Serum thyroglobulin in the monitoring of differentiated thyroid cancer

Changes in Thyroglobulin Antibody Levels in Differentiated Thyroid Cancer Patients After Thyroidectomy: A Retrospective Study in Basrah, Iraq

INTRODUCTION

Differentiated thyroid cancer (DTC), the most common endocrine malignancy is subdivided into papillary (the most common) and follicular type. Generally, DTC has a good prognosis with standard treatments such as surgery and, in some cases, radioactive iodine (RAI). Post-treatment follow-up includes thyroglobulin (Tg) and anti-thyroglobulin antibody (TgAb) measurement and imaging to assess treatment success and detect recurrence. However, TgAb can interfere with Tg measurements, making it essential to measure TgAb at different times (months).  Aim of the study: The aim of this study was to evaluate the changes in TgAb level in DTC patients after thyroidectomy and its association with recurrence.

METHODS

This was a retrospective cohort study done at the Faiha Specialized Diabetes, Endocrine, and Metabolism Center (FDEMC), Basrah, Iraq, for individuals diagnosed with DTC between 2008 and 2023. The data collected were analyzed using IBM SPSS Statistics for Windows, Version 21.0 (Released 2012; IBM Corp., Armonk, New York, United States). The categories were classified according to the TgAb level as: (i) elevated (>115 IU/ml) and (ii) normal (<115 IU/ml), where TgAb levels measured at 0-6 months, 6-12 months, 24-36 months, 36-48 months, and beyond 48 months.

RESULTS

The mean age at diagnosis of the study population (n=108) was 40.15 years with a female-to-male ratio of 4:1. Among these individuals, 52.8% (n=57) were found to be obese. Total thyroidectomy was performed on 84.3% (n=91). Papillary thyroid cancer was diagnosed in 69.5% (n=75). TgAb levels were influenced by body mass index (BMI); higher BMI (>30kg/m2) was associated with less consistent TgAb normalization, particularly beyond 48 months (P = 0.04). The study found no significant differences in TgAb normalization based on gender, age, BMI, type of surgery, type of cancer, American Thyroid Association (ATA) risk of recurrence, or radioactive iodine (RAI) treatment.

CONCLUSION

 Factors including gender, age, type of surgery, type of cancer, ATA risk of recurrence, and RAI treatment did not significantly affect TgAb normalization in DTC individuals over the study period. However, higher BMI is associated with less consistent TgAb normalization in the long term.

Recent development on nanomaterial-based biosensors for identifying thyroid tumor biomarkers

The incidence of thyroid tumors has been increasing yearly over the past decade, making it the fourth highest tumor in women. This places various biological burdens on those affected. Currently, thyroid tumors are primarily diagnosed using percutaneous fine needle aspiration and ultrasound. However, these methods are complex, expensive, and less accurate, and they may fail to detect some thyroid nodules. As an alternative, researchers are focusing on blood-based biomarkers in addition to the traditional diagnostic methods, assisted predominantly by nanomaterials. Early identification of thyroid cancer is crucial as it is highly treatable. Various sensing systems have been developed using nanomaterial-mediated approaches to enhance the detection system. Nanomaterials are effectively applied in biosensors for surface functionalization and are conjugated with biomolecules to improve the interaction with the target analyte. This review discusses nanomaterial-assisted thyroid tumor detection, with a special focus on nanomaterial-based biosensors.

CTC, ctDNA, and Exosome in Thyroid Cancers: A Review

Thyroid cancer has become more common in recent years all around the world. Many issues still need to be urgently addressed in the diagnosis, treatment, and prognosis of thyroid cancer. Liquid biopsy (mainly circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and circulating exosomes) may provide a novel and ideal approach to solve these issues, allows us to assess the features of diseases more comprehensively, and has a function in a variety of malignancies. Recently, liquid biopsy has been shown to be critical in thyroid cancer diagnosis, treatment, and prognosis in numerous previous studies. In this review, by testing CTCs, ctDNA, and exosomes, we focus on the possible clinical role of liquid biopsy in thyroid cancer, including diagnostic and prognostic biomarkers and response to therapy. We briefly review how liquid biopsy components have progressed in thyroid cancer by consulting the existing public information. We also discuss the clinical potential of liquid biopsy in thyroid cancer and provide a reference for liquid biopsy research. Liquid biopsy has the potential to be a useful tool in the early detection, monitoring, or prediction of response to therapies and prognosis in thyroid cancer, with promising clinical applications.

Thyroid Cancer Persistence in Patients with Unreliable Thyroglobulin Measurement: Circulating microRNA as Candidate Alternative Biomarkers

BACKGROUND

We aimed to evaluate the role of circulating miRNAs as a biomarker of the persistence of papillary thyroid cancer (PTC) in patients with an "uninformative" thyroglobulin (Tg) measurement.

METHODS

We prospectively enrolled 49 consecutive PTC patients with Tg-positive antibodies (TgAb) who had undergone a (near)-total thyroidectomy and ¹³¹I therapy (RIT). The serum thyroid stimulating hormone (TSH), Tg, and TgAb levels were measured before and at 6 and 12 months after RIT, respectively. The serum miRNA (221, 222, 375, 155, and 146b) levels were measured simultaneously.

RESULTS

The response to the initial therapy was assessed according to the 2015 ATA criteria. A decrease in 50% or more of serum miRNA over time was observed in 41/49 PTC patients, who showed an excellent response (ER), but six and two patients were classified to have an indeterminate/incomplete biochemical or incomplete structural response to initial therapy.

CONCLUSION

Serum miRNA kinetics emerge as a promising biomarker for the early detection of a persistent disease in PTC patients with uninformative Tg results.

Serum Linkage-Specific Sialylation Changes Are Potential Biomarkers for Monitoring and Predicting the Recurrence of Papillary Thyroid Cancer Following Thyroidectomy

BACKGROUND

Although papillary thyroid cancer (PTC) could remain indolent, the recurrence rates after thyroidectomy are approximately 20%. There are currently no accurate serum biomarkers that can monitor and predict recurrence of PTC after thyroidectomy. This study aimed to explore novel serum biomarkers that are relevant to the monitoring and prediction of recurrence in PTC using N-glycomics.

METHODS

A high-throughput quantitative strategy based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used to obtain serum protein N-glycomes of well-differentiated PTC, postoperative surveillance (PS), postoperative recurrence (PR), and matched healthy controls (HC) including linkage-specific sialylation information.

RESULTS

Serum N-glycan traits were found to differ among PTC, PS, PR, and HC. The differentially expressed N-glycan traits consisting of sixteen directly detected glycan traits and seven derived glycan traits indicated the response to surgical resection therapy and the potential for monitoring the PTC. Two glycan traits representing the levels of linkage-specific sialylation (H4N3F1L1 and H4N6F1E1) which were down-regulated in PS and up-regulated in PR showed high potential as biomarkers for predicting the recurrence after thyroidectomy.

CONCLUSIONS

To the best of our knowledge, this study provides comprehensive evaluations of the serum N-glycomic changes in patients with PS or PR for the first time. Several candidate serum N-glycan biomarkers including the linkage-specific sialylation have been determined, some of which have potential in the prediction of recurrence in PTC, and others of which can help to explore and monitor the response to initial surgical resection therapy. The findings enhanced the comprehension of PTC.

Undetectable thyroglobulin makes 123I whole-body scan and stimulated thyroglobulin obsolete in follow-up care of differentiated thyroid cancer: a retrospective study

Background

Differentiated thyroid cancer (DTC) is a common malignancy with increasing incidence. Follow-up care for DTC includes thyroglobulin (Tg) measurement and ultrasound (US) of the neck, combined with ¹³¹I remnant ablation when indicated. Diagnostic precision has evolved with the introduction of the new high-sensitive Tg-assays (sensitivity ≤0.1 ng/mL). The aim of the study was to determine the prognostic utility of high-sensitive Tg and the need for other diagnostic tests in DTC.

Methods

This was a retrospective, observational study. Patients with pathologically confirmed DTC, treated with total thyroidectomy and ¹³¹I remnant ablation, who had their complete follow-up care in our institution were selected (October 2013–December 2018). Subjects with possible thyroglobulin autoantibody interference were excluded. Statistical analysis was performed using the IBM SPSS® Statistics 24 software package.

Results

Forty patients were eligible for analysis. A total of 24 out of the 40 patients (60%) had an undetectable high-sensitive Tg 6 months after total thyroidectomy. None of these patients had a stimulated Tg above 1 ng/mL, or remnant on the ¹²³I Whole-Body Scan (WBS) after 1 year of follow-up. Ultrasound of the neck, performed between 6 and 12 months postoperative, was negative in 21 out of the 24 patients.

Conclusions

This study shows that an undetectable high-sensitive Tg can change the management of patients with DTC and decrease the use and need of stimulated Tg and ¹²³I WBS.

Effect of ¹³¹I Therapy on Complete Blood Count in Patients with Differentiated Thyroid Cancer

Background

The aim of this study was to investigate the effects of ¹³¹I therapy on complete blood count (CBC) in patients with differentiated thyroid cancer (DTC).

Materia/Methods

We analyzed CBC in 542 patients with DTC who were grouped according to treatment cycles and cumulative dose and then subdivided by sex and age. The effects of ¹³¹I therapy among the different groups and subgroups were analyzed.

Results

After sorting patients by treatment cycles and doses, ¹³¹I therapy was found to have different effects on CBC depending on patient sex and age. The effect on white blood cell (WBC) counts persisted longer in women, while increases in hemoglobin (Hb) were more significant in men. The influence on red blood cell (RBC) counts was short-lived in patients aged 45 to 54 years. Monocyte counts were significantly decreased only in patients aged 55 years and older who had undergone 3 or 4 treatment cycles. In men, CBC was more affected by cumulative dose. ¹³¹I therapy only influenced platelet and monocyte counts in patients aged 55 years or older. Hb was significantly decreased and increased in the high- and low-dose groups, respectively. No significant complications were observed during follow-up.

Conclusions

¹³¹I therapy had a greater impact on WBC counts in women, while changes in RBC counts and Hb were more obvious in men. During ¹³¹I therapy, clinicians should pay attention to different CBC indicators based on a patient’s sex and age, but risks associated with an altered CBC are unlikely to outweigh the benefits of ¹³¹I. The results of the present study may help alleviate the concerns of a large proportion of patients with DTC and their families about the effects of ¹³¹I therapy on CBC.

The Prognostic Role of Postablative Non-Stimulated Thyroglobulin in Differentiated Thyroid Cancer

Simple Summary

In the management of patients with differentiated thyroid cancer, thyroglobulin (Tg) is used as a tumor marker to predict residual disease. After surgery, the presence or absence of persistent disease and the risk for recurrent disease should be assessed. Risk categories may be changed during the course of disease; the reclassification of patients influences the management of the disease and the intensity of follow-up. The diagnostic and prognostic roles of postoperative stimulated and one-year postablative non-stimulated Tg was evaluated. The individual lowest and highest non-stimulated Tg values during the entire follow-up were also assessed. Non-stimulated Tg values had excellent diagnostic accuracy in predicting structural disease, and the risk classification based on these was significantly more accurate regarding outcome than that based on the postoperative stimulated Tg. Analysis of the lowest and highest Tg values highlighted that a patient’s risk category can be revised based on a single Tg measurement.

Abstract

Thyroglobulin (Tg) is the most important tumor marker in differentiated thyroid cancer (DTC). The aim of this study was to assess the diagnostic and prognostic roles of postoperative stimulated and postablative lowest, highest, and one-year non-stimulated Tg values obtained during the follow-up of patients with DTC. In this retrospective study, 222 radioiodine-treated, anti-thyroglobulin antibody (TgAb)-negative DTC patients having at least 9 months’ follow-up time were included (172 papillary and 50 follicular cancers; median age: 48 (from 15 to 91) years; female–male ratio: 158/64; median (quartiles) follow-up time: 54 (22–97) months). The 2015 American Thyroid Association guidelines were applied as criteria of the therapeutic response. Postoperative stimulated Tg values had significantly lower diagnostic accuracy than any of the non-stimulated postablative Tg values. One-year non-stimulated Tg had excellent prognostic value for structural disease: a cut-off value of 0.85 ng/mL had an 88.1% diagnostic accuracy. If the Tg value did not decrease below 0.75 ng/mL at any time during follow-up, the risk of residual disease was 25 times higher. The highest non-stimulated Tg during follow-up was the best predictor of residual disease (e.g., a Tg value exceeding 7.7 ng/mL indicated a 30-fold increase in risk). Non-stimulated Tg values measured during follow-up have excellent diagnostic accuracy to predict structural disease in DTC patients. The risk classification of a patient can safely be modified based on even a single Tg measurement.

Early detection of progressive disease using thyroglobulin doubling-time in metastatic differentiated thyroid carcinoma treated with radioactive iodine

OBJECTIVE

Detectable serum thyroglobulin (Tg) in patients with differentiated thyroid carcinoma (DTC) after total thyroidectomy indicates progression of the disease. Thyroglobulin doubling-time (TgDT) is a powerful prognostic predictor in patients with DTC. We aimed to evaluate the value of the dynamic TgDT for early detection of progressive disease (PD) in the patients of metastatic DTC with I radioactive iodine (RAI) therapy.

METHODS

We retrospectively evaluated 21 patients undergoing RAI therapy with metastatic DTC. Patients were defined as PD or non-PD according to Response Evaluation Criteria in Solid Tumors 1.1. TgDT was calculated by Excel-based software using Tg values measured during routine follow-up. Whole data (WDT), initial four data (IDT) and recent four data (RDT) of TgDT after total thyroidectomy were calculated and compared.

RESULTS

Among the 21 patients (10 men; median age, 62 years old; range, 33-80), 11 patients were classified into PD and 10 were into non-PD. The initial Tg after total thyroidectomy showed a significant difference between PD and non-PD patients (P = 0.013). Short WDT, IDT and RDT (less than one year) showed a high correlation with PD (P < 0.05). RDT showed the highest predictive value for PD (P < 0.001). All the 11 PD patients showed RDT less than one year before PD (median follow-up, 157 days; range, 88-252).

CONCLUSIONS

RDT is a powerful PD predictor in patients with metastatic DTC. Dynamic monitoring of RDT should be applied for the early detection of PD in clinic.

Personalized management of differentiated thyroid cancer in real life - practical guidance from a multidisciplinary panel of experts

PURPOSE

The standard of care for differentiated thyroid carcinoma (DTC) includes surgery, risk-adapted postoperative radioiodine therapy (RaIT), individualized thyroid hormone therapy, and follow-up for detection of patients with persistent or recurrent disease. In 2019, the nine Martinique Principles for managing thyroid cancer were developed by the American Thyroid Association, European Association of Nuclear Medicine, Society of Nuclear Medicine and Molecular Imaging, and European Thyroid Association. In this review, we present our clinical practice recommendations with regard to implementing these principles in the diagnosis, treatment, and long-term follow-up of patients with DTC.

METHODS

A multidisciplinary panel of five thyroid cancer experts addressed the implementation of the Martinique Principles in routine clinical practice based on clinical experience and evidence from the literature.

RESULTS

We provide a suggested approach for the assessment and diagnosis of DTC in routine clinical practice, including the use of neck ultrasound, measurement of serum thyroid-stimulating hormone and calcitonin, fine-needle aspiration, cytology, and molecular imaging. Recommendations for the use of surgery (lobectomy vs. total thyroidectomy) and postoperative RaIT are also provided. Long-term follow-up with neck ultrasound and measurement of serum anti-thyroglobulin antibody and basal/stimulated thyroglobulin is standard, with ¹²³/¹³¹I radioiodine diagnostic whole-body scans and ¹⁸F-fluoro-2-deoxyglucose positron emission tomography/computed tomography suggested in selected patients. Management of metastatic DTC should involve a multidisciplinary team.

CONCLUSIONS

In routine clinical practice, the Martinique Principles should be implemented in order to optimize clinical management/outcomes of patients with DTC.

The Blood Biomarkers of Thyroid Cancer

Introduction

With the gradual increase in the incidence of thyroid cancer, people’s attention to thyroid cancer has also gradually increased. Although the prognosis of thyroid cancer is rather mild compared to other cancers, it will still bring a heavy psychological burden on people who have been diagnosed. At present, the diagnosis of thyroid cancer mainly depends on ultrasound and percutaneous fine needle aspiration (pFNA). Due to the unsatisfactory accuracy of the diagnosis methods we use now, there are still some thyroid nodules that cannot be clearly diagnosed before surgery.

Methods

In this article, we have searched for relevant research on blood markers of thyroid cancer in the past five years and categoried them into four groups.

Discussion

Though we have not found a biomarker which can diagnose thyroid cancer both sensitively and specifically, we do found many substances that are related to it, and have the potential to recognize it and help the diagnosis. And perhaps combined models can do it better.

Clinical Applicability of Low Levels of Thyroglobulin Autoantibodies as Cutoff Point for Thyroglobulin Autoantibody Positivity

BACKGROUND

Thyroglobulin (Tg) is an established tumor marker in differentiated thyroid carcinoma (DTC). However, Tg assays can be subject to interference by autoantibodies against Tg (TgAbs). No clinical consensus exists on the cutoff value of TgAb positivity and its relationship to Tg assay interference. The aims of this study were to investigate the most applicable cutoff value for TgAb positivity in clinical practice and to evaluate whether tumor characteristics differ between TgAb+ and TgAb- patients during ablation therapy using the manufacturer's cutoff (MCO) and institutional cutoff (ICO).

METHODS

This single-center cohort study included 230 DTC patients diagnosed between January 2006 and December 2014. Serum Tg and TgAbs were measured with the Tg-IRMA (Thermo Fisher Scientific) and ARCHITECT Anti-Tg (Abbott Laboratories) assays. Patients were divided into TgAb- and TgAb+ based on the limit of detection (LoD; ≥0.07 IU/mL), functional sensitivity (FS; ≥0.31 IU/mL), MCO (≥4.11 IU/mL), and ICO (≥10 IU/mL).

RESULTS

All patients were TgAb+ based on the LoD; one patient was negative on FS. Fifty-five (23.9%) and 34 (14.8%) patients had TgAbs above the MCO and ICO, respectively. Histology, presence of multifocality, tumor-node-metastasis, and American Thyroid Assocation risk stratification did not differ between TgAb- and TgAb+ patients using MCO and ICO during ablation.

CONCLUSIONS

This study supports the use of a higher cutoff value than that of the FS for TgAb positivity in clinical settings. The LoD and FS are too sensitive to discriminate TgAb positivity and negativity in DTC patients during ablation therapy. The presence of TgAbs during ablation is not related to tumor characteristics and risk profile. This implies that TgAb positivity should not be considered a separate risk factor.

Comparison of Serum Thyroglobulin Levels in Differentiated Thyroid Cancer Patients Using In-House Developed Radioimmunoassay and Immunoradiometric Procedures

Thyroglobulin (Tg) is a proven tumor marker in the follow-up and post-operative management of patients with differentiated thyroid cancer (DTC). All assays for serum thyroglobulin (s-Tg) are based on immunoassays, however, the assay technique has a bearing on the variations seen in the estimations. We studied this using four in-house developed radioimmunoassays (RIA) and immunoradiometric assays (IRMA). Limit of detection, working range, recovery, dilution test, precision profiles and method comparison were evaluated. All four methods were used for the estimation of s-Tg in DTC patients and also compared for their performance using commercially available Tg IRMA kits from DiaSorin and Izotop. The s-Tg values measured by six different immunoassays showed very significant inter-method correlation (0.84-0.99, p < 0.001). However, among the in-house developed assays; the coated tube IRMA showed a better sensitivity and precision at the lower concentration range and hence, is preferable for the routine measurement of s-Tg in patients negative for Tg autoantibodies (TgAb). Although the second generation IRMAs offer practical benefits of having higher sensitivity, shorter turn-around time and convenience of automation, they, unfortunately, also have higher tendency for interference from both TgAb and heterophilic antibodies, if present in the sample. On the contrary, RIA is less prone to such interference and, hence, can be used in patients with TgAb. In order to effectively use this test, it is important that nuclear medicine physicians and endocrinologists understand these intrinsic technical limitations encountered during s-Tg measurement.

Role of ultrasound in the assessment of percutaneous laser ablation of cervical metastatic lymph nodes from thyroid carcinoma

Background Few studies have examined the feasibility and efficiency of performing ultrasound and contrast-enhanced ultrasound (CEUS) after percutaneous laser ablation (PLA) of cervical metastatic lymph nodes from thyroid cancer. Purpose To investigate and describe the use of conventional ultrasound and CEUS in evaluating PLA of metastatic lymph nodes. Material and Methods PLA was performed in a small, prospective, observational study of 21 metastatic lymph nodes in 17 thyroid cancer patients who underwent radical thyroid resection. CEUS was conducted prior to PLA and 1 h and seven days after ablation. Conventional ultrasound examination of all nodes was performed during follow-up after ablation. We observed contrast agent perfusion in the lymph nodes, calculated perfusion defect volumes using CEUS and determined the rates of reduction for metastatic lymph nodes for a mean duration of 17.86 ± 4.704 months (range = 12-27 months). Results CEUS demonstrated that the perfusion defect volume was larger on day 7 than on day 1 post-ablation in 47% of the ablated nodes. Compared to the largest diameters and volumes pre-PLA, the corresponding post-PLA values significantly decreased ( P < 0.05 versus baseline). No statistically significant change in thyroglobulin (Tg) levels before and after PLA was observed in this study ( P > 0.05 versus baseline). Conclusion CEUS can be effectively used to distinguish the margins of ablated regions, assess the accuracy of PLA, and monitor short-term changes in necrotic areas. However, long-term follow-up assessments of the curative effect of PLA will predominantly rely on conventional ultrasonography.

Thyrotropin Suppressive Therapy for Low-Risk Small Thyroid Cancer: A Propensity Score-Matched Cohort Study

BACKGROUND

Thyrotropin (TSH) suppression has improved the clinical outcomes of patients with differentiated thyroid cancer (DTC). However, the efficacy of TSH suppressive therapy (TST) is unclear in patients with low-risk DTC. This study aimed to evaluate the efficacy of TST and optimal TSH levels of patients with low-risk DTC.

METHODS

This retrospective propensity score-matched cohort study included DTC patients (n = 446) who underwent lobectomy from 2002 to 2008 with or without TST (TST group and No-TST group). Disease-free survival (DFS) and dynamic risk stratification were compared between both groups using serum TSH levels.

RESULTS

Approximately 74% of TST patients and 11% of No-TST patients had suppressed serum TSH levels (<2 mIU/L). The median follow-up period was 8.6 years. During follow-up, the disease recurred in 10 (2.7%) patients, with no significant difference in DFS between the groups (p = 0.63). The proportion of patients with excellent treatment response was similar between the TST (65.2%) and No-TST (64.4%) groups. Incomplete biochemical response was noted in 17.2% of the TST group patients and 9.4% of the No-TST group patients. No significant difference was observed in the DFS between both groups by comparing serum TSH level (p = 0.57).

CONCLUSIONS

TST did not improve clinical outcomes, and serum TSH levels were not associated with recurrence in patients with low-risk small DTC. No clinical benefits were shown for TSH suppression in low-risk patients who underwent lobectomy. Thus, levothyroxine is not necessary for patients without evidence of hypothyroidism.