Can preoperative thyroglobulin antibody levels be used as a marker for well differentiated thyroid cancer?

Prognostic value of preoperative thyroid autoantibodies for post-thyroidectomy patient pathology: A retrospective cohort study

OBJECTIVE

The aim of this study was to evaluate the clinical value of preoperative thyroid autoantibodies with reference to the post-thyroidectomy patient pathology.

DESIGN

A retrospective cohort study.

SETTING

Two tertiary care academic hospitals.

MATERIALS AND METHODS

A total of (n = 473) subjects who underwent thyroidectomy from 2009 to 2019 were included. Preoperative serum thyroid autoantibodies (anti-thyroglobulin [anti-Tg] and anti-thyroperoxidase [anti-TPO]) were measured, and the potential predictors of postoperative pathological diagnosis (age, gender, and thyroid autoantibodies) were assessed using multivariable regression models.

RESULTS

Patients with positive thyroid autoantibodies were more likely to have malignant disease than benign disease; adjusted odds ratio (AOR) = 1.6 (1.3-2.7, p = 0.002) for anti-Tg, and AOR = 1.6 (1.1-2.5, p = 0.027) for anti-TPO. A subset analysis of the same predictors performed on patients with cancer (malignant vs. microcarcinoma) showed that patients with ages ≥40 were more likely to develop microcarcinoma as opposed to malignant disease; AOR = 1.8 (1.1-3.1, p = 0.03) for anti-TPO, and AOR = 1.7 (1.0-2.9, p = 0.04) for anti-Tg.

CONCLUSION

Preoperative thyroid autoantibodies could be used clinically to predict the risk of malignancy in thyroid nodules, thus helping guide treatment decisions in patients with thyroid nodules and speeding up the decision to undergo surgical intervention.

Current controversies in the management of patients with indeterminate thyroid nodules

The management of cytologically indeterminate thyroid nodules remains debatable as their malignancy is difficult to establish. Most nodules have benign postoperative histology, but an accurate assessment of their proclivity for malignant transformation is crucial. Numerous studies have investigated the effects of various tools, including clinical, radiological, and cytological features, as well as biochemical and molecular markers, on the management of these heterogeneous nodules. Collectively, strategies aim to treat malignant nodules and avoid unnecessary surgery for asymptomatic benign nodules. Currently, no clear guidelines for the optimal management of cytologically indeterminate thyroid nodules exist to determine whether a conservative approach with long-term observation or surgical intervention should be selected. Thus, personalized approaches have been recommended. Large-scale multicenter prospective studies are needed to elucidate controversial issues. As this topic has not been comprehensively covered based on publications from the Gulf region, this review aims to shed light on remaining controversies.

Ultrasound evolution of parenchymal changes in the thyroid gland with autoimmune thyroiditis in children prior to the development of papillary thyroid carcinoma - a follow-up study

Background

Follicular cell-derived thyroid carcinoma represents the vast majority of paediatric thyroid cancers (TCs). Papillary thyroid carcinoma (PTC) accounts for over 90% of all childhood TC cases, and its incidence in paediatric patients is increasing. The objective of this follow-up study was to present the outcome of ultrasound (US) and laboratory monitoring of paediatric patients with autoimmune thyroiditis (AIT) prior to the development of PTC.

Patients and methods

This prospective study included 180 children and adolescents (132 females; 73.3%) with a suspicion of thyroid disorder referred to the Outpatient Endocrine Department. The patients were divided into four groups: 1) 28 patients with a mean age of 10.7 [standard deviation (SD), 3.1] y, in whom PTC was detected during the active surveillance of AIT [AIT(+), PTC(+) follow up (F)]; 2) 18 patients with a mean age of 12.8 (SD, 3.4) y, in whom PTC and AIT were detected upon admission (A) [AIT(+), PTC(+) A]; 3) 45 patients with a mean age of 13.0 (SD, 3.4) y, in whom PTC was detected upon admission and AIT was excluded [AIT(-), PTC(+) A]; and 4) an age- and sex-matched control group of 89 patients with AIT and with a mean age of 9.4 (SD, 3.0) y. The analysis included clinical, US, and laboratory assessment results of children on admission (groups 1-4) and during follow-up (groups 1 and 4) in the Paediatric Endocrine Outpatient Department.

Results

Upon admission of those in group 1, the US evaluation revealed a hypoechogenic thyroid gland in 12 and an irregular normoechogenic gland in 16 patients. US monitoring revealed an increase in thyroid echogenicity and an increased irregularity of the thyroid structure during the follow-up period of all of the patients from group 1. Such changes were not noticed in group 4. PTC was diagnosed at the mean time of 3.6 y (3 mo-9 y) since AIT confirmation in group 1. The mean maximum PTC diameter as per the US was significantly smaller in group 1 than in groups 2 and 3 [13.2 (10.8) mm vs. 22.2 (12.8) and 22.05 (15.4) mm]. Fewer patients in group 1 were referred to 131I than in groups 2 and 3 (71.4% vs. 94.4 and 93.3%). Interestingly, significant differences were observed in the thyroglobulin antibody (TgAb)/thyroid peroxidase antibody (TPOAb) ratio between groups 2 and 3, as opposed to group 4, at the beginning of observation [15.3 (27.6) and 3.5 (8.8] vs. 0.77 (1.9)]. In group 1, after the follow-up, an increase in the TgAb/TPOAb ratio was observed [1.2 (9.8) to 5.2 (13.5)]. There were no significant differences between groups 1-3 in labeling index Ki67, lymph nodes metastasis, extrathyroidal extension, and angioinvasion. There were no associations between thyroid-stimulating hormone, TgAb, and the extent of the disease.

Conclusion

The use of thyroid US focused on the search for developing tumours in the routine follow-up of patients with AIT may not only help in the early detection of thyroid malignancies that are not clinically apparent but may also influence the invasiveness of oncological therapy and reduce the future side effects of 131I therapy. We propose that the repeat evaluation of TPOAb and TgAb warrants further exploration as a strategy to determine TC susceptibility in paediatric patients with AIT in larger multicentre studies.

[Expression of thyroglobulin antibody and thyroid peroxidase antibody in children with immune thrombocytopenia]

OBJECTIVES

To examine the expression of serum thyroglobulin antibody (TGAb) and thyroid peroxidase antibody (TPOAb) in children with immune thrombocytopenia (ITP).

METHODS

A total of 120 children with ITP who were admitted from October 2019 to October 2021 were enrolled as the ITP group. A total of 60 children without ITP were enrolled as the non-ITP group. According to the clinical classification of ITP, the children in the ITP group were further divided into a newly diagnosed ITP group, a persistent ITP group, and a chronic ITP group. The clinical data were compared between the ITP group and the non-ITP group and between the children with different clinical classifications of ITP. The expression levels of serum TGAb and TPOAb in children with ITP were measured and their association with the clinical classification of ITP was analyzed.

RESULTS

Compared with the non-ITP group, the ITP group had significantly lower levels of CD3+, CD4+, and platelet count (PLT) and significantly higher levels of CD8+, TGAb, and TPOAb (P<0.05). The children with chronic ITP had significantly lower levels of CD3+, CD4+, and PLT and significantly higher levels of CD8+, TGAb, and TPOAb than those with newly diagnosed ITP or persistent ITP (P<0.05). The logistic regression analysis showed that CD3+, CD4+, CD8+, TGAb, and TPOAb were the influencing factors for chronic ITP (P<0.05). A decision curve was plotted, and the results showed that TGAb combined with TPOAb within the high-risk threshold range of 0.0-1.0 had a net benefit rate of >0 in evaluating the clinical classification of ITP in children.

CONCLUSIONS

TGAb and TPOAb are abnormally expressed in children with ITP and are associated with the clinical classification of ITP in children.

Can preoperative serum thyroglobulin levels predict the risk of malignancy? Results from prospective analysis of biochemical predictors of malignancy in thyroid nodules

Although thyroid nodule is a common presentation, malignancy is rare. The present study investigated biochemical predictors of malignancy in enlarged thyroid. This is a prospective study of all willing patients 18 to 70 years presenting with a complaint of thyroid swelling and who underwent definitive surgery over a period of 19 months. All subjects were initially evaluated with detailed history, physical examination, ultrasonography of neck and fine needle aspiration cytology (FNAC). Preoperative estimation of serum thyroid stimulating hormone (TSH), thyroglobulin (Tg) and anti-thyroglobulin (anti Tg) antibody was obtained. The treatment plan was based on FNAC results and included hemi- or total thyroidectomy. During the study period, 110 patients underwent thyroidectomy, and met the selection criteria, of which 47 patients had malignancy on final histopathology. The majority were females, 30 to 60 years old. Median serum Tg, TSH and anti Tg levels in the benign group were, respectively 29 ng/ml, 1,6 mIU/L and 1,1 IU/ml, whereas in malignant nodules they were 162 ng/ml. 1,7 mIU/L and 0,9 IU/ml. On receiver operating characteristic curve analysis, a Tg cut off value of 53 ng/ml predicted malignancy risk with a sensitivity and specificity of 72% and 73%, respectively (p < 0.001). Our study showed the utility of preoperative Tg in predicting risk of malignancy. Its role should be further explored especially in the backdrop of indeterminate cytology through a larger study.

Fine Needle Aspiration Cytology and Thyroglobulin Antibodies in Preoperative Diagnosis of Thyroid Malignancy

Introduction:

Most important in the evaluation of thyroid thyroid disease is to differentiate a disease that is treated medically from a disease that requires surgical treatment. In preoperative differentiation of a malignant from a benign lesion are used different diagnostic methods (US, scintigraphy, FNAC, MRI).

Aim:

The aim of the study was to determine the diagnostic value of fine needle aspiration cytology (FNAC) and serum thyroglobulin antibodies (TgAb) values in individual cytological categories.

Methods:

The prospective study included 100 patients with scintigraphic cold thyroid nodules divided into two groups. The first group consisted of 50 patients with histopathological verified benign nodules and the second group of 50 patients with histopathological verified benign nodules. Demographic datas, FNAC findings, TgAb levels and final histopathological findings were recorded. FNAC with ultrasound (US) guidance was performed by the so-called Free hand technique. TgAtb values were estimated by the radio-immunity assay (RIA) method.

Results:

In patients with histopathological findings of a benign nodule, 20 patients had a cytological finding of a colloidal nodule, 18 patients had a cellular nodule, 12 had a finding of follicular neoplasm. In patients with a histopathological finding of the malignant nodule, 9 patients had a cytological finding of a colloidal nodule, 8 had a cellular nodule, 21 follicular neoplasm and 12 patients had cancer. FNAC had a sensitivity of 66%, specificity of 76%, a positive predictive value of 73%, a negative predictive value of 69%. The highest preoperative serum TgAb values were in patients with cytologic findings of cancer, and the lowest in the cellular nodule.

Conclusion:

The finding of FNAC together with serum TgAb values contributes to better diagnosis and selection of patients requiring surgery.

Clinical Analysis of Preoperative Anti-thyroglobulin Antibody in Papillary Thyroid Cancer Between 2011 and 2015 in Beijing, China: A Retrospective Study

The anti-thyroglobulin antibody (TgAb) has been suggested to be more common in patients with papillary thyroid cancer (PTC). Here, we performed a retrospective study investigated the correlation between TgAb level and PTC in Chinese patients between 2011 and 2015. Patients with goiter who underwent thyroidectomy and received a confirmed pathological diagnosis were enrolled into the study. Clinical characteristics and preoperative thyroglobulin antibody (TgAb) level data were collected from all enrolled patients. Based on the preoperative TgAb test results, patients were divided into a TgAb negative (TgAb-) group (<60 IU/mL) and a TgAb positive (TgAb+) group (≧60 IU/mL). Of the 4,046 patients, 671 patients were TgAb+ while 3,375 patients were TgAb-. There were 535 (79.7%) patients with PTC in the TgAb+ group, and 2,154 (63.8%) patients with PTC in the TgAb- group. The prevalance of PTC was significantly higher in TgAb+ patients than in TgAb- patients. TgAb+ patients were stratified into four groups based on the TgAb titer. The prevalence of PTC did not increase with TgAb titer. No significant difference in TgAb level was noted in patients with different clinicopathologies, including TNM stage, lymph node metastasis, and multifocal carcinoma. Regression analysis suggested a higher risk of PTC malignancy among TgAb+ patients. Preoperative TgAb level ≥60 IU/mL might be associated with a higher risk of PTC. However, there was no titer-dependent association between elevated TgAb titer and PTC malignancy.

Positive thyroid antibodies and risk of thyroid cancer: A systematic review and meta-analysis

Previous studies assessing the association between thyroid antibodies and the risk of thyroid cancer (TC) have produced inconsistent results. The present study therefore conducted a meta-analysis of the available data. PubMed, Embase and the Cochrane Library were searched for the retrieval of relevant studies and a meta-analysis was conducted to systematically evaluate the association between positive thyroid antibodies and the risk of TC. This search identified 16 articles containing 17 studies on thyroglobulin antibodies (TgAb), which involved a total of 34,488 patients. Positive TgAb was associated with an increased risk of TC [odds ratio (OR)=1.93, 95% confidence interval (CI)=1.64–2.27, I²=67.2%]. Whether to adjust for confounding factors (gender and thyroid nodule number) was the main cause of heterogeneity. A stronger association between positive TgAb and an increased risk of TC was identified in the studies with an unadjusted thyroid nodule number (OR=2.14, 95% CI=1.82–2.52), as compared to those with an adjusted thyroid nodule number (OR=1.61, 95% CI=1.29–2.00; P=0.04). In addition, 12 studies on thyroid peroxidase antibodies (TPOAb) involving 30,007 patients were included. Positive TPOAb was associated with an increased risk of TC (OR=1.50, 95%CI=1.16–1.95, I²=83.0%). No significant heterogeneity was observed in the PTC group. Positive TgAb is an independent risk factor for TC. The association between positive TPOAb and increased risk of TC needs to be further studied.

Clinical implications of anti-thyroglobulin antibody measurement before surgery in thyroid cancer

Thyroglobulin antibody (TgAb) is a class G immunoglobulin and a conventional marker for thyroid autoimmunity. From a clinical perspective, TgAb is less useful than thyroid peroxidase antibodies for predicting thyroid dysfunction. However, TgAb is found more frequently in differentiated thyroid cancer (DTC) and can interfere with thyroglobulin (Tg) measurements, which are used to monitor the recurrence or persistence of DTC. Recent studies suggested a small but consistent role for preoperative TgAb in predicting DTC in thyroid nodules, and in reflecting adverse tumor characteristics or prognosis, including lymph node metastasis, but this is still controversial. Postoperative TgAb can serve as a biomarker for remnant thyroid tissue, so follow-up measures of TgAb are useful for predicting cancer recurrence in DTC patients. Since high serum TgAb levels may also affect the fine needle aspiration washout Tg levels from suspicious lymph nodes of DTC patients, it is important to use caution when interpreting the washout Tg levels in patients who are positive for TgAb.

Circulating thyroid cancer biomarkers: Current limitations and future prospects

Differentiated thyroid cancer (DTC) is the most common malignancy of the endocrine system. There has been a significant increase in its incidence over the past two decades attributable mainly to the use of more sensitive diagnostic modalities. Ultrasound-guided fine needle aspiration cytology is the mainstay of diagnosis of benign disorders and malignancy. However, approximately 20% of lesions cannot be adequately categorized as benign or malignant. In the postoperative setting, monitoring of thyroglobulin (Tg) levels has been employed for the detection of disease recurrence. Unfortunately, Tg antibodies are common and interfere with Tg measurement in this subset of patients. Despite this limitation, Tg remains the sole widely used thyroid cancer biomarker in the clinical setting. In an attempt to bypass antibody interference, research has focused mainly on mRNA targets thought to be exclusively expressed in thyroid cells. Tg and thyroid stimulating hormone receptor (TSHR) mRNA have been extensively studied both for discerning between benign disease and malignancy and in postoperative disease surveillance. However, results among reports have been inconsistent probably reflecting considerable differences in methodology. Recently, microRNA (miRNA) targets are being investigated as potential biomarkers in DTC. MiRNAs are more stable molecules and theoretically are not as vulnerable as mRNA during manipulation. Initial results have been encouraging but large-scale studies are warranted to verify and elucidate their potential application in diagnosis and postoperative surveillance of thyroid cancer. Several other novel targets, primarily mutations and circulating cells, are currently emerging as promising thyroid cancer circulating biomarkers. Although interesting and intriguing, data are limited and derive from small-scale studies in specific patient cohorts. Further research findings demonstrating their value are awaited with anticipation.