Patterns of Initial Recurrence in Completely Resected Papillary Thyroid Carcinoma

Enhancement on CT for preoperative diagnosis of metastatic lymph nodes in thyroid cancer: a comparison across experience levels

OBJECTIVES

To investigate the diagnostic performance and interobserver agreement of quantitative CT parameters indicating strong lymph node (LN) enhancement in differentiated thyroid cancer (DTC), comparing them with qualitative analysis by radiologists of varying experience.

MATERIALS AND METHODS

This study included 463 LNs from 399 patients with DTC. Three radiologists independently analyzed strong LN enhancement on CT. Qualitative analysis of strong enhancement was defined as LN cortex showing greater enhancement than adjacent muscles on the arterial phase. Quantitative analysis included the mean attenuation value (MAV) of LN on arterial phase (LNA) and venous phase (LNV), LNA normalized to the common carotid artery (NAVCCA), internal jugular vein (NAVIJV), and sternocleidomastoid muscle (NAVSCM), attenuation difference [AD; (LNA - MAVSCM)], and relative washout ratio [((LNA - LNV)/LNA) × 100]. The interobserver agreement and diagnostic performance of the quantitative and qualitative analyses were evaluated.

RESULTS

Interobserver agreement was excellent for all quantitative CT parameters (ICC, 0.83-0.94) and substantial for qualitative assessment (κ = 0.61). All CT parameters except for LNV showed good diagnostic performance for metastatic LNs (AUC, 0.81-0.85). NAVCCA (0.85, 95% CI: 0.8-0.9) and AD (0.85, 95% CI: 0.81-0.89) had the highest AUCs. All quantitative parameters except for NAVIJV had significantly higher AUCs than qualitative assessments by inexperienced radiologists, with no significant difference from assessments by an experienced radiologist.

CONCLUSION

Quantitative assessment of LN enhancement on arterial phase CT showed higher interobserver agreement and AUC values than qualitative analysis by inexperienced radiologists, supporting the need for a standardized quantitative CT parameter-based model for determining strong LN enhancement.

CLINICAL RELEVANCE STATEMENT

When assessing strong LN enhancement in DTC, quantitative CT parameters indicating strong enhancement can improve interobserver agreement, regardless of experience level. Therefore, the development of a standardized diagnostic model based on quantitative CT parameters might be necessary.

KEY POINTS

Accurate preoperative assessment of LN metastasis in thyroid cancer is crucial. Quantitative CT parameters indicating strong LN enhancement demonstrated excellent interobserver agreement and good diagnostic performance. Quantitative assessment of contrast enhancement offers a more objective model for the identification of metastatic LNs.

An age-and sex-matched postoperative therapy should be required in thyroid papillary carcinoma

Background and purpose

Thyroid papillary carcinoma (PTC) had a high possibility of recurrence after surgery, and thyroid stimulating hormone (TSH) suppression and radioactive iodine (131I) were used for postoperative therapy. This study explored the potential mechanism of lymph node metastasis (LNM) and aimed to develop differentiated treatments for PTC.

Method

This study explored the risk factors of lymph node metastasis in PTC by analyzing the clinical information of 2073 cases. The Cancer Genome Atlas Thyroid Cancer (TCGA-THCA) and the Gene Expression Omnibus (GEO) databases of gene expression were analyzed to identify the interrelationships between gene expression to phenotype.

Results

Analyzing clinical data, we found that male gender, younger age, larger tumor size, and extra-thyroidal extension (ETE) were risk significant risk factors for lymph node metastasis(P<0.05). Conversely, thyroid function parameters such as TSH, FT3, FT4, TSH/FT3, and TSH/FT4 didn't correlate with LNM(P>0.05), and TSH levels were observed to be higher in females(P<0.05). Gene expression analysis revealed that SLC5A5 was down-regulated in males, younger individuals, and those with lymph node metastasis, and a lower level of SLC5A5 was associated with a worse disease-free survival(P<0.05). Additionally, our examination of single-cell RNA sequencing (scRNA-seq) data indicated that SLC5A5 expression was reduced in tumors and lymph node metastasis samples, correlating positively with the expression of TSHR.

Conclusion

The impact of TSH on PTC behavior remained unclear, while the capacity for absorbing 131I in dependence on SLC5A5 showed variations across different genders and ages. We conclude that postoperative treatment of PTC should take into account the differences caused by gender and age.

Integration of ultrasound-based radiomics with clinical features for predicting cervical lymph node metastasis in postoperative patients with differentiated thyroid carcinoma

OBJECTIVE

The primary objective was to establish a radiomics model utilizing longitudinal +cross-sectional ultrasound (US) images of lymph nodes (LNs) to predict cervical lymph node metastasis (CLNM) following differentiated thyroid carcinoma (DTC) surgery.

METHODS

A retrospective collection of 211 LNs from 211 postoperative DTC patients who underwent neck US with suspicious LN fine needle aspiration cytopathology findings at our institution was conducted between June 2021 and April 2023. Conventional US and clinicopathological information of patients were gathered. Based on the pathological results, patients were categorized into CLNM and non-CLNM groups. The database was randomly divided into a training cohort (n = 147) and a test cohort (n = 64) at a 7:3 ratio. The least absolute shrinkage and selection operator algorithm was applied to screen the most relevant radiomic features from the longitudinal + cross-sectional US images, and a radiomics model was constructed. Univariate and multivariate analyses were used to assess US and clinicopathological significance features. Subsequently, a combined model for predicting CLNM was constructed by integrating radiomics, conventional US, and clinicopathological features and presented as a nomogram.

RESULTS

The area under the curves (AUCs) of the longitudinal + cross-sectional radiomics models were 0.846 and 0.801 in the training and test sets, respectively, outperforming the single longitudinal and cross-sectional models (p < 0.05). In the testing cohort, the AUC of the combined model in predicting CLNM was 0.901, surpassing that of the single US model (AUC, 0.731) and radiomics model (AUC, 0.801).

CONCLUSIONS

The US-based radiomics model exhibits the potential to accurately predict CLNM following DTC surgery, thereby enhancing diagnostic accuracy.

Retroauricular endoscopic thyroidectomy: initial single-institution experiences

Conventional thyroidectomy often results in visible scarring postoperatively. Endoscopic thyroidectomy offers the advantage of scarless surgery, especially beneficial for young adult women. The retroauricular approach uses a facelift incision well-known among surgeons and eliminates the need for gas insufflation due to the large working space. An early retrospective analysis was conducted on thirty-one individuals who underwent gasless retroauricular endoscopic thyroidectomy approach, focusing on isthmolobectomies (n = 26) and lobectomies (n = 5), with one case necessitating conversion to open thyroidectomy, from January 2016 to April 2017. Physical examination, laboratory, and histopathology findings were collected. The scar was evaluated using the Vancouver Scale System, while other surgical and oncological outcomes were documented and assessed. The average operative time was 154.2 ± 21.3 min, with an average bleeding volume of 69.2 ± 52.1 mL. The average length of stay was 4.7 ± 2.2 days. All complications occurred were temporary and all subjects remained in good condition throughout the follow-up period. Most subjects (65.6%) were very satisfied with the scar concealed in the retroauricular area. Retroauricular endoscopic thyroidectomy is a safe and feasible remote access technique with excellent postoperative results.

Deep learning-based computer-aided diagnosis system for the automatic detection and classification of lateral cervical lymph nodes on original ultrasound images of papillary thyroid carcinoma: a prospective diagnostic study

PURPOSE

This study aims to develop a deep learning-based computer-aided diagnosis (CAD) system for the automatic detection and classification of lateral cervical lymph nodes (LNs) on original ultrasound images of papillary thyroid carcinoma (PTC) patients.

METHODS

A retrospective data set of 1801 cervical LN ultrasound images from 1675 patients with PTC and a prospective test set including 185 images from 160 patients were collected. Four different deep leaning models were trained and validated in the retrospective data set. The best model was selected for CAD system development and compared with three sonographers in the retrospective and prospective test sets.

RESULTS

The Deformable Detection Transformer (DETR) model showed the highest diagnostic efficacy, with a mean average precision score of 86.3% in the retrospective test set, and was therefore used in constructing the CAD system. The detection performance of the CAD system was superior to the junior sonographer and intermediate sonographer with accuracies of 86.3% and 92.4% in the retrospective and prospective test sets, respectively. The classification performance of the CAD system was better than all sonographers with the areas under the curve (AUCs) of 94.4% and 95.2% in the retrospective and prospective test sets, respectively.

CONCLUSIONS

This study developed a Deformable DETR model-based CAD system for automatically detecting and classifying lateral cervical LNs on original ultrasound images, which showed excellent diagnostic efficacy and clinical utility. It can be an important tool for assisting sonographers in the diagnosis process.

Management of surgical diseases of thyroid gland indications of the United Italian Society of Endocrine Surgery (SIUEC)

A task force of the United Italian society of Endocrine Surgery (SIUEC) was commissioned to review the position statement on diagnostic, therapeutic and health‑care management protocol in thyroid surgery published in 2016, at the light of new technologies, recent oncological concepts, and tailored approaches. The objective of this publication was to support surgeons with modern rational protocols of treatment that can be shared by health-care professionals, taking into account important clinical, healthcare and therapeutic aspects, as well as potential sequelae and complications. The task force consists of 13 members of the SIUEC highly trained and experienced in thyroid surgery. The main topics concern clinical evaluation and preoperative workup, patient preparation for surgery, surgical treatment, non-surgical options, postoperative management, prevention and management of major complications, outpatient care and follow-up.

Comparison of staging and recurrence predictors in patients with differentiated thyroid cancer between the 7th and 8th editions of the American Joint Committee on Cancer staging systems

BACKGROUND

The predictive value of American Joint Committee on Cancer (AJCC) 8 for recurrence in differentiated thyroid cancer (DTC) is not known. We aimed to compare AJCC 7 and 8 regarding the differences in staging and recurrence predictors in DTC.

METHODS

Demographic, clinical (duration of disease and follow-up, the extent of surgery), laboratory (TSH, fT4, thyroglobulin, and antithyroglobulin), pathological (type of thyroid cancer, localization, multifocality, diameter, extrathyroidal extension [ETE], and lymph node [LN] metastasis), and imaging findings (sonography, and whole-body scan), and follow-up features (metastases, recurrence and/or persistence, and RAI need) were retrospectively analyzed in adult patients with DTC followed-up for at least six months. Staging was determined in accordance with AJCC 7 and AJCC 8, prediction of recurrence and persistence by ATA risk stratification, and death risk by AMES systems. The alterations in staging and recurrence predictors were analyzed.

RESULTS

A majority of study patients (N.=524) were female (N.=424) and diagnosed with papillary cancer (N.=511), the median age at diagnosis was 44. 97.89% (N.=93) of stage 2-4 patients (N.=95) in AJCC 7 were down-staged in AJCC 8. We down-staged 41 patients of 45-55 years of age into stage 1 in AJCC 8 independent of LN status. A percentage of 26.71% of patients (N.=140) did have persistence, 9.54% (N.=50) persistence at the last follow-up, and 9.54% (N.=50) had recurrence. According to AJCC 8, T4 and AMES high risk were predictors for recurrence (hazard ratio: 3.053, P=0.023; hazard ratio:2.465, and P=0.005; respectively). Both AJCC 7 and 8 were associated with recurrence (P=0.008 and P<0.001, respectively). Stage 4 in AJCC 7, and stages 3 and 4 in AJCC 8 better predicted the probability of recurrence.

CONCLUSIONS

Our findings suggest that AJCC 8 better predicted the recurrence in DTC than AJCC 7. In AJCC 8, T4 tumor, AMES high risk, stages 3 and 4 predicted recurrence. The vast majority of patients with stages 2-4 in AJCC 7 were down-staged in AJCC 8.

Computational modeling of locoregional recurrence with spatial structure identifies tissue-specific carcinogenic profiles

Introduction

Local and regional recurrence after surgical intervention is a significant problem in cancer management. The multistage theory of carcinogenesis precisely places the presence of histologically normal but mutated premalignant lesions surrounding the tumor - field cancerization, as a significant cause of cancer recurrence. The relationship between tissue dynamics, cancer initiation and cancer recurrence in multistage carcinogenesis is not well known.

Methods

This study constructs a computational model for cancer initiation and recurrence by combining the Moran and branching processes in which cells requires 3 or more mutations to become malignant. In addition, a spatial structure-setting is included in the model to account for positional relativity in cell turnover towards malignant transformation. The model consists of a population of normal cells with no mutation; several populations of premalignant cells with varying number of mutations and a population of malignant cells. The model computes a stage of cancer detection and surgery to eliminate malignant cells but spares premalignant cells and then estimates the time for malignant cells to re-emerge.

Results

We report the cellular conditions that give rise to different patterns of cancer initiation and the conditions favoring a shorter cancer recurrence by analyzing premalignant cell types at the time of surgery. In addition, the model is fitted to disease-free clinical data of 8,957 patients in 27 different cancer types; From this fitting, we estimate the turnover rate per month, relative fitness of premalignant cells, growth rate and death rate of cancer cells in each cancer type.

Discussion

Our study provides insights into how to identify patients who are likely to have a shorter recurrence and where to target the therapeutic intervention.

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.

Lymph Node Metastases Identified at the Post-Ablation 131I SPECT/CT Scan Is a Prognostic Factor of Intermediate-Risk Papillary Thyroid Cancer

The intermediate-risk category of papillary thyroid cancer (PTC) comprises heterogeneous patients within a wide range of stages and varied care management. Understanding the risk features of recurrence observed after the initial therapy should be emphasized. We aimed to evaluate the prognostic significance of radioactive iodine-avid lymph nodes observed during the initial treatment of patients with PTC that were considered to be at intermediate risk. Data on patients with intermediate-risk PTC treated from 2012 to 2018 were retrospectively reviewed. Post-therapeutic SPECT/CT (Rx SPECT/CT) was evaluated in the enrolled patients. The clinical, pathologic, and incidence of radioiodine-avid (RAI-avid) lymph node metastasis (mLN) on Rx SPECT/CT were reviewed, and risk factors related to recurrent disease were analyzed. After a median follow-up of 37.26 (30.90, 46.33) months, structural persistent/recurrent disease was detected in 9.81% (36/367) of patients with intermediate-risk tumors. The incidence of recurrence was higher in patients who demonstrated RAI-avid mLN after the initial therapy than in those who did not (p < 0.001). In a multivariate Cox proportional hazard regression analysis, RAI-avid mLN appeared to be a robust risk factor for recurrent disease after the initial therapy (HR: 8.967, 95% CI: 3.433−23.421, p = 0.000). RAI-avid mLN is a significant risk factor for recurrent intermediate-risk PTC after the initial treatment.

Risk factors of skip lateral cervical lymph node metastasis in papillary thyroid carcinoma: a systematic review and meta-analysis

OBJECTIVE

To analyze and explore the risk factors of skip lateral cervical lymph node metastasis (SLLNM) in papillary thyroid carcinoma (PTC).

METHODS

PubMed, Web of Science, Embase, Cochrane, Wanfang, China National Knowledge Infrastructure, and China Science and Technology Journal databases, updated to April 4, 2021, were systematically searched for literature on the risk factors of SLLNM in PTC. The meta-analysis was completed using Stata 15.0 software after quality evaluation. The odds ratio (OR) and 95% confidence interval (CI) of each variable were calculated using fixed or random-effects models, and the publication bias was evaluated by the Egger's test.

RESULTS

A total of 28 studies with 10,682 cases were included in our meta-analysis; 1592 (14.90%) cases were positive for SLLNM. The meta-analysis showed that female sex (OR = 1.16, 95% CI = 1.02-1.31, P = 0.021), age ≥45 (OR = 1.60, 95% CI = 1.19-2.15, P = 0.002), tumor diameter ≤10 mm (OR = 2.23, 95% CI = 1.62-3.06, P < 0.001), and upper location of tumor (OR = 3.60, 95% CI = 2.65-4.89, P < 0.001) were risk factors for SLLNM in PTC patients. Hashimoto's thyroiditis (OR = 1.02, 95% CI = 0.88-1.19, P = 0.777), multifocality (OR = 0.98, 95% CI = 0.75-1.28, P = 0.873), bilateral tumors (OR = 0.92, 95% CI = 0.70-1.19, P = 0.515), extrathyroidal extensions (OR = 1.07, 95% CI = 0.83-1.39, P = 0.598), and capsular invasion (OR = 0.93, 95% CI = 0.65-1.31, P = 0.660) were not closely related to SLLNM risk.

CONCLUSION

This study confirmed significant associations between SLLNM and female sex, age ≥45, tumor diameter ≤10 mm, and upper location of the tumor.

Methylation-Driven Gene PLAU as a Potential Prognostic Marker for Differential Thyroid Carcinoma

Purpose: Aberrant DNA methylation plays a crucial role in the tumorigenesis of differentiated thyroid cancer (DTC); nevertheless, the factors leading to the local and regional recurrence of DTC are not well understood. This study aimed to establish the connection between DNA methylation-driven genes and the recurrence of DTC.

Methods: RNA sequencing profiles and DNA methylation profiles of DTC were downloaded from The Cancer Genome Atlas (TCGA) database. Combined application of the methylmix R package and univariate Cox regression analyses were used to screen and distinguish prognosis-related methylation-driven genes. Multivariate Cox regression analyses were utilized to identify the target genes that were closely associated with the recurrence of DTC. Then, correlations between the expression levels of the target genes and the clinicopathological features were verified, as well as their potential biological functions.

Results: A total of 168 Methylation-driven genes were differentially expressed in thyroid cancer, among which 10 genes (GSTO2, GSTM5, GSTM1, GPX7, FGF2, LIF, PLAU, BCL10, SHARPIN and TNFRSF1A) were identified as Hub genes. We selected PLAU for further analysis because PLAU was most strongly correlated with DTC recurrence and the DNA methylation levels of PLAU were closely associated with multiple clinicopathological features of DTC. PLAU was significantly upregulated in DTC, and patients with a high expression level of PLAU had a higher risk of recurrence (p < 0.05). Functional predictions suggested that PLAU-related genes were mainly involved in the regulation of immune-related signaling pathways. Moreover, the mRNA level of PLAU was found to be positively correlated with the cell markers of neutrophils and dendritic cells. In addition, we found that two DNA methylation sites (cg06829584, cg19399285) were associated with abnormal expression of PLAU in DTC.

Conclusion: The methylation-driven gene PLAU is an independent risk factor for the recurrence of DTC and it functions as an oncogene through the regulation of immune-related signaling pathways, which offers new insight into the molecular mechanisms of thyroid cancer and provides new possibilities for individualized treatment of thyroid cancer patients.

Preoperative Nodal US Features for Predicting Recurrence in N1b Papillary Thyroid Carcinoma

Simple Summary

The presence of lateral neck lymph node (LN) metastasis (N1b) is a known prognostic factor for poor prognosis and high morbidity after surgery in papillary thyroid carcinoma (PTC). Previous studies have suggested that tumor size and metastatic LN characteristics, including LN size, number, ratio, and extranodal extension, are associated with recurrence; however, the prognostic role of imaging features of LNs in the lateral neck have rarely been reported. In this study, we investigated whether ultrasound imaging features of lateral neck LN metastases can be prognostic markers for predicting recurrence and thereby guide surgical extent and posttreatment surveillance in N1b PTC.

Abstract

This study aimed to investigate whether preoperative ultrasonographic (US) features of metastatic lymph nodes (LNs) are associated with tumor recurrence in patients with N1b papillary thyroid carcinoma (PTC). We enrolled 692 patients (mean age, 41.9 years; range, 6–80 years) who underwent total thyroidectomy and lateral compartment LN dissection between January 2009 and December 2015 and were followed-up for 12 months or longer. Clinicopathologic findings and US features of the index tumor and metastatic LNs in the lateral neck were reviewed. A Kaplan-Meier analysis and Cox proportion hazard model were used to analyze the recurrence-free survival rates and features associated with postoperative recurrence. Thirty-seven (5.3%) patients had developed recurrence at a median follow-up of 66.5 months. On multivariate Cox proportional hazard analysis, male sex (hazard ratio [HR], 2.277; 95% confidence interval [CI]: 1.131, 4.586; p = 0.021), age ≥55 years (HR, 3.216; 95% CI: 1.529, 6.766; p = 0.002), LN size (HR, 1.054; 95% CI: 1.024, 1.085; p < 0.001), and hyperechogenicity of LN (HR, 8.223; 95% CI: 1.689, 40.046; p = 0.009) on US were independently associated with recurrence. Preoperative US features of LNs, including size and hyperechogenicity, may be valuable for predicting recurrence in patients with N1b PTC.

A New Dynamic Response to Therapy Assessment in Postoperative Patients With Low-Risk Differentiated Thyroid Cancer Treated Without Radioactive Iodine

Background

Total thyroidectomy (TT) or lobectomy without radioactive iodine (RAI) is becoming a common management for patients with low-risk differentiated thyroid cancer (DTC). However, the assessment of response to therapy for these patients remains controversial. The aim of this study was to propose and validate a new dynamic evaluation strategy to assess the response to therapy in patients with low-risk DTC treated with TT or lobectomy but without RAI.

Methods

We performed a retrospective analysis of 543 adult patients with low-risk DTC who underwent TT or lobectomy without RAI therapy. Follow-up consisted of trends of serum thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb) levels and neck ultrasonography (US) were conducted every 6-24 months. Response to therapy assessments were defined as excellent response, biochemical incomplete response, structural incomplete response, and indeterminate response according to the follow-up findings.

Results

At a median follow-up of 51 months (range 33-66 months), 517 (95%) had excellent response, while the other 26 had either biochemical incomplete response (an increasing trend of suppressed serum Tg levels, n=9; an increasing trend of TgAb levels, n=3) or indeterminate response (a stable or decreasing trend of suppressed serum Tg levels, but a stable positive trend of TgAb levels, n=14). No patients had structural incomplete response or no deaths related to thyroid cancer. The risk of incomplete response was significantly higher in lobectomy than in TT (p<0.001).

Conclusion

Our study proposed and validated a new dynamic response to therapy assessment depending on trends of suppressed serum Tg, TgAb levels, and neck US findings which could be an appropriate tool for postoperative follow-up in low-risk DTC patients without RAI therapy. Our findings provided further evidence to support no routine recommendation of RAI after surgery in low-risk DTC.

Outcomes after radioiodine ablation in patients with thyroid cancer: Long-term follow-up of a Chinese randomized clinicaltrial

OBJECTIVE

Two large randomized trials of patients with differentiated thyroid cancer (DTC) reported recently (HiLo and ESTIMABL1) found that the recurrence rate among patients who underwent 1.1 GBq radioactive iodine (RAI) ablation was not higher than that of patients who underwent 3.7 GBq radioactive iodine (RAI) ablation. However, no similar studies have been conducted in China. We aimed to report clinical outcomes in Chinese patients with low/intermediate risk of recurrence DTC after long-term follow-up, and evaluate the risk factors that influence the presence or absence of incomplete response at the final follow-up.

DESIGN

A long-term follow-up of a Chinese randomized clinical trial (October 2014 and February 2021) was conducted.

PATIENTS

A total of 506 DTC patients at low/intermediate risk of recurrence who were randomized into two groups to receive 1.1 (n = 251) or 3.7 GBq (n = 255) RAI ablation following thyroid hormone withdrawal were followed on levothyroxine treatment for a median of 4.5 years (range: 1.6-6.3).

MEASUREMENTS

Suppressed serum thyroglobulin (Tg) and anti-thyroglobulin antibody (TgAb) levels were determined, and neck ultrasonography was performed.

RESULTS

At the final follow-up, 499 (98.6%) patients showed an excellent response. The other seven patients (two patients underwent 1.1 GBq and five patients underwent 3.7 GBq RAI ablation, respectively) showed either structural incomplete response (lymph node metastasis, n = 1), biochemical incomplete response (increased serum Tg ≥ 1 ng/ml, or increased positive TgAb levels, n = 5), or indeterminate response (stable positive TgAb levels, n = 1). The risk of incomplete response at the final follow-up was significantly increased in patients with stimulated serum Tg ≥ 10 ng/ml at ablation (p = .003) and in patients with unsuccessful ablation (p = .008).

CONCLUSION

Our findings indicated that there was no difference in the long-term outcomes with RAI ablation using either 1.1 or 3.7 GBq in patients with low/intermediate risk of recurrence DTC, and 1.1 GBq RAI might be suitable for patients who are recommended for ablation.

Combined role of lymph node ratio and serum thyroglobulin levels in predicting prognosis of papillary thyroid carcinoma

OBJECTIVES

The aim of this study was to evaluate a prognostic value of the extent of metastatic lymph node combined with TSH-stimulated serum thyroglobulin (sTg) measured just before radioactive iodine (RAI) therapy in patients with papillary thyroid cancer (PTC).

METHODS

The retrospective study included 468 patients with PTC who underwent total thyroidectomy with neck dissection and postoperative RAI therapy. The extent of metastatic lymph node was evaluated with the lymph node ratio (LNR) which was defined as the number of metastatic lymph nodes out of the number of total removed lymph nodes. We investigated which factors could significantly predict persistent or recurrent disease (PRD).

RESULTS

LNR ≥0.4 (P = 0.002) and sTg ≥6.0 ng/mL (P < 0.001) were associated with PRD in univariate analysis. In multivariate analysis, only male [hazard ratio: 2.35, 95% confidence interval (CI): 1.18-4.66, P = 0.014] and sTg (hazard ratio: 9.35, 95% CI: 4.44-19.67, P < 0.001) were associated with PRD prediction. When we divided patients into two groups (patients with sTg level < 6.0 ng/mL and those with sTg level ≥ 6.0 ng/mL), LNR (≥0.4) was a significant predictor of PRD in patients with sTg <6.0 ng/mL (hazard ratio: 4.38, 95% CI: 1.22-15.72, P = 0.024).

CONCLUSIONS

LNR ≥0.4 was a significant predictor of PRD when the sTg level was <6.0 ng/mL. LNR should be used in combination with a relatively low level of serum sTg to predict the prognosis of patients with PTC.

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.

Carbon nanoparticle-guided intraoperative lymph node biopsy predicts the status of lymph nodes posterior to right recurrent laryngeal nerve in cN0 papillary thyroid carcinoma

BACKGROUND

The lymph nodes in the right central compartment can be divided into 2 parts by the right recurrent laryngeal nerve (RLN), and there is a lack of an accurate and convenient method for assessing metastases in the lymph node posterior to the right recurrent laryngeal nerve (LN-prRLN) in cN0 thyroid papillary carcinoma patients.

METHODS

Patients diagnosed with cN0 thyroid papillary carcinoma and underwent intraoperative carbon nanoparticle-guided lymph node biopsy from January 2017 to November 2020 at the Center for Thyroid and Breast Surgery of Xuanwu Hospital were retrospectively analyzed. The intraoperative frozen section examination and postoperative LN-prRLN status should have been comprehensively recorded. The participants were divided into the LN-prRLN positive group and LN-prRLN negative group according to their recorded LN-prRLN status.

RESULTS

In total, 189 cases (LN-prRLN positive group, n=30; LN-prRLN negative group, n=159) were included in the analysis. The univariate and multivariate regression analyses revealed that the number of metastatic lymph nodes during intraoperative lymph node biopsy was the potential predictor for LN-prRLN metastasis [odds ratio (OR): 1.320, 95% confidence interval (CI): 1.057 to 1.649, P=0.014]. The receiver operating characteristic (ROC) curve showed that the area under the curve (AUC) reached 0.7 upon a combined analysis of multiple lymph node statuses located at pre-laryngeal (Delphian), pre-tracheal, and para-tracheal lymph nodes ipsilateral to the tumor in predicting the metastasis of LN-prRLN, and the cut-off value was 0.5.

CONCLUSIONS

Number of metastatic lymph nodes in intraoperative biopsy was an indicator of LN-prRLN metastasis in cN0 thyroid carcinoma patients. Patients staging in cN0 with negative intraoperative lymph node status might be considered not to require LN-prRLN dissection during central lymph nodes dissection.

Value of Combining Clinical Factors, Conventional Ultrasound, and Contrast-Enhanced Ultrasound Features in Preoperative Prediction of Central Lymph Node Metastases of Different Sized Papillary Thyroid Carcinomas

Purpose

Early and accurate preoperative diagnosis of central lymph node metastasis (CLNM) is crucial to improve surgical management of patients with clinical lymph node-negative papillary thyroid carcinoma (PTC). Towards improving diagnosis of CLNM, we assessed the value of combining preoperative clinical characteristics, conventional ultrasound, and contrast-enhanced ultrasound (CEUS) in preoperative prediction of CLNM of different sized PTCs.

Patients and Methods

Patients were divided according to tumor size: a PTC group (>10 mm) and a papillary thyroid microcarcinoma (PTMC) group (≤10 mm). We retrospectively analyzed the clinical and ultrasonographic features of 120 PTC patients and 165 PTMC patients. Multivariate logistic regression analysis was used to screen independent risk factors and establish prediction models. Receiver operating characteristic curves were used to determine the best cut-off values for continuous variables and assess the performance of prediction models.

Results

Independent risk predictors of CLNM for the PTC group were extrathyroidal extension in CEUS (OR=7.923), tumor size >14 mm (OR=5.491), and multifocality (OR=3.235). For the PTMC group, the independent risk factors were the distance from the thyroid capsule =0 mm (OR=4.629), male (OR=3.315), tumor size >5 mm (OR=3.304), and microcalcification (OR=2.560). The predictive model of combined method had better performance in predicting CLNM of PTC compared with models based on CEUS and conventional ultrasound alone (area under the curve: 0.832 vs 0.739, P=0.0011; 0.832 vs 0.678, P=0.0012). For PTMC, comparing with CEUS, the combined method and conventional ultrasound performed better than CEUS alone in predicting CLNM (area under the curve: 0.783 vs 0.636, P=0.0016; 0.738 vs 0.636, P=0.0196).

Conclusion

The predictive models of combined method obtained from significant preoperative clinical and ultrasonographic features can potentially improve the preoperative diagnosis and individual treatment of CLNM in patients with PTC and PTMC. CEUS may be helpful in predicting CLNM of PTC, but CEUS would be ineffective in predicting CLNM of PTMC.

Management of Sonographically Suspicious Thyroid Nodules 1 cm or Smaller and Candidacy for Active Surveillance: Experience of a Tertiary Center in China

OBJECTIVE

Our objective was to investigate the management of patients with asymptomatic suspicious thyroid nodules ≤1 cm.

METHODS

We retrospectively reviewed medical records of patients with sonographically suspicious thyroid nodules ≤1 cm and without distant metastases, suspicious lymph node metastasis (LNM), or extrathyroidal extension (ETE).

RESULTS

Of the 386 enrolled patients, 174 (45.1%) had immediate surgery (IS), while 212 (54.9%) underwent active surveillance (AS). In the IS group, 166 (95.4%) patients were confirmed as having papillary thyroid microcarcinoma. LNM and ETE were observed in 24.7% and 2.4% cases, respectively. In the AS group, nodule size increased by ≥3 mm in 11 (5.2%) patients and 39 (18.4%) had a >50% increase in nodule volume after a median follow-up of 12 months. Nodules with smaller volume at diagnosis were more likely to increase in volume later. Newly suspicious LNM was detected in 23 (10.8%) patients. Delayed surgery (DS) was performed in 101 patients, with 27 showing disease progression. ETE and LNM were detected in 3% and 36%, respectively, of patients with papillary thyroid microcarcinoma. Compared with IS, tumors in the DS group more frequently showed lateral LNM and capsular invasion (P < .05). No patient had recurrence or died of thyroid cancer during postoperative follow-up (median 26 [4-60] months).

CONCLUSIONS

IS or DS of patients with asymptomatic suspicious thyroid nodules ≤1 cm was relatively high in China. The inertia of low-risk nodules and the effectiveness of DS for those that progressed make AS a feasible strategy.

Clinical Relevance and Management of Recurrent Laryngeal Nerve Inlet Zone Lymph Nodes Metastasis in Papillary Thyroid Cancer

BACKGROUND

Recurrent nodal disease often occurs in recurrent laryngeal nerve inlet zone (RLNIZ), leading to difficult surgical management.

METHODS

Medical records of 947 patients with PTC and 33 patients with recurrent PTC were retrospectively reviewed. Totally 169 sides of RLNIZ dissection in 152 patients (17 cases were bilateral and 135 cases were unilateral) with primary surgery and 4 patients with structural recurrent disease were included for the analysis.

RESULTS

The rate of lymph node metastasis in RLNIZ was 31.3% (47/150). The incidence of transient hypoparathyroidism was 5.9% and no RLN injury and permanent hypoparathyroidism occurred. RLNIZ lymph nodes metastasis (LNM) was significantly associated with age <45 years, larger tumor size, number of CNLNM, and lateral node metastasis. CNLNM and lateral node metastasis were independent risk factors for RLNIZ LNM. Recurrent nodal disease in RLNIZ was identified in four of 33 patients and permanent recurrent laryngeal nerve (RLN) injury was observed in one of four patients.

CONCLUSION

Lymph nodes in RLNIZ are usually involved in patients with heavy tumor burden and can be removed safely at initial surgery. Once central or lateral LNM was confirmed preoperatively or intraoperatively, RLNIZ lymph node dissection should be carefully performed to reduce the rate of structural recurrence in the central compartment.

Salvage surgery for structural local recurrence of papillary thyroid cancer: recurrence patterns and surgical outcome

To clarify the patterns of the recurrence and to assess the oncological and functional outcomes after salvage surgery for the patients with structural local recurrence of papillary thyroid cancer (PTC), twenty-five patients who underwent salvage surgery for structural local recurrence of PTC were retrospectively reviewed. Structural recurrences were observed in the tracheal lumen in 5 patients, intraluminal or intramuscular esophagus in 5 patients, trachea, and cricoid cartilage in 9 patients, cricoid and thyroid cartilage in 2 patients, intra-lumen of the larynx in 1 patient and soft tissue around thyroid in 3 patients, respectively. Although all local disease was resected with macroscopically negative margin, 10 patients diagnosed as microscopically positive margin. Major surgical complications occurred in 6 patients, including common carotid artery injury (n = 1), unintentional pharyngeal or esophageal injury (n = 2), recurrent laryngeal nerve paralysis (n = 2), and pharyngeal fistula resulting in common carotid artery rupture (n = 1), and were successfully managed. During the follow-up periods, 6 patients were alive without disease, 15 patients survived with distant metastases and/or locoregional recurrence, and 4 patients died of the disease. While tracheocutaneous fistula remained in 7 patients, the vocal function was preserved in all patients but one who underwent total laryngectomy. Normal oral intake was retained in all patients. In conclusion, although salvage surgery for structural recurrence of PTC has a high risk of complications, it may be worthwhile when macroscopic curative resection is available. The decision should be made considering various factors including curability, risk of surgical procedure, functional outcome, and life expectancy.

Predictive factors of lateral lymph node metastasis in conventional papillary thyroid carcinoma

BACKGROUND

Lymph node metastasis (LNM) has been a significant predictor for local recurrence and distant metastasis in papillary thyroid carcinoma (PTC). However, the clinical predictors for conventional papillary thyroid carcinoma (CPTC) with lateral lymph node metastasis (LLNM) have yet to be established. Our work aimed to effectively identify the risk factors of LLNM in CPTC, helping surgeons to devise better individualized therapy strategies.

METHODS

We retrospectively analyzed 652 patients who were diagnosed with CPTC in the Department of General Surgery at Guangdong Provincial People's Hospital between October 2015 and June 2019. Univariate and multivariate logistic regression was used to analyze the correlation between clinicopathological characteristics and the LLNM of CPTC.

RESULTS

The incidence of LLNM in CPTC was 29.75% (194 of 652 patients). Univariate analysis found that LLNM was significantly associated with gender, age, number of central lymph nodes (CLNs), primary tumor location, multifocality, maximum tumor diameter, and BRAF V600E mutation. Independent risk factors for LLNM were multifocality (P=0.017, OR =4.325, 95% CI: 1.298-14.408), maximum tumor diameter (P<0.001, OR =4.076, 95% CI: 1.945-8.540), primary tumor location (P=0.037, OR =2.127, 95% CI: 1.046-4.328), number of CLNs (P<0.001, OR =8.604, 95% CI: 3.630-20.390), and BRAF V600E mutation (P=0.001, OR =3.913, 95% CI: 1.803-8.496) by multivariate analysis.

CONCLUSIONS

LLNM in CPTC was related to the large volume of central lymph node metastasis (CLNM), tumor located in the upper lobe, multifocality, tumor diameter >2 cm, and BRAF V600E mutation-negative, which should be considered when examining patients with suspected metastasis in the lateral compartment.

Endoscopic thyroidectomy via axillary-breast-shoulder approach: Early experience of 42 cases

BACKGROUND

Most patients in Indonesia present with large-sized thyroid nodules, which need surgical removal to exclude malignancy. Many surgeons prefer endoscopic thyroidectomy to avoid a large and visible surgical scar on the neck and to reduce postoperative complications. This study aims to evaluate and analyze surgical feasibility, safety, oncologic outcome, and patient satisfaction of endoscopic thyroidectomy via the axillary-breast-shoulder approach.

METHODS

Between August 2010 and September 2015, 42 endoscopic thyroidectomies via the axillary-breast-shoulder approach with carbon dioxide insufflation up to 8-10 mmHg were performed and retrospectively reviewed.

RESULTS

Mean tumor size and operative time were 3.11 ± 0.99 cm and 189 ± 45 min, respectively. Mean blood loss was 68.3 mL. There were temporary complications such as hoarseness (19%), emphysema (2.3%) and hematoma (2.3%). Mean hospital length of stay was 3.98 days. Most subjects (61.9%) were very satisfied with the postoperative scar. The visual analog score of postoperative pain decreased from 4.83 on day-1 to 2.28 on day-7. The tumor recurrence was 9.6%.

CONCLUSIONS

Endoscopic thyroidectomy via the axillary-breast-shoulder approach is feasible, safe, and minimally invasive with excellent postoperative results.

Prophylactic Central Lymph Node Dissection Improves Disease-Free Survival in Patients with Intermediate and High Risk Differentiated Thyroid Carcinoma: A Retrospective Analysis on 399 Patients

The role of prophylactic central lymph node dissection (pCLND) in the treatment of differentiated thyroid cancer (DTC) is controversial and still a matter of debate. The primary outcome of our study was to assess whether pCLND is effective in reducing the incidence of recurrent disease, and the secondary goal was to estimate the incidence of postoperative complications in patients who underwent pCLND and to evaluate the prognostic value of occult node metastases. In this retrospective study, we included patients with preoperative diagnosis of DTC and clinically uninvolved lymph nodes (cN0). The patients were divided into two groups, depending on the surgical approach: total thyroidectomy alone (TT group) or total thyroidectomy and pCLND (pCLND group). Three hundred and ninety-nine patients were included in this study, 320 (80.2%) in the TT group and 79 (19.8%) in the pCLND group. There were no significant differences in morbidity among the two groups. Histopathological evaluation demonstrated a similar distribution of aggressive features, especially regarding multicentricity, extrathyroidal extension, and angioinvasivity between the two groups. Occult lymph node metastases were found in 20 (25.3%) patients in the pCLND group. Prophylactic CLND was effective in improving disease-free survival in patients with intermediate and high risk of disease recurrence (p = 0.0392); occult lymph node metastases resulted as a significant negative prognostic factor (p < 0.001).

Preoperative Serum Thyroglobulin and Its Correlation with the Burden and Extent of Differentiated Thyroid Cancer

Lymph node metastasis (LNM) in differentiated thyroid cancer (DTC) is usually detected with preoperative ultrasonography; however, this has limited sensitivity for small metastases, and there is currently no predictive biomarker that can help to inform the extent of surgery required. We evaluated whether preoperative serum thyroglobulin levels can predict tumor burden and extent. We retrospectively reviewed the clinical records of 4029 DTC cases diagnosed and treated at a Samsung Medical Center between 1994 and 2016. We reviewed primary tumor size, number and location of LNM, and presence of distant metastases to reveal relationships between tumor burden and extent and preoperative serum thyroglobulin levels. We found a linear association between increasing preoperative thyroglobulin levels, the size of the primary tumor, and the number of LNM (r = 0.34, p < 0.001, r = 0.20, p < 0.001, respectively). Tumor extent also increased with each decile of increasing preoperative thyroglobulin level (r = 0.18, p < 0.001). Preoperative thyroglobulin levels of 13.15 ng/mL, 30.05 ng/mL, and 62.9 ng/mL were associated with the presence of ipsilateral lateral LNM, contralateral lateral LNM, and distant metastasis, respectively. Our results suggest that preoperative measurement of serum thyroglobulin may help to predict LNM and help to tailor surgery.

Preoperative serum thyroglobulin is a risk factor of skip metastasis in papillary thyroid carcinoma

BACKGROUND

Lymph node metastasis of papillary thyroid carcinoma (PTC) was a significant risk factor of local recurrence and distant metastasis, and our study aimed to identify predictive factors of skip metastasis in PTC, helping surgeons to build a strategy when facing patients in N1b stage with clinical central lymph node-negative.

METHODS

A total of 304 patients who underwent total thyroidectomy with central and lateral lymph node dissection and were diagnosed PTC with lateral lymph node metastasis (LLNM) in the Department of General Surgery at Guangdong Provincial People's Hospital were enrolled. We collected clinicopathological characteristics and analyzed their correlation with skip metastasis by univariate and multivariate analysis.

RESULTS

The incidence of skip metastasis in PTC was 14.8%. Univariate analysis showed that age, tumor diameter, primary tumor location, and preoperative serum thyroglobulin (Tg) were risk factors. Age (P=0.049, OR =3.418), primary tumor location (P<0.001, OR =7.279), and Tg (P=0.038, OR =9.412) were independent predictors in PTC by multivariate analysis.

CONCLUSIONS

Skip metastasis of PTC was significantly associated with preoperative serum Tg ≤77 ng/mL, tumor diameter ≤10 mm, age ≥55, and tumor located in the upper lobe. It is the first time to demonstrate that Tg is associated with skip metastasis of PTC.

Radiomics signature for prediction of lateral lymph node metastasis in conventional papillary thyroid carcinoma

Purpose

Preoperative neck ultrasound (US) for lateral cervical lymph nodes is recommended for all patients undergoing thyroidectomy for thyroid malignancy, but it is operator dependent. We aimed to develop a radiomics signature using US images of the primary tumor to preoperatively predict lateral lymph node metastasis (LNM) in patients with conventional papillary thyroid carcinoma (cPTC).

Methods

Four hundred consecutive cPTC patients from January 2004 to February 2006 were enrolled as the training cohort, and 368 consecutive cPTC patients from March 2006 to February 2007 served as the validation cohort. A radiomics signature, which consisted of 14 selected features, was generated by the least absolute shrinkage and selection operator (LASSO) regression model in the training cohort. The discriminating performance of the radiomics signature was assessed in the validation cohort with the area under the receiver operating characteristic curve (AUC).

Results

The radiomics signature was significantly associated with lateral cervical lymph node status (p < 0.001). The AUC of its performance in discriminating metastatic and non-metastatic lateral cervical lymph nodes was 0.710 (95% CI: 0.649–0.770) in the training cohort and was 0.621 (95% CI: 0.560–0.682) in the validation cohort.

Conclusions

The present study showed that US radiomic features of the primary tumor were associated with lateral cervical lymph node status. Although their discriminatory performance was slightly lower in the validation cohort, our study shows that US radiomic features of the primary tumor alone have the potential to predict lateral LNM.

Improved survival after early detection of asymptomatic distant metastasis in patients with thyroid cancer

The incidence of thyroid cancer (TC) has been increasing in many countries and concerns about overdiagnosis are also widely shared. However, early detection may be helpful in some high-risk TC patients, such as those with initial distant metastasis. We conducted this study to evaluate the usefulness of early detection in TC patients with initial distant metastasis. We retrospectively reviewed the clinical data of 13,249 TC patients, and found 127 patients with initial distant metastasis. Enrolled patients were divided into two groups according to the diagnostic periods; before and after 2004, when the early detection of TC by ultrasonography began in earnest in Korea. Patients were also divided into two groups according to the presence of symptoms. Prior to 2004, 33 patients (1.7% of TC patients) were diagnosed with TC with initial distant metastasis and 16 (48.5%) of them died. After 2004, 94 patients (0.8% of TC patients) were diagnosed with TC with initial distant metastasis and 29 (30.9%) of them died. Prior to 2004, the disease-specific death rates were similar between the asymptomatic and symptomatic groups (46.2% vs. 50.0%, P = 0.566). Conversely, after 2004, the asymptomatic group showed a significantly lower disease-specific death rate as compared with that of the symptomatic groups (17.2% vs. 60.0%; P < 0.001). Early detection had a significant positive impact on survival outcomes only after 2004, especially in asymptomatic TC patients with initial distant metastasis.

Prognostic implications of the BRAF-V600E mutation in papillary thyroid carcinoma based on a new cut-off age stratification

The BRAF-V600^E mutation is the most common and specific oncogenic event known in papillary thyroid carcinoma (PTC). However, it remains controversial whether there is an association between the BRAF-V600^E mutation and clinicopathologically aggressive characteristics of PTC. The purpose of the present retrospective study was to investigate the significance of the BRAF-V600^E mutation in predicting prognostic and aggressive clinicopathological characteristics according to a new age-based stratification. Clinical data and the BRAF-V600^E mutation status of 475 patients with PTC were downloaded from The Cancer Genome Atlas database. The association between BRAF-V600^E status and clinicopathological characteristics was analyzed by χ² test or Fisher's exact test. Recurrence-free survival rate (RFS) was analyzed using the Kaplan-Meier method. Aggressive clinicopathological factors associated with recurrence were analyzed by Cox multivariate regression. This study was conducted on 219 cases of patients with PTC with a known BRAF-V600^E mutational status. In the ≥55 years age group, BRAF-V600^E was found to be significantly associated with aggressive PTC characteristics, including tumor size, PTC subtype, radioactive iodine (RAI) dose, follow-up time, recurrence, recurrence risk stage, advanced T stage, advanced N stage and American Joint Committee on Cancer (III/IV) stage (all P<0.05). RFS was analyzed by the log-rank test and exhibited statistically significant differences in the ≥55 years group (P=0.041), but there was no significant difference in the <55 group (P=0.757), according to the BRAF-V600^E mutation status. The BRAF-V600^E gene was excluded from the recurrence Cox multivariate regression model. The BRAF-V600^E mutation was found to better predict aggressive and recurrent PTC based on age stratification with the cut-off age of 55 years. The synergistic interaction between BRAF-V600^E mutation and the new age stratification may help clinicians reach the optimal decision in terms of surgical approach and the extent of surgery.

Risk of Recurrence in Differentiated Thyroid Cancer: A Population-Based Comparison of the 7th and 8th Editions of the American Joint Committee on Cancer Staging Systems

BACKGROUND

Differentiated thyroid cancer (DTC) survival is excellent, making recurrence a more clinically relevant prognosticator. We hypothesized that the new American Joint Committee on Cancer (AJCC) 8th edition improves on the utility of the 7th edition in predicting the risk of recurrence in DTC.

METHODS

A population-based retrospective review compared the risk of recurrence in patients with DTC according to the AJCC 7th and 8th editions using the Surveillance, Epidemiology, and End Results-based Kentucky Cancer Registry from 2004 to 2012.

RESULTS

A total of 3248 patients with DTC were considered disease-free after treatment. Twenty percent of patients were downstaged from the 7th edition to the 8th edition. Most patients had stage I disease (80% in the 7th edition and 94% in the 8th edition). A total of 110 (3%) patients recurred after a median of 27 months. The risk of recurrence was significantly associated with stage for both editions (p < 0.001). In the 7th edition, there was poor differentiation between lower stages and better differentiation between higher stages (stage II hazard ratio [HR] 0.91, 95% confidence interval [CI] 0.39-2.11; stage III HR 3.72, 95% CI 2.29-6.07; stage IV HR 11.66, 95% CI 7.10-19.15; all compared with stage I). The 8th edition better differentiated lower stages (stage II HR 4.06, 95% CI 2.38-6.93; stage III HR 13.07, 95% CI 5.30-32.22; stage IV 11.88, 95% CI 3.76-37.59; all compared with stage I).

CONCLUSIONS

The AJCC 8th edition better differentiates the risk of DTC recurrence for early stages of disease compared with the 7th edition. However, limitations remain, emphasizing the importance of adjunctive strategies to estimate the risk of recurrence.

Impact of Extranodal Extension on Risk Stratification in Papillary Thyroid Carcinoma

Background: The current American Thyroid Association risk-stratification system for papillary thyroid carcinoma (PTC) incorporates the number and size of positive lymph nodes (LNs) but places less weight on extranodal extension (ENE). This study investigated how to incorporate ENE into the current system to predict recurrence better in PTC N1 patients. Methods: A total of 369 N1 PTC patients without distant metastasis were enrolled. The combination of number of positive LNs and LNs with ENE that had the highest C-index were identified with multivariable Cox proportional hazards models. ENE number was incorporated into the current system considering the recurrence rate and unadjusted and adjusted hazard ratios (HRs) of the subgroups. Kaplan-Meier curves for recurrence based on current and alternative systems were compared by log-rank test. Results: The recurrence rate for the subgroup with five or fewer positive LNs and one to three ENEs (7/61; 11.5%) was higher than that of the subgroup with five or fewer positive LNs without ENE (5/129; 3.9%; adjusted HR = 3.42 [confidence interval (CI) 0.99-11.75]; p = 0.050). In contrast, adjusted HRs of the subgroup with more than five positive LNs and one to three ENEs (2.33 [CI 0.52-10.35]) or with four or more ENEs (3.86 [CI 1.05-14.17]) were not higher than those of the subgroup with more than five LNs without ENE (4.47 [1.16-17.19]). Incorporating ENE into the current system as an intermediate-risk group yielded a lower log-rank p-value (0.05 vs. 0.01) than the current system. Conclusions: The presence of ENE in low volume LN metastasis confers an intermediate risk of recurrence. Incorporating ENE into the current system allows more accurate decisions regarding further management of PTC N1 patients.

Radiation-induced papillary thyroid cancer: is it a distinct clinical entity?

PURPOSE OF REVIEW

To present the current status of knowledge regarding radiation-induced papillary thyroid cancer (RIPTC), defining its epidemiologic, pathologic, and clinical characteristics, with ensuing possible therapeutic and prognostic consequences.

RECENT FINDINGS

Cumulative evidence shows that RIPTC resembles sporadic papillary thyroid cancer (PTC) of comparable age, both in terms of clinical-pathological features and prognosis. Therefore, more aggressive treatment does not seem to be required when managing RIPTC as its prognosis is comparable to that of never-irradiated patients.

SUMMARY

Radiation exposure in childhood is a well-documented risk factor for development of PTC. Therefore, increased exposure to medical or environmental radiation may be in part responsible, along with increased screening, of the recent burgeoning incidence of PTC. A specific morphological and molecular portrait of RIPTC is unlikely to exist. The more aggressive histologic and clinical features initially reported in radiation-induced cases are consistent with the expectations in nonradiation-related PTC of a comparable age. Aggressive histology, nodal, and distant metastases correlate with early age at onset rather than with radiation exposure. Although relapses are frequent in children, long-term cancer-specific mortality is approximately 1%, lower than that observed for adults and comparable between irradiated and nonirradiated cohorts. RIPTC does not require more aggressive surgery or more adjuvant treatments, as prognosis is as good as that of sporadic PTC when matched for stage and treatment received.

Impact of the new guidelines of the American Thyroid Association on the treatment of the differentiated thyroid tumor in an Italian center with medium-high volume thyroid surgery

Background

The therapy for differentiated thyroid tumors is currently built upon two cornerstones: the stage of the disease and the new guidelines of the American Thyroid Association, jointly converging to lobohystmectomy for selected cases that meet certain criteria. The aim of the study was to relate these guidelines to the activity of an Italian center with a medium-high volume of thyroidectomies in a region with a high rate of endemic disease of the thyroid.

Methods

In order to conduct the analysis, the clinical records of the last 3 years, including 194 cases of total thyroidectomy and 3 lobohystmectomy, were taken into consideration. There were 46 cases of differentiated thyroid cancer (18 incidental tumors were found during thyroidectomies for benign diseases). Postoperative complications, patient characteristics and the stage of the tumor were assessed in relation to the new ATA guidelines.

Results

All patients underwent total thyroidectomy, with 2 of them also undergoing lymphadenectomy. The incidence of transient hypoparathyroidism was 19% with 1 case of permanent deficit. No cases of recurrent nerve injury were reported. Twenty-five out of the 28 patients with cancer preoperatively diagnosed were found with more nodules and in 15 of them the nodule had a diameter bigger than 1 cm. All the parameters suggested lobohystmectomy only for one case.

The treatment for the differentiated thyroid tumor is still widely discussed. Above all, differences between populations, screening methods and surveillance programs are still evident.

Conclusions

The ATA guidelines applied to our cases, even if limited, have shown limited applicability to our study, mainly due to the high incidence of multinodularity and the size of the nodule: typical characteristics of a region with a high rate of endemic thyroid pathology.

Repeat Ultrasonography in the First Years after Therapy with Radioiodine Is Not Necessary in Most Patients with Papillary Thyroid Carcinoma when Postoperative Ultrasonography Is Negative: A Reduction of Costs and False-Positives

BACKGROUND

Periodic ultrasonography (US) examination is recommended in many patients with papillary thyroid carcinoma (PTC) after treatment with radioactive iodine (RAI), but recurrences are confirmed in few cases. This study determined whether the indication of US in the first years after treatment with RAI can be selective when postoperative US and posttherapy whole-body scanning (RxWBS) ruled out persistent neck disease.

METHODS

This was a prospective study. Two hundred and fifty-four patients with PTC (242 of intermediate risk) undergoing thyroidectomy and RAI, who had no apparent disease at the time of initial therapy (including negative postoperative US and RxWBS), were studied. The patients were followed up for 5 years after treatment with RAI by annual US.

RESULTS

At the end of 5 years, 47 patients (18.5%) had at least one suspicious US, but neck recurrence was confirmed in only 4 patients (1.5% of all patients and 8.5% of those with suspicious US). The remaining cases were considered false-positives. US did not reveal disease in the first or second year after treatment with RAI in any patient. In the third, fourth, and fifth year after treatment with RAI, considering only patients with unstimulated Tg < 1 ng/mL in these assessments, US revealed disease in 0, 1 (0.4%), and 1 (0.4%) patient, respectively.

CONCLUSION

The results suggest that low- or intermediate-risk patients with PTC without persistent disease after thyroidectomy (including negative postoperative US and RxWBS) do not require repeat US examination in the first two years after treatment with RAI. In the following years until the fifth year, US can be restricted to patients with Tg ≥1 ng/mL.

Active Surveillance of Low-Risk Papillary Thyroid Microcarcinoma: A Multi-Center Cohort Study in Korea

BACKGROUND

Active surveillance has been introduced as a management option for low-risk papillary thyroid microcarcinoma (PTMC) due to its mostly indolent course.

METHODS

This was a multicenter study of 370 PTMC patients who underwent active surveillance more than one year. The changes in volume and maximum diameter between initial and last ultrasonography were evaluated to identify the natural course of PTMC during active surveillance.

RESULTS

Patients' age at diagnosis was 51 ± 12 years, and 110 (30%) patients were <45 years of age. The initial maximum diameter and volume of PTMCs were 5.9 ± 1.7 mm and 81.0 ± 77.7 mm³, respectively. During the median 32.5 months of follow-up, 86 (23.2%) patients were found to have an increase in tumor volume, and 13 (3.5%) patients showed an increase in the maximal diameter of the tumor. The cumulative incidence of volume increase gradually rose with time (6.9%, 17.3%, 28.2%, and 36.2% after two, three, four, and five years, respectively). The risk of volume increase in patients <45 years of age was twice as high as in older patients (p = 0.002). There was no significant difference in tumor size change according to sex, levothyroxine treatment, or presence of Hashimoto's thyroiditis. During the period, 58 (15.7%) patients underwent delayed thyroid surgery due to anxiety (37.9%), tumor size increase (32.8%), or appearance of cervical lymph node metastasis (8.6%). Lymph node metastasis was found in 29.3% of patients on pathological examination.

CONCLUSIONS

A significant number of PTMCs grow during active surveillance, and tumor volume change is a more sensitive means of evaluating tumor growth. Active surveillance can be carefully applied for selected patients. Although it is not contraindicated, it should be applied more cautiously for younger patients.

Prognostic Value of Stimulated Thyroglobulin Levels at the Time of Radioiodine Administration in Differentiated Thyroid Cancer

OBJECTIVE

The prognostic value of stimulated thyroglobulin (sTg) and Tg-related parameters prior to and immediately after radioactive iodine (RAI) administration was assessed in a cohort of patients presenting with differentiated thyroid cancer (DTC) as a predictor of recurrent or progressive structural disease.

METHODS

Clinical records of 180 DTC patients were retrospectively reviewed, and serum TSH, Tg, and Tg antibodies were recorded just before RAI administration (pre-) and at the time of whole body scanning (post-). Based on the results of initial staging and RAI scintigraphy, patients were divided into two groups: those who were considered to be structurally disease-free after thyroidectomy and RAI (group 1) and those who were not (group 2). Univariate analyses were performed for pre-Tg, ratioTg (post-Tg/pre-Tg), and other clinical and pathological markers for long-term outcome, as well as separate bivariate analyses focusing on pre-Tg to correct for possible confounders. Different pre-Tg cut-off values for predicting structural disease recurrence were assessed in a subgroup of patients in group 1 prepared with thyroid hormone withdrawal.

RESULTS

In group 1, (n = 166) male gender, higher T-stage and both Tg-related parameters proved to be significant risk factors for structural disease relapse. Of all candidate variables, only higher T-stage served to predict progressive structural disease in group 2 (n = 14). Subgroup analysis showed a negative predictive value of 91.67$ for pre-Tg < 10 µg/L.

CONCLUSION

The sTg value at the time of RAI administration may be helpful in predicting structural disease recurrence in patients with DTC.

Outcome after ablation in patients with low-risk thyroid cancer (ESTIMABL1): 5-year follow-up results of a randomised, phase 3, equivalence trial

BACKGROUND

In ESTIMABL1, a randomised phase 3 trial of radioactive iodine (131I) administration after complete surgical resection in patients with low-risk thyroid cancer, 92% of patients had complete thyroid ablation at 6-10 months, defined as a recombinant human thyroid-stimulating hormone (rhTSH)-stimulated serum thyroglobulin concentration of 1 ng/mL or less and normal findings on neck ultrasonography. Equivalence was shown between low-activity (1·1 GBq) and high-activity (3·7 GBq) radioactive iodine and also between the use of rhTSH injections and thyroid hormone withdrawal. Here, we report outcomes after 5 years of follow-up.

METHODS

This multicentre, randomised, open-label, equivalence trial was done at 24 centres in France. Between March 28, 2007, and Feb 25, 2010, we randomly assigned (1:1:1:1) adults with low-risk differentiated thyroid carcinoma who had undergone total thyroidectomy to one of four strategies, each combining one of two methods of thyrotropin stimulation (rhTSH or thyroid hormone withdrawal) and one of two radioactive iodine activities (1·1 GBq or 3·7 GBq). Randomisation was by computer-generated sequence, with variable block size. Follow-up consisted of a yearly serum thyroglobulin measurement on levothyroxine treatment. Measurement of rhTSH-stimulated thyroglobulin and neck ultrasonography were done at the discretion of the treating physician. No evidence of disease was defined as serum thyroglobulin of 1 ng/mL or less on levothyroxine treatment and normal results on neck ultrasonography, when performed. This study was registered with ClinicalTrials.gov, number NCT00435851.

FINDINGS

726 patients (97% of the 752 patients originally randomised) were followed up. At a median follow-up since randomisation of 5·4 years (range 0·5-9·2), 715 (98%) had no evidence of disease. The other 11 had either structural disease (n=4), raised serum thyroglobulin concentration (n=5), or indeterminate findings on neck ultrasonography (n=2). At ablation, six of these patients had received 1·1 GBq radioactive iodine (five after rhTSH and one after withdrawal) and five had received 3·7 GBq (two after rhTSH and three after withdrawal). TSH-stimulated (either after rhTSH injections or thyroid hormone withdrawal according to the treatment group) thyroglobulin concentration measured at the time of ablation was prognostic for structural disease status at ablation, ablation status at 6-10 months, and the final outcome.

INTERPRETATION

Our findings suggest that disease recurrence was not related to the strategy used for ablation. These data validate the use of 1·1 GBq radioactive iodine after rhTSH for postoperative ablation in patients with low-risk thyroid cancer.

FUNDING

French National Cancer Institute (INCa), French Ministry of Health, and Sanofi Genzyme.

Prognosis of Differentiated Thyroid Carcinoma with Initial Distant Metastasis: A Multicenter Study in Korea

BACKGROUND

Most patients with differentiated thyroid cancer (DTC) have a favorable prognosis. However, patients with DTC and initial distant metastasis have not been commonly found, and their clinical characteristics have seldom been reported. In this study, we analyzed the clinical features and prognosis of patients with DTC and initial distant metastasis in Korea.

METHODS

We retrospectively reviewed the clinical data of 242 patients with DTC and initial distant metastasis treated from 1994 to 2013, collected from five tertiary hospitals in Korea.

RESULTS

The patients' median age was 51 years, and 65% were women. They were followed for a median of 7 years. Lung was the most common site of distant metastasis: only lung 149 patients (62%), only bone 49 (20%), other single site one (pleura), and combined sites 43 (40 were lung and bone, two were bone and other site, and one was lung and other site). At the time of diagnosis, 50 patients (21%) had non-radioactive iodine (RAI) avidity. Five-year disease-specific survival (DSS) was 85% and 10-year DSS was 68%, which were better than those in previous studies. After multivariate analysis, old age, male sex, metastatic site, and histologic type (follicular type) were significant factors for poor prognosis. However, negative RAI avidity status was not a significant prognostic factor after adjusting for other variables.

CONCLUSION

The prognosis of Korean patients with DTC and initial distant metastasis was better than in previous studies. Old age, male sex, metastasis site, and histologic type were significant prognostic factors.

The role of two tumor foci for predicting central lymph node metastasis in papillary thyroid carcinoma: A meta-analysis

BACKGROUND AND OBJECTIVE

Two tumor foci are the most common in multifocal papillary thyroid carcinoma, but whether they should be regarded as the indicator of central lymph node metastasis remains unclear. To investigate the role of two tumor foci for predicting central lymph node metastasis, we performed a meta-analysis of published studies.

METHODS

We performed a systematic literature search of PubMed, Embase and Web of Science prior to September 29, 2017. The relevant articles were examined and the eligible studies were included to assess the metastatic risk of central lymph node in papillary thyroid carcinoma with one, two and more than two (>2) tumor foci.

RESULTS

Five eligible studies included 4045 patients in this meta-analysis. Two tumor foci were the most common in multifocal papillary thyroid carcinoma (63.8%, 939/1471). Multifocality group showed a higher risk of central lymph node metastasis compared with unifocality group (odds ratio: 1.58, 95% confidence interval: 1.37-1.81). The risk of central lymph node metastasis was higher in two tumor foci group than unifocality group (odds ratio: 1.38, 95% confidence interval: 1.17-1.62). However, this risk in two tumor foci group was lower than >2 tumor foci group (odds ratio: 0.62, 95% confidence interval: 0.42-0.92). Begg's test revealed no obvious publication bias.

CONCLUSION

This meta-analysis suggested that two tumor foci should be regarded as the predictive factor of central lymph node metastasis, but the role of it was less important than three or more than three tumor foci. Understanding the role of two tumor foci for predicting central lymph node metastasis may help clinicians make an optimal decision of treatment and the extent of surgery for multifocal papillary thyroid carcinoma.

Active Surveillance for Papillary Thyroid Microcarcinoma: Challenges and Prospects

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.