTC). This paper seeks to devise and validate a predictive model based on clinical parameters for the early anticipation of high-volume CLNM (hv-CLNM, > 5 nodes) in high-risk patients. A retrospective analysis of the pathological and clinical data of patients with PTC who underwent surgical treatment at Medical Centers A and B was conducted. The data from Center A was randomly divided into training and validation sets in an 8:2 ratio, with those from Center B serving as the test set. Multifactor logistic regression was harnessed in the training set to select variables and construct a predictive model. The generalization ability of the model was assessed in the validation and test sets. The model was evaluated through the receiver operating characteristic area under the curve (AUC) to predict the efficiency of hv-CLNM. The goodness of fit of the model was examined via the Brier verification technique. The incidence of hv-CLNM in 5897 PTC patients attained 4.8%. The occurrence rates in males and females were 9.4% (128/1365) and 3.4% (156/4532), respectively. Multifactor logistic regression unraveled male gender (OR = 2.17, p < .001), multifocality (OR = 4.06, p < .001), and lesion size (OR = 1.08 per increase of 1 mm, p < .001) as risk factors, while age emerged as a protective factor (OR = 0.95 per an increase of 1 year, p < .001). The model constructed with four predictive variables within the training set exhibited an AUC of 0.847 ([95%CI] 0.815-0.878). In the validation and test sets, the AUCs were 0.831 (0.783-0.879) and 0.845 (0.789-0.901), respectively, with Brier scores of 0.037, 0.041, and 0.056. Subgroup analysis unveiled AUCs for the prediction model in PTC lesion size groups (≤ 10 mm and > 10 mm) as 0.803 (0.757-0.85) and 0.747 (0.709-0.785), age groups (≤ 31 years and > 31 years) as 0.778 (0.720-0.881) and 0.837 (0.806-0.867), multifocal and solitary cases as 0.803 (0.767-0.838) and 0.809 (0.769-0.849), and Hashimoto's thyroiditis (HT) and non-HT cases as 0.845 (0.793-0.897) and 0.845 (0.819-0.871). Male gender, multifocality, and larger lesion size are risk factors for hv-CLNM in PTC patients, whereas age serves as a protective factor. The clinical predictive model developed in this research facilitates the early identification of high-risk patients for hv-CLNM, thereby assisting physicians in more efficacious risk stratification management for PTC patients.

BRAFV600E mutation does not predict lymph node metastases and recurrence in Chinese papillary thyroid microcarcinoma patients

OBJECT

Previous studies suggest BRAFV600E mutation is a marker for poor prognosis in papillary thyroid cancer, however, its ability to further risk stratify papillary thyroid microcarcinoma (PTMC) remains controversial. We aimed to explore the association between BRAFV600E mutation and the clinicopathological features and recurrence in Chinese PTMC patients.

METHODS

We retrospectively reviewed 2094 PTMC patients who underwent surgery and had a valid BRAFV600E mutation test result. Among them, 1292 patients had complete follow-up data. The mutation incidence was determined. Moreover, the clinicopathological characteristics, disease-free survival (DFS), and response to therapy distribution were compared between the mutation and non-mutation groups.

RESULTS

BRAFV600E mutation was observed in 90.6 % of all patients and 89.2 % of patients with complete follow-up data. No significant difference was observed in lymph node metastases (LNM) number categories between the mutation and non-mutation groups among all patients (P = 0.329) and 1292 patients (P = 0.408). Neither the 3-year DFS (97.9 % vs. 98.0 %, P = 0.832) nor the response to therapy distribution (P > 0.05) indicated a significant difference between the mutation and non-mutation groups. The 3-year DFS differs among patients having different LNM number categories (99.8 % vs. 98.5 % vs. 77.3 %, P < 0.001). Multivariate analysis revealed that high-volume (over 5) LNM (Total thyroidectomy (TT): OR = 4.000, 95 % CI 2.390-6.694, P < 0.001; Unilateral thyroidectomy (UT): OR = 4.183, 95 % CI 1.565-11.190, P = 0.004), rather than BRAFV600E mutation (P > 0.05), was an independent risk factor of response to therapy.

CONCLUSIONS

Our results suggested that BRAFV600E mutation could not accurately predict LNM or the recurrence of Chinese PTMC patients. Moreover, high-volume LNM is significantly associated with PTMC prognosis.

Risk factors for tumor enlargement in low-risk papillary thyroid microcarcinoma patients: a systematic review and meta-analysis

PURPOSE

The current management guidelines for low-risk papillary thyroid microcarcinoma (PTMC) do not specify how to screen for growing tumors. We sought to explore the possible risk factors for tumor enlargement in patients with low-risk PTMC under active surveillance (AS).

METHODS

We searched the PubMed and Embase databases for high quality studies up to January 10th, 2024. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the included studies, and Review Manager 5.4 was used to analyze possible risk factors and calculate pooled risk ratios (RRs) via the inverse-variance calculation method.

RESULTS

Eleven studies were included in our meta-analysis. Among the 8880 participants, 464 experienced tumor growth, and the incidence of tumor growth varied from 3.4% to 19.4%. The results of the meta-analysis showed that tumor enlargement was associated with younger age (pooled RR = 2.32, 95% CI = 1.85-2.90, p < 0.00001; 8 studies), and higher serum thyroid-stimulating hormone (TSH) levels (pooled RR = 2.28, 95% CI = 1.19-4.37, p = 0.01; 6 studies), and could be related to pregnancy (pooled RR = 2.54, 95% CI = 1.17-5.52, p = 0.02; 2 studies). However, these following factors showed no significant association with tumor growth: sex (pooled RR = 1.07, 95% CI = 0.63-1.84, p = 0.79; 7 studies), tumor size at diagnosis (pooled RR = 1.08, 95% CI = 0.63-1.85, p = 0.77; 5 studies), and Hashimoto's thyroiditis (HT) (pooled RR = 1.56, 95% CI = 0.93-2.60, p = 0.09; 2 studies).

CONCLUSION

Our analysis identified that younger age and higher serum TSH levels were higher risk factors for tumor enlargement in low-risk PTMC patients. Pregnancy is a suspected risk factor.

Active Surveillance for Low-Risk Thyroid Cancers: A Review of Current Practice Guidelines

The indolent nature and favorable outcomes associated with papillary thyroid microcarcinoma have prompted numerous prospective studies on active surveillance (AS) and its adoption as an alternative to immediate surgery in managing low-risk thyroid cancer. This article reviews the current status of AS, as outlined in various international practice guidelines. AS is typically recommended for tumors that measure 1 cm or less in diameter and do not exhibit aggressive subtypes on cytology, extrathyroidal extension, lymph node metastasis, or distant metastasis. To determine the most appropriate candidates for AS, factors such as tumor size, location, multiplicity, and ultrasound findings are considered, along with patient characteristics like medical condition, age, and family history. Moreover, shared decision-making, which includes patient-reported outcomes such as quality of life and cost-effectiveness, is essential. During AS, patients undergo regular ultrasound examinations to monitor for signs of disease progression, including tumor growth, extrathyroidal extension, or lymph node metastasis. In conclusion, while AS is a feasible and reliable approach for managing lowrisk thyroid cancer, it requires careful patient selection, effective communication for shared decision-making, standardized follow-up protocols, and a clear definition of disease progression.

Lateral lymph node metastasis in papillary thyroid microcarcinoma: a study of 5241 follow-up patients

PURPOSE

To investigate the impact of lateral lymph node metastasis in papillary thyroid microcarcinoma (PTMC).

METHODS

5241 PTMC patients with follow-up information were enrolled in the current study. These patients underwent primary surgery in our situation from January 1997 to December 2016. Additionally, a validation cohort consisting of 274 PTMC patients who underwent primary surgery between January 2020 and December 2021 was also included. Univariable and multivariate logistic analyses were conducted to identify the association between clinicopathologic features and lateral lymph node metastasis (LLNM). Kaplan-Meier survival curve analysis was used to calculate the disease-free survival (DFS) rate. The fitting curve was generated to identify the quantitative relationship between central lymph node metastases (CLNM) and LLNM.

RESULTS

Of 5241 PTMC patients, cervical lymph node metastasis was detected in 1494 (28.5%) cases, including 1364 (26.0%) with CLNM only and 130 (2.5%) with LLNM. With a median follow-up time of 60 months (interquartile range [IQR], 44-81), recurrence was detected in 114 patients (2.2%). Multivariate Cox regression analyses showed that LNM was the only independent risk factor for recurrence, with HR values of 3.03 in CLNM and 11.14 in LLNM, respectively. Tumor diameter >0.5 cm (hazard ratio [HR]:1.80), multifocality (HR:2.59), bilaterality (HR:2.13), extrathyroidal invasion (HR:2.13), and CLNM (HR:5.11) were independent risk factors for LLNM. The prevalence of LLNM escalated significantly with increasing number of lymph node involvement in CLNM when stratified by the number of metastatic lymph nodes and trend was observed similarly in the validation cohort. The fitting curve showed that the incidence of LLNM could be as high as 20.7% when the number of CLNM ≥ 5.

CONCLUSIONS

By analyzing a large database with follow-up information, our study provides evidence that LLNM is significantly correlated with tumor recurrence in patients with PTMC. Tumor size (>0.5 cm), multifocality, bilaterality, extrathyroidal extension (ETE) and CLNM are independent risk factors for LLNM.

The Impact of Total Tumor Diameter on Lymph Node Metastasis and Tumor Recurrence in Papillary Thyroid Carcinomas

(1) Introduction: The impact of multifocality/bilaterality on the prognosis of papillary thyroid carcinoma (PTC) is a matter of debate. In order to clarify this debate, several studies have attempted to identify additional parameters associated with poor prognosis, including total tumor diameter (TTD), in the context of multifocal PTCs. In this context, this study was carried out to investigate the impact of TTD on tumor recurrence and lymph node metastasis (LNM) in PTCs. (2) Materials and Methods: The sample of this single-center retrospective study consisted of 706 patients diagnosed with PTC. TTD was calculated as the sum of the largest diameters of tumor foci in multifocal tumors. The resulting TTDs were grouped into TTDs ≤ 10 mm, TTDs > 10 mm, TTDs ≤ 20 mm, and TTDs > 20 mm, using 10 mm and 20 mm as cutoff values. (3) Results: There was no significant difference between multifocal papillary microcarcinomas (PTMCs) with a TTD of >10 mm and unifocal PTCs with a primary tumor diameter (PTD) of >10 mm except for advanced age and lymphovascular invasion (LVI). In addition, perineural invasion (PNI) and TTD > 10 mm were found to be significant risk factors for LNM, and PNI, TTD > 10 mm, TTD > 20 mm, and bilaterality were found to be significant risk factors for recurrence. LVI, and TTD > 10 mm were found to be independent significant predictors for recurrence, and LVI and extrathyroidal extension (ETE) were found to be independent significant predictors for LNM. (4) Conclusions: Considering TTD > 10 mm in recurrence risk categorization models and adopting a clinical approach that takes into account multifocal PTMCs with TTD > 10 mm along with unifocal PTCs with PTD > 10 mm may be more useful in terms of clinical management of the disease.

Carbon nanoparticles beneficial for prophylactic central compartment lymph node dissection in cN0 papillary thyroid carcinoma

Objective

This study explored prophylactic central compartment lymph node dissection (pCCLND) for patients with cN0 papillary thyroid carcinoma (PTC) and the effect of carbon nanoparticles (CNP) on surgical outcomes.

Methods

This retrospective study reviewed PTC cases treated at our tertiary medical institution between January 2019 and December 2022. Only patients with indications for total thyroidectomy and cN0 disease were included. CNP has been associated with a higher number of harvested lymph nodes and a lower rate of accidental parathyroid gland (PTG) removal. Patients who used CNP in this study were classified as group 1, while those who denied its use were classified as group 2.

Results

In total, 116 cases were included, with 80 patients in group 1 and 36 in group 2. Most patients were in stage T1, with 68 (85.0 %) patients in group 1 and 31 (86.1 %) in group 2. Postoperative hoarseness occurred in 3 (3.8 %) patients in group 1 and 1 (2.8 %) in group 2, which recovered within two months. In group 2, 250 nodes were harvested, 72 (28.8 %) of which were metastatic; in group 1, 889 nodes were harvested, 316 (35.5 %) of which were metastatic; the difference regarding the rates of metastatic lymph nodes between the 2 groups was statistically significant (P = 0.047). Differences in postoperative blood calcium and parathyroid hormone levels between the two groups were statistically significant (P = 0.035 and P = 0.034, respectively). There were symptoms of hypocalcemia in 6 (16.7 %) patients in group 2 but in only 2 (2.5 %) in group 1, all of which recovered within three months; the difference was statistically significant (p = 0.017).

Conclusion

pCCLND is worth undertaking for cN0 PTC. CNP is beneficial for achieving more thorough dissection and reducing temporary hypoparathyroidism.

Diagnosing postoperative lymph node metastasis in thyroid cancer with multimodal radiomics and clinical features

Purpose

This study aims to evaluate the diagnostic value of texture analysis for lymph node metastasis after thyroid cancer surgery.

Methods

We retrospectively analyzed patients who underwent positron emission tomography/computed tomography (PET/CT) examination before 131I treatment at Shanghai Tenth People's Hospital between 2017 and 2020. Clinical follow-up results were used as the criterion for determining the presence of lymph node metastasis. The study included 119 patients, who were then randomly divided into training and test groups in a 7:3 ratio. Regions of interest were identified, and radiomics features were extracted using LIFEx 7.3.0. Mann-Whitney U test and LASSO regression were employed to screen radiomics parameters for modeling. Subsequently, a nomogram model was built by combining radscore and clinical features. SPSS 26.0 software was utilized for statistical analysis, and p < 0.05 was considered statistically significant.

Results

Follow-up confirmed 54 patients with thyroid cancer lymph node metastasis and 65 patients in the non-metastasis group. A total of 119 lymph nodes were delineated. For each lesion, 164 CT texture features and 164 PET texture features were extracted, and 107 significant parameters were identified, including 16 CT texture parameters and 91 PET texture parameters. After screening, 3 CT parameters, 4 PET parameters and 12 PET/CT parameters were selected to establish three radiomic models. The AUC values were as follows: AUC (CT) = 0.730, AUC (PET) = 0.759 and AUC (PET/CT) = 0.864. We then combined clinical features and radscore to construct a nomogram, resulting in a C-index of 0.915 in the training group. In the test group, the C-index was confirmed to be 0.868.

Conclusions

Radiomics may enhance the diagnostic efficiency of lymph node metastases after thyroid cancer surgery and could potentially assist clinicians in future diagnoses. The developed nomogram, which combines radiomics and clinical features, offers relatively high accuracy in helping clinicians assess the risk of metastasis in thyroid patients after surgery.

Integrating US-guided FNAB, BRAFV600E mutation, and clinicopathologic characteristics to predict cervical central lymph-node metastasis in preoperative patients with cN0 papillary thyroid carcinoma

BACKGROUND

The prevalence of cervical central lymph-node metastasis (CLNM) is high in patients with papillary thyroid carcinoma (PTC). There is considerable controversy surrounding the benefits of prophylactic central lymph-node dissection (pCLND) in patients with clinically negative central compartment lymph nodes (cN0). Therefore, it is crucial to accurately predict the likelihood of cervical CLNM before surgery to make informed surgical decisions.

METHODS

Date from 214 PTC patients (cN0) who underwent partial or total thyroidectomy and pCLND at the Guizhou Provincial People's Hospital were collected and retrospectively analyzed. They were divided into two groups in accordance with cervical CLNM or not. Their information, including clinical characteristics, ultrasound (US) features, pathological results of fine-needle aspirations biopsy (FNAB), and other characteristics of the groups, was analyzed and compared using univariate and multivariate logistic regression analyses.

RESULTS

A total of 214 patients were eligible in this study. Among them, 43.5% (93/214) of PTC patients had cervical CLNM, and 56.5% (121/214) did not. The two groups were compared using a univariate analyses, and there were no significant differences between the two groups in aspect ratio, boundary, morphology, component, and BRAFV600E (P > 0.05), and there were significant differences between gender, age, maximum tumor size, tumor location, capsule contact, microcalcifications, color Doppler flow imaging (CDFI), and Hashimoto's thyroiditis (HT) (P < 0.05). A multivariate logistic regression analysis was performed to further clarify the correlation of these indices. However, only age (OR = 2.455, P = 0.009), maximum tumor size (OR = 2.586, P = 0.010), capsule contact (OR = 3.208, P = 0.001), and CDFI (OR = 2.225, P = 0.022) were independent predictors of cervical CLNM. Combining these four factors, the area under the receiver-operating characteristic (ROC) curve for the joint diagnosis is 0.8160 (95% 0.7596-0.8725). Univariate analysis indicated that capsule contact (P = 0.001) was a possible predictive factor of BRAFV600E mutation.

CONCLUSIONS

In conclusion, four independent predictors of cervical CLNM, including age < 45 years, tumor size > 1.0 cm, capsule contact, and rich blood flow, were screened out. Therefore, a comprehensive assessment of these risk factors should be conducted when designing individualized treatment regimens for PTC patients.

Constructing a nomogram based on the distribution of thyroid nodules and suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies to predict metastasis in papillary thyroid carcinoma

Purpose

Elevated concentrations of thyroglobulin eluent is a risk factor for lateral cervical lymph node metastasis (LLNM) in patients with papillary thyroid cancer (PTC). We aimed to develop a practical nomogram based on the distribution of thyroid nodules and the presence of suspicious lateral cervical lymph nodes in fine-needle aspiration biopsies (LN-FNABs), including the cytopathology and the suspicious lateral cervical lymph node (LLN) thyroglobulin eluent (Tg), to predict the possibility of LLNM preoperatively in patients with PTC.

Methods

The clinical data of PTC patients who were admitted to the Third Affiliated Hospital of Soochow University from January 2022 to May 2023 to undergo fine-needle aspiration biopsy (FNAB) were included in this study. A total of 208 patients in 2022 served as the training set (70%), and 89 patients in 2023 served as the validation set (30%). The clinical characteristics and LN-FNAB results were collected to determine the risk factors of LLNM. A preoperative nomogram was developed for predicting LLNM based on the results of the univariate and multivariate analyses. Internal calibration, external calibration, and decision curve analysis (DCA) were performed for these models.

Results

The multivariate logistic regression analysis showed that the maximum thyroid nodule diameter (Odds Ratio (OR) 2.323, 95% CI 1.383 to 3.904; p = 0.001), Tg level (OR 1.007, 95% CI 1.005 to 1.009; p = 0.000), Tg divided by serum thyroglobulin, (Tg/sTg) [odds ratio (OR) 1.005, 95% CI 1.001 to 1.008; p = 0.009], and cytopathology (OR 9.738, 95% CI 3.678 to 25.783; p = 0.000) (all p <  0.05) had a significant impact on the LLNM of patients with suspicious LLNs. The nomogram showed a better predictive value in both the training cohort [area under the curve, (AUC) 0.937, 95% CI 0.895 to 0.966] and the validation cohort (AUC 0.957, 95% CI 0.892 to 0.989). The nomogram also showed excellent internal and external calibration in predicting LLNM. According to the DCA, the diagnostic performance of this model was dependent on the following variables: maximum thyroid nodule diameter, Tg level, Tg/sTg, and cytopathology.

Conclusion

Based on the aforementioned risk factors, we believe that it is necessary to establish a personalized LLNM model for patients with PTC. Using this practical nomogram, which combines clinical and Tg risk factors, surgeons could accurately predict the possibility of LLNM preoperatively. The nomogram will also help surgeons to establish personalized treatment plans before surgery.

US Predictors of Papillary Thyroid Microcarcinoma Progression at Active Surveillance

Background Active surveillance (AS) is an accepted strategy for patients with low-risk papillary thyroid microcarcinoma (PTMC). While previous studies have evaluated the prognostic value of US features, results have been inconsistent. Purpose To determine if US features can help predict tumor progression in patients with low-risk PTMC undergoing AS. Materials and Methods This prospective study enrolled 1177 participants with PTMC from three hospitals between June 2016 and January 2021. Participants were self-assigned to either immediate surgery or AS, and those with two or more US examinations in the absence of surgery were included in the analysis. A χ2 test was used to compare estimated tumor progression rate at 4 years between participants stratified according to US features. Multivariable Cox regression analysis was used to assess the association of clinical and US features with overall tumor progression and specific progression criteria. Results Among 699 participants included in the analysis, 68 (mean age, 49 years ± 12 [SD]; 40 female participants) showed tumor progression (median follow-up, 41.4 months ± 16 [SD]). Tumor progression was associated with the US features of diffuse thyroid disease (DTD) (hazard ratio [HR], 2.3 [95% CI: 1.4, 3.7]; P = .001) and intratumoral vascularity (HR, 1.7 [95% CI: 1.0, 3.0]; P = .04) and the participant characteristics of male sex (HR, 2.8 [95% CI: 1.7, 4.6]; P < .001), age less than 30 years (HR, 2.9 [95% CI: 1.2, 6.8]; P = .01), and thyroid-stimulating hormone level of 7 µU/mL or higher (HR, 6.9 [95% CI: 2.7, 17.4]; P < .001). The risk of tumor progression was higher for participants with DTD (14%, P = .001) or intratumoral vascularity (14%, P = .02) than for participants without these features (6%). DTD and intratumoral vascularity were associated with tumor enlargement (HR, 2.7 [95% CI: 1.4, 5.1]; P = .002) and new lymph node metastasis (HR, 5.0 [95% CI: 1.3, 19.4]; P = .02), respectively. Conclusion DTD and intratumoral vascularity were associated with an increased risk of tumor progression in participants with PTMC undergoing AS. Clinical trial registration no. NCT02938702 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Reuter and the review "International Expert Consensus on US Lexicon for Thyroid Nodules" by Durante et al in this issue.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Extrathyroidal extension or tumor size of primary lesion influences thyroid cancer outcomes

AIMS

Extrathyroidal extension (ETE) is a determined factor of T3 and T4 stage of differentiated thyroid cancer (DTC) in American Joint Committee on Cancer. We aimed to compare clinical outcomes between different extent of ETE according to tumor size.

METHODS

Patients diagnosed with DTC were collected from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. They were categorized into two groups by presence of lymph node metastases (LNM) or distant metastases (DM): group A: no presence of LNM and DM, and group B: presence of LNM or DM. Each group was further divided into four groups according to tumor size: <1 cm, 1-2 cm, 2-4 cm, >4 cm. ETE was divided into three groups by the extent: no ETE, microscopic ETE, and macroscopic ETE. Kaplan-Meier method and log-rank test were used to analyze cancer-specific survival (CSS).

RESULTS

91,975 patients were included. In groups A and B, for tumor size 1 cm, there was no significant difference in CSS between no ETE and microscopic ETE, while a significant difference was observed between no ETE and macroscopic ETE. For tumor size >1 cm, there were significant differences in CSS (both no ETE vs. micro ETE and no ETE vs. macro ETE).

CONCLUSION

We suggests that when tumor size is more than 1 cm, micro ETE is significantly associated with poorer outcome. T3 and T4 stages may take account into tumor size rather than merely based on the presence and extent of ETE. It may be prudent to revisit the omission of micro ETE in TNM staging.

Assessing the role of central lymph node ratio in predicting recurrence in N1a low-to-intermediate risk papillary thyroid carcinoma

Introduction

Lymph node metastasis in patients with papillary thyroid carcinoma (PTC) is associated with postoperative recurrence. Recently, most studies have focused on the evaluation of recurrence in patients with late-stage PTC, with limited data on those with early-stage PTC. We aimed to assess the relationship between lymph node ratio (LNR) and recurrence in low-to-intermediate-risk patients and validate its diagnostic efficiency in both structural (STR) and biochemical recurrence (BIR).

Methods

Clinical data of patients with PTC diagnosed at the Affiliated Hospital of Jining Medical University were retrospectively collected. The optimal LNR cut-off values for disease-free survival (DFS) were determined using X-tile software. Predictors were validated using univariate and multivariate Cox regression analyses.

Results

LNR had a higher diagnostic effectiveness than metastatic lymph nodes in patients with low-to-intermediate recurrence risk N1a PTC. The optimal LNR cutoff values for STR and BIR were 0.75 and 0.80, respectively. Multivariate Cox regression analysis showed that LNR≥0.75 and LNR≥0.80 were independent factors for STR and BIR, respectively. The 5-year DFS was 90.5% in the high LNR (≥0.75) and 96.8% in low LNR (<0.75) groups for STR. Regarding BIR, the 5-year DFS was 75.7% in the high LNR (≥0.80) and 86.9% in low LNR (<0.80) groups. The high and low LNR survival curves exhibited significant differences on the log-rank test.

Conclusion

LNR was associated with recurrence in patients with low-to-intermediate recurrence risk N1a PTC. We recommend those with LNR≥0.75 require a comprehensive evaluation of lateral neck lymphadenopathy and consideration for lateral neck dissection and RAI treatment.

Prediction model of cervical lymph node metastasis based on clinicopathological characteristics of papillary thyroid carcinoma: a dual-center retrospective study

Background

The overall prevalence of papillary thyroid carcinoma (PTC) patients is expanding along with an ongoing increase in thyroid cancer incidence. Patients with PTC who have lymph node metastases have a poor prognosis and a high death rate. There is an urgent need for indicators that can predict lymph node metastasis (LNM) before surgery as current imaging techniques, such as ultrasonography, do not have sufficient sensitivity to detect LNM. To predict independent risk factors for Central lymph node metastasis (CLNM) or Lateral lymph node metastasis (LLNM), we therefore developed two nomograms based on CLNM and LLNM, separately.

Methods

In two centers, the Second Affiliated Hospital of Nanchang University and Yichun People's Hospital, we retrospectively analyzed clinicopathological characteristics of PTC patients. We utilized multivariate analysis to screen for variables that might be suspiciously related to CLNM or LLNM. Furthermore, we developed nomograms to graphically depict the independent risk valuables connected to lymph node metastasis in PTC patients.

Result

Ultimately, 6068 PTC patients in all were included in the research. Six factors, including age<45, male, mETE, TSH>1.418, tumor size>4cm, and location (multicentric and lobe), were observed to be related to CLNM. Age<45, male, mETE (minimal extrathyroidal extension), multifocality, TSH≥2.910, CLNM positive, and tumor size>4cm were regarded as related risk factors for LLNM. The two nomograms developed subsequently proved to have good predictive power with 0.706 and 0.818 and demonstrated good clinical guidance functionality with clinical decision curves and impact curves.

Conclusion

Based on the successful establishment of this dual-institution-based visual nomogram model, we found that some clinical features are highly correlated with cervical lymph node metastasis, including CLNM and LLNM, which will better help clinicians make individualized clinical decisions for more effectively rationalizing managing PTC patients.

Association between iodine nutrition and cervical lymph node metastasis of papillary thyroid microcarcinoma

We aimed to investigate the association between iodine intake and nodal metastasis stratified by central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) of papillary thyroid microcarcinoma (PTMC). Urinary iodine concentration (UIC) and clinicopathological characteristics were used to identify factors associated with CLNM and LLNM using logistic regression analysis. A sum of 3,858 PTMC patients were enrolled. The median UIC (MUI) of patients with CLNM or LLNM was not statistically different from those without nodal metastasis. Male patients had a higher MUI than females (183.4 μg/L vs. 173.6 μg/L). Female patients with extracapsular extension had a higher MUI than those without it (210.0 μg/L vs. 172.1 μg/L). Male patients with LLNM had a significantly lower MUI than those without LLNM (134.7 μg/L vs. 187.9 μg/L). Female patients with more than adequate iodine intake were more likely to present with CLNM and extrathyroidal extension than those with adequate iodine intake with an odds ratio (95% confidence interval) of 1.23 (1.01-1.51) and 1.59 (1.09-2.32) after adjustment. Iodine nutrition was not found to be associated with LLNM. In addition, patients with a younger age, larger tumors, extrathyroidal extension, and intrathyroidal spread were more likely to be CLNM, whereas nodular goiter presented with a protective factor; CLNM was the only factor associated with LLNM of PTMC in both genders. In conclusion, iodine nutrition has a much closer association with female than male patients, and high iodine intake may be associated with CLNM and extrathyroidal extension in female PTMC patients.

A nomogram for predicting lateral lymph node metastasis in cN0 unifocal papillary thyroid microcarcinoma

BACKGROUND

Identifying risk factors for occult lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC) can provide valuable insights into the necessity of lateral neck dissection (LND). The objective of this study was to develop a nomogram for predicting the probability of LLNM in patients with cN0 unifocal PTMC.

METHODS

We conducted a retrospective analyzed a total of 4872 patients with cN0 unifocal PTMC who were treated at our center from January 2013 to June 2018. Logistic regression analysis was used to determine the risk factors for LLNM, and a nomogram was constructed based on these risk factors.

RESULTS

The rate of LLNM was 3.2%. Tumors located in the upper lobe(odds ratio [OR] = 2.56, 95% confidence interval [CI] 1.80-3.62; p < 0.001) and size greater than 7 mm (OR = 2.59, 95% CI 1.85-3.62; p < 0.001) had a significantly higher risk of LLNM compared to tumors in the lower or middle lobe and size less than or equal to 7 mm. Tumors with extrathyroidal extension (ETE) had a significantly higher risk of LLNM (OR = 1.41, 95% CI 1.01-1.99; p = 0.044). The presence of three or more central lymph node metastases (CLNMs) (OR = 5.84, 95% CI 3.83-8.93; p < 0.001) or one or two CLNMs (OR = 2.91, 95% CI 1.93-4.42; p < 0.001) also increased the risk of LLNM compared to having no CLNMs. A nomogram incorporating these risk factors was developed, and the receiver operating characteristic (ROC) curve demonstrated an area under the curve (AUC) of 0.777, indicating a high degree of predictive accuracy.

CONCLUSION

Tumor location in the upper lobe, greater than 7 mm in size, ETE, and CLNMs, especially three or more, were independent risk factors for LLNM in cN0 unifocal PTMC. The nomogram based on these factors exhibited favorable predictive value and consistency.

Reliable neck sonography of nodal thyroglobulin to diagnose recurrent/persistent disease from papillary thyroid carcinoma

OBJECTIVE

This study evaluates the correlation between the sonographic features and the nodal fine-needle aspiration thyroglobulin (FNA-Tg) in papillary thyroid carcinoma (PTC) patients with the recurrent/persistent lymph node for the purpose of the reasonable selection of lymph nodes.

METHODS

This study prospectively contained PTC patients with the suspicious cervical lymph nodes in one medical center from April 2018 to January 2019. Each suspected lymph node was aspirated with a 22-gauge needle and the value of FNA-Tg was measured as well.

RESULTS

There were 136 lymph nodes related to the disease involved. The FNA-Tg levels of 89 (65.44%) metastatic lymph nodes were significantly higher than those of the benign. The median value of the former was 631.550 ng/mL while the latter was 0.056 ng/mL (p = 0.000). The cut-off value of the metastatic lymph nodes diagnosed by FNA-Tg was 2.71 ng/mL, and 6.5 by FNA-Tg/sTg. The suspicious ultrasonographic features including cystic, hyperechoic content, and lack of hilum were closely related to the high level of FNA-Tg value (p < 0.05). However, the round shape (Solbiati index <2) and calcification were not significantly correlated with the positive FNA-Tg (p > 0.05).

CONCLUSION

FNA-Tg is an effective supplement to fine-needle aspiration (FNA) cytology in the nodal metastasis diagnosis. The FNA-Tg level was much higher in the metastatic lymph nodes. The reliable sonographic features of lymph nodes suggested the positive FNA-Tg were cystic content, hyperechoic content and lack hilum. Solbiati index <2 and calcification did not show an exact correlation with the result of FNA-Tg.

Causal inference between aggressive extrathyroidal extension and survival in papillary thyroid cancer: a propensity score matching and weighting analysis

Background

Extrathyroidal extension is a major risk factor for poor prognosis in papillary thyroid cancer. However, the effect of different degrees of extrathyroidal extension on prognosis remains controversial. We performed a retrospective study to elucidate how the extent of extrathyroidal extension in papillary thyroid cancer affected the clinical prognosis of patients and its covariates.

Methods

The study included 108,426 patients with papillary thyroid cancer. We categorized the extent of extension into none, capsule, strap muscles, and other organs. Three causal inference methods for retrospective studies, namely, inverse probability of treatment weighting, standardized mortality ratio weighting, and propensity score matching analysis, were used to minimize potential selection bias. Kaplan-Meier analysis and univariate Cox regression analyses were applied to analyze the precise effect of ETE on survival in papillary thyroid cancer patients.

Results

In the Kaplan-Meier survival analysis, only extrathyroidal extension into or beyond the strap muscles was statistically significant for both overall survival (OS) and thyroid cancer-specific survival (TCSS). In univariate Cox regression analyses before and after matching or weighting based on causal inference, extrathyroidal extension into soft tissues or other organs is a high-risk factor for both overall survival and thyroid cancer-specific survival. Sensitivity analysis revealed that lower overall survival was observed in patients with older age (≥55) and larger tumor size (>2 cm) of papillary thyroid cancer with extrathyroidal extension into or beyond the strap muscles.

Conclusions

Our study indicates that extrathyroidal extension into soft tissues or other organs is a high-risk factor in all papillary thyroid cancer. Even though invasion into the strap muscles did not seem to be a marker for poor prognosis, it still impaired the overall survival of patients with older age (≥55 years old) or larger tumor size (>2 cm). Further investigation is needed to confirm our results and to clarify further risk factors independent of extrathyroidal extension.

Retrospective comparison of individual risk factors hemithyroidectomy and thyroidectomy in patients with papillary carcinoma of the thyroid gland in combination with autoimmune thyroiditis

Introduction. Papillary thyroid carcinoma is the most common subtype of thyroid cancer as it comprises 95 % of cases. Frequently, this pathology develops in the presence of autoimmune thyroiditis (Hashimoto’s thyroiditis) which is the main cause of hypothyroidism in various rich in iodine regions. Papillary thyroid carcinoma is characterized by good prognosis, however some patients experience recurrence which depends on the volume of surgical intervention.

Aim. To compare clinical outcomes and complications after hemithyroidectomy (HE) and thyroidectomy (TE) in patients with papillary thyroid carcinoma secondary to autoimmune thyroiditis.

Materials and methods. The retrospective study included 2031 patients with papillary thyroid carcinoma. Considering individual risk factors, 67 patients were excluded from the HE group, and 588 patients were excluded from the TE group. Each group included 688 patients for whom data were matched. Such individual factors as age, sex, primary tumor size, extrathyroidal invasion, multifocal tumor and cervical lymph node metastasis were taken into account.

Results. During 10‑year follow-up, recurrence was diagnosed in 26 (3.8 %) patients of the HE group and 11 (1.6 %) patients of the TE group. Relative risk of recurrence was significantly lower after TE than after HE (risk ratio (RR) 0.41; 95 % confidence interval (CI) 0.21–0.81; р = 0.01). In the HE group, for the majority of patients recurrence was observed in the contralateral lobe of the thyroid (84.6 %). In the TE group, there were no recurrences in all patients. There were no significant differences between the groups after exclusion of recurrence in the contralateral thyroid lobe (RR 2.75; 95 % CI 0.08–8.79; р = 0.08). In the TE group, the number of patients with transient and permanent hypothyroidism in the TE group was significantly higher than in the HE group (р <0.001).

Conclusion. Hemithyroidectomy is appropriate for the majority of patients with papillary thyroid carcinoma in the absence of extrathyroidal invasion in the neighboring tissues per preoperative examination. For patients after HE, preoperative and postoperative diagnostic examinations are important as most recurrences develop in the contralateral thyroid lobe.

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.

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

Purpose

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

Materials and Methods

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

Results

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

Conclusion

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

A clinical and molecular pathology prediction model for central lymph node metastasis in cN0 papillary thyroid microcarcinoma

BACKGROUND

The frequency of thyroid cancer has rapidly increased in recent years globally. Thus, more papillary thyroid microcarcinoma (PTMC) patients are being diagnosed, including clinical lymph node-negative (cN0) patients. Our study attempted to develop a prediction model for assessing the probability of central lymph node metastasis (CLNM) in cN0 PTMC patients.

METHODS

A total of 595 patients from the Affiliated Hospital of Qingdao University (training cohort: 456 patients) and the Affiliated Hospital of Jining Medical University (verification cohort: 139 patients) who underwent thyroid surgery between January 2020 and May 2022 were enrolled in this study. Their clinical and molecular pathology data were analyzed with multivariate logistic regression to identify independent factors, and then we established a prediction model to assess the risk of CLNM in cN0 PTMC patients.

RESULTS

Multivariate logistic regression analysis revealed that sex, Hashimoto's thyroiditis (HT), tumor size, extrathyroidal extension, TERT promoter mutations and NRAS mutation were independent factors of CLNM. The prediction model demonstrated good discrimination ability (C-index: 0.757 and 0.753 in the derivation and validation cohorts, respectively). The calibration curve of the model was near the optimum diagonal line, and decision curve analysis (DCA) showed a noticeably better benefit.

CONCLUSION

CLNM in cN0 PTMC patients is associated with male sex, tumor size, extrathyroidal extension, HT, TERT promoter mutations and NRAS mutation. The prediction model exhibits good discrimination, calibration and clinical usefulness. This model will help to assess CLNM risk and make clinical decisions in cN0 PTMC patients.

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.

Nomogram for preoperative estimation risk of cervical lymph node metastasis in medullary thyroid carcinoma

Objectives

Cervical lymph node metastasis (CLNM) is common in medullary thyroid carcinoma (MTC), but how to manage cervical lymph node involvement of clinically negative MTC is still controversial. This study evaluated the preoperative features and developed an ultrasound (US)-based nomogram to preoperatively predict the CLNM of MTC.

Materials and methods

A total of 74 patients with histologically confirmed MTC were included in this retrospective study and assigned to the CLNM-positive group and CLNM-negative group based on the pathology. The associations between CLNM and preoperative clinical and sonographic characteristics (size, location, solid component, shape, margin, echogenicity, calcification, and extracapsular invasion of the tumor) were evaluated by the use of univariable and multivariable logistic regression analysis. A nomogram to predict the risk of the CLNM of MTC was built and assessed in terms of discrimination, calibration, and clinical usefulness.

Results

The nomogram was based on three factors (tumor margin, US-reported suspicious lymph node, and extracapsular invasion US features) and exhibited good discrimination with an area under the curve (AUC) of 0.919 (95% CI, 0.856–0.932). The calibration curves of the nomogram displayed a good agreement between the probability as predicted by the nomogram and the actual CLNM incidence.

Conclusions

We constructed and validated a US-based nomogram to predict the risk of CLNM in MTC patients, which can be easily evaluated before surgery. This model is helpful for clinical decision-making.

Prophylactic central lymph node dissection in differentiated thyroid cancer - benefits and risk

INTRODUCTION

Papillary thyroid cancer is the most common thyroid malignancy. Lymph nodes involvement is common in differentiated thyroid cancer, and cervical lymph node micrometastases are observed in up to 85% of patients with papillary thyroid cancer during surgery. While the therapeutic central lymph node dissection has been accepted, the debate on the prophylactic in differentiated thyroid carcinoma (DTC) continues.

Clinical outcomes of multifocal papillary thyroid cancer: A systematic review and meta‐analysis

Objective

Methods

Results

Level of Evidence

Conclusion

Quantification and Pattern of Central Compartment Lymph Nodes in pN1a Papillary Thyroid Cancer Patients

Background: The background is to investigate the results of central compartment lymphadenectomy for pN1a papillary thyroid carcinoma (PTC) with regard to quantification and pattern of resected lymph nodes thereby providing basis for future compartment VI surgical intervention. Methods: The study comprised 443 pN1a PTC patients whose clinicopathological characteristics and central compartment lymphadenectomy results were compared and correlated with the primary thyroid cancer and lymph node metastasis (LNM) features. Ultimately, multivariate analysis was conducted to identify statistically significant impact factors for a high metastatic ratio (MR). Results: Dissected lymph nodes (DLNs) were more frequently identified in right level VI than left (P < .05) although there was no difference in in the number of resected metastatic lymph nodes (MLNs). Male sex, multifocality, extrathyroidal extension (ETE), and fewer DLNs were related to a high MR. There was a positive correlation between DLN and MLN, and a negative correlation between DLN and MR. Disease multifocality and ETE were identified more frequently in the left than the right thyroid lobe. Conclusion: The outcome of central compartment lymphadenectomy in pN1a PTC patients is associated with several factors, and a thorough dissection of lymph nodes improves the rate of metastatic lymph node resection.

The optimal extent of lymph node dissection in N1b papillary thyroid microcarcinoma based on clinicopathological factors and preoperative ultrasonography

BACKGROUND

The optimal extent of lymph node (LN) dissection in the management of N1b papillary thyroid microcarcinoma (PTMC) is still under debate in clinical practice, so we aimed to identify the risk factors associated with multilevel lateral lymph node metastasis (LLNM) with regard to the extent of LN dissection.

METHODS

The clinical data of 182 N1b PTMC patients between January 2019 and June 2021 at Tianjin Medical University Cancer Institute and Hospital were retrospectively reviewed. The frequency pattern and distribution of LLNM were analyzed for risk factors. We assessed the diagnostic value of preoperative ultrasonography (USG) for identifying levels II-V metastasis in PTMC patients.

RESULTS

The proportion of multilevel LLNM in N1b PTMC was 72.1%, and the most common pattern was metastasis at two levels (41.2%). Capsule invasion [odds ratio (OR) =6.861, 95% confidence interval (CI): 1.462-32.190, P=0.015], upper pole [OR =2.125, 95% CI: 1.010-4.473, P=0.047], central LN ratio [OR =7.315, 95% CI: 1.309-40.877, P=0.023], thyroid-stimulating hormone (TSH) >1.5 mIU/mL [OR =2.773, 95% CI: 1.269-6.060, P=0.011], and extranodal extension (ENE) [OR =2.632, 95% CI: 1.207-5.739, P=0.015] were independent risk factors for multilevel metastasis. In addition, unltrasonography had high sensitivity and specificity in the diagnosis of metastasis at level V (75.0%, 78.4%) and multilevel LLNM (67.2%, 64.8%).

CONCLUSIONS

Modified radical neck dissection (MRND) in N1b PTMC patients may be reserved for patients with simultaneous 3-level LLNM or clinically evident metastasis at level V. Preoperative USG may have certain suggestive significance in the diagnosis of multilevel LLNM in primary PTMC.

Risk-stratified papillary thyroid microcarcinoma: post-operative management and treatment outcome in a single center

PURPOSE

This article aims to review and assess the post-operative management and treatment outcomes of papillary thyroid microcarcinoma (PTMC) in risk-stratified patients.

METHODS

We retrospectively analyzed the data of PTMC patients who underwent thyroid surgery with or without radioactive iodine treatment (RAI) in a single center between January 2011 and December 2017. Demographic and clinicopathologic data were collected. Risk stratification according to the 2015 American Thyroid Association guideline was applied.

RESULTS

Three hundred forty PTMC patients were included. Post-operative RAI was performed in 216/340 (63.53%) patients. In the non-RAI scenario, there were 122 low-risk and two intermediate-risk patients. In total, 261 (76.77%), 57 (16.76%), and 22 (6.47%) patients were classified as low, intermediate, and high risk, respectively. With a median follow-up time of 36 months (interquartile range: 23, 52), we found unfavorable outcomes (evidenced by imaging or out-of-range serum tumor marker levels: high thyroglobulin [Tg] or rising Tg antibody [TgAb] levels) in 8/340 (2.35%) patients, all of which received RAI. PTMC patients with unfavorable outcomes were stratified as low risk (4/261 [1.53%]), intermediate risk (1/57 [1.75%]), or high risk (3/22 [13.64%]). One death occurred in a patient with initial distant metastasis in the high-risk group. Initial high-risk stratification and initial stimulated Tg (of at least 10 ng/mL) were demonstrated as independent predictors for PTMC unfavorable outcomes (persistent or recurrent disease). Five patients with unfavorable outcomes (four with persistent disease and one with recurrent disease) had abnormal Tg or TgAb values despite unremarkable imaging findings. Moreover, 79/124 (63.71%) patients in the non-RAI scenario were only followed up with neck ultrasound.

CONCLUSIONS

In general, at least 98% of low-risk and intermediate-risk PTMC patients showed favorable outcomes without persistent or recurrent disease, defined by either imaging or serum tumor markers. Nevertheless, aggressive disease could occur in few PTMC patients. Decisions on post-operative management and follow-up may be guided by initial high-risk stratification and initial stimulated Tg levels (≥10 ng/mL) as independent predictors for PTMC unfavorable outcomes. Monitoring using both imaging and serum tumor markers is crucial and should be implemented for patients with PTMC.

Minimal extrathyroidal extension is associated with lymph node metastasis in single papillary thyroid microcarcinoma: a retrospective analysis of 814 patients

Background

Extrathyroidal extension (ETE) is considered a major prognostic factor in papillary thyroid carcinoma (PTC). Patients with gross ETE are at increased risk of recurrence and mortality. The importance of minimal ETE still remains controversial, especially in patients with papillary thyroid microcarcinoma (PTMC). The purpose of this study was to evaluate the association between ETE and lymph node (LN) metastasis in single PTMC.

Methods

A retrospective analysis was performed of 1994 patients underwent thyroidectomy for PTC between 2012 and 2016 in a single institution. Patients with combined thyroid carcinoma of other types and those who underwent completion thyroidectomy were excluded. After further exclusion of PTC larger than 1 cm and multifocal tumors, 814 patients with single PTMC were included in the study.

Results

72.9% patients had no ETE, 25.1% minimal ETE, and 2.1% gross ETE. ETE was associated with lymphatic invasion, perineural invasion, and vascular invasion. Patients with minimal and gross ETE were also more likely to have LN metastasis, including lateral neck metastasis, compared to those without ETE. In univariate analysis, LN metastasis was associated with male gender, conventional PTC, lymphatic invasion, perineural invasion, and ETE. In multivariate analysis, male gender (OR = 1.987; 95% CI 1.369–2.884), lymphatic invasion (OR = 4.389; 95% CI 1.522–12.658), perineural invasion (OR = 6.545; 95% CI 1.262–33.948), and minimal ETE (OR = 1.852; 95% CI 1.298–2.643) were found to be independent risk factors of LN metastasis.

Conclusions

Minimal ETE is associated with LN metastasis in single PTMC, compared to no ETE. Minimal ETE should be considered in the management of patients with single PTMC, whether surgical or during active surveillance.

What Are the Characteristics of Papillary Thyroid Microcarcinoma Prone to High-Volume Lateral Lymph Node Metastasis? - An Analysis of 2981 Consecutive Cases

PURPOSE

To identify candidate factors for predicting high-volume lateral lymph node metastasis (LLNM) in papillary thyroid microcarcinoma (PTMC).

METHODS

We retrospectively studied 2981 patients with PTMC who underwent thyroidectomy from 2013 to 2016. LLNM was identified by histopathology. Patients with different LLNM statuses were compared according to clinical, sonographic and pathological parameters. A multivariate logistic model was established to predict high-volume LLNM (number of metastatic lymph nodes >5).

RESULTS

High-volume LLNM of PTMC was independently associated with age < 40 years (OR = 1.791, P = 0.023), male sex (OR = 2.401, p = 0.001), tumor size > 0.5 cm (OR = 4.839, p < 0.001), extrathyroidal extension (OR = 2.097, p = 0.007) and microcalcification (OR = 2.894, p = 0.002). These five factors were incorporated together to develop a multivariate analysis, which showed good predictive ability (AUC = 0.78, 95% CI 0.72-0.83), with a sensitivity of 80.0% and a specificity of 61.4%. Moreover, more level II or V lateral regions were involved in patients with high-volume LLNM than in those with small-volume LLNM (69.2% vs. 25.0%, p < 0.001; 10.8% vs. 4.7%, p < 0.001).

CONCLUSION

Multilevel LLNM tended to be more common in patients with PTMC who had high-volume LLNM. The high-volume LLNM rates of patients with PTMC with age < 40 years, male sex, tumor size > 0.5 cm, extrathyroidal extension and microcalcification were relatively higher than those without. These findings may be useful for identifying patients at higher high-volume LLNM risk who may require more aggressive treatment or intensive follow-up management.

Clinicopathologic predictors of central lymph node metastases in clinical node-negative papillary thyroid microcarcinoma: a systematic review and meta-analysis

Background

The presence of central lymph node metastases (CLNM) has been suggested as a risk factor for poorer prognosis and recurrence in papillary thyroid microcarcinoma (PTMC). However, the clinicopathologic factors for CLNM in clinical node-negative (CN0) PTMC were not well defined. This study aimed to perform a systematic review and meta-analysis to investigate the significant clinicopathologic predictors of CLNM in CN0 PTMC.

Methods

A systematic literature search was performed in PubMed, Embase, Cochrane Library, and Web of Science. Case-control studies on the association of clinicopathologic risk factors with CLNM in CN0 PTMC were included.

Results

Thirteen eligible studies involving 6068 patients with CN0 PTMC were included. From the pooled analyses, male (odds ratio [OR]: 2.07, 95% CI: 1.49–2.87, P < 0.001), multifocality (OR: 1.88, 95% CI: 1.54–2.29, P < 0.001), tumor size > 5 mm (OR: 1.84, 95% CI: 1.55–2.18, P < 0.001), and extrathyroidal extension (OR: 1.96, 95% CI: 1.30–2.95, P = 0.001) are significantly associated with increased risk of CLNM in CN0 PTMC. A sample size with a cutoff point of 200 was identified as the source of heterogeneity for sex according to meta-regression (t = 3.18, P = 0.033). Then, the subgroup analysis of male was performed, which illustrated that male increased the risk of CLNM in the small sample group (SG) and the large sample group (LG) by 6.11-folds and 2.01-folds, respectively (SG: OR, 6.11, 95% CI, 3.16–11.81, P < 0.001; LG: OR, 2.01, 95% CI, 1.65–2.46, P < 0.001).

Conclusions

Male, multifocality, tumor size > 5 mm, and extrathyroidal extension may be reliable clinical predictors of CLNM in CN0 PTMC. Moreover, prophylactic central lymph node dissection should be considered in surgical decision-making for CN0 PTMC patients, who are male, multifocal, with tumor size > 5 mm, and with extrathyroidal extension.

Trial registration

CRD42021242211 (PROSPERO)

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02573-7.

Clinical Factors Predictive of Lymph Node Metastasis in Thyroid Cancer Patients: A Multivariate Analysis

BACKGROUND

Early-stage thyroid cancers have excellent survival. However, lymph node metastases (LNM) confer a worse prognosis and are not always known preoperatively. Therefore, investigation on the clinical and histological factors predictive of LNM in thyroid cancers was conducted to tailor the extent of surgery and radioactive iodine therapy.

STUDY DESIGN

Multivariate logistic regressions were performed based on retrospective data from thyroid cancer patients seen between 2013 and 2020 at a single institution.

RESULTS

Among 913 patients, mean age was 49.4 years, 76.5% were female, 58.3% were White, 21.2% were Black, and 27.9% had LNM. In the multivariate analyses in which the outcome was LNM, White (odds ratio [OR] 1.74, 95% CI 0.98 to 3.15, p = 0.064) and Hispanic patients (OR 2.36, 95% CI 0.97 to 5.77, p = 0.059) trended toward higher risk of LNM compared to Black patients, whereas age (OR 0.98, 95% CI 0.97 to 1.00, p = 0.008) showed protective effect. Tumor size (OR 1.04, 95% CI 1.01 to 1.07, p = 0.007), extrathyroidal extension (OR 2.46, 95% CI 1.53 to 3.97, p < 0.001), lymphovascular invasion (OR 6.30, 95% CI 3.68 to 11.14, p < 0.001), and multifocality (OR 1.47, 95% CI 1.01 to 2.12, p = 0.042) were associated with higher risk of LNM. In another model with outcome as >5 LNM, tumor size (OR 1.07, 95% CI 1.03 to 1.11, p = 0.001), age (OR 0.95, 95% CI 0.93 to 0.97, p < 0.001), extrathyroidal extension (OR 3.20, 95% CI 1.83 to 5.61, p < 0.001), and lymphovascular invasion (OR 6.82, 95% CI 3.87 to 12.17, p < 0.001) remained significant predictors.

CONCLUSION

Our analyses demonstrated and confirmed that age, tumor size, extrathyroidal extension, and lymphovascular invasion are independent predictors of significant LNM, thereby conferring higher risk of recurrence. Risk of LNM based on these patient characteristics should be considered when planning an operative approach.

Comparative BRAF V600E immunohistochemical expression in differentiated thyroid tumors with papillary features

Differentiated thyroid tumors (DTC) are the most common indolent tumors associated with a good prognosis compared with other tumors. Its incidence during the last few decades has increased. DTC includes papillary carcinoma and follicular carcinoma. The BRAF is the most prevalent genetic mutation in thyroid carcinoma, occurring in more than 50% of papillary thyroid cancers (PTCs). The study aimed to evaluate BRAF expression in differentiated thyroid tumors with papillary-like nuclear features. Formalin-fixed paraffin-embedded blocks (FFPE) were collected from archival samples of patients in private histopathology labs in Al-Najaf city from 55 cases, which included 27 papillary thyroid carcinoma (PTC) cases, 10 cases of NIFTP, 13 FVPTC cases, 2 papillary microcarcinoma cases, and 3 NIFTP coexist with papillary microcarcinoma cases. All samples were stained using the immunohistochemistry method in the Middle Euphrates unit for cancer research at the University of Kufa/Faculty of Medicine. 15/55 (27.3%) of cases increased BRAF expression. The BRAF expression was statistically significant with tumor type (p=0.008). The higher expression was associated with 13 (48.15%) of PTC cases. However, the BRAF expression did not correlate with gender (p=0.2), tumor size (p=0.07), and tumor focality (p=0.09). BRAF V600E has prognostic value as it correlates with tumor progression.

The localization of thyroid cancers on the thyroid gland is a new risk factor for metastases of perithyroidal, peritracheal and central lymph nodes

OBJECTIVE

Lymph node metastasis is frequently detected in differentiated thyroid cancers. Central dissection is performed to the lymph nodes in patients with microscopic metastases in the intraoperative evaluation. Other indications for central dissections are tumor size and cervical lateral lymph node metastasis. We consider that the localization of thyroid cancer in the thyroid lodge may be another risk factor for central lymph node metastasis. For this reason, the purpose of the present study was to investigate the relations between thyroid cancer localization and lymph node metastasis in differentiated thyroid cancer patients who had no preoperative cervical metastases and who underwent total thyroidectomy, and peritracheal, perithyroidal, and central lymph node dissection.

METHOD

A total of 213 differentiated thyroid cancer cases followed in our general surgery and endocrinology clinic between September 2016 and May 2020 were evaluated retrospectively. Based on the data in the files, the patients who underwent total thyroidectomy, and central, perithyroidal, and peritracheal lymph node dissection were included in the study. The patients were divided into four Groups according to tumor localizations, those with tumors adjacent to the trachea (Group 1), upper thyroid pole (Group 2), thyroid middle part (Group 3), thyroid inferior (Group 4). The demographic characteristics, laboratory parameters, cancer types, and lymph node metastasis rates of the Groups were evaluated.

RESULTS

A total of 84% (179) of the cases had thyroid papillary cancer, 11.73% (25) had thyroid follicular cancer, and 4.2% (9) had poorly differentiated thyroid cancer. The mean age of all patients was found to be 49 ± 8.3 years, and the female/male ratio was 2.4. It was found that the differentiated thyroid cancers metastasized to the perithyroidal, peritracheal, and central lymph nodes at a rate of 57.74%. The distribution of these metastases according to the Groups was; 62.85% in Group 1, 11.53% in Group 2, 43.9% in Group 3, and 88.57% in Group 4. It was also found that 80.32% of the papillary cancer cases and 57.14% of the follicular cancer cases metastasized to central (level VI) lymph nodes in Group 4.

CONCLUSION

The localization of differentiated thyroid cancers is a new risk factor for perithyroidal metastases.

Risk Factors for Central Lymph Node Metastases and Benefit of Prophylactic Central Lymph Node Dissection in Middle Eastern Patients With cN0 Papillary Thyroid Carcinoma

Background

Prophylactic central lymph node dissection (PCLND) for adult patients with papillary thyroid carcinoma (PTC) is still a matter of debate. Data on incidence, risk and benefits of PCLND in Middle Eastern patients is lacking. Therefore, we aimed to identify the incidence and predictive clinico-pathological and molecular marker of PCLND in adult patients with clinically node negative (cN0) Middle Eastern PTC.

Methods

This retrospective study included 942 adult Middle Eastern patients with cN0 PTC who underwent total thyroidectomy (TT) or TT+PCLND. Clinico-pathological associations of central lymph node metastasis (CLNM) were assessed. Multivariate analysis was performed using logistic regression and Cox proportional hazards model.

Results

213 patients underwent PCLND and 38.0% (81/213) had positive CLNM. Multivariate analysis demonstrated age ≤55 years (Odds Ratio (OR) = 7.38; 95% Confidence Interval (CI) = 1.59 – 34.31; p = 0.0108), tumor bilaterality (OR = 3.01; 95% CI = 1.01 – 9.21; p = 0.0483), lymphovascular invasion (OR = 2.92; 95% CI = 1.18 – 7.23; p = 0.0206) and BRAF mutation (OR = 3.24; 95% CI = 1.41 – 7.49; p = 0.0058) were independent predictors of CLNM in adult PTC. Furthermore, patients who underwent PCLND showed significant association with improved recurrence-free survival (RFS; p = 0.0379). Multivariate analysis demonstrated that PCLND was an independent predictor of improved recurrence-free survival.

Conclusions

cN0 Middle Eastern PTC patients treated with PCLND showed a significantly better prognosis. PCLND was effective in improving RFS in Middle Eastern PTC patients and should be encouraged for patients with potential risk factors for CLNM.

Can Cervical Lymph Node Metastasis Increase the Risk of Distant Metastasis in Papillary Thyroid Carcinoma?

BACKGROUND

Distant metastasis (DM) is a rare event and has a negative effect on the prognosis for papillary thyroid carcinoma (PTC). The relationship between cervical lymph node metastasis and DM is complicated and unclear. This study aimed to evaluate the impact of N stage subclassification on different distant metastasis sites based on age stratification, especially for patients with papillary thyroid microcarcinoma.

METHODS

A total of 28,712 patient with PTC cases between 2010 and 2018 were extracted from the Surveillance, Epidemiology, and End Results database. Multivariable logistic regression analysis was utilized to adjust for confounding variables. Risk stratification, including positive lymph node number and lymph node ratio, was established by receiver operating characteristic curves to help predict DM.

RESULTS

Lung was the most common metastatic site regardless of N0, N1a disease, or N1b disease. As the N stage increased, the higher the rate of DM identified. After age stratification, only N1b disease significantly increased the risk of lung metastasis (LM; odds ratio, OR = 20.45, P < 0.001) rather than bone metastasis (BM; OR = 3.46, P > 0.05) in younger patients. However, in older patients, N1b disease significantly increased the risk of both LM (OR = 4.10, P < 0.001) and BM (OR = 2.65, P = 0.007). In patients with papillary thyroid microcarcinoma (PTMC), N1a disease did not increase the risk of DM, LM, and BM compared with N0 disease (P > 0.05). Furthermore, combined N stage with risk stratification has well performance in predicting DM (area under the curve, AUC = 0.761). Similar results were shown in PTC patients with LM (AUC = 0.770) and BM (AUC = 0.729).

CONCLUSION

Overall, the incidence of DM significantly increased with the progress of N disease after age stratification. N1a disease did not increase the risk of DM in PTMC patients, regardless of LM or BM. Combined N stage with risk stratification may be beneficial for DM prediction.

Risk Factor Analysis for Central Lymph Node Metastasis in Papillary Thyroid Microcarcinoma

Purpose

Although the prognosis of papillary thyroid microcarcinoma (PTMC) is excellent, cervical lymph node metastasis (CLNM) is commonly observed in PTMC. This study aimed to investigate the incidence and risk factors for CLNM in PTMC.

Patients and Methods

Altogether, 687 patients with PTMC who initially underwent unilateral thyroidectomy with unilateral central lymph node dissection or bilateral thyroidectomy with bilateral central lymph node dissection between January 2014 and June 2018 at our hospital were included. The patients were divided into two groups: PTMC with CLNM and PTMC with no CLNM. The clinicopathologic characteristics and ultrasound features were compared between the groups. Univariate and multivariate logistic regression analyses were used to identify the risk factors for CLNM.

Results

CLNM was observed in 121/687 (17.6%) patients with PTMC. PTMC patients aged <55 years exhibited a greater incidence of CLNM (87.6% vs 12.4%) than those aged ≥55 years. PTMC patients with CLNM were more likely to have capsular extension (24.0% vs 15.4%) and extension to the adjacent structures (9.9% vs 4.2%). Patients with microcalcification on ultrasound images were more likely to have CLNM (66.1% vs 47.9%). Multivariate logistic regression analysis revealed that microcalcification (odds ratio [OR]: 2.066, 95% confidence interval [CI]: 1.361-3.135, P<0.001), age <55 years (OR: 2.341, 95% CI: 1.309-4.187, P=0.004), capsular invasion (OR: 1.772, 95% CI: 1.082-2.879, P=0.023), and invasion of the adjacent tissues (OR: 2.872, 95% CI: 1.355-4.187, P=0.004) were significant risk factors for CLNM.

Conclusion

Microcalcification, age <55 years, capsular invasion, and invasion of the adjacent tissues were significant risk factors for CLNM in PTMC.

A Nomogram Based on Clinicopathological and Ultrasound Imaging Characteristics for Predicting Cervical Lymph Node Metastasis in cN0 Unilateral Papillary Thyroid Microcarcinoma

Objective: The aim of this study was to establish a practical nomogram for preoperatively predicting the possibility of cervical lymph node metastasis (CLNM) based on clinicopathological and ultrasound (US) imaging characteristics in patients with clinically node-negative (cN0) unilateral papillary thyroid microcarcinoma (PTMC) in order to determine a personal surgical volume and therapeutic strategy. Methods: A total of 269 consecutive patients diagnosed with cN0 unilateral PTMC by postoperative pathological examination from January 2018 to December 2020 were retrospectively analyzed. All the patients underwent lobectomy or thyroidectomy with routine prophylactic central lymph node dissection (CLND) and were divided into a CLNM group and a non-CLNM group. Using logistic regression, the least absolute shrinkage and selection operator (LASSO) regression analysis was applied to determine the risk factors for CLNM in patients with unilateral cN0 PTMC. A nomogram including risk-factor screening using LASSO regression for predicting the CLNM in patients with cN0 unilateral PTMC was further developed and validated. Results: Risk factors identified by LASSO regression, including age, sex, tumor size, presence of extrathyroidal extension (ETE), tumor diameter/lobe thickness (D/T), tumor location, and coexistent benign lesions, were potential predictors for CLNM in patients with cN0 unilateral PTMC. Meanwhile, age (odds ratio [OR] = 0.261, 95% CI.104-0.605; P = 0.003), sex (men: OR = 3.866; 95% CI 1.758-8.880; P < 0.001), ETE (OR = 3.821; 95% CI 1.168-13.861; P = 0.032), D/T (OR = 72.411; 95% CI 5.483-1212.497; P < 0.001), and coexistent benign lesions (OR = 3.112 95% CI 1.407-7.303; P = 0.007) were shown to be significantly related to CLNM by multivariant logistic regression. A nomogram for predicting CLNM in patients with cN0 unilateral PTMC was established based on the risk factors identified by the LASSO regression analysis. The receiver operating characteristic (ROC) curve for predicting CLNM by nomogram showed that the area under the curve (AUC) was 0.777 and exhibited an excellent consistency. Conclusions: A nomogram based on clinical and US imaging characteristics for predicting the probability of CLNM in patients with cN0 unilateral PTMC was developed, which showed a favorable predictive value and consistency. Further prospective research to observe the oncological outcomes is necessary to determine whether the nomogram could potentially guide a personalized surgical volume and surgical approach.

Prevalence of Central Compartment Lymph Node Metastases in Papillary Thyroid Micro-Carcinoma: A Retrospective Evaluation of Predictive Preoperative Features

Simple Summary

The present study focused on patients affected by stage pT1a papillary thyroid micro-carcinomas that were treated with surgery and central lymph node dissection. In this study, male sex, low age, and sub-capsular carcinoma localization resulted as independent predictive factors for central lymph node metastases.

Abstract

Papillary thyroid micro-carcinomas are considered relatively indolent carcinomas, often occult and incidental, with good prognosis and favorable outcomes. Despite these findings, central lymph node metastases are common, and are related to a poor prognosis for the patient. We performed a retrospective analysis on patients treated with surgery for stage pT1a papillary thyroid micro-carcinomas. One hundred ninety-five patients were included in the analyses. The presence of central lymph node metastases was identified and studied. A multivariate analysis employing binary logistic regression was used to calculate adjusted odds ratios with 95% confidence intervals of possible central lymph node metastases risk factors. In the performed multivariate analysis, male gender, younger age, and histopathological characteristics, such as a tumor sub-capsular localization, were significantly associated with central lymph node metastases in pT1a patients. Central compartment lymph node metastases are present in a non-negligible number of cases in patients with papillary thyroid micro-carcinoma undergoing surgical resection. Studying these factors could be an effective tool for predicting patients’ central lymph node metastases in papillary thyroid micro-carcinomas, defining a tailored surgical treatment in the future.

A new prediction model for lateral cervical lymph node metastasis in patients with papillary thyroid carcinoma: Based on dual-energy CT

PURPOSE

The current study aimed to develop and validate a prediction model to estimate the independent risk factors for lateral cervical lymph node metastasis (LLNM) in papillary thyroid carcinoma (PTC) patients based on dual-energy computed tomography (DECT).

METHOD

This study retrospectively conducted 406 consecutive patients from July 2015 to June 2019 to form the derivation cohorts and performed internal validation. 101 consecutive patients from July 2019 to June 2020 were included to create the external validation cohort. Univariable and multivariable logistic regression analyses were used to evaluate independent risk factors for LLNM. A prediction model based on DECT parameters was built and presented on a nomogram. The internal and external validations were performed.

RESULTS

Iodine concentration (IC) in the arterial phase (OR 2.761, 95% CI 1.028-7.415, P 0.044), IC in venous phase (OR 3.820, 95% CI 1.430-10.209, P 0.008), located in the superior pole (OR 4.181, 95% CI 2.645-6.609, P 0.000), and extrathyroidal extension (OR 4.392, 95% CI 2.142-9.004, P 0.000) were independently associated with LLNM in the derivation cohort. These four predictors were incorporated into the nomogram. The model showed good discrimination in the derivation (AUC, 0.899), internal (AUC, 0.905), and external validation (AUC, 0.912) cohorts. The decision curve revealed that more advantages would be added using the nomogram to estimate LLNM, which implied that the lateral lymph node dissection was recommended.

CONCLUSIONS

DECT parameters could provide independent indicators of LLNM in PTC patients, and the nomogram based on them may be helpful in treatment decision-making.

Predictive Factors of Recurrence of Papillary Thyroid Microcarcinomas: Analysis of 2,538 Patients

Introduction  The incidence of papillary thyroid microcarcinoma (PTMC) has increased, and its treatment remains controversial.

Objective  To identify the clinical and pathological factors predictive of tumor recurrence.

Methods  We retrospectively analyzed 2,538 consecutive patients treated for PTMC, most submitted to total thyroidectomy (98%) followed by radioactive iodine (RAI) ablation (51.7%) at a cancer center from 1996 to 2015. The patients were stratified according to the American Thyroid Association (ATA) risk categories (low, intermediate, or high), and the clinicopathological features were evaluated by multivariate Cox regression analysis to identify independent prognostic factors for recurrence.

Results  After a mean follow-up of 58 months (range: 3 to 236.5 months), tumor recurrence was diagnosed in 63 (2.5%) patients, mostly in the lymph nodes. Distant metastasis occurred in 2 (0.1%) patients. There were no cancer-related deaths. The multivariate analysis showed that age < 55 years ( p  = 0.049; hazard ratio [HR]: 2.54; 95% confidence interval [95%CI]: 0.95 to 0.99), multifocality ( p  = 0.032; HR: 1.76; 95%CI: 1.05 to 2.96), and the presence of lymph-node metastasis ( p  < 0.001; HR: 3.69; 95%CI: 2.07–6.57) were independent risk factors for recurrence. Recurrence was observed in 29 (1.5%) out of 1,940 low-risk patients, 32 (5.4%) out of 590 intermediate-risk patients, and in 2 (25%) out of 8 high-risk patients.

Conclusions  The prognosis of PTMC is excellent, favoring a conservative treatment for most patients. Age < 55 years, multifocality, and node metastasis at diagnosis, as well the ATA staging system effectively predict the risk of recurrence. The presence of these risk factors can help identify patients who should be considered for more aggressive management and more frequent follow-up.

A cohort study of microwave ablation and surgery for low-risk papillary thyroid microcarcinoma

BACKGROUND

The optimal treatment method for papillary thyroid microcarcinoma (PTMC) is lacking consensus. Here we aimed to compare the efficacy and safety of surgery and microwave ablation (MWA) for PTMC.

METHODS

The clinical data of 644 patients with PTMC treated between July 2013 and June 2020 were retrospectively analyzed. A total of 320 and 324 patients underwent MWA and surgery, respectively. We observed lesion changes in the MWA group and compared the recurrence, metastasis, complications, and other health economic indicators between the 2 groups.

RESULTS

The mean follow-up time was 890.7 ± 532.9 (187.9-2679.0) days in the MWA group and 910.9 ± 568.4 (193.8-2821.5) days in the surgery group. In the MWA group, lesion volume increased significantly after ablation and then gradually decreased. The final lesion volume reduction rate was 90.73% ± 7.94%, and 193 lesions (60.3%) disappeared completely. There were no significant intergroup differences in recurrence or metastasis. The incidence of main complications (temporary hypothyroidism, hypoparathyroidism, and temporary hoarseness) was significantly lower in the MWA group than in the surgery group (p < 0.001). The treatment time, intraoperative blood loss, and hospital stay were significantly lower in the MWA group than in the surgery group (p < 0.001).

CONCLUSIONS

MWA is effective for treating PTMC, with a low incidence of complications and less trauma. The rates of post-treatment recurrence and metastasis are similar to those of surgery, indicating that MWA is a suitable alternative to surgery.

Reevaluation of Criteria and Establishment of Models for Total Thyroidectomy in Differentiated Thyroid Cancer

Introduction

After the publication of the 2015 American Thyroid Association (ATA) guidelines, the indication for total thyroidectomy (TT) was reported to be underestimated before surgery, which may lead to a substantial rate of secondary completion thyroidectomy (CTx).

Methods and Materials

We retrospectively analyzed differentiated thyroid cancer patients from Wuhan Union Hospital (WHUH). Univariate analysis was performed to evaluate all preoperative and intraoperative factors. New models were picked out by comminating and arranging all significant factors and were compared with ATA and National Comprehensive Cancer Network (NCCN) guidelines in the multicenter prospective Differentiated Thyroid Cancer in China (DTCC) cohort.

Results

A total of 5,331 patients from WHUH were included. Pre- and intraoperative criteria individually identified 906 (17.0%) and 213 (4.0%) patients eligible for TT. Among all factors, age <35 years old, clinical N1, and ultrasound reported local invasion had high positive predictive value to predict patients who should undergo TT. Accordingly, we established two new models that minorly revised ATA guidelines but performed much better. Model 1 replaced “nodule size >4 cm” with “age <35 years old” and achieved significant increase in the sensitivity (WHUH, 0.711 vs. 0.484; DTCC, 0.675 vs. 0.351). Model 2 simultaneously demands the presence of “nodule size >4 cm” and “age <35 years old,” which had a significant increase in the specificity (WHUH, 0.905 vs. 0.818; DTCC, 0.729 vs. 0.643).

Conclusion

All high-risk factors had limited predictive ability. Our model added young age as a new criterion for total thyroidectomy to get a higher diagnostic value than the guidelines.

Association between preoperative serum TSH and tumor status in patients with papillary thyroid microcarcinoma

Thyroid-stimulating hormone (TSH) is a growth factor affecting the initiation or progression of papillary thyroid cancer (PTC). However, the relationship between preoperative serum TSH and papillary thyroid microcarcinoma (PTMC) remains controversial. To investigate the relationship between preoperative serum TSH and tumor status of PTMC, a multicentered retrospective study was performed from January 2014 to December 2016. The cohort of this study consisted of 1997 patients who underwent thyroid surgery. Serum TSH concentrations were measured and PTMC was diagnosed based on the post-operation pathological report. Results showed that the preoperative serum TSH concentration was not related to age and gender but was positively associated with tumor size. Furthermore, higher TSH level was associated with extra-thyroidal extension and lymph node metastasis (LNM). These results indicated that TSH might not be involved in the development of PTMC but may be associated with PTMC progression. Preoperative serum TSH concentration should be considered as risk predictor for tumor progression in patients with PTMC.

Papillary thyroid microcarcinomas that metastasize to lymph nodes

PURPOSE

We aimed to determine clinicopathological features that can predict lymph node metastasis (LNM) in papillary thyroid microcarcinomas (PTMC).

METHODS

Medical records of 872 patients with papillary thyroid cancer >1 cm (PTC > 1 cm) and 1184 patients with papillary thyroid microcancer (PTMC) (≤1 cm) were reviewed retrospectively. Demographical, clinical and histopathological features of (PTC > 1 cm) and PTMC were compared. Association between clinicopathological features and LNM in PTMC was investigated.

RESULTS

The median age of patients with PTMC was significantly higher than patients with PTC > 1 cm (49 vs 46 years old, p < 0.001). Multifocality, capsular invasion, vascular invasion, extrathyroidal extension (ETE) and LNM were more frequent in patients with PTC > 1 cm compared to patients with PMTC (p < 0.001 for each). In PTMC group, those with LNM had significantly higher proportion of multifocality, capsular invasion, vascular invasion and ETE compared to those without LNM (p = 0.007, <0.001, p = 0.011 and p < 0.001, respectively). Multifocality and ETE were significant factors for LNM with logistic regression analysis. Multifocality increased the risk of LNM by 1.737 times (95% CI: 1.079-2.979) and ETE increased the risk by 3.528 times (95%: 1.914-6.503). Primary tumor diameter ≥ 5.75 mm was predictive for LNM with a sensitivity of 0.782 and a specificity of 0.517 in PTMC.

CONCLUSIONS

LNM should be investigated more carefully in patients with PTMC in the presence of tumor diameter ≥ 5.75 mm, multifocality or ETE.

Investigation and management of papillary thyroid microcarcinoma - a Scottish regional case series and literature review

BACKGROUND AND AIMS

Papillary thyroid microcarcinoma is defined as papillary thyroid cancer with a diameter of ≤1 cm. Despite its prevalence, there is wide variation in practice in the investigation and management of patients with papillary thyroid microcarcinoma throughout the UK and internationally. The primary aim of this paper is to describe the experience of investigation and management in a Scottish health board over the past 10 years.

METHODS AND RESULTS

Retrospective analysis of thyroidectomy and hemithyroidectomy resection samples from March 2009 to March 2020. 532 specimens were reviewed and 20 patients with PTMC were identified. 12 patients had an incidental finding of PTMC. Median U score- 3, Median Thy score- 2.5 for dominant or radiologically suspicious nodules. 8 specimens demonstrated aggressive histopathological features. 1 patient with positive nodal disease in the neck and 0 patients with positive nodal disease in the thorax on CT Neck and Chest.

CONCLUSION

Here we report the first UK Cohort describing the radiological investigation and management of papillary thyroid microcarcinoma. The results of our study are in accordance with a recent meta-analysis which found 4% nodal disease and 0.025% distant metastasis at time of presentation in patients with PTMC.

Extent of Surgery and the Prognosis of Unilateral Papillary Thyroid Microcarcinoma

It remains controversial whether patients with papillary thyroid microcarcinoma (PTMC) benefit from total thyroidectomy (TT) or thyroid lobectomy (TL). We aimed to investigate the impact of extent of surgery on the prognosis of patients with unilateral PTMC. Patients were obtained from the Surveillance, Epidemiology, and End Results database from 2004 to 2015. Cancer-specific survival (CSS) and overall survival (OS) were evaluated by Cox regression and Kaplan-Meier curves with propensity score matching. Of 31167 PTMC patients enrolled, 22.2% and 77.8% of which underwent TL and TT, respectively. Patients with TT were more likely to be younger, females, present tumors of multifocality, extrathyroidal extension, cervical lymph node metastasis (CLNM), distant metastasis, and receive radioactive iodine (RAI) compared with those receiving TL. The multivariate Cox regression model showed that TT was not associated with an improved CSS and OS compared with TL with hazard ratio (HR) and 95% confidence interval (CI) of 0.53 (0.25-1.12) and 0.86 (0.72-1.04), respectively. In addition, the Kaplan-Meier curves further confirmed the similar survival between TL and TT after propensity score matching. The subgroup analysis showed that TT was associated with better CSS for patients < 55 years, those with tumors of gross extrathyroidal extension, CLNM (N1b), and cases not receiving RAI with HR 95% CI of 0.13 (0.02-0.81), 0.12 (0.02-0.66), 0.11 (0.02-0.64) and 0.36 (0.13-0.90), respectively. TT predicted a trend of better OS for patients with N1b and distant metastasis after adjustment. In addition, TT was associated with better CSS than TL for patients with risk factors like N1b combined with gross extrathyroidal extension, and/or multifocality after matching. In conclusion, TL may be enough for low-risk PTMC patients. TT may improve the prognosis of unilateral PTMC patients with 2 or more risk clinicopathologic factors like CLNM, multifocality, extrathyroidal extension and a younger age compared with TL.