Thyroid Cancer Nodal Metastases: Biologic Significance and Therapeutic Considerations

Ten-Year Outcomes of Radiofrequency Ablation for Locally Recurrent Papillary Thyroid Cancer

OBJECTIVE

This study investigates the long-term efficacy and safety of ultrasound (US)-guided radiofrequency ablation (RFA) for treating locally recurrent papillary thyroid cancer (PTC).

MATERIALS AND METHODS

We retrospectively analyzed 39 consecutive patients with 61 locally recurrent PTCs (14 males, 25 females; mean ± standard deviation age, 52.8 ± 16.7 years; range 21-92 years) who underwent US-guided RFA with curative intent between September 2008 and April 2012. A subgroup of 24 patients with 37 recurrent PTCs who had a follow-up of at least 10 years were analyzed separately. All patients were followed for changes in lesion size on US and thyroglobulin (Tg) levels at 1, 3, 6, and 12 months after RFA, with follow-up every 6-12 months thereafter. Any complications were documented during the follow-up period. Recurrence-free survival (RFS) rates were assessed using Kaplan-Meier estimates. Long-term outcomes were evaluated in patients with follow-up of at least 10 years.

RESULTS

The follow-up period ranged from 7 to 180 months (median 133 months). The RFS rates for the 39 patients at 3, 5, and 10 years were 86.8%, 75.5%, and 60.6%, respectively. Among the 24 patients with 37 recurrent PTCs followed for more than 10 years, the volume reduction rate was 99.9% (range 96%-100%), and the complete tumor disappearance rate was 91.9%. The mean serum Tg level also decreased significantly, from 2.66 ± 86.5 mIU/L before ablation to 0.43 ± 0.73 mIU/L (P < 0.001) at the final follow-up. In 14 (58.3%) of the 24 patients, Tg levels were undetectable (below 0.08 mIU/L) at the last follow-up. No life-threatening or delayed complications were observed during the 10-year follow-up period.

CONCLUSION

The high RFS throughout the follow-up period, with efficacy and safety lasting beyond 10 years, supports US-guided RFA as a valuable option for local control of recurrent PTCs.

Comparison of actual prognosis between unilateral and bilateral central neck dissection in modified radical neck dissection patients with no clinical central lymph node metastasis: a retrospective cohort study

Purpose

This study aimed to evaluate the long-term prognosis of contralateral central neck dissection (CND) in papillary thyroid cancer (PTC) patients with ipsilateral lateral neck metastasis. We compared the actual recurrence rate according to the extent of CND-ipsilateral and contralateral sides.

Methods

A total of 708 PTC patients who underwent total thyroidectomy and concomitant ipsilateral or bilateral CND with ipsilateral lateral neck dissection between January 1997 and December 2022 at Samsung Medical Center were retrospectively analyzed.

Results

The median follow-up time was 118 months. Locoregional recurrence was observed in 26 patients (7.9%) and 30 patients (7.9%) in the ipsilateral and bilateral CND groups, respectively. There were 6 contralateral recurrence cases (1.8%) in the ipsilateral CND group and 6 cases (1.6%) in the bilateral CND group. There was only 1 contralateral central neck recurrence in the ipsilateral CND group. The incidence of hypocalcemia (P = 0.007) was higher in the bilateral CND group compared to the ipsilateral CND group.

Conclusion

Surgeons may consider performing only unilateral CND-the side where tumor is for therapeutic purposes to reduce surgical complications.

An Orally Efficacious Thyrotropin Receptor Ligand Inhibits Growth and Metastatic Activity of Thyroid Cancers

CONTEXT

Thyroid-stimulating hormone (or thyrotropin) receptor (TSHR) could be a selective target for small molecule ligands to treat thyroid cancer (TC).

OBJECTIVE

We report a novel, orally efficacious ligand for TSHR that exhibits proliferation inhibitory activity against human TC in vitro and in vivo, and inhibition of metastasis in vivo.

METHODS

A35 (NCATS-SM4420; NCGC00241808) was selected from a sublibrary of >200 TSHR ligands. Cell proliferation assays including BrdU incorporation and WST-1, along with molecular docking studies were done. In vivo activity of A35 was assessed in TC cell-derived xenograft (CDX) models with immunocompromised (NSG) mice. Formalin-fixed, paraffin-embedded sections of tumor and lung tissues were observed for the extent of cell death and metastasis.

RESULTS

A35 was shown to stimulate cAMP production in some cell types by activating TSHR but not in TC cells, MDA-T32, and MDA-T85. A35 inhibited proliferation of MDA-T32 and MDA-T85 in vitro and in vivo, and pulmonary metastasis of MDA-T85F1 in mice. In vitro, A35 inhibition of proliferation was reduced by a selective TSHR antagonist. Inhibition of CDX tumor growth without decreases in mouse weights and liver function showed A35 to be efficacious without apparent toxicity. Lastly, A35 reduced levels of Ki67 in the tumors and metastatic markers in lung tissues.

CONCLUSION

We conclude that A35 is a TSHR-selective inhibitor of TC cell proliferation and metastasis, and suggest that A35 may be a promising lead drug candidate for the treatment of differentiated TC in humans.

Occult Thyroid Carcinoma with Cervical Lymph Node Metastasis: A Rare Case Report

Cervical lymph node metastasis is one of the most common clinical presentations of papillary thyroid carcinoma (PTC). Occult thyroid carcinoma is described as absence of primary tumour or with presence of microcarcinoma in thyroid with cervical lymph node metastasis. Frequency of occult thyroid cancer has decreased due to developments in imaging and improved accuracy of histological examinations. 38 year old male presented to us with complaints of swelling over the left side of neck for the past 2 months. Ultrasonography was suggestive of multiple suspicious enlarged nodes in left level II, III, IV and V and fine needle aspiration cytology showed features of metastatic PTC. He was planned for total thyroidectomy with central compartment clearance and bilateral functional neck dissection. Final histopathology staging was pT0N1b. Radioactive iodine (RAI) screening showed residual functioning thyroid and later therapeutic RAI was administered. He has been on regular follow up and disease free for 1 year post treatment. Occult thyroid carcinoma is a rare diagnosis with multiple treatment plans. Few hypothesis for this entity includes tumor regression, ectopic thyroid carcinoma or missed pathological findings.

Predictors of treatment response in lymphogenic metastasized papillary thyroid cancer: a histopathological study

BACKGROUND

Lymph node metastases in papillary thyroid cancer (PTC) increase the risk for persistent and recurrent disease. Data on the predictive value of histopathological features of lymph node metastases, however, are inconsistent. The aim of this study was to evaluate the prognostic significance of known and new histopathological features of lymph node metastases in a well-defined cohort of PTC patients with clinically evident lymph node metastases.

METHODS

A total of 1042 lymph node metastases, derived from 129 PTC patients, were reexamined according to a predefined protocol and evaluated for diameter, extranodal extension, cystic changes, necrosis, calcifications, and the proportion of the lymph node taken up by tumor cells. Predictors for a failure to achieve a complete biochemical and structural response to treatment were determined.

RESULTS

The presence of more than 5 lymph node metastases was the only independent predictor for a failure to achieve a complete response to treatment (odds ratio [OR] 3.39 [95% CI, 1.57-7.33], P < .05). Diameter nor any of the other evaluated lymph node features were significantly associated with the response to treatment.

CONCLUSIONS

Detailed reexamination of lymph nodes revealed that only the presence of more than 5 lymph node metastases was an independent predictor of failure to achieve a complete response to treatment. No predictive value was found for other histopathological features, including the diameter of the lymph node metastases. These findings have the potential to improve risk stratification in patients with PTC and clinically evident lymph node metastases.

A diagnostic model based on DNA methylation haplotype block characteristics for identifying papillary thyroid carcinoma from thyroid adenoma

Papillary thyroid carcinoma (PTC) is the most prevalent form of thyroid cancer. Methylation of some genes plays a crucial role in the tendency to malignancy as well as poor prognosis of thyroid cancer, suggesting that methylation features can serve as complementary markers for molecular diagnosis. In this study, we aimed to develop and validate a diagnostic model for PTC based on DNA methylation markers. A total of 142 thyroid nodule tissue samples containing 84 cases of PTC and 58 cases of thyroid adenoma (TA) were collected for reduced representation bisulfite sequencing (RRBS) and subsequent analysis. The diagnostic model was constructed by the logistic regression (LR) method followed by 5-cross validation and based on 94 tissue methylation haplotype block (MHB) markers. The model achieved an area under the receiver operating characteristic curve (AUROC) of 0.974 (95% CI, 0.964-0.981) on 108 training samples and 0.917 (95% CI, 0.864-0.973) on 27 independent testing samples. The diagnostic model scores showed significantly high in males (P = 0.0016), age ≤ 45 years (P = 0.026), high body mass index (BMI) (P = 0.040), lymph node metastasis (P = 0.00052) and larger nodules (P = 0.0017) in the PTC group, and the risk score of this diagnostic model showed significantly high in recurrent PTC group (P = 0.0005). These results suggest that the diagnostic model can be expected to be a powerful tool for PTC diagnosis and there are more potential clinical applications of methylation markers to be excavated.

Efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes from papillary thyroid carcinoma

OBJECTIVE

To evaluate the efficacy and safety of percutaneous ultrasound-guided thermal ablation in the treatment of cervical metastatic lymph nodes (LNs) from papillary thyroid carcinoma (PTC).

MATERIALS AND METHODS

A total of 77 patients with 79 LNs ablated by microwave ablation (MWA) or radiofrequency ablation (RFA) between September 2018 and October 2022 were enrolled in this study. After treatment, patients were followed up with measurement of diameters of LNs and serum thyroglobulin (s-Tg) at 1, 3, 6, and 12 months and annually thereafter. The paired t-test was used to compare the changes of s-Tg level, diameters of LNs before and after ablation.

RESULTS

There were no serious complications related to ablation while one case of incomplete ablation in MWA was found during follow-up. The mean longest and shortest diameter of the ablated LNs reduced from 11.6 ± 4.3 mm to 5.0 ± 4.1 mm (p < 0.001), and from 6.1 ± 1.9 mm to 3.0 ± 2.5 mm (p < 0.001) at the last follow-up visit. Besides, the final volume reduction rate (VRR) was 61.8 ± 56.4% (range, -67.0 -100%). The complete disappearance rate was 46.8%, but there were 4 (5.1%) LNs becoming bigger than before. The average s-Tg level was 9.2 ± 26.6 ng/mL, a data significantly decreased to 3.7 ± 7.0 ng/mL at the last follow-up, but no statistical difference was shown.

CONCLUSION

Thermal ablation is an effective and safe modality for the treatment of metastatic LNs from PTC.

Validation of CT-Based Risk Stratification System for Lymph Node Metastasis in Patients With Thyroid Cancer

OBJECTIVE

To evaluate the computed tomography (CT) features for diagnosing metastatic cervical lymph nodes (LNs) in patients with differentiated thyroid cancer (DTC) and validate the CT-based risk stratification system suggested by the Korean Thyroid Imaging Reporting and Data System (K-TIRADS) guidelines.

MATERIALS AND METHODS

A total of 463 LNs from 399 patients with DTC who underwent preoperative CT staging and ultrasound-guided fine-needle aspiration were included. The following CT features for each LN were evaluated: absence of hilum, cystic changes, calcification, strong enhancement, and heterogeneous enhancement. Multivariable logistic regression analysis was performed to identify independent CT features associated with metastatic LNs, and their diagnostic performances were evaluated. LNs were classified into probably benign, indeterminate, and suspicious categories according to the K-TIRADS and the modified LN classification proposed in our study. The diagnostic performance of both classification systems was compared using the exact McNemar and Kosinski tests.

RESULTS

The absence of hilum (odds ratio [OR], 4.859; 95% confidence interval [CI], 1.593-14.823; P = 0.005), strong enhancement (OR, 28.755; 95% CI, 12.719-65.007; P < 0.001), and cystic changes (OR, 46.157; 95% CI, 5.07-420.234; P = 0.001) were independently associated with metastatic LNs. All LNs showing calcification were diagnosed as metastases. Heterogeneous enhancement did not show a significant independent association with metastatic LNs. Strong enhancement, calcification, and cystic changes showed moderate to high specificity (70.1%-100%) and positive predictive value (PPV) (91.8%-100%). The absence of the hilum showed high sensitivity (97.8%) but low specificity (34.0%). The modified LN classification, which excluded heterogeneous enhancement from the K-TIRADS, demonstrated higher specificity (70.1% vs. 62.9%, P = 0.016) and PPV (92.5% vs. 90.9%, P = 0.011) than the K-TIRADS.

CONCLUSION

Excluding heterogeneous enhancement as a suspicious feature resulted in a higher specificity and PPV for diagnosing metastatic LNs than the K-TIRADS. Our research results may provide a basis for revising the LN classification in future guidelines.

Thermal ablation for cervical lymph node metastasis from papillary thyroid carcinoma: A meta-analysis

BACKGROUND

Traditionally, surgery has been the standard treatment for cervical lymph node metastasis in patients with papillary thyroid carcinoma (PTC). However, thermal ablation is currently recommended by several guidelines. This study aimed to evaluate the efficacy and safety of thermal ablation for lymph node metastasis in patients with PTC.

METHODS

We searched PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases until March 2022 to collect studies on thermal ablation (including radiofrequency, microwave, and laser ablations) for cervical lymph node metastasis from PTC.

RESULTS

A total of 190 patients were included, ranging from 5 to 39 in each study, with a sex ratio (male/female) ranging from 1/4 to 17/20, an average age ranging from 15.6 ± 3.0 to 62.3 ± 13.2 (yr), and a total of 270 cervical lymph nodes, ranging from 8 to 98. The follow-up results showed that thermal ablation significantly reduced the maximum diameter and volume of metastatic lymph nodes in PTC (P < .01). The pooled complete disappearance rate was 86% (95% confidence interval 79% to 93%). Thyroglobulin levels were significantly lower after surgery (P < .01). No major complications occurred, and the combined voice change rate was as low as 1% [CI 0% to 3%].

CONCLUSION

Our meta-analysis showed that thermal ablation is an effective and safe method for the treatment of cervical lymph node metastases from PTC. Considering the limitations of this study, more prospective, multicenter, large-sample studies are needed in the future.

Evaluation of recurrence risk in patients with papillary thyroid cancer through tumor-node-metastasis staging: A single-center observational study in Taiwan

BACKGROUND

Many patients with papillary thyroid cancer (PTC) demonstrate satisfactory outcomes. However, 8%-28% of patients with PTC show tumor recurrence, which may affect prognosis. Therefore, identifying factors associated with tumor recurrence in patients with PTC may be helpful to refine therapeutic strategies.

METHODS

To identify factors associated with PTC recurrence, we retrospectively reviewed demographic features (sex and age), operation method, image character, serum thyroglobulin (Tg), accumulated radioactive iodine (I-131) therapeutic dose, I-131 uptake, and metastases at diagnosis in 829 patients with PTC. Patients were grouped into early (stage I and II; n = 698) and advanced (stage III and IV; n = 131) tumor-node-metastasis (TNM) stages. Recurrence rate, mortality rate, risk factors of recurrence, recurrent free survival and overall survival curve were compared between two groups.

RESULTS

Patients in the early stage demonstrated a lower recurrence rate (7.2%) than did those in the advanced stage (28.2%, p < 0.05). The mortality rate of patients with recurrence in the advanced stage was higher than that of those in the early stage (51.4% vs. 12.0%). The major impact factors on tumor recurrence in early TNM stage were distant metastasis and lymph node metastasis, while in advanced TNM stage were distant metastasis, male gender, total thyroidectomy with limited lymph node dissection, and a high serum Tg level.

CONCLUSIONS

Strategies to monitor tumor recurrence might be refined according to the TNM stages of PTC patients.

Prediction of Cervical Lymph Nodes Metastasis in Papillary Thyroid Carcinoma (PTC) Using Nodal Staging Score (NSS)

Background

Cervical lymph node metastasis is commonly seen in papillary thyroid carcinoma. Surgery is the preferred treatment for PTC with cervical lymph node metastasis. There is no alternate ultrasound, neck CT, and thyroglobulin (Tg) methods to assess the occult lymph node metastasis. For moderate-and high-risk PTC, the number of lymph nodes to be dissected should be increased to remove the occult lymph node metastasis.

Objective

This study was designed to develop a nodal staging score model to predict the likelihood of lymph node metastasis in papillary thyroid carcinoma (PTC), and further guide the treatments. Material and Methods. Data were collected from the SEER database. Patients with PTC from 2000 to 2005 were selected. The beta-binomial model was adopted to establish a nodal staging score (NSS)-based model. The NSS-based model was built according to gender, age, extrathyroidal invasion, tumor multifocality, tumor size, and T stage of the patients. A total of 12,431 PTC patients were included in our study. Various types of lymph nodes were examined based on various categories (incidence, risk assessment) to evaluate the results.

Results

5,959 (47.9%) patients in the study were positive and 6,472 (52.1%) were confirmed negative for lymph node metastasis. The corrected incidence of lymph node metastasis was higher than that of direct calculation, regardless of the factors that affected lymph node metastasis. There were significant differences in the OS of PTC patients among the four groups and T stage (p is less than 0.05), indicating that cervical lymph node metastasis would have an impact on the prognosis of patients.

Conclusion

In conclusion, an NSS-based model base on a variety of clinicopathological factors can be used to predict lymph node metastasis. It is important to evaluate the risk of occult lymph node metastasis in the treatment of PTC.. Since, this statistical model can describe the risk of occult lymph node metastasis in patients; therefore, it can be used as basis for decision-making related to the number of lymph nodes that can be dissected in operations.

Non-Iodine-Avid Disease Is Highly Prevalent in Distant Metastatic Differentiated Thyroid Cancer With Papillary Histology

CONTEXT

Patients with radioactive iodine (RAI) refractory metastatic differentiated thyroid cancer (DTC) have poor prognosis. Early identification of RAI refractoriness may improve care.

OBJECTIVE

This work aimed to characterize DTC patients with distant metastases (DM) at diagnosis who presented with non-iodine-avid disease.

METHODS

Retrospective analyses of DTC patients with DM at diagnosis who presented between 2012 and 2020 were performed. Iodine uptake in DM was correlated with tumor histology and mutational profile. The difference in uptake between BRAFV600E-like (BVL) and RAS-like (RL) cancers based on insights from The Cancer Genome Atlas was evaluated.

RESULTS

Among 78 patients, 48.7% had negative uptake in DM on the first posttherapy scan. Negative scans were highly prevalent in papillary thyroid carcinoma (PTC) with papillary architecture, PTC with BRAFV600E mutation, and PTC with both BRAFV600E and TERT promoter mutations (71.1%, 80.9%, and 100%, respectively). BVL and RL tumors exhibited distinct uptake patterns with negative scan prevalence of 76.9% and 14.3% (P = .005). Multivariate logistical regression confirmed high odds of negative uptake in BVL tumors with either BVL mutations or papillary architecture, 19.8 (95% CI, 2.72-144), and low odds of negative uptake in RL tumors with either RL mutations or follicular architecture, 0.048 (95% CI, 0.006-0.344), after adjusting for age, sex, race, RAI preparation method, bone metastases, and RAI dose. Patients with negative scans were significantly older (62.4 vs 47.0 years, P = .03).

CONCLUSION

Among DTC patients with DM at diagnosis, non-iodine-avid disease is highly prevalent in patients with BVL cancers, particularly with BRAFV600E and TERT promoter mutations, and is associated with an older age. Better strategies are needed to improve RAI treatment response for these patients.

Diagnostic accuracy of ultrasound, CT and their combination in detecting cervical lymph node metastasis in patients with papillary thyroid cancer: a systematic review and meta-analysis

OBJECTIVES

To determine the diagnostic accuracy of ultrasound (US), CT and their combination in detecting cervical lymph node metastasis (CLNM) in patients with papillary thyroid cancer (PTC).

METHODS

Medline (via PubMed), Web of Science, Embase were searched to identify studies published till 5 December 2021 that used US and CT to detect CLNM in patients with PTC. The primary outcomes were sensitivity, specificity and diagnostic ORs in neck-level-based (lymph nodes are analysed by neck level) or patient-based (lymph nodes are analysed by patient) analysis. Secondary outcomes were sensitivity, specificity and DORs in the central and lateral compartments.

RESULTS

Fourteen studies (6167 patients with 11 601 neck lymph nodes) met the inclusion criteria. Based on the neck-level-based analysis, the pooled sensitivity, specificity and DORs were 0.35 (95% CI 0.34 to 0.37), 0.95 (95% CI 0.94 to 0.95) and 13.94 (95% CI 9.34 to 20.82) for US, were 0.46 (95% CI 0.44 to 0.47), 0.88 (95% CI 0.87 to 0.89) and 7.24 (95% CI 5.46 to 9.62) for CT, were 0.51 (95% CI 0.49 to 0.52), 0.85 (95% CI 0.84 to 0.86), 6.01 (95% CI 3.84 to 9.40) for the combination of US and CT. In the patient-based analysis, the pooled estimates of sensitivity, specificity and DOR were 0.41 (95% CI 0.36 to 0.46), 0.92 (95% CI 0.89 to 0.94) and 7.56 (95% CI 4.08 to 14.01) for US, were 0.49 (0.44 to 0.54), 0.91 (0.89 to 0.94), 9.40 (5.79 to 15.27) for CT, and were 0.64 (95% CI 0.57 to 0.71), 0.83 (95% CI 0.77 to 0.88), 8.59 (95% CI 5.37 to 13.76) for the combination of US and CT.

DISCUSSION

These findings suggest US, with a DOR almost twice that of CT in the neck-level-based analysis, was superior to CT in detecting CLNM in patients with PTC, especially in the lateral compartment. The combination of US and CT increased the sensitivity from 41%-49% for the individual modalities to 64% for combined modalities in the patient-based analysis.

Risk factors for metastasis in indeterminate lymph nodes in preoperative patients with thyroid cancer

OBJECTIVES

To investigate the relevance of clinical and sonographic features as indicators of metastasis in indeterminate lymph node (LN), to determine possible indications for fine-needle aspiration (FNA).

METHODS

Consecutive patients who underwent US-guided FNA for sonographic indeterminate LNs from differentiated thyroid carcinoma between January 2014 and December 2018 were retrospectively reviewed. Indeterminate LNs were defined as LNs which had neither an echogenic hilum nor hilar vascularity in the absence of any suspicious finding in accordance with the Korean Society of Thyroid Radiology (KSThR) guidelines. Univariate and multivariate logistic regression analyses were performed to identify significant risk factors related to malignancy of indeterminate LNs.

RESULTS

Of the 236 LNs in 212 patients enrolled in this study, 67 LNs (28.3%) were metastatic. The multivariate logistic regression analysis showed that the long diameter of LNs has a negative association with metastasis in indeterminate LNs and the sonographic features of extrathyroidal extension (ETE) and nonparallel orientation of the primary tumor are associated with metastasis in indeterminate LNs. The sensitivity and positive predictive value were increased when FNA was performed for LNs with primary tumors showing ETE or nonparallel orientation than when FNA was performed for LNs larger than 5 mm (59.7% and 40.4% vs. 11.94% and 15.69%).

CONCLUSIONS

The size of LNs has a negative association with metastasis in indeterminate LNs. Performing FNA for indeterminate LNs in patients whose primary tumor shows ETE or a nonparallel orientation can improve the diagnostic performance and decrease the rate of unnecessary FNA.

KEY POINTS

• The size of lymph nodes was negatively related to the risk of metastasis in indeterminate lymph nodes. • Extrathyroidal extension and a nonparallel orientation of the primary tumor were suggested as sonographic features predicting metastasis in indeterminate lymph nodes. • The routine practice of FNA for large indeterminate lymph nodes detected during preoperative evaluation of thyroid cancer should be discouraged.

Clinical impact of radioactive iodine dose selection based on the number of metastatic lymph nodes in patients with papillary thyroid carcinoma: A multicenter retrospective cohort study

OBJECTIVE

The aim of this study is to investigate whether the number of metastatic lymph nodes (LNs) could be used as a basis in the radioactive iodine (RAI) dose selection for patients with papillary thyroid carcinoma (PTC).

PATIENTS

A total of 595 patients with PTC who received first RAI therapy after total or near-total thyroidectomy and had no evidence of disease in treatment response assessment were retrospectively enroled from five hospitals. The patients were classified into two subgroups based on the number of metastatic LNs (>5). The multivariate Cox-proportional hazard model was performed to identify the significant factors for recurrence prediction in each group as well as all enroled patients.

RESULTS

Overall, 22 (3.7%) out of 595 patients had the recurrent disease during the follow-up period. The number of metastatic LNs (>5) was only a significant factor for recurrence prediction in all enroled patients (odds ratio: 7.834, p < .001). In the subgroup with ≤5 metastatic LNs, the presence of extrathyroidal extension was only associated with recurrence (odds ratio: 7.333, p = .024) in multivariate analysis. RAI dose was significantly associated with recurrence rate in which the patients with high-dose RAI (3.7 GBq or higher) had less incidence of recurrence than those with low-dose RAI (1.11 GBq) in the subgroup with more than five metastatic LNs (odds ratio: 6.533, p = .026).

CONCLUSIONS

High-dose RAI (≥3.7 GBq) therapy significantly lowered the recurrence rate in patients with more than five metastatic LNs. Therefore, RAI dose should be determined based on the number of metastatic LNs as well as conventional risk factors.

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.

BRAF V600E Status Sharply Differentiates Lymph Node Metastasis-associated Mortality Risk in Papillary Thyroid Cancer

CONTEXT

How lymph node metastasis (LNM)-associated mortality risk is affected by BRAF V600E in papillary thyroid cancer (PTC) remains undefined.

OBJECTIVE

To study whether BRAF V600E affected LNM-associated mortality in PTC.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed the effect of LNM on PTC-specific mortality with respect to BRAF status in 2638 patients (2015 females and 623 males) from 11 centers in 6 countries, with median age of 46 [interquartile range (IQR) 35-58] years and median follow-up time of 58 (IQR 26-107) months.

RESULTS

Overall, LNM showed a modest mortality risk in wild-type BRAF patients but a strong one in BRAF V600E patients. In conventional PTC (CPTC), LNM showed no increased mortality risk in wild-type BRAF patients but a robustly increased one in BRAF V600E patients; mortality rates were 2/659 (0.3%) vs 4/321 (1.2%) in non-LNM vs LNM patients (P = 0.094) with wild-type BRAF, corresponding to a hazard ratio (HR) (95% CI) of 4.37 (0.80-23.89), which remained insignificant at 3.32 (0.52-21.14) after multivariate adjustment. In BRAF V600E CPTC, morality rates were 7/515 (1.4%) vs 28/363 (7.7%) in non-LNM vs LNM patients (P < 0.001), corresponding to an HR of 4.90 (2.12-11.29) or, after multivariate adjustment, 5.76 (2.19-15.11). Adjusted mortality HR of coexisting LNM and BRAF V600E vs absence of both was 27.39 (5.15-145.80), with Kaplan-Meier analyses showing a similar synergism.

CONCLUSIONS

LNM-associated mortality risk is sharply differentiated by the BRAF status in PTC; in CPTC, LNM showed no increased mortality risk with wild-type BRAF but a robust one with BRAF mutation. These results have strong clinical relevance.

Long-term follow-up results of PTMC treated by ultrasound-guided radiofrequency ablation: a retrospective study

OBJECTIVES

To confirm the long-term efficacy and safety of radiofrequency ablation (RFA) for low-risk papillary thyroid microcarcinoma (PTMC).

METHODS

We retrospectively reviewed data of 102 primary papillary thyroid carcinoma patients (82 women, 20 men; mean age: 43 [19] years) treated with radiofrequency ablation and thyroid-stimulating hormone (TSH) suppression therapy before December 2018. All patients were at high surgical risk or refused surgery. They were followed up at 1, 3, 6, 9, and 12 months and every 6-12 months thereafter using ultrasound and contrast-enhanced ultrasound. The volume and volume reduction ratio was calculated. Recurrence and lymph node or distant metastasis were evaluated.

RESULTS

The mean initial tumor diameter was 0.50 (0.29) cm; the mean initial volume was 0.06 (0.09) mL. At 1, 3, 6, 9, 12, 24, 36, 48, and 60 months after RFA, complete resorption rates were 0, 0, 9.8 (10/102), 33.3 (34/102), 91.2 (93/102), 96.1 (98/102), 99 (101/102), 100, and 100%, respectively. Two patients had developed ipsilateral neck lymph node metastasis in regions IV and VI at 30- and 18-month follow-ups, respectively. After RFA, 3/102 patients (2.9%) developed hoarseness-the main side effect. No life-threatening or delayed complications occurred. The TSH value in the initial period was 0.06 (0.02) µIU/mL; the rate of reaching the TSH target was 85.7%. The TSH value at follow-up was 1.47 (0.91) µIU/mL; the compliance rate was 99.3%.

CONCLUSIONS

Ultrasound-guided RFA for PTMC is highly effective and safe. RFA can serve as a minimally invasive treatment for PTMC patients who refuse surgery or active surveillance.

Video mediastinoscopy-assisted superior mediastinal dissection in the treatment of thyroid carcinoma with mediastinal lymphadenopathy: preliminary results

Background

Mediastinal lymph node metastases (MLNM) are not rare in thyroid cancer, but their treatment has not been extensively studied. This study aimed to explore the preliminary application of video mediastinoscopy-assisted superior mediastinal dissection in the diagnosis and treatment of thyroid carcinoma with mediastinal lymphadenopathy.

Materials and methods

We retrospectively reviewed the clinical pathologic data and short-term outcomes of thyroid cancer patients with suspicious MLNM treated with video mediastinoscopy-assisted mediastinal dissection at our institution from 2017 to 2020.

Results

Nineteen patients were included: 14 with medullary thyroid carcinoma and five with papillary thyroid carcinoma. Superior mediastinal nodes were positive in nine (64.3%) patients with medullary thyroid carcinoma and in four (80.0%) patients with papillary carcinoma. No fatal bleeding occurred. There were three cases of temporary recurrent laryngeal nerve (RLN) palsy postoperatively, one of which was bilateral. Four patients had temporary hypocalcemia requiring supplementation, one had a chyle fistula, and one developed wound infection after the procedure. Postoperative serum molecular markers decreased in all patients. One patient died of cancer while the other 18 patients remained disease-free, with a median follow-up of 33 months.

Conclusion

Video mediastinoscopy-assisted superior mediastinal dissection can be performed relatively safely in patients with suspicious MLNM. This diagnostic and therapeutic approach may help control locoregional recurrences.

Inability of Radioiodine Remnant Ablation to Improve Postoperative Outcome in Adult Patients with Low-Risk Papillary Thyroid Carcinoma

OBJECTIVE

To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence (TR) rate after bilateral lobar resection (BLR).

PATIENTS AND METHODS

There were 2952 low-risk adult papillary thyroid cancer (LRAPTC) patients (with MACIS scores <6) who underwent potentially curative BLR during 1955-2014. During 1955-1974, 1975-1994, and 1995-2014, RRA was administered in 3%, 49%, and 28%. Statistical analyses were performed using SAS software.

RESULTS

During 1955-1974, the 20-year CSM and TR rates after BLR alone were 1.0% and 6.8%; rates after BLR+RRA were 0% (P=.63) and 5.9% (P=.82). During 1975-1994, post-BLR 20-year rates for CSM and TR were 0.3% and 7.5%; after BLR+RRA, rates were higher at 0.9% (P=.31) and 12.8% (P=.01). When TR rates were examined separately for 448 node-negative and 317 node-positive patients, differences were nonsignificant. In 1995-2014, post-BLR 20-year CSM and TR rates were 0% and 9.2%; rates after BLR+RRA were higher at 1.4% (P=.19) and 21.0% (P<.001). In 890 pN0 cases, 15-year locoregional recurrence rates were 3.4% after BLR and 3.7% after BLR+RRA (P=.99). In 740 pN1 patients, 15-year locoregional recurrence rates were 10% higher after BLR+RRA compared with BLR alone (P=.01). However, this difference became nonsignificant when stratified by numbers of metastatic nodes.

CONCLUSION

RRA administered to LRAPTC patients during 1955-2014 did not reduce either the CSM or TR rate. We would therefore not recommend RRA in LRAPTC patients undergoing BLR with curative intent.

Reduction of overtreatment without reduction of overdiagnosis in patients with differentiated thyroid cancer: mission impossible

PURPOSE

Lateral neck nodal metastases are common in patients with differentiated thyroid cancer (DTC) and usually have an indolent nature. They may be detected via neck palpation or preoperative ultrasound (US) of the neck. We hypothesized that preoperative neck metastases detected with US did not affect regional recurrence or long-term survival.

METHODS

A retrospective analysis of patients' records treated for DTC at our institution between January 2006 and December 2016 was performed. Information about preoperative US of the neck, treatment, demographics, staging, and histopathology was obtained. The endpoints for the study were nodal recurrence and survival. Differences in survival were analyzed between three groups of patients divided by presence or lack of preoperative US and/or palpable cervical lymph nodes (PLN). Furthermore, the prognostic value of multiple variables was tested by univariate and multivariate analysis.

RESULTS

There were 1108 patients with DTC, 221 males and 887 females. The median age was 48.3 years (range 3 to 86), the median time of observation was 68 months (range 0 to 142). Eight hundred sixty-two patients without PLN or preoperative US represented group 1, 112 patients with PLN were in group 2, and 134 patients without PLN and with preoperative US were in group 3. Only five patients had a regional recurrence, one died due to distant metastases. There was no statistically significant difference in survival between the groups (p = 0.841) and neck US was not significantly associated with overall survival neither in univariate nor in multivariate analysis.

CONCLUSION

In patients with DTC, the benefits of preoperative US of cervical lymph nodes are probably limited and "less is more" approach is advised.

Value of Pyruvate Carboxylase in Thyroid Fine-Needle Aspiration Wash-Out Fluid for Predicting Papillary Thyroid Cancer Lymph Node Metastasis

The incidence of papillary thyroid carcinoma (PTC) is increasing. Lymph node metastatic status of PTC is a major factor for decision marking of surgery and surgical extend, however, no reliable tool exists for prediction of PTC nodal metastasis, for example, ultrasound cannot qualitatively diagnose and effectively detect central lymph node metastasis (CLNM). Therefore, the development of a new diagnostic biomarker is crucial for CLNM. Metabolic dysregulation is an important factor associated with malignancy and metastasis of tumors. Pyruvate carboxylase (PC) is a major anaplerotic enzyme that catalyzes the carboxylation of pyruvate to form oxaloacetate, which has been suggested to be involved in the tumorigenesis of several cancers, including PTC. This study aimed to explore the role of PC expression in thyroid fine-needle aspiration (FNA) wash-out fluid for predicting CLNM in PTC, and to explore how PC is involved in PTC development. The expression levels of PC in PTC tissues and normal thyroid tissues were first compared based on bioinformatics analysis of public databases, including the Gene Expression Profiling (GEPIA), Oncomine and Gene Expression Omnibus (GEO) databases. Then, the PC mRNA and protein expression levels were measured by RT-PCR and Immunohistochemistry (IHC) in surgical tissues from a total of 42 patients with surgically confirmed PTC, and compared in patients with and without CLNM. Further, to assess PC expression in diagnostic biopsies, a total of 71 thyroid nodule patients with ultrasound-guided FNA wash-out fluid samples and cytological diagnosis were prospectively enrolled in the study. Then, we analyzed the mechanism of PC-mediated PTC progression in vitro. This study showed that PC expression was higher in PTC tissues and thyroid FNA wash-out fluid samples from patients with CLNM than those from patients without CLNM, and that PC-induced PTC metastasis may occur through the TGF-β/Smad-regulated epithelial-mesenchymal transition (EMT) pathway.

A Stepwise Approach Using Metastatic Lymph Node Ratio-Combined Thyroglobulin for Customization of [18F]FDG-PET/CT Indication to Detect Persistent Disease in Patients with Papillary Thyroid Cancer

We investigated whether an indication for [¹⁸F]FDG-PET/CT to detect FDG-avid persistent disease (PD) could be identified precisely using the extent of metastatic lymph nodes (MLNs) and serum thyroglobulin (Tg) in papillary thyroid cancer (PTC) patients. This retrospective study included 429 PTC patients who underwent surgery and radioactive iodine (RAI) therapy. [¹⁸F]FDG-PET/CT and serum Tg were evaluated just before RAI therapy. The MLN ratio (LNR) was defined as the ratio of the number of MLNs to the number of removed LNs. To derive the LNR-combined criteria, different Tg cut-off values for identifying the PET/CT-indicated group for PD detection were applied individually to subgroups initially classified based on LNR cut-off values. The cut-off values for serum Tg, the number of MLNs, and LNR for a PET/CT indication were 6.0 ng/mL, 5, and 0.51, respectively. Compared to a single parameter (serum Tg, total number of MLNs, and LNR), the LNR-combined criteria showed significantly superior diagnostic performance in detecting FDG-avid PD (p < 0.001). The diagnostic performance of PET/CT in detecting FDG-avid PD was significantly improved when the PET/CT-indicated group was identified through the LNR-combined criteria in a stepwise manner; this can contribute to a customized PET/CT indication in PTC patients.

Analyze and compare the predictors of ipsilateral central lymph node metastasis in papillary thyroid carcinoma with cT1a and cT1b stage

PURPOSE

Central lymph node metastasis (CLNM) is common in papillary thyroid carcinoma (PTC). The aim of this study was to compare the cT1a and cT1b stages of PTC and to analyze the predictive factors of ipsilateral central lymph node metastasis (CLNM).

METHODS

In total, 212 PTC (cT1N0) patients underwent hemi-thyroidectomy with ipsilateral central lymph node dissection (CLND) between 2019 and 2020 in our hospital. Univariate and multivariate analyses identified the predictive factors for CLNM of PTC (cT1aN0 and cT1bN0), and compared the differences between the two stages.

RESULTS

The total rate of ipsilateral CLNM was 31.13% (66/212), and the ipsilateral CLNM rate in cT1b stage was higher than that in cT1a stage (48.84% vs. 26.63%), with significant differences (p = 0.005). cT1b stage was more prone to capsule invasion than cT1a stage (41.86% vs. 2.37%), with significant differences (p‹0.001). The multivariate analysis showed that tumor size (n > 5 mm) was an independent predictive factor for CLNM in cT1a stage (p = 0.002), with an odds ratio (OR) of 0.228 (95% confidence interval (95% CI): 0.079-0.655). Capsular invasion (p = 0.048) and tumors located in the middle and lower parts (p = 0.022) were independent predictive factors for CLNM in cT1b stage, with ORs of 0.157 (95% CI: 0.034-0.724) and 0.075 (95% CI: 0.007-0.847), respectively.

CONCLUSIONS

The rate of CLNM increases with increase of tumor size. Patients in cT1b stage are more prone to capsule invasion and CLNM. For the cT1b stage of PTC, predictive factors should be correctly evaluated to guide surgical treatment for PTC patients.

Ultrasonographic Indeterminate Lymph Nodes in Preoperative Thyroid Cancer Patients: Malignancy Risk and Ultrasonographic Findings Predictive of Malignancy

Objective

Proper management of lymph nodes (LNs) with ultrasonographic (US) indeterminate features in thyroid cancer patients remains elusive. We aimed to evaluate the malignancy risk and US findings predictive of malignancy for US indeterminate LNs in preoperative thyroid cancer patients through node-by-node correlation.

Materials and Methods

A total of 348 LNs in 284 thyroid cancer patients, who underwent fine-needle aspiration or core-needle biopsy between December 2006 and June 2015, were included. We determined the malignancy risks for US probably benign, indeterminate, and suspicious categories. For US indeterminate LNs, which had neither echogenic hilum nor hilar vascularity in the absence of any suspicious finding, US findings were compared between benign and metastatic LNs using Mann-Whitney U test and Fisher's exact test.

Results

US imaging diagnoses were probably benign in 20.7% (n = 72) cases, indeterminate in 23.6% (n = 82), and suspicious in 55.7% (n = 194). Malignancy risk of US indeterminate LNs (19.5% [16/82]) differed from those of the US probably benign (2.8% [2/72]) (p = 0.002) and US suspicious LNs (78.4% [152/194]) (p < 0.001). Among US indeterminate LNs, there were no significant differences in short, long, and long-to-short diameter (L/S) ratios between benign and metastatic LNs (3.9 vs. 3.8 mm, p = 0.619; 7.3 vs. 7.3 mm, p = 0.590; 1.9 vs. 1.9, p = 0.652).

Conclusion

US indeterminate LNs were frequently encountered during preoperative evaluation and had intermediate malignancy risk. Given the lack of discriminative power of size criteria and L/S ratio, clinical factors such as surgical strategy and node size should be considered for proper triage of US indeterminate LNs in thyroid cancer.

High-risk factors for lymph node metastasis in contralateral central compartment in unilateral papillary thyroid carcinoma（cT1N0）

OBJECTIVE

The incidence of papillary thyroid carcinoma (PTC) increases yearly. Central lymph node metastasis (CLNM) is common in PTC. Many studies have addressed ipsilateral CLNM; however, few studies have evaluated contralateral CLNM. The purpose of this study is to investigate the high-risk factors of lymph node metastasis in the contralateral central compartment of cT1 stage in PTC.

METHODS

In total, 369 unilateral PTC (cT1N0) patients who underwent total-thyroidectomy with bilateral central lymph node dissection (CLND) between 2013 and 2016 in our hospital were retrospectively enrolled. Univariate and multivariate analyses identified the high-risk factors for contralateral CLNM of PTC.

RESULTS

The total metastasis rate of the ipsilateral central neck compartment was 31.71% (117/369). The total metastasis rate of the contralateral central neck compartment was 8.13% (30/369). The multivariate analysis showed that multifocality (p = 0.009), ipsilateral CLNM (p＜0.001), number of ipsilateral CLNM ＞2 (p = 0.006), tumor located at the inferior pole (p = 0.032) and tumor diameter ＞ 1 cm (p = 0.029) were independent risk factors for contralateral CLNM at cT1 stage in PTC, with odds ratios (ORs) of,4.132 (95% confidence intervals (CI): 1.430-11.936) ，8.591 (95% CI: 3.200-23.061) ，0.174 (95% CI: 0.050-0.601) ，0.353 (95% CI: 0.136-0.917)and 0.235 (95% CI: 0.064-0863), respectively.

CONCLUSION

The combinational use of these risk factors will help surgeons devise an appropriate surgical plan preoperatively. This information could provide reference for the readers who are interested and help to determine the optimal extent of CLND in patients with PTC, especially for cT1b patients.

Occurrence and Natural History of Thyroid Cancer in Patients with Cowden Syndrome

INTRODUCTION

Cowden syndrome patients are at an increased risk of developing differentiated thyroid carcinoma (DTC). There are limited studies of thyroid cancer biology within this population. We aimed to describe the frequency and progression of DTC in this population.

METHOD

We reviewed all patients with clinically or genetically confirmed Cowden syndrome treated at our institution between 1979 and 2017. Presentation, operative details, pathology, and adjuvant treatment for all thyroid diseases were analyzed.

RESULTS

Forty-seven patients were identified. Thirty-seven received a clinical diagnosis while 10 tested positive on genetic testing for the PTEN gene. Average follow-up time was 10 years. Twenty-three patients underwent a total thyroidectomy. Nine patients were diagnosed with thyroid cancer, with a mean age of 28.5 years, 4 cases of the follicular variant of papillary thyroid cancer (PTC), 4 of PTC, and 1 of cystic PTC. One patient required an interval lateral neck dissection but no patients developed distant metastasis. Fourteen patients underwent thyroidectomy, 12 due to follicular adenoma, Hürthle cell adenoma, or multinodular goiter, 1 due to Graves' disease, and 1 who elected to undergo a prophylactic thyroidectomy. No mortality was associated with thyroid cancer in these patients.

CONCLUSION

Patients with Cowden syndrome are at a significantly increased risk of developing DTC and have a younger age of onset. In this study, 20% of the patients with Cowden syndrome were diagnosed with DTC, but distant metastasis and overall mortality were absent. Clinical features were similar to those of sporadic DTC, proving that, apart from screening, Cowden syndrome-related DTC can be treated in similar fashion.

Impact of Surgeon-Performed Ultrasound on Treatment of Thyroid Cancer Patients

BACKGROUND

The 2015 American Thyroid Association Management Guidelines for patients with thyroid nodules recommended a comprehensive sonographic evaluation of thyroid nodules' characteristics and the presence of any suspicious cervical lymph nodes (LNs) in the central and lateral compartments. This detailed sonographic assessment is still not routinely performed. We hypothesized that an endocrine surgeon-performed ultrasound (SUS) significantly enhances the management of thyroid cancer patients when compared with referral ultrasound (RUS).

METHODS

We conducted a retrospective review of 267 consecutive thyroid surgery patients who were diagnosed with thyroid cancer on final pathology. All patients had undergone a SUS, but only 130 cohorts with both RUS and SUS were included. Features of thyroid nodules and LN and changes in the management plan were recorded.

RESULTS

Based on SUS assessment, 26 patients (20%) were noted to have suspicious thyroid nodules which warranted a fine-needle aspiration (FNA) and were missed in RUS. On FNA, there were 12 patients with Bethesda categories III/IV and 14 patients with Bethesda V/VI. Those 26 patients were found to have a malignancy in the final pathology assessment. Thirty-eight patients (29.2%) were noted to have suspicious central/lateral neck findings on SUS but were not reported in RUS. Additionally, 8 patients (6.1%) were found to have a parathyroid adenoma by SUS and required concurrent parathyroidectomy.

DISCUSSION

A comprehensive neck ultrasound in thyroid cancer patients, performed by their endocrine surgeon, could enhance management planning and outcomes. This finding highlights the critical need for education and improvement of routine neck ultrasonographic examination performed in the community.

Prophylactic central lymph node dissection informs the decision of radioactive iodine ablation in papillary thyroid cancer

BACKGROUND

Prophylactic central lymph node dissection (CLND) in papillary thyroid cancer (PTC) is controversial. We aimed to investigate if prophylactic CLND aids risk stratification and contributes to the decision for postoperative RAI ablation.

METHODS

Patients undergoing thyroidectomy for PTC and prophylactic CLND were identified from an endocrine surgical unit database. Pathology reports where reviewed for number and size of lymph nodes and patients stratified by risk according to the ATA guidelines.

RESULTS

426 patients were identified with PTC ≤4 cm and prophylactic CLND. 96 patients (23%) had central lymph node metastasis (CLNM) that qualified them for the intermediate risk group. In 17 patients (4%), the CLNM data led to upgrading independently of other histopathological characteristics. Correcting for multiple variables, CLNM was an independent factor contributing to RAI treatment.

CONCLUSION

Prophylactic CLND provides information to aid the selection of RAI ablation independent of primary cancer histology for risk stratification in 4% of patients. This benefit should be carefully balanced with the risk of CLND and patient treatment choice when deciding on management of PTC ≤4 cm.

Prophylactic lymph node dissection in clinically N0 differentiated thyroid carcinoma: example of personalized treatment

Considering the 'differentiated thyroid carcinoma (DTC) epidemic', the indolent nature of DTC imposes a treatment paradigm shift toward elimination of recurrence. Lymph node metastases in cervical compartments, encountered in 20-90% of DTC, are the main culprit of recurrent disease, affecting 5-30% of patients. Personalized risk-stratified cervical prophylactic lymph node dissection (PLND) at initial thyroidectomy in DTC with no clinical, sonographic or intraoperative evidence of lymph node metastases (clinically N0) has been advocated, though not unanimously. The present review dissects the controversy over PLND. Weighing the benefit yielded from PLND up against the PLND-related morbidity is so far hampered by the inconsistent profit yielded by PLND and the challenging patient selection. Advances in tailoring PLND are anticipated to empower optimal patient care.

circITGA7 Functions as an Oncogene by Sponging miR-198 and Upregulating FGFR1 Expression in Thyroid Cancer

BACKGROUND

Emerging evidence has indicated that circular RNAs (circRNAs), recognized as functional noncoding transcripts in eukaryotic cells, may be involved in regulating many physiological or pathological processes. However, the regulation and function of circular RNA circITGA7 in thyroid cancer (TC) remains unknown.

METHODS

In this study, we found that circITGA7 is upregulated in TC cell lines. We then performed functional analyses in the cell lines to support clinical findings. Mechanistically, we demonstrated that circITGA7 can directly bind to miR-198 and reduce the inhibition effect of miR-198 on target FGFR1 expression.

RESULTS

We reported an upregulation of circITGA7 in patients with TC. Silencing of circITGA7 inhibits metastasis and proliferation of TC cell lines in vitro. In addition, in the TC cell lines, the knockdown of circITGA7 or overexpression of miR-198 significantly suppressed FGFR1 levels. Mechanistically, we found that circITGA7 acts as miR-198 competitive endogenous RNA (ceRNA) to regulate FGFR1 expression.

CONCLUSIONS

In summary, circRNA circITGA7 may play a regulatory role in TC and may be a potential marker for TC diagnosis or progression.

Deep learning enables automated localization of the metastatic lymph node for thyroid cancer on 131I post-ablation whole-body planar scans

The accurate detection of radioactive iodine-avid lymph node (LN) metastasis on 131I post-ablation whole-body planar scans (RxWBSs) is important in tracking the progression of the metastatic lymph nodes (mLNs) of patients with papillary thyroid cancer (PTC). However, severe noise artifacts and the indiscernible location of the mLN from adjacent tissues with similar gray-scale values make clinical decisions extremely challenging. This study aims (i) to develop a multilayer fully connected deep network (MFDN) for the automatic recognition of mLNs from thyroid remnant tissue by utilizing the dataset of RxWBSs and (ii) to evaluate its diagnostic performance using post-ablation single-photon emission computed tomography. Image patches focused on the mLN and remnant tissues along with their variations of probability of pixel positions were fed as inputs to the network. With this efficient automatic approach, we achieved a high F1-score and outperformed the physician score (P < 0.001) in detecting mLNs. Competitive segmentation networks on RxWBS displayed moderate performance for the mLN but remained robust for the remnant tissue. Our results demonstrated that the generalization performance with the multiple layers by replicating signal transmission overcome the constraint of local minimum optimization, it can be suitable to localize the unstable location of mLN region on RxWBS and therefore MFDN can be useful in clinical decision-making to track mLN progression for PTC.

Prediction mode of more than 5 central lymph nodes metastases in clinically node-negative ipsilateral papillary thyroid carcinoma with tumor size 1 to 4 cm

According to the 2015 American Thyroid Association guidelines, either lobectomy or total thyroidectomy was recommended for patients with papillary thyroid carcinoma (PTC) of 1 to 4 cm without extrathyroidal extension and lymph node metastasis. However, lymph node metastases showed strong association with recurrence and low survival rate, especially in PTC patients with more than 5 metastatic lymph nodes. Therefore, this study aimed to investigate the predictive factors of more than 5 central lymph nodes metastases (CLNM) in PTC patients with tumor sizes of 1 to 4 cm. A total of 382 patients with clinically node-negative (cN0) ipsilateral PTC who underwent thyroidectomy with central neck dissection between January 2012 and December 2016 were retrospectively analyzed. CLNMs of >5 were found in 54 (14.1%) patients, while CLNM was detected in 230 (60.2%) patients. Multivariate logistic regression revealed age < 45 years (P < .001), male gender (P = .013), and tumor sizes of >2 cm (P = .001) as independent predictive factors of >5 CLNMs in cN0 ipsilateral PTC patients with tumor sizes 1 to 4 cm. The prediction equation (Y = 1.694 × age + 0.807 × gender + 1.190 × tumor size - 3.530) was developed, with a sensitivity (57.4%) and a specificity (80.8%), respectively, at an optimal cut-off point of -1.685. Therefore, if the predictive value was higher than -1.685 according to the equation in cN0 ipsilateral PTC patients with tumor sizes 1 to 4 cm, then total thyroidectomy might be considered.

Lymph node metastasis around the entrance point to recurrent laryngeal nerve in papillary thyroid carcinoma

There are few reports on the lymph nodes of entrance point to recurrent laryngeal nerve (LN-epRLN) in patients with papillary thyroid carcinoma (PTC). Thus, we investigated the clinical significance of LN-epRLN and implications it may have. An observational analysis of 878 consecutive patients with PTC who underwent thyroidectomy from April 2016 to March 2017 was conducted. We explored the surrounding tissue of laryngeal entry point, during routine central lymph node dissection (CLND). The lymph node specimens were sent separately for routine histopathological examination. Thereafter, complications and follow-ups were recorded. LN-epRLNs were found in 73 of the 878 patients, with the metastatic rate of 3.76%. Univariate and multivariate analysis showed central lymph node metastases can serve as independent predictors for LN-epRLN metastasis. In summary, we confirmed the significance of LN-epRLN in metastasis and recurrence, which required precise anatomy and thorough CLND. In PTC patients, especially in suspicious presence of central cervical lymph node metastasis, attention should be given to excising the nodal tissue at the laryngeal entry point.

Comparative study of gasless endoscopic selective lateral neck dissection via the anterior chest approach versus conventional open surgery for papillary thyroid carcinoma

BACKGROUND

Although there has been increasing interest in aesthetical approaches for treating patients with papillary thyroid carcinoma (PTC), there have been no studies comparing the safety and effectiveness of gasless endoscopic selective lateral neck dissection (SLND) via the anterior chest approach (ACA) with that of conventional open surgery (OPEN) for papillary thyroid carcinoma.

METHODS

A total of 91 patients with PTC who underwent either gasless endoscopic thyroidectomy, central compartment neck dissection and SLND via the ACA or conventional open surgery between Nov. 2008 to Dec. 2018 were included. Primary outcomes and demographic data were compared between the two groups.

RESULTS

Thirty-one patients were in the ACA group and 60 were in the OPEN group. The ACA group was younger and had a longer operative time but less intraoperative hemorrhage (P < 0.001 for all). There were no differences in other clinicopathological features. During the median follow-up of 48 months (ACA group) and 35 months (OPEN group), no recurrence on US/CT was found. The patients in the ACA group had better cosmetic results assessed postoperatively.

CONCLUSION

It appeared that gasless endoscopic selective lateral neck dissection via the anterior chest approach achieved comparable safety and effectiveness as conventional open surgery for PTC and resulted in better cosmetic results.

Predictive Risk-scoring Model For Central Lymph Node Metastasis and Predictors of Recurrence in Papillary Thyroid Carcinoma

There are about half of papillary thyroid carcinoma (PTC) patients with the experience of central lymph node metastasis (CLNM), while the model to predict high-risk groups of CLNM from PTC patients is uncertain. The aim of this study was to evaluate candidate risk factors of CLNM and identify risk factors of recurrence to guide the postoperative therapeutic decision and follow-up for physicians and patients.A total of 4107 patients(4884 lesions) who underwent lymph node dissection in two hospitals from 2005 to 2014 were evaluated. CLNM risk was stratified and a risk-scoring model was developed on the basis of the identified independent risk factors for CLNM. Cox's proportional hazards regression model was used to investigate the risk factors for recurrence.CLNM was proved in 37.96% (1559/4107) of patients and 33.96% (1659/4884) of lesions. In the multivariate analysis, Male, Age ≤35 years, Tumor size >0.5 cm,Lobe dissemination (+), Psammoma body (+), Multifocality and Capsule invasion (+) were independent risk predictors of CLNM (P  < 0.01). A 14-point risk-scoring model was built to predict the stratified CLNM in PTC patients and the area under receiver operating characteristic curve of the model for the prediction of CLNM was 0.672 (95% CI: 0.656-0.688) (P < 0.01). COX regression model showed that Tumor size >0.5 cm, Lobe dissemination (+), Multifocality and CLNM were significant risk factors associated with poor outcomes. The research suggested that prophylactic CLN dissection could be performed in patients with total score ≥4 according to the risk-scoring model, and more aggressive treatment and more frequent follow-up should be considered for patients with Tumor size >0.5 cm, Lobe dissemination (+), Multifocality and CLNM.

Identifying risk factors for metastasis to the level VII lymph node in papillary thyroid carcinoma patients

Background

The level VI lymph nodes are anatomically connected to the level VII lymph nodes and papillary thyroid carcinoma (PTC) can metastasis to both regions. The aim of this study was to identify clinicopathologic factors associated with level VII lymph node metastasis.

Methods

Between March 2015 and September 2016, a total of 275 consecutive patients were operated on for PTC with prophylactic level VII dissection at the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, ZheJiang, China. Patients with PTC were performed via video-assisted approach. Multivariate logistic regression analysis was performed to evaluate the associations between clinicopathologic factors.

Results

Of the 275 subjects enrolled in this study, 79 patients (28.73%) showed lymph node metastasis to the level VII. The multivariate logistic regression analysis showed ultrasonography-positive lymph nodes (p < 0.001), the location of primary carcinoma (p = 0.002) and hashimoto thyroiditis (HT) (p = 0.04) were associated with level VII lymph node metastasis.

Conclusions

Based on the results of our study, we considered central-compartment lymph node dissection (CLND) as an integral strategy. On the basis of surgery safety, transcervical level VII lymph node dissection could be considered for PTC patients with high risk factors such as ultrasonography-positive lymph nodes, tumor located in middle and lower thirds of the thyroid lobe and the patients without HT. In future, prognostic significance of level VII lymph node dissection should be evaluated through long-term surveillance.

Clinical application of the ultrasound-guided fine needle aspiration for thyroglobulin measurement to diagnose lymph node metastasis from differentiated thyroid carcinoma-literature review

Papillary thyroid carcinoma (PTC) generally has a good prognosis, but disease recurs in 25% to 30% of PTC patients and significantly reduces the survival rate. Lymph node metastasis (LNM) is reported in 20% to 50% of PTC patients, mainly in the neck, and 20% originates from recurrence. LNM of papillary thyroid carcinoma are a plausible prognostic factor to determine disease recurrence. Currently, fine needle lymph node aspiration for cytology (LN-FN-cytology) is the best modality to diagnose LNM but is limited by diagnostic sensitivity and sample error. Fine needle lymph node aspiration for thyroglobulin measurement (LN-FNA-Tg) could offer a reliable and quantitative diagnostic method for LNM. The combination of LN-FNA-cytology and LN-FNA-Tg could achieve almost 100% diagnostic sensitivity and specificity for LNM. Both treatment guidelines of the American Thyroid Association and European Thyroid Association recommend LN-FNA-Tg to diagnose LNM after total thyroidectomy. Diagnostic accuracy of the LN-FNA-Tg depends on optimal equipment, scanning protocol, skill, and experience of operators. Normal saline is mainly used for aspiration needle wash-out and buffer solution. And radioimmunoassay or immunoradiometric assay are widely used for the LN-FNA-Tg measurement. So far, there is no consensus about the diagnostic threshold of LN-FNA-Tg for positive LNM, but high LN-FNA-Tg, especially higher than 10 ng/mL, strongly favors LNM.

The Number of Central Lymph Nodes on Preoperative Ultrasound Predicts Central Neck Lymph Node Metastasis in Papillary Thyroid Carcinoma: A Prospective Cohort Study

To evaluate the effectiveness of the number of central compartment lymph nodes (CLNs) on ultrasound (US) in predicting CLN metastasis (CLNM). We prospectively studied 309 papillary thyroid cancer (PTC) patients who underwent thyroidectomy with CLN dissection at our center from May 2017 to July 2017. The number and features of CLNs were evaluated preoperatively via US. All US examinations were performed using a Philips iU 22 or a GE Logiq 9 machine. Correlations between CLNs observed via preoperative US and amount of CLNM were evaluated. We found that ≥2 CLNs on the preoperative US was associated with CLNM (P < 0.01). For this feature, the sensitivity, specificity, and area under the curve (AUC) were 54.3%, 66.1%, and 0.61, respectively. The presence of both suspected metastasis and ≥2 CLNs on US had a specificity of 86.5%. In addition, ≥3 CLNs on preoperative US was associated with large-volume CLNM (>5 metastatic CLNs) (P < 0.01). For this feature, the sensitivity, specificity and AUC were 54.8%, 74.5% and 0.65, respectively. The presence of both suspected metastasis and ≥3 CLNs on US had a specificity of 84.9%. The presence of suspected metastasis and/or ≥3 CLNs had a sensitivity of 80.6%. Our results suggest that ≥2 and ≥ 3 CLNs on preoperative US may serve as ancillary preoperative markers for predicting CLNM.

Risk factors for right paraesophageal lymph node metastasis in papillary thyroid carcinoma: A meta-analysis

OBJECTIVE

Prophylactic dissection of the right paraesophageal lymph node (RPELN) in thyroid cancer is controversial. We performed a meta-analysis to provide evidence for RPELN dissection in thyroid cancer.

METHODS

We searched the PubMed and Science Citation Index Expanded (SCIE) databases for relevant studies published up to January 31, 2019. The patients involved all had a pathological diagnosis of papillary thyroid cancer (PTC) and had undergone total thyroidectomy or right lobectomy with central compartment lymph node dissection. The RPELNs had been kept aside during the operation.

RESULTS

Fourteen cohort studies involving 11,090 patients with PTC were included in the meta-analysis. There was RPELN metastases (RPELNM) in 1038 patients (9.36%). The factors related to RPELNM were: age <45 years, male sex, right lobe tumor, tumor >1 cm, extrathyroidal extension, capsular invasion, right paratracheal lymph node metastasis (RPTLNM), central lymph node metastasis (CLNM), lateral lymph node metastasis (LLNM), and tumor multifocality. There was no association between RPELNM and Hashimoto's thyroiditis (HT) and inferior pole tumors or tumor in the middle of the gland. With superior pole tumors, there was even less RPELNM.

CONCLUSIONS

The clinical features related to RPELNM are age <45 years, male sex, tumor >1 cm, tumor diameter >2 cm, right lobe tumor, RPTLNM, extrathyroidal extension, capsular invasion, CLNM, CLNM ≥3, LLNM and multifocality, which should be considered when evaluating RPELN dissection.

Right Central Lymph Node Dissection in Thyroidectomy: Can Endoscopic Chest-Breast Approach Be Used?

Background: The purpose of this research was to investigate the feasibility and strategies of right central lymph node dissection (CLND) in endoscopic thyroidectomy through chest-breast approach. Materials and Methods: Retrospective analysis on the conduction of 68 cases of endoscopic thyroidectomy through chest-breast approach with right side CLND (endoscopic group) and 31 cases of thyroidectomy through low-neck collar cervical approach with right side CLND (open group) from July 2014 to February 2019. The intraoperative and postoperative data were compared between the two groups. Results: All the surgeries in open group were successfully completed as well as the endoscopic group without any intraoperative conversion into open surgery. There were no difference in sizes of tumor, incidence of lymph node metastasis, number of dissected and metastatic lymph nodes, and postoperative hospitalization days between the two groups. Temporal hypoparathyroidism occurred in both groups with endoscopic group to be 24 cases and open group to be 15 cases but no case in both groups suffering from permanent hypoparathyroidism, recurrent laryngeal nerve injury, lymphatic leakage, or death. One case in endoscopic group was treated with secondary surgery for lateral cervical lymph node metastasis and no evidence of recurrence or metastasis was found in other cases during postoperative follow-up. Conclusions: With strict control in surgical indications and contraindications, endoscopic surgery is safe and feasible for selected cases with the same effect as open surgery on dissection of lymph nodes in the right central region, which is in line with the principle of radical treatment of tumors.

Association of Lymph Node Density With Survival of Patients With Papillary Thyroid Cancer

Importance

Lymph node metastases are common in papillary thyroid cancer (PTC), yet the impact of nodal metastases on survival remains unclear. Lymph node density (LND) is the ratio between the number of positive lymph nodes excised and the total number of excised lymph nodes. Lymph node density has been suggested as a prognostic factor in many types of cancer.

Objective

To evaluate the prognostic role of LND in PTC.

Design, Setting, and Participants

This cohort study reviewed medical records of patients with PTC who were treated at the University of Texas MD Anderson Cancer Center between January 1, 2000, and December 31, 2015. Survival and recurrence outcomes were calculated by using the Kaplan-Meier method. Significant variables on univariate analysis were subjected to a Cox proportional hazards regression multivariate model.

Main Outcomes and Measures

Primary study outcome was disease-specific survival (DSS); other measurements included overall survival (OS).

Results

The study cohort included data for 2542 patients (1801 [71%] male; median age, 48 years [range, 18-97 years]) with a median follow-up of 55 months (range, 4-192 months). The 10-year disease-specific survival rate was 98% for patients with LND of 0.19 or less, compared with 90% for those with LND greater than 0.19 (effect size, 8%; 95% CI, 4%-15%). The 10-year overall survival was 87% for patients with LND of 0.19 or less, compared with 79% for patients with LND greater than 0.19 (effect size, 8%; 95% CI, 3%-15%). Multivariable analysis revealed that LND greater than 0.19 was independently associated with an adverse DSS (hazard ratio [HR], 4.11; 95% CI, 2.11-8.97) and OS (HR, 1.96; 95% CI, 1.24-4.11). Subgroup analysis of patients with 18 or more lymph nodes analyzed revealed that LND greater than 0.19 remained a significant marker for DSS (HR, 2.94; 95% CI, 1.36-9.81) and OS (HR, 2.26; 95% CI, 1.12-5.34). Incorporating LND into the current American Joint Committee on Cancer staging system successfully stratified risk groups compared with the traditional TNM staging system.

Conclusions and Relevance

This single-institute study demonstrates the reproducibility of LND as a predictor of outcomes in PTC. Lymph node density can potentially assist in identifying patients with poorer survival who may benefit from more aggressive adjuvant therapy.

Predictive factors for non-small-volume central lymph node metastases (more than 5 or ≥ 2 mm) in clinically node-negative papillary thyroid carcinoma

The benefits of prophylactic central neck dissection (pCND) for treating patients with clinical node-negative (cN0) papillary thyroid carcinoma (PTC) remain controversial. Lymph node metastases have been strongly associated with local recurrence and low survival, especially in PTC patients with 5 or more or ≥2 mm metastatic lymph nodes. The following study investigates the incidence and risk factors of more than 5 or ≥2 mm metastatic lymph nodes in the central compartment.A total of 611 patients with cN0 PTC were retrospectively analyzed. Cervical lymph nodes were harvested, and the size of metastatic lymph nodes was consequently analyzed.Non-small-volume central lymph node metastases (NSVCLNM), defined as more than 5 or ≥2 mm metastatic lymph nodes) were detected in 67 (11.0%) patients. Male gender, age ≤36 years, multifocal lesions, extrathyroidal extension, and tumor size > 0.85 cm were independent risk factors for NSVCLNM in cN0 PTC. The sensitivity and specificity of having ≥3 risk factors for predicting NSVCLNM was 46.3% and 86.8%, respectively.These findings suggest that pCND is a suitable treatment strategy for cN0 PTC patients with 3 or more risk factors for NSVCLNM.

Relationship between ultrasonographic and pathologic calcification patterns in papillary thyroid cancer

Ultrasonographic microcalcification is highly related to papillary thyroid cancer (PTC) and pathologic psammoma body is a poor prognostic factor. However, it is little known about whether the microcalcifications seen on ultrasonography are consistent with the pathologic psammoma bodies. We evaluated the relationship between ultrasonographic (US) calcification types and pathologic calcification features, and the consistency between observed pathologic and US calcifications.US calcifications were classified into microcalcification (MC) and nonmicrocalcification (non-MC) types, and pathologic calcifications were classified into 3 types: psammoma bodies, stromal calcifications, and ossifications.Among the 411 nodules that were reviewed by a pathologist, 38.9% (n = 160) had any type of US calcification. The larger the size of pathologic calcification, the more calcification was present in US (psammoma 46.1% < stromal 53.7% < ossification 73.3%). Psammoma bodies occurred in all US MC type. Ossification nodules occurred in nearly all (92.3%) non-MC type. The stromal-only nodules were 36.8% MC-type and 63.2% non-MC type. MC-type had a significantly higher odds ratio than non-MC type for predicting psammoma bodies according to the logistic regression.The presence of MC in ultrasonography was consistent with the presence of psammoma bodies. This study suggests that US identification of MC may be a useful prognostic indicator of PTC aggressiveness.

Predictive gene signatures of nodal metastasis in papillary thyroid carcinoma

BACKGROUND

Cervical lymph node metastases (LNM) in papillary thyroid carcinomas (PTCs) are common and develop in approximately 30-80% of PTCs. The presence of cervical LNM significantly increases the rate of locoregional recurrence in PTCs.

OBJECTIVE

To search for predictive gene signatures for nodal metastasis in PTCs.

METHODS

We used unsupervised clustering with unbiased manner to compare molecular profiles between PTCs with nodal metastasis and PTCs without nodal metastasis using mRNA-seq of TCGA data. Using gene ontology (GO) and logistic regression test, we generated 12-predictive genes for nodal metastasis in PTCs.

RESULTS

Unsupervised clustering of mRNA-seq (training set, N = 158) revealed that PTCs with nodal metastasis showed different gene expression patterns compared to PTCs without nodal metastasis. We generated 12 predictive genes and these gene signatures showed consistency for predicting nodal metastasis when we applied them to a validation set (N = 80). Based on multivariate analysis, these 12 predictive gene signatures showed more significant odds ratio compared to other variables.

CONCLUSIONS

These 12 gene signatures could be used to predict the chance of nodal metastasis in PTCs in preoperative evaluation using fine needle aspiration biopsy (FNAB) so that appropriate plan such as central neck dissection could be made.