Active Surveillance of Differentiated Thyroid Cancer Metastatic Cervical Lymph Nodes: A Retrospective Single-Center Cohort Study

The predictive value of thyroid hormone sensitivity parameters for cervical lymph node metastasis in patients with differentiated thyroid cancer

OBJECTIVE

To comprehensively investigate the predictive value of thyroid hormone sensitivity parameters for cervical lymph node metastasis in patients diagnosed with differentiated thyroid cancer (DTC) undergoing total thyroidectomy and neck lymph node dissection.

METHODS

A retrospective cohort study was conducted involving patients diagnosed with DTC and evaluated for cervical lymph node metastasis. Relevant demographic, tumour, lymph node and thyroid hormone sensitivity parameter data were extracted from medical records and laboratory reports. Thyroid hormone sensitivity parameters including thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), thyroglobulin antibodies (TgAbs), thyroid peroxidase antibody, thyroid hormone receptor α and TSH receptor antibody were assessed. Statistical analyses including descriptive statistics, comparative analysis, Pearson's correlation analysis, logistic regression analysis, receiver operating characteristic (ROC) analysis and construction of a multivariable prediction model based on machine learning using the xgbTree method were employed to evaluate the associations and predictive value of thyroid hormone sensitivity parameters for cervical lymph node metastasis.

RESULTS

The study revealed significant associations between several thyroid hormone sensitivity parameters and cervical lymph node metastasis in patients with DTC. Specifically, higher levels of T4, T3, Tg, TgAbs and TSH receptor antibody were associated with lymph node metastasis. Pearson's correlation analysis, logistic regression analysis and ROC analysis further underscored the predictive performance of these parameters, with strong overall discriminative abilities. The machine learning-based prediction model demonstrated promising performance with a high area under the curve (AUC) of 0.979.

CONCLUSIONS

The findings provide compelling evidence for the predictive value of thyroid hormone sensitivity parameters, particularly T3, T4, Tg, TgAbs and TSH receptor antibody, in identifying and evaluating the likelihood of cervical lymph node metastasis in patients with DTC. These parameters hold potential implications for risk stratification, clinical decision-making and personalized management strategies, contributing to improved outcomes for patients at risk of lymph node metastasis.

Clinically Significant Central Lymph Node Metastasis is Not Common in Patients with Clinically N0 Papillary Thyroid Carcinoma on Both Ultrasonography and CT

Background: The necessity of prophylactic central lymph node dissection (p-CLND) in patients with clinically node-negative papillary thyroid carcinoma (PTC) is unclear. The present study evaluated the central lymph node (LN) metastases status in patients with clinically node-negative PTC on both preoperative thyroid ultrasonography (USG) and neck computed tomography (CT) who underwent p-CLND. Methods: This retrospective cohort study included 3002 clinically node-negative patients diagnosed with PTC who had undergone thyroidectomy with p-CLND from January 2000 to September 2022. Clinically node-negative was defined as the absence of suspicious metastatic LNs on preoperative USG and neck CT. Low-risk central LN metastases were defined as LN metastases <2 mm in size with metastatic LNs ≤5. The median follow-up duration was 4.52 (interquartile range [IQR]: 1.6-7.5) years. Results: Of the 3002 patients, 1194 (39.7%) had central LN metastases, whereas 1808 (60.3%) did not. The 1194 patients with central LN metastases included 507 (16.9%) with intermediate-risk metastases and 610 (20.3%) with low-risk LN metastases, with a total of 2428 (80.5%) patients having low-risk LN metastases or no central LN metastases. High-risk metastases were observed in only 77 (2.5%) patients. Of the 584 patients with intermediate-/high-risk metastases, 577 (98.8%) had central LN metastases <1 cm in size, whereas only 7 (1.2%) had central LN metastases ≥1 cm. The disease recurrence rates for the no LN metastases, low-risk LN metastases, and intermediate-/high-risk LN metastases groups were 0.4%, 1.1%, and 1.9%, respectively (p = 0.012). Factors independently associated with intermediate-/high-risk central LN metastases included age <55 years (odds ratio [OR] = 2.29), male sex (OR = 2.33), tumor size >1 cm on USG (OR = 1.94), and the presence of extrathyroidal extension on CT scans (OR = 1.53), with p < 0.001 for all factors. Conclusions: Most LNs confirmed after CLND in cN0 PTC patients assessed by USG and CT were either metastasis-free or classified as low-risk metastatic LNs. Furthermore, the majority of metastatic LNs were small in size, typically measuring <1 cm. p-CLND may be unnecessary if preoperative thyroid USG and neck CT show no evidence of central neck LN metastaes.

131I SPECT/CT provides prognostic information in patients with differentiated thyroid cancer

PURPOSE

The aim of this study is to investigate the impact of lymph node metastases (LNM) detected on cervical 131I single photon emission computed tomography/computed tomography (SPECT/CT) after the first radioiodine therapy (RAI) on complete response (CR) and progression-free survival (PFS) in patients with differentiated thyroid cancer (DTC).

METHODS

This retrospective study included 942 DTC patients who underwent cervical 131I SPECT/CT after their first RAI. LNM were categorized based on CT (enlarged ≥ 1 cm, small < 1 cm) and 131I uptake. CR and PFS were analysed using Kaplan-Meier curves and Cox regression.

RESULTS

Patients with no LNM had a shorter median time to CR (9.4 months) than those with LNM (44 months, HR 2.2; p < 0.01) and a lower risk of progression (median PFS not reached, HR 0.46; p < 0.01). Among patients with LNM, those with enlarged 131I negative LNM had the longest time to CR (24 months, HR 0.36; p < 0.01). Patients with small LNM had a PFS similar to patients without LNM (median PFS not reached, HR 1.22; p = 0.54). Reoperation after first RAI (13.5 months) led to earlier CR than second RAI (median not reached) in patients with enlarged LNM. For small LNM, second RAI was associated with longer PFS than reoperation (38.4 months vs. not reached, HR 4.0; p = 0.02).

CONCLUSION

Patients without LNM on post-therapy 131I SPECT/CT have better chances for early CR and longer PFS. Patients with LNM benefit from early reoperations but treatment strategies should be tailored based on LNM characteristics.

External validation of a predictive model for post-treatment persistent disease by 131I whole-body scintigraphy in patients with differentiated thyroid cancer

PURPOSE

We performed an external validation of a predictive model for persistent/metastatic disease in patients with differentiated thyroid cancer (DTC) at post-treatment 131I whole-body scintigraphy (WBS).

METHODS

Our study population included 836 patients (median age 44 years, 78% women) with DTC referred from 1994 to 2021 at our center. Age, sex, histology, T stage, N stage, American Thyroid Association risk classes, thyroid-stimulating hormone, radioactive iodine (RAI) activity, and thyroglobulin (Tg) levels were considered potential predictors of post-treatment WBS results. For the external validation, N stage and Tg levels were put into the decision tree (DT) model using its same Tg cut-off values.

RESULTS

Ninety-nine patients (12%) had positive post-treatment WBS. The area under receiver operating characteristic (ROC) curve for predicting WBS findings through the external validation was 0.60 (95% confidence interval, CI, 0.56-0.64), and positive and negative predictive values were 58% (95% CI, 41-74%) and 90% (95% CI, 88-92%). We also developed an internal model including the independent predictors of WBS findings (i.e., Tg levels, T stage, N stage, and RAI activity). For this model the area under ROC curve was 0.75 (95% CI, 0.69-0.81), and positive and negative predictive values were 90% (95% CI, 68-99% and 88-92%).

CONCLUSIONS

The external validation of the proposed DT model has a limited value for predicting post-treatment 131I-WBS findings in our patients. The internal model including also T stage and RAI activity demonstrates higher predictive value.

Long term outcomes after repeat lymph node dissections for persistent or recurrent differentiated thyroid cancer

BACKGROUND

The primary treatment for locoregional recurrent/persistent differentiated thyroid cancer (DTC) is repeated lymph node dissection; however, there are limited reports on the safety and long-term efficacy of multiple operations.

METHODS

Patients who underwent a cervical lymph node dissection between 1998 and 2022 were included in this study. Demographics, initial thyroid surgery, subsequent lymph node dissections, follow up information, and response to therapy were acquired.

RESULTS

After one, two, three and four re-operations, 112/314 (35.7 ​%), 16/79 (20.3 ​%), 3/25 (12 ​%), and 0/3 (0 ​%) patients (p ​< ​0.001) had an excellent response, respectively, resulting in a cumulative rate of 41.7 ​% (131/314). The risk for permanent hypoparathyroidism (2.9 ​%) or recurrent laryngeal nerve injury (2.2 ​%) was 5.1 ​% (14/272). This was higher in patients undergoing re-operative central neck dissection (CNDx) (8.7 ​%, 10/114) versus those who did not undergo a previous CNDx (2.5 ​%, 4/158, p ​< ​0.02).

CONCLUSIONS

Surgery remains the primary treatment for recurrent/persistent DTC, however, the likelihood of an excellent response decreases with additional operations. The risk of permanent complications is low but is more likely to occur during redo CNDx.

The diagnosis and management of small and indeterminate lymph nodes in papillary thyroid cancer: preoperatively and intraoperatively

Although thyroid cancer is an indolent tumor with a favorable prognosis, lymph node metastasis (LNM) serves as a major concern for many patients. Because LNM is strongly correlated with recurrence, distant metastasis, and shortened survival, a precise and timely diagnosis and following appropriate management for LNM are necessary. However, significant challenges still exist in the diagnosis of small LNs (<1 cm in diameter), and their low volume makes it difficult to determine whether they are metastatic or benign. Therefore, the diagnostic technique for these small and indeterminate LNs (siLNs) has been one of the leading research subjects in recent years. The implementation of innovative technologies, such as contrast-enhanced ultrasonography, frozen section, and molecular detection, has brought great progress to the diagnosis of siLNs. Meanwhile, the strategies for managing siLNs in clinical practice have evolved considerably over the past several years, with several appropriate options recommended by guidelines. In this review, we aim to provide a systematic overview of the latest studies and potential evidence about effective approaches for detecting and evaluating siLNs. Furthermore, the following management modalities of siLNs in different situations are well discussed.

Active surveillance of nodal metastasis in differentiated thyroid carcinoma: a systematic review and meta-analysis

PURPOSE

Cervical lymph nodes (LN) represent the most common site of recurrence in differentiated thyroid cancer (DTC), frequently requiring repeated interventions that contribute to increase morbidity to a usually indolent disease. Data on active surveillance (AS) of nodal metastasis are limited. Therefore, we performed a systematic review and meta-analysis to evaluate AS in nodal metastasis of DTC patients.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched up to July 2023 for studies including DTC patients with metastatic LN who were followed up with AS. The primary outcome was disease progression, according to the study's definition. Additional outcomes were LN enlargement ≥3 mm, occurrence of new cervical metastasis, and conversion from AS to surgical treatment.

RESULTS

The search identified 375 studies and seven were included, comprising 486 patients with metastatic nodal DTC. Most were female (69.5%) and had papillary thyroid cancer (99.8%). The mean AS follow-up ranged from 28-86 months. Following each study's definition of progression, the pooled incidence was 28% [95% confidence interval (CI), 20-37%]. The pooled incidence of LN growth ≥ 3 mm was 21% [95% CI, 17-25%] and the emergence of new LN sites was 19% [95% CI, 14-25%]. Combining growth of 3 mm and the emergence of new LN criteria, we found an incidence of 26% [95% CI, 20-33%]. The incidence of neck dissection during AS was 18% [95% CI, 12-26%].

CONCLUSIONS

AS seems to be a suitable strategy for selected DTC patients with small nodal disease, avoiding or postponing surgical reintervention.

PROSPERO REGISTRATION

CRD42023438293.

Preoperative Serum Thyroglobulin Levels Predict Radioiodine Therapy Outcome in Papillary Thyroid Microcarcinoma Patients

Our previous study showed that elevated preoperative thyroglobulin (pre-Tg) level predicted the risk of developing radioiodine refractory in PTC patients. In the present study, we aimed to evaluate the prognostic value of pre-Tg in papillary thyroid microcarcinoma (PTMC). After a specific inclusion and exclusion criteria were applied, a total of 788 PTMCs were enrolled from Jiangyuan Hospital affiliated to Jiangsu Institute of Nuclear Medicine between Jan 2015 and Dec 2019. Among them, 107 PTMCs were treated with radioiodine therapy (RAIT) and the response to therapy was grouped as excellent response (ER), and non-excellent response (NER: indeterminate response, IDR and biochemical incomplete response, BIR). Multivariable logistic regression was used to identify predictors for the response of RAIT in PTMCs. Higher pre-Tg levels were detected in PTMCs with RAIT as compared with PTMCs without RAIT (p=0.0018). Higher levels of pre-Tg were also found in patients with repeated RAIT as compared with patients with single RAIT (p<0.0001). Furthermore, pre-Tg level was higher in PTMC with IDR (n=16) and much higher in BIR (n=9) as compared with patients with ER (n=82, p=0.0003) after RAIT. Multivariate analysis showed that pre-Tg level over 16.79 ng/ml [OR: 6.55 (2.10-20.39), p=0.001] was the only independent predictor for NER in PTMC with RAIT. We found that high level of pre-Tg predicted a poor RAIT outcome in PTMC. Our finding explores a prospective way in identifying high-risk PTMCs with poor response to RAIT.

The Oncologic Outcomes of Bilateral Central Lymph Node Dissection in Unilobar Papillary Thyroid Cancer and Its Risks: A Prospective Cohort Study

Background Indications for performing a prophylactic central neck dissection (pCND) in papillary thyroid cancer (PTC) remain controversial. Thyroidectomy and central neck dissection (CND) are often recommended in all cases with proven differentiated thyroid cancer (DTC) and clinically positive lymph nodes (LNs), as well as in high risk for micro-metastasis patients with T3-T4 tumors or established metastatic nodes in the lateral compartments. Aims The aims of this study were to ascertain the role of performing bilateral central LN dissection in unilobar PTC in improving the oncological outcomes and outline the risks involved. Methods This was a department-based, prospective cohort study. We included all 20 patients who had unilobar PTC and underwent total thyroidectomy with bilateral CND. A postoperative histopathological analysis was used to identify metastatic central LNs. Results Twenty total thyroidectomies plus bilateral CNDs were performed, of which 10 were prophylactic bilaterally (those with N0), and all 20 were prophylactic on the contralateral side of PTC. Conventional risk factors (age, tumor size, and extrathyroidal extension) were not associated with performing a pCND. The presence of unilobar PTC by preoperative FNAC was the only factor associated with performing bilateral CND. Positive ipsilateral LNs were retrieved in 55% of CNDs, while positive contralateral LNs were retrieved in only 15% of the patients. Conclusions The incidence of contralateral cervical LN metastasis in patients with unilateral PTC is low, while there is clear evidence of postoperative morbidity from routine contralateral CND in unilobar PTC. Contralateral CND in patients with unilobar PTC may be reserved for high-risk patients: males, those aged ≤45 years, tumors larger than 1.0 cm, and cases with extrathyroidal extension and micro-calcification on ultrasound.

Ultrasound-guided approach to surgery for nodal recurrence following lateral neck dissection for differentiated thyroid carcinoma. A single institution experience

Introduction

Total thyroidectomy (TT) and central neck dissection (CND) had a significant effect on the reduction of local recurrence compared with TT alone. Lateral Neck Dissection (LND) was performed in all the cases with therapeutic intent. The suspicion of nodal recurrence is provided by the appearance of one or more enlarged nodes in the central and/or laterocervical compartment during the follow up period.

Methods

From January 2018 to November 2023, 16 patients at the University General Surgery unit of the Polyclinic of Foggia underwent reoperation due to nodal recurrence after previously undergoing total thyroidectomy with central and lateral cervical dissection.

Results

All surgical interventions were approached with intraoperative ultrasound performed by the operating surgeon. In all cases, ultrasound identification of the suspicious lymph node led to histological confirmation of malignancy. In only two cases it was necessary to carry out an extemporaneous intraoperative histological examination. No complications were recorded during the operations.

Conclusions

Surgical reintervention in patients with nodal recurrence is challenging and requires an assessment by members of the interdisciplinary team. The ideal method should be economically convenient, easy to practice, with a quick learning curve, easily reproducible, and safe for patients. Intraoperative, ultrasound-guided, is a safe and effective technique. It facilitates tumor localization and removal, especially in patients requiring re-operative neck surgery.

Active surveillance is a feasible and safe strategy in selected patients with papillary thyroid cancer and suspicious cervical lymph nodes detected after thyroidectomy

Objective

After initial treatment, up to 30% of patients with papillary thyroid cancer (PTC) have incomplete response, mainly cervical lymph node (LN) disease. Previous studies have suggested that active surveillance (AS) is a possible option for these patients. Our aim was to report the results of AS in patients with PTC and cervical LN disease.

Materials and methods

In this retrospective observational study, we included adult patients treated and followed for PTC, who presented with cervical LN disease and were managed with AS. Growth was defined as an increase ≥ 3mm in either diameter.

Results

We included 32 patients: 27 (84.4%) women, age of 39 ± 14 years, all initially treated with total thyroidectomy, and 22 (69%) with therapeutic neck dissection. Cervical LN disease was diagnosed 1 year (0.3-12.6) after initial management, with a diameter of 9.0 mm (6.0-19.0). After a median AS of 4.3 years (0.6-14.1), 4 (12.5%) patients had LNgrowth: 2 (50%) of whom were surgically removed, 1 (25%) was effectively treated with radiotherapy, and 1 (25%) had a scheduled surgery. Tg increase was the only predictive factor of LN growth evaluated as both the delta Tg (p < 0.0366) and percentage of Tg change (p < 0.0140). None of the included patients died, had local complications due to LN growth or salvage therapy, or developed distant metastases during follow-up.

Conclusion

In selected patients with PTC and suspicious cervical LNs diagnosed after initial treatment, AS is a feasible and safe strategy as it allows effective identification and treatment of the minority of patients who progress.

Summary and update on the management of differentiated thyroid cancer in 2023

The 6-fold increase in the incidence of differentiated thyroid cancer over the past 30 years in industrialized countries can be mainly attributed to improved detection. At the same time, in addition to the excellent prognosis for low-risk cancers, improved survival in metastatic forms has been also reported, likely due to the progress made recently in the treatment of aggressive forms, for which there is now an extensive therapeutic arsenal. Today, clinical management of differentiated thyroid cancer represents a paradigm of precision oncology, with personalized, risk-adapted therapeutic strategies. This has led to therapeutic de-escalation in those forms with a good prognosis, while targeted treatments play an increasingly important role in the management of radioiodine-refractory or advanced cancers. While endocrinologists will not always have the opportunity to prescribe these treatments, they will be called on to support and monitor patients during treatment. The aim of this article is to provide an overview of treatment options for differentiated thyroid cancer in 2023.

Management of radioiodine refractory differentiated thyroid cancer: the Latin American perspective

Radioiodine (RAI) refractory differentiated thyroid cancer is an uncommon and challenging situation that requires a multidisciplinary approach to therapeutic strategies. The definition of RAI-refractoriness is usually a clear situation in specialized centers. However, the right moment for initiation of multikinase inhibitors (MKI), the time and availability for genomic testing, and the possibility of prescribing MKI and selective kinase inhibitors differ worldwide.Latin America (LA) refers to the territories of the world that stretch across two regions: North America (including Central America and the Caribbean) and South America, containing 8.5% of the world's population. In this manuscript, we critically review the current standard approach recommended for patients with RAI refractory differentiated thyroid cancer, emphasizing the challenges faced in LA. To achieve this objective, the Latin American Thyroid Society (LATS) convened a panel of experts from Brazil, Argentina, Chile, and Colombia. Access to MKI compounds continues to be a challenge in all LA countries. This is true not only for MKI but also for the new selective tyrosine kinase inhibitor, which will also require genomic testing, that is not widely available. Thus, as precision medicine advances, significant disparities will be made more evident, and despite efforts to improve coverage and reimbursement, molecular-based precision medicine remains inaccessible to most of the LA population. Efforts should be undertaken to alleviate the discrepancies between the current state-of-the-art care for RAI-refractory differentiated thyroid cancer and the present situation in Latin America.

Development of a Clinical-Radiomics Nomogram That Used Contrast-Enhanced Ultrasound Images to Anticipate the Occurrence of Preoperative Cervical Lymph Node Metastasis in Papillary Thyroid Carcinoma Patients

Background and Objectives

Papillary thyroid carcinoma (PTC) is a prevalent histological type of thyroid cancer; however, noninvasive assessment of cervical lymph node metastasis (LNM) poses a challenge. This study aims to develop a novel clinical-radiomics nomogram that utilizes ultrasound (US) images to predict the presence of cervical LNM metastasis in patients with PTC.

Methods

A total of 423 patients with PTC were recruited to participate in this study between January 2020 and December 2022, of which 282 were classified into the training group and 141 patients were classified into the validation set. Contrast-enhanced ultrasound (CEUS) and B-mode ultrasound (BMUS) images were subjected to radiomic analysis, leading to the extraction of 912 radiomic features. Thereafter, a radiomics score (Radscore) was developed to effectively integrate the information derived from BMUS and CEUS modalities. Univariate and multivariate backward stepwise logistic regression analysis techniques were used to construct the clinical and clinical-radiomics models, respectively.

Results

The findings revealed that the clinical-radiomics nomogram incorporated age, sex, CEUS Radscore, and US-reported LNM as risk factors. The nomogram demonstrated good performance using data from the training (AUC = 0.891) and validation (AUC = 0.870) sets. The decision curve analysis implied that this nomogram exhibited good clinical utility, which was further supported by the results of the calibration curves and Hosmer-Lemeshow test.

Conclusion

The CEUS Radscore-based clinical radiomics nomogram could serve as a valuable tool for predicting cervical LNM metastasis in patients with PTC, thereby tailoring individualized treatment strategies for them.

Recurrent Differentiated Thyroid Cancer: The Current Treatment Options

Differentiated thyroid carcinomas (DTC) have an excellent prognosis, but this is sometimes overshadowed by tumor recurrences following initial treatment (approximately 15% of cases during follow-up), due to unrecognized disease extent at initial diagnosis or a more aggressive tumor biology, which are the usual risk factors. The possible sites of recurrence are local, regional, or distant. Local and regional recurrences can usually be successfully managed with surgery and radioiodine therapy, as are some isolated distant recurrences, such as bone metastases. If these treatments are not possible, other therapeutic options such as external beam radiation therapy or systemic treatments should be considered. Major advances in systemic treatments have led to improved progression-free survival in patients previously considered for palliative treatments; among these treatments, the most promising results have been achieved with tyrosine kinase inhibitors (TKI). This review attempts to give a comprehensive overview of the current treatment options suited for recurrences and the new treatments that are available in cases where salvage surgery is not possible or in cases resistant to radioiodine.