Is thyroglobulin a reliable biomarker of differentiated thyroid cancer in patients treated by lobectomy? A systematic review and meta-analysis

Thyroid lobectomy for unilateral TNM T1 and T2 papillary thyroid carcinoma patients with lateral lymph node metastasis

BACKGROUND

This study aimed to evaluate the prognostic outcomes of thyroidectomy extent in unilateral TNM T1 or T2 papillary thyroid carcinoma with lateral lymph node metastasis.

METHODS

Retrospective data were collected from unilateral papillary thyroid carcinoma patients with unilateral lymph node metastasis who underwent surgery at Qilu Hospital of Shandong University from 2011 to 2022. Patients were categorized into 2 groups based on the extent of the thyroidectomy (total thyroidectomy versus lobectomy). The primary endpoint was recurrence-free survival. The secondary endpoint was the incidence of complications. The Cox proportional hazards model was used to explore independent risk factors for structural recurrence.

RESULTS

A total of 372 patients with unilateral TNM T1 or T2 papillary thyroid carcinoma and unilateral lymph node metastasis were followed for a median of 55 months. Among them, 119 patients underwent lobectomy, whereas 253 patients underwent total thyroidectomy. During the follow-up period, 11 patients experienced structural recurrence. Kaplan-Meier analysis found no significant difference in recurrence-free survival between the groups (P > .05). However, the total thyroidectomy group had higher rates of both transient and permanent hypoparathyroidism, as well as transient recurrent laryngeal nerve injury (P < .05). Multivariate analysis identified minor extrathyroidal extension and lymph nodes ratio >0.49 as independent risk factors for structural recurrence, whereas the extent of thyroidectomy was not.

CONCLUSION

This study suggests that lobectomy does not impact the prognosis in unilateral TNM T1 and T2 papillary thyroid carcinoma patients with unilateral lymph node metastasis. Minor extrathyroidal extension and lymph nodes ratio >0.49 are identified as independent risk factors for structure recurrence, and patients exhibiting these risk factors should be subjected to vigilant postoperative monitoring.

Predictive Factors of Athyroglobulinemia After Total Thyroidectomy for Papillary Thyroid Cancer

Background: Thyroglobulin (Tg) is the specific tumor marker for epithelial thyroid cancer. It holds significant value in the postoperative period, and somehow, the goal of surgery in papillary thyroid cancer (PTC) undergoing total thyroidectomy is to achieve undetectable levels of postoperative thyroglobulin (uTg). Methods: This is a retrospective single-center study in which first basal Tg values were evaluated post-surgery in PTC patients undergoing total thyroidectomy. Patients with elevated antithyroglobulin antibodies were excluded. The impact of various demographic, clinical, therapeutic, tumor-stage related, and histopathological variables on the achievement of undetectable thyroglobulin levels (uTg, <1 ng/mL) was studied. A descriptive and logistic regression-based bivariate and multivariate analysis was planned using STATA vs. 16.1. program. The significance level was stated at 0.05. Results: Basal athyroglobulinemia was obtained in 89.6% of 202 patients operated on between January 2015 and June 2023 in a single referral institution. Due to the limited number of cases with detectable Tg, multivariate analysis could not be performed. The main factors that favored its achievement on bivariate analysis were a smaller tumor size (p = 0.003), no need for extended resections due to local invasion beyond the thyroid gland (p = 0.003) or neck dissection (p = 0.039), absence of distant metastases (p = 0.000), and a lower MACIS score (p < 0.000). Conclusions: The achievement of uTg was closely related to factors related to tumor stage (tumor diameter, lymph node spread, and metastatic disease), and it was not influenced by differences in epidemiological data, clinic manifestations, preoperative diagnosis, multifocality, or the presence of aggressive cytological variants.

Lobectomy in patients with differentiated thyroid cancer: experience of a Chilean tertiary center

PURPOSE

Thyroid lobectomy (TL) is an appropriate treatment for up to 4 cm intrathyroidal differentiated thyroid cancer (DTC). There is scarce data regarding TL outside first-world centers. Our aim is to report a cohort of patients with DTC treated with TL in Chile.

METHODS

We included DTC patients treated with TL, followed for at least 6 months, characterized their clinicopathological features and classified their risk of recurrence and response to treatment.

RESULTS

Eighty-two patients followed for a median of 2.3 years (0.5-7.0). Seventy-three (89%) patients had papillary, 8 (9.8%) follicular and 1 (1.2%) high-grade DTC. The risk of recurrence was low in 56 (68.3%) and intermediate in 26 (31.7%). Eight (9.8%) patients required early completion thyroidectomy and radioiodine. At last follow-up, 52 (70.3%) had excellent, 19 (25.7%) had indeterminate, and 1 (1.4%) had structural incomplete response.

CONCLUSION

In a developing country, TL is an adequate option for appropriately selected DTC patients.

Thyroglobulin measurement is the most powerful outcome predictor in differentiated thyroid cancer: a decision tree analysis in a European multicenter series

OBJECTIVES

An accurate prognostic assessment is pivotal to adequately inform and individualize follow-up and management of patients with differentiated thyroid cancer (DTC). We aimed to develop a predictive model for recurrent disease in DTC patients treated by surgery and 131I by adopting a decision tree model.

METHODS

Age, sex, histology, T stage, N stage, risk classes, remnant estimation, thyroid-stimulating hormone (TSH), thyroglobulin (Tg), administered 131I activities and post-therapy whole body scintigraphy (PT-WBS) were identified as potential predictors and put into regression algorithm (conditional inference tree, c-tree) to develop a risk stratification model for predicting persistent/recurrent disease over time.

RESULTS

The PT-WBS pattern identified a partition of the population into two subgroups (PT-WBS positive or negative for distant metastases). Patients with distant metastases exhibited lower disease-free survival (either structural, DFS-SD, and biochemical, DFS-BD, disease) compared to those without metastases. Meanwhile, the latter were further stratified into three risk subgroups based on their Tg values. Notably, Tg values >63.1 ng/mL predicted a shorter survival time, with increased DFS-SD for Tg values <63.1 and <8.9 ng/mL, respectively. A comparable model was generated for biochemical disease (BD), albeit different DFS were predicted by slightly different Tg cutoff values (41.2 and 8.8 ng/mL) compared to DFS-SD.

CONCLUSIONS

We developed a simple, accurate and reproducible decision tree model able to provide reliable information on the probability of structurally and/or biochemically persistent/relapsed DTC after a TTA. In turn, the provided information is highly relevant to refine the initial risk stratification, identify patients at higher risk of reduced structural and biochemical DFS, and modulate additional therapies and the relative follow-up.

Prise en charge des cancers thyroïdiens localisés de souche vésiculaire différenciée

MANAGEMENT OF LOCALIZED FOLLICULAR-DERIVED THYROID CANCER

The incidence of follicular-derived thyroid cancers has increased worldwide in recent decades, mainly papillary thyroid cancers at low recurrence risk. A process of de-escalation in the initial management and follow-up of these patients has therefore been implemented in parallel. This article provides the best practice recommendations made by the French learned societies (Société française d'endocrinologie, Société française de médecine nucléaire, Association française de chirurgie endocrine, Société française d'oto-rhino-laryngologie et de chirurgie de la face et du cou), european and international learned societies (European Society for Medical Oncology and the American Thyroid Association), in the management of follicular-derived thyroid cancer without distant metastases. The extent of thyroid surgery and lymph node dissection, strategies of radioiodine ablation, follow-up protocols and the management of excellent prognosis papillary cancers ≤ 10 mm will be addressed.

A homogeneous electrochemiluminescence immunoassay platform based on carbon quantum dots and magnetic beads enrichment for detection of thyroglobulin in serum

Considering the high probability of recurrence or metastasis after thyroidectomy, it is meaningful to develop a rapid, sensitive and specific method for monitoring thyrophyma-related biomarkers. In this study, a homogeneous electrochemiluminescence immunoassay (HO-ECLIA) coupled with magnetic beads (MBs)-based enrichment tactic was established for the determination of thyrophyma-related thyroglobulin (Tg). Importantly, owing to the abundant surface groups and good biocompatibility of carbon quantum dots (CQDs), the incorporation of CQDs onto the Tg antigen surface was achieved, resulting in the formation of Tg-encapsulated CQDs (CQDs-Tg), which served not only as an ECL probe but as a biorecognition element. Under optimal experimental conditions, the proposed platform demonstrated a wide linear range from 0.01 to 100 ng·mL-1 with a detection limit of 6.9 pg·mL-1 (S/N = 3), and performed well in real serum sample analysis against interference. Collectively, the proposed platform exhibited the rapid response, satisfactory sensitivity and specificity toward Tg in complex serum milieu, and held a considerable potential for clinical prognosis monitoring of thyrophyma.

Nodal metastasis in noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP)

The term noninvasive tumor with a follicular growth pattern and nuclear features of papillary thyroid cancer (NIFTP) is used to describe a tumor currently considered as a pre-malignant lesion for which a conservative therapeutic approach (i.e., lobectomy without radioiodine therapy) is strongly suggested. However, some patients with NIFTP and loco-regional or distant metastases have been already reported. We present an adult male patient with a final histological diagnosis of NIFTP and lymph node metastasis noted at post-therapy whole-body scintigraphy performed some days after radioiodine therapy.

Long-Term Changes of Urinary Exosomal Peptide Levels After Thyroidectomy in Patients with Thyroid Cancer: A Prospective Observational Study

Background

The recurrence rate of thyroid cancer can be as high as 30%. The purpose of this study was to examine changes of urine exosomal peptide levels after thyroidectomy in patients with thyroid cancer to determine if levels can predict the risk of recurrence.

Methods

Patients >20 years old as newly diagnosed with papillary thyroid cancer who had received a thyroidectomy were recruited. Urine samples were collected at 12 months after enrollment to the study, and 1 year later. Urine exosomes containing different peptides were identified and compared.

Results

A total of 70 patients were enrolled in the study, and were classified by the interval between surgery and enrollment: 42 patients with < 5 years between surgery and enrollment, 14 patients between 5-10 years, and 14 patients longer than 10 years. No recurrence was observed in any patient during the 2 years after enrollment. No significant differences were found in the levels of serum proteins or urine exosomal peptides between groups, or between intervals. Known risk factors for high-risk thyroid cancer had only a mild correlation with serum protein levels and urine exosomal peptides.

Conclusion

Our study revealed the long-term basal fluctuation ranges of serum proteins and urine exosomal peptides in patients with thyroid cancer who underwent thyroidectomy. For high-risk patients after thyroidectomy, concentrations of serum proteins or urine exosomal peptides within the ranges may indicate there is a lower risk of thyroid cancer recurrence during long-term follow-up.

Trial Registration

ClinicalTrials.gov: NCT03488134.

Diagnostic, Theranostic and Prognostic Value of Thyroglobulin in Thyroid Cancer

Thyroglobulin (Tg) is an iodinated glycoprotein, which is normally stored in the follicular colloid of the thyroid, being a substrate for thyroid hormone production. Since it is produced by well-differentiated thyroid cells, it is considered a reliable tumor marker for patients with differentiated thyroid carcinoma (DTC) during their follow-up after total thyroidectomy and radioiodine ablation. It is used to monitor residual disease and to detect recurrent disease. After total thyroid ablation, unstimulated highly sensitive Tg measurements are sufficiently accurate to avoid exogenous or endogenous thyrotropin (TSH) stimulation and provide accurate diagnostic and prognostic information in the great majority of DTC patients. Adopting sophisticated statistical analysis, i.e., decision tree models, the use of Tg before radioiodine theranostic administration was demonstrated to be useful in refining conventional, pathology-based risk stratification and providing personalized adjuvant or therapeutic radioiodine administrations. The follow-up of DTC patients aims to promptly identify patients with residual or recurrent disease following primary treatment. Our review paper covers the diagnostic, theranostic and prognostic value of thyroglobulin in DTC patients.

Dynamic risk assessment in patients with differentiated thyroid cancer

The current approach for patients with differentiated thyroid carcinoma should be individualized according to the risk of recurrence, and this stratification could be used to identify the risk of persistent/recurrent disease in three scenarios: preoperatively, immediately postoperatively, and during long-term follow-up. The initial risk of recurrence will tailor the management of the patient in the preoperative and immediate postoperative settings, while the dynamic risk, which considers the responses to treatment, could guide the decision-making process for remnant ablation and long-term management.This review provides a summary of the existing information regarding the dynamic risk of recurrence and recommended management for patients with differentiated thyroid cancer. The application of this approach is essential to avoid unnecessary treatments for most patients who will have a favorable prognosis. On the other hand, it allows specific therapeutic interventions for those patients at high risk of recurrence. In the future, analysis of tumor biology and prospective studies will surely improve the accuracy of recurrence risk prediction.

Thyroglobulin and thyroglobulin antibody: an updated clinical and laboratory expert consensus

OBJECTIVE

Thyroglobulin measurement is the cornerstone of modern management of differentiated thyroid cancer, with clinical decisions on treatment and follow-up based on the results of such measurements. However, numerous factors need to be considered regarding measurement with and interpretation of thyroglobulin assay results.

DESIGN

The present document provides an integrated update to the 2013 and 2014 separate clinical position papers of our group on these issues.

METHODS

Issues concerning analytical and clinical aspects of highly-sensitive thyroglobulin measurement will be reviewed and discussed based on an extensive analysis of the available literature.

RESULTS

Thyroglobulin measurement remains a highly complex process with many pitfalls and major sources of interference, especially anti-thyroglobulin antibodies, need to be assessed, considered and, when necessary, dealt with appropriately.

CONCLUSIONS

Our expert consensus group formulated 53 practical, graded recommendations for guidance on highly-sensitive thyroglobulin and TgAb in laboratory and clinical practice, especially valuable where current guidelines do not offer sufficient guidance.

Thyroglobulin Cutoff Values for Detecting Excellent Response to Therapy in Patients With Differentiated Thyroid Cancer

Context

Serum thyroglobulin (Tg) is a biochemical marker for detecting persistent or recurrent differentiated thyroid carcinoma (DTC) post-thyroidectomy. Tg can indicate DTC before structural disease (SD) is visible with imaging procedures.

Objective

This work aimed to evaluate the clinical performance of the Elecsys® Tg II assay at a Tg cutoff of 0.2 ng/mL for ruling out SD in adults with DTC after total/near-total thyroidectomy, with or without radioiodine ablation (RAI).

Methods

Patients were enrolled into 2 cohorts: longitudinal (Tg assessed every 6 months over 2 years under thyroid-stimulating hormone [TSH] suppression therapy following thyroidectomy with or without RAI) and cross-sectional with confirmed SD (Tg assessed once >12 weeks after thyroidectomy). Analyses were performed for both cohorts combined and in the longitudinal cohort.

Results

The study included 530 clinically evaluable samples, the majority (n = 424 samples) from patients who had not received RAI treatment. Following correction for SD prevalence (4.97% in the longitudinal cohort), an Elecsys Tg II cutoff of 0.2 ng/mL ruled out SD with a negative predictive value of 99.9% (95% CI, 99.5%-100%). The assay had excellent sensitivity (98.5%-100%) and acceptable specificity (53.4%-53.5%) for detecting SD (Tg ≥ 0.2 ng/mL) for both cohorts combined and in the longitudinal cohort, with similar findings in RAI-treated and non-RAI-treated subgroups.

Conclusion

In this cohort of DTC patients post-thyroidectomy, a Tg cutoff of 0.2 ng/mL was highly effective for ruling out the presence of SD under TSH-suppressed conditions, including in patients who had not received RAI treatment.

Postoperative thyroglobulin as a yard-stick for radioiodine therapy: decision tree analysis in a European multicenter series of 1317 patients with differentiated thyroid cancer

PURPOSE

An accurate postoperative assessment is pivotal to inform postoperative 131I treatment in patients with differentiated thyroid cancer (DTC). We developed a predictive model for post-treatment whole-body scintigraphy (PT-WBS) results (as a proxy for persistent disease) by adopting a decision tree model.

METHODS

Age, sex, histology, T stage, N stage, risk classes, remnant estimation, TSH, and Tg were identified as potential predictors and were put into regression algorithm (conditional inference tree, ctree) to develop a risk stratification model for predicting the presence of metastases in PT-WBS.

RESULTS

The lymph node (N) stage identified a partition of the population into two subgroups (N-positive vs N-negative). Among N-positive patients, a Tg value  > 23.3 ng/mL conferred a 83% probability to have metastatic disease compared to those with lower Tg values. Additionally, N-negative patients were further substratified in three subgroups with different risk rates according to their Tg values. The model remained stable and reproducible in the iterative process of cross validation.

CONCLUSIONS

We developed a simple and robust decision tree model able to provide reliable informations on the probability of persistent/metastatic DTC after surgery. These information may guide post-surgery 131I administration and select patients requiring curative rather than adjuvant 131I therapy schedules.

Lobectomy or Total Thyroidectomy-Where Is the Pendulum now for Differentiated Thyroid Cancer?

Thyroid surgery remains an essential treatment of thyroid cancer. The historical one-size-fits-all approach to differentiated (papillary and follicular) thyroid carcinoma of total thyroidectomy with central lymph node dissection has been shown to be overtreatment with associated risk of perioperative complications including nerve palsy and hypoparathyroidism. Furthermore, thyroid lobectomy may obviate life-long thyroid hormone replacement. Low-risk thyroid cancers have a low risk of recurrence and those that do recur can be salvaged with reoperation without compromising prognosis. Perioperative risk stratification for recurrence and death greatly influence the need for total thyroidectomy.

Evolution of thyroid cancer biomarkers: from laboratory test to patients’ clinical management

Over the past three decades, laboratory medicine has significantly evolved thanks to technological advances made possible by new materials and evidence. Clinicians’ ongoing requests for powerful, rapid, and minimally invasive tests has led manufacturers to develop rapid, accurate, and sensitive tests that can increase diagnostic accuracy and improve follow-up, bringing laboratory medicine ever closer to personalized medicine. The aim of this study was to critically review the main problems of the current Tg and CT biomarkers for the diagnosis/monitoring of DTC and MTC, respectively, and to identify the advantages and challenges of using the new laboratory biomarkers in the clinical management of patients with differentiated and medullary thyroid cancer. Insufficient harmonization of Tg and CT assays and lack of interchangeability of laboratory results and cutoff values pose challenges for comparability and standardization of procedures and methods. New diagnostic and monitoring approaches such as PCT or the Tg doubling time have proven to be effective. Close collaboration between clinicians and laboratory specialists remains essential to translate the advantages and limitations of current assays into appropriate clinical interpretation criteria. Over the years, the journal Clinical Chemistry and Laboratory Medicine (CCLM) has taken many steps to develop advanced research and technology in the diagnosis and monitoring of tumor cancer and to help clinicians translate it into clinical practice.