Investigating Antithyroglobulin Antibody As a Prognostic Marker for Differentiated Thyroid Cancer: A Meta-Analysis and Systematic Review

Prognostic value of postoperative anti-thyroglobulin antibody in patients with differentiated thyroid cancer

Purpose

Postoperative thyroglobulin (Tg) generally serves as a biomarker to monitor the recurrence or persistence of differentiated thyroid cancer (DTC), whereas it constrains to interference from anti-thyroglobulin antibody (TgAb). This study aimed to determine the value of postoperative TgAb as a surrogate for monitoring tumor status in DTCs with positive TgAb after successful radioactive iodine (RAI) remnant ablation.

Methods

We retrospectively enrolled DTC patients with positive (≥40 IU/mL, Roche) postoperative TgAb measurements. An index of TgAb change (ΔTgAb) was defined to describe the TgAb decrease rate. DTC status was defined as either no evidence of disease (NED) or persistent/recurrent disease (PRD). Univariate and multivariate binary logistic analyses were used to identify the independent risk factors of PRD. Receiver operating characteristic (ROC) curves were performed to determine the optimal cutoff values of each risk factor, and DeLong's test was conducted to compare their predictive powers. Kaplan-Meier curves were used to assess the impact of different TgAb trends in the first year on progression-free survival.

Results

Of the 232 patients enrolled, the median diagnosis age was 34 years (range, 18-62 years), with a male-to-female ratio of 1:4.66 (41/191). Among them, after a median follow-up of 44 months (range, 4-128 months),183 (78.87%) patients were evaluated as NED, while the other 49 (21.12%) had either persistent (n = 25) or recurrent disease (n = 24). Multivariate regression showed that ΔTgAb (P < 0.001) and lymph node metastasis (LNM) rate (P = 0.009) were independently relevant to the presence of PRD, with optimal cutoff values of 47.0% and 35.1%, respectively. It is important to note that there is a high negative predictive value (96.93%) of ΔTgAb with the cutoff of 47.0%. DeLong's test showed that ΔTgAb alone and the combination of ΔTgAb and LNM rate were significantly greater than the isolated LNM rate (both P < 0.001) in predicting NED, while there was no statistical difference of the predictive power between ΔTgAb and the combination (P = 0.203). Additionally, patients with ΔTgAb >47.0% had longer progression-free survival than those with ΔTgAb ≤47.0% (not reached vs. 50 months, P < 0.001), and those with ΔTgAb >47.0% or negative conversion within the first year after RAI ablation had longer progression-free survival.

Conclusion

Our study suggested that ΔTgAb could serve as a valuable indicator of disease status in DTC patients with positive TgAb. A ΔTgAb of >47.0% is conducive to identify those with NED and may help to obviate their overtreatment. The decrease rate and negative conversion of TgAb in the first year were good predictors of disease-free survival in patients.

The relationship between thyroid peroxidase antibody and differentiated thyroid cancer: a systematic review and meta-analysis

Background

Thyroglobulin antibody (TgAb) has been found to be associated with the occurrence and development of differentiated thyroid cancer (DTC) for several years, but there is still controversy over whether thyroid peroxidase antibody (TPOAb) is related to differentiated thyroid cancer.

Methods

We scrutinized relevant studies published up to July 2023 across four major databases including PubMed, Embase, Cochrane Library, and Web of Science, to examine the association between TPOAb and DTC. Clinical outcome measures include the incidence of DTC, tumor size, extrathyroidal invasion, lymph node metastasis, multifocality, recurrence and bilaterality.

Results

12 original studies were included, involving a total of 20,330 subjects. Our analysis of the included studies revealed that TPOAb+ individuals exhibited a higher risk of developing DTC (OR=1.57 [95% CI: 1.00-2.45], p=0.049) than TPOAb- individuals. Furthermore, TPOAb+ DTC patients were more prone to present with bilateral (OR=1.40 [95% CI: 1.21-1.62], p<0.00001) and multifocal (OR=1.40 [95% CI: 1.23-1.60], p<0.00001) tumors than TPOAb- patients. Sensitivity analysis indicated a high sensitivity for these three findings. No significant differences in the risk of extrathyroidal extension and lymph node metastasis, recurrence rate, tumor size, were observed between TPOAb+ and TPOAb- DTC patients.

Conclusion

The presence of TPOAb is correlated with an increase prevalence of DTC. However, its effectiveness as a prognostic marker for DTC patients warrants further investigation.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42023448824.

The Frequency of Differentiated Thyroid Cancer Recurrence in 2302 Patients With Excellent Response to Primary Therapy

CONTEXT

Discrepant data on the recurrence rate of differentiated thyroid cancer (DTC) are reported.

OBJECTIVE

To evaluate the frequency and risk factors of true recurrence in DTC patients with excellent responses (ExR) to initial therapy.

METHODS

A retrospective analysis of the 2302 consecutive DTC patients with ExR to primary therapy, treated during 24 years at single center. The percentage of recurrence and cumulative recurrence rate (CRR) were analyzed. Risk factors for recurrence for patients with papillary thyroid cancer (PTC) were investigated and methods for establishing a diagnosis of recurrence were evaluated.

RESULTS

Of DTC patients, 32 (1.4%) experienced recurrence. PTC patients with recurrence were more likely to have younger age (P = .0182), larger tumor size (P = .0013), lymph node metastases (P = .0013), incomplete resection (P = .0446), higher ATA risk (P = .0002), and had more frequently been treated with 131I (P = .0203). CRRs at 5, 10, 15, 20, and 24 years after surgery were 1.2%, 1.9%, 2.5%, 2.9%, and 2.9%, respectively. The CRRs according to histological type were highest for poorly differentiated thyroid cancer (PDTC), lower for oncocytic (OTC) and follicular thyroid cancer (FTC), and lowest for PTC. Most recurrences occurred within the first 5 years of observation. The most effective method for detecting local recurrence was ultrasonography with fine needle aspiration cytology, and for distant metastases, 18F-FDG PET.

CONCLUSION

True recurrence is rare in DTC patients. PTC patients with ExR to primary therapy and N0/Nx can be dismissed from oncological follow-up. Despite ExR to primary therapy, DTC patients with N1, and PDTC, OTC, FTC should remain under oncological follow-up.

Exploration of aminopeptidase N as new biomarker for early diagnosis of thyroid cancer

False-positive diagnosis and overdiagnosis are ongoing issues in clinical diagnosis of thyroid cancer. Identifying new disease markers is crucial for early diagnosis and improved treatment. Aminopeptidase N (APN) is a promising biomarker for cancer diagnosis due to its critical roles in tumor invasion, metastasis, angiogenesis, and other processes. However, its potential as biomarker for thyroid cancer diagnosis needs further investigation. This study developed an ultra-sensitive near-infrared fluorescence probe, LAN-apn, to investigate the expression level of APN in thyroid cancer and evaluate its potential as biomarker of thyroid cancer. LAN-apn could accurately and sensitively determine APN through fluorescence method (DL = 0.069 ng/mL) and colorimetric method (DL = 4.5 ng/mL). In addition, LAN-apn allowed for successful fluorescence imaging of APN in thyroid cancer cells and thyroid cancer tumors both in vivo and in vitro, and confirmed that APN was significantly upregulated in thyroid cancer. Therefore, APN may become a new biomarker for thyroid cancer diagnosis, and LAN-apn could be used as a new imaging tool for the study of APN-thyroid cancer relationship and the early diagnosis of thyroid cancer.

Thyroglobulin Antibody (TgAb) Positive is an Independent Risk Factor for Lymph Node Metastasis in Patients with Differentiated Thyroid Carcinoma

Objective

To investigate the relationship between lymph node metastasis and the clinicopathologic features of differentiated thyroid carcinoma (DTC) patients with thyroglobulin antibody (TgAb) positive and negative.

Methods

A total of 443 patients with DTC were included in this study. Clinicopathological data of the patients were collected, including tumor size, clinical stage, calcification, Hashimoto's thyroiditis, extra-membrane infiltration, BRAF V600E mutation status, and thyroid-related hormone and antibody levels. The relationship between of lymph node metastasis and clinicopathologic features was analyzed.

Results

There were 227(51.2%) TgAb negative and 216(48.8%) TgAb positive DTC patients. Compared with patients without lymph node metastasis, DTC patients with lymph node metastasis had a higher proportion of patients with <55 years of age, maximum tumor diameter >1cm, calcification, BRAF V600E mutation, and TgAb positive. Multivariate regression logistic analysis showed that <55 years old (odds ratio (OR): 2.744, 95% CI: 1.665-4.522, P<0.001), maximum tumor diameter >1cm (OR: 2.163, 95% CI: 1.431-3.271, P<0.001), BRAF V600E mutation (OR: 2.489, 95% CI: 1.397-4.434, P=0.002), and TgAb positive (OR: 1.540, 95% CI: 1.020-2.326, P=0.040) were risk factors for lymph node metastasis. Maximum tumor diameter >1cm and BRAF V600E increased the risk by more than one fold for lymph node metastasis in TgAb-negative and TgAb-positive DTC patients.

Conclusion

Younger age (<55 years old), maximum tumor diameter >1cm, BRAF V600E mutation, and TgAb positive were independent risk factors for lymph node metastasis in DTC. And maximum tumor diameter >1cm and BRAF V600E mutation were risk factors for lymph node metastasis both in TgAb positive and negative DTC patients.

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.

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.

Serum Anti-Thyroglobulin Autoantibodies Are Specific in Predicting the Presence of Papillary-like Nuclear Features and Lymphocytic Infiltrate in the Thyroid Gland

(1) Background: Previous studies have reported a correlation between serum anti-Thyroglobulin-antibodies (TgAb) and papillary thyroid carcinoma. The aim of our study was to evaluate whether serum TgAb and anti-thyroid-peroxidase antibody (TPO) positivity was also related to pre-neoplastic histological changes such as papillary-like nuclear features (PLNF) and with the presence of lymphocytic infiltrate (LI) in thyroid surgical specimens. (2) Methods: The study was retrospectively carried out on 70 consecutively recruited patients who underwent thyroidectomy for benign process and whose TgAb and TPOAb values were retrieved from clinical records. Histological sections of thyroid surgical samples were revised, looking for PLNF and lymphocytic infiltrate. HBME1 expression was assessed by immunohistochemistry. (3) Results: Our results showed a significant association between TgAb, PLNF, and lymphocytic infiltrate. The presence of TgAb was highly specific, but less sensitive, in predicting the presence of PLNF (sensitivity = 0.6, specificity = 0.9; positive predictive value (PPV) = 0.88; negative predictive value (NPV) = 0.63). TgAb positivity showed a good association with the presence of lymphocytic infiltrate (sensitivity = 0.62, specificity = 0.9; PPV = 0.88 and NPV = 0.68). HBME1 immunoreactivity was observed in the colloid of follicles showing PLNF and/or closely associated with LI. (4) Conclusions: The presence of PLNF and LI is associated with serum TgAb positivity. The presence of TgAb and of LI could be triggered by an altered thyroglobulin contained in the HBME1-positive colloid, and could be a first defense mechanism against PLNF that probably represent early dysplastic changes in thyrocytes.

Persistent or recurrent disease in thyroid cancer survivors who have elevated serum anti-thyroglobulin antibodies

OBJECTIVE

Detection of residual differentiated thyroid cancer is important but difficult. A variety of imaging modalities and biochemical markers have been used with moderately good success. We hypothesized that elevated perioperative serum anti-thyroglobulin antibodies (TgAb) would also be a predictive marker for persistent or recurrent thyroid cancer.

METHODS

We performed a retrospective analysis of 277 differentiated thyroid cancer survivors divided into two groups: those with low or normal serum TgAb (TgAb-) and those with elevated serum TgAb (TgAb+). All patients were seen at one major academic medical center. Patients were followed for a median of 7.54 years.

RESULTS

Patients in the TgAb+ group were more likely to have positive lymph nodes at initial surgery, to be assigned to a higher AJCC Stage, and to have significantly higher incidence of persistent/recurrent disease. The higher incidence of persistent/recurrent cancer was significant under univariable and multivariable (including TgAb status, age, and sex) Cox proportional hazards model analysis.

CONCLUSION

We conclude that individuals with elevated serum TgAb at the outset should be followed with a higher index of suspicion for persistent/recurrent thyroid cancer.

[Antibody proteomics]

Antibodies represent an essential component of humoral immunity; therefore their study is important for molecular biology and medicine. The unique property of antibodies to specifically recognize and bind a certain molecular target (an antigen) determines their widespread application in treatment and diagnostics of diseases, as well as in laboratory and biotechnological practices. High specificity and affinity of antibodies is determined by the presence of primary structure variable regions, which are not encoded in the human genome and are unique for each antibody-producing B cell clone. Hence, there is little or no information about amino acid sequences of the variable regions in the databases. This differs identification of antibody primary structure from most of the proteomic studies because it requires either B cell genome sequencing or de novo amino acid sequencing of the antibody. The present review demonstrates some examples of proteomic and proteogenomic approaches and the methodological arsenal that proteomics can offer for studying antibodies, in particular, for identification of primary structure, evaluation of posttranslational modifications and application of bioinformatics tools for their decoding.

Thyroid autoantibodies

Thyroid-stimulating hormone (TSH) receptor antibody (TSH-R-Ab or TRAb) testing plays a pivotal role in arriving at the aetiological diagnosis in patients with thyrotoxicosis. A positive test establishes the diagnosis of Graves' disease (GD) while a negative result in conjunction with imaging studies supports other possible aetiologies. In patients with GD, TRAb levels at diagnosis and at the time of withdrawal of antithyroid drugs can identify patients who are unlikely to achieve remission and guide clinical management decisions. We provide an algorithm that incorporates TRAb in the decision-making process for the management of thyrotoxicosis. The utility of TRAb in predicting the risk of fetal and neonatal thyroid dysfunction is established and widely accepted in guidelines. TRAb may also help in the diagnosis of Graves' orbitopathy, especially in euthyroid or hypothyroid patients and its role in guiding its management is evolving as a useful adjunct to the clinical parameters used in making therapeutic decisions.Anti-thyroid peroxidase antibodies (TPOAb) and anti-thyroglobulin antibodies (TgAb) indicate thyroid autoimmunity. The most common use of TPOAb is to identify patients at a higher risk of progression to treatment-requiring hypothyroidism. They also aid the diagnosis of immune thyroiditis and Hashimoto's encephalopathy. Thyroglobulin measurement is used to help guide differentiated thyroid cancer treatment. TgAb is used as an accompanying test with thyroglobulin measurement as its presence can interfere with the thyroglobulin assay. A negative TgAb result reduces the likelihood of, but does not exclude, interference with thyroglobulin assay.

The correlation between preoperative serum thyroglobulin and pathological features of thyroid follicular carcinoma.. [DOI: 10.21203/rs.3.rs-1965404/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Purpose: To explore more meaningful information for making individualized medical decisions for patients with follicular thyroid carcinoma (FTC), we investigated the correlations between pathological features of FTC and preoperative serum markers, including thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb), thyroid peroxidase antibodies (TPOAb), thyroid stimulating hormone (TSH), free triiodothyronine (fT3), free thyroxine (fT4), and fT3/fT4 ratio.Methods:We retrospectively analyzed 82 patients with FTC. Data collected included demographics (sex and age), pathological features (infiltration extent, tumor stage, presence of multifocal FTC, and presence of concomitant PTC), and preoperative serum markers (Tg, TgAb, TPOAb, TSH, fT3, fT4, and fT3/fT4 ratio). The correlations between preoperative serum markers and pathological features were analyzed.Results:72.0% patients were female. Mean age was 46.4±16.5 years. In univariate analysis, older age (≥55 years) was associated with non-minimally invasive (P=0.016), larger (>T2 category, P=0.006), and multifocal (P=0.034) FTC; elevated preoperative serum Tg level (≥500.00 ng/mL) was associated with non-minimally invasive (P=0.015) and larger (>T2 category, P=0.001) FTC; higher fT3/fT4 ratio (≥0.541) was associated with multifocal FTC (P=0.031). In multivariable analysis, Tg ≥500.00 ng/mL was an independent risk factor for non-minimally invasive FTC [P=0.015, OR=3.289 (1.260-8.583)] and for >T2 category FTC [P=0.001, OR=5.397 (1.963-14.840)]; older age [≥55 years, P=0.045, OR=4.756 (1.037-21.818)] and higher fT3\fT4 ratio [≥0.541, P=0.044, OR=4.626 (1.043-20.525)] was an independent risk factor multifocal FTC, respectively.Conclusions: Preoperative serum Tg was correlated with the local tumor extent and primary tumor diameter of FTC. Further research regarding the utility of preoperative serum Tg in FTC is still needed.

The utility of serum anti-thyroglobulin antibody and thyroglobulin in the preoperative differential diagnosis of thyroid follicular neoplasms

PURPOSE

Distinguishing follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA) before surgery is inherently challenging owing to the lack of malignant features on ultrasound, poor sensitivity of fine-needle biopsy, and the absence of definitive markers. We investigated whether thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb), thyroid peroxidase antibodies (TPOAb), and thyroid stimulating hormone (TSH) can help differentiate FTC from FTA.

METHODS

Data pertaining to 319 patients with follicular neoplasms were retrospectively analyzed. We compared the serum markers between patients with confirmed FTC and FTA. We also analyzed the prevalence of FTC in different subgroups of patients based on serum marker levels.

RESULTS

TgAb was a risk factor for FTC. Compared to TgAb ≤11.68 IU/mL group, the odds ratio (OR) for FTC in TgAb 11.69-30.50 IU/mL group and TgAb >30.50 IU/mL group were 2.206 (1.114-4.369, P = 0.023) and 3.247 (1.684-6.260, P < 0.001), respectively. The prevalence of malignancy in TgAb >30.50 IU/mL group was significantly higher than in the TgAb ≤11.68 IU/mL group (32.9 vs. 13.1%, P = 0.001). In patients with TgAb (-) status, Tg was another risk factor for FTC. Compared to Tg ≤38.51 ng/mL group, OR of Tg >434.60 ng/mL group was 3.836 (1.625-9.058, P = 0.002); the prevalence of malignancy in the Tg >434.60 ng/mL group was 47.2% and higher than other groups.

CONCLUSIONS

TgAb and Tg levels may be useful markers for preoperative differential diagnosis of follicular neoplasms. Higher TgAb and Tg levels were associated with greater malignant risk. Thus, we should be cautious of preoperative TgAb and Tg in follicular neoplasms.

Change in Antithyroglobulin Antibody Levels is a Good Predictor of Responses to Therapy in Antithyroglobulin Antibody-Positive Pediatric Papillary Thyroid Carcinoma Patients

OBJECTIVE

Antithyroglobulin antibodies (TgAbs) could be used as a surrogate tumor marker of TgAb-positive-differentiated thyroid carcinoma. This study aims to determine whether the change in TgAb levels over time could be used as a predictor of responses to therapy in pediatric papillary thyroid carcinoma (PTC) patients.

METHODS

We retrospectively analyzed the records of 48 pediatric PTC patients with TgAb levels ≥50 IU/ml 6 months after initial ¹³¹I treatment. Suppressed thyroglobulin (Tg) levels 6 months after initial ¹³¹I treatment were used to divide the patients into positive Tg (P-Tg, Tg ≥ 0.2 ng/ml) and negative Tg (N-Tg, Tg < 0.2 ng/ml) groups. Responses to therapy were classified as the acceptable response (AR) group and the not acceptable response (NAR) group.

RESULTS

Of 48 enrolled patients with 58 months (range, 24-143 months) of follow-up, 28 patients had NAR and 20 patients had AR. TgAb levels were decreasing ≥50% in 28 patients, decreasing <50% in 8 patients, and increasing in 12 patients. Multivariate analysis showed that high initial risk stratification and TgAb levels decreasing <50% or increasing were significantly associated with NAR (p < 0.05). Changes in Tg levels were also associated with NAR in the P-Tg group (p < 0.05).

CONCLUSION

Changes in TgAb levels over time could be used as a predictor of responses to therapy in TgAb-positive pediatric PTC patients. Changes in Tg levels over time are also associated with NAR to therapy in both TgAb-positive and Tg-positive pediatric PTC patients.

Indication for radioactive iodine in patients with papillary thyroid carcinoma without apparent disease after total thyroidectomy but with elevated antithyroglobulin antibodies

OBJECTIVE

To evaluate a criterion for the selective indication of radioactive iodine (RAI) based on the short-term behaviour of antithyroglobulin antibodies (TgAb) in patients with papillary thyroid carcinoma (PTC) who have negative thyroglobulin (Tg) and neck ultrasonography (US) without abnormalities after total thyroidectomy but elevated TgAb.

DESIGN

This was a prospective study that evaluated 216 patients with low- or intermediate-risk PTC who had nonstimulated Tg ≤ 0.2 ng/ml and no US abnormalities but elevated TgAb 3 months after thyroidectomy. RAI was not indicated in patients with negative TgAb or a >50% reduction in TgAb concentrations 6 months after initial assessment followed by a negative test or an additional reduction (also >50%) after 12 months.

RESULTS

Only two of the 114 patients who did not receive RAI developed recurrences; another 108 patients met the criterion of an excellent response to therapy in the last assessment and TgAb persisted in four patients but there was an additional reduction in their concentration during follow-up. Among the 102 patients who received RAI, post-therapy whole-body scanning (RxWBS) detected persistent disease in 8 (8%). Two of the 94 patients without persistent disease on RxWBS developed recurrences. In the last assessment, in the absence of additional treatment, 54/92 patients (58.7%) without structural recurrence had negative TgAb.

CONCLUSIONS

The indication for RAI can be based on the short-term behaviour of TgAb in patients with PTC and elevated TgAb after thyroidectomy who are not high risk and who do not have apparent disease (nonstimulated Tg ≤ 0.2 ng/ml and no US abnormalities).

Pre-Operative Anti-Thyroid Antibodies in Differentiated Thyroid Cancer

OBJECTIVE

To evaluate the significance of anti-thyroglobulin and anti-thyroid peroxidase antibody levels in locoregional metastatic disease in patients with well-differentiated thyroid cancer.

METHODS

Included patients underwent initial treatment for well-differentiated thyroid cancer at our institution between 2014 and 2018. The following variables were collected: age, sex, pre-operative thyroid stimulating hormone (TSH), thyroglobulin (Tg), anti-thyroglobulin antibody (TgAb), anti-thyroid peroxidase antibody (TPOAb); extent of surgery; T-stage; N-stage; extrathyroidal extension (ETE), extranodal extension (ENE), lymphovascular invasion (LVI), and multifocal disease. The relationships between pre-operative TPOAb, TgAb, Tg, and TSH and disease status were analyzed.

RESULTS

405 patients were included in the study. 66.4% were female. Mean age was 52 years. Elevated TgAb was associated with the presence of lymph node metastases (LNM) in both the central and lateral neck (p<0.01), with stronger correlation with N1b compared with N1a disease (p=0.03). Presence of ETE was inversely associated with TgAb titer (p=0.03). TPOAb was associated with lower T- stage, fewer LNM, and lower likelihood of ETE (p=0.04, p=0.04, p=0.02). In multivariable analysis, TgAb≥40 IU/mL was an independently predictive factor of higher N-stage (p<0.01 for N0 v. N1 and p=0.01 for N1a v. N1b), and for ENE (p<0.01). TPOAb≥60 IU/mL was associated with lower T-stage (p=0.04 for T< 3) and absence of ETE (p=0.01).

CONCLUSIONS

Elevated pre-operative TgAb was an independent predictor of nodal metastases and ENE, while elevated TPOAb was associated with a lower pathologic T and N stage. Pre-operative anti-thyroid antibody titers may be useful to inform disease extent and features.

Thyroid cancer, recent advances in diagnosis and therapy

Over the past several decades, the approach to the diagnosis and management of patients with follicular cell-derived thyroid cancer has evolved based on improved classification of patients better matching clinical outcomes, as well as advances in imaging, laboratory, molecular technologies and knowledge. While thyroid surgery, radioactive iodine therapy and TSH suppression remain the mainstays of treatment, this expansion of knowledge has enabled de-escalation of therapy for individuals diagnosed with low-risk well-differentiated thyroid cancer; better definition of treatment choices for patients with more aggressive disease; and improved ability to optimize treatments for patients with persistent and/or progressive disease. Most recently, the advancement of knowledge regarding the molecular aspects of thyroid cancer has improved thyroid cancer diagnosis and has enabled individualized therapeutic options for selected patients with the most aggressive forms of the disease. Guidelines from multiple societies across the world reflect these changes, which focus on taking a more individualized approach to clinical management. In this review, we discuss the current more personalized approach to patients with follicular cell-derived thyroid cancer and point toward areas of future research still needed in the field.

Antithyroglobulin Antibody Variation During Follow-Up Has a Good Prognostic Value for Preoperative Antithyroglobulin Antibody-Positive Differentiated Thyroid Cancer Patients: A Retrospective Study in Southwest China

OBJECTIVE

Antithyroglobulin antibody (TgAb) is a potential tumour marker for detecting differentiated thyroid cancer (DTC) recurrence, but insufficient data have supported its clinical applications. Our study aimed to describe the changing trend of TgAb after surgery and identify the relationship between this trend and clinical outcomes.

PATIENTS AND METHODS

We reviewed the electronic records of 1,686 DTC patients who had undergone total thyroidectomy (TT) and radioactive iodine (¹³¹I) therapy at West China Hospital of Sichuan University from January 2015 to December 2017. Finally, 289 preoperative TgAb-positive DTC patients were included and divided into four subgroups depending on the clinical outcome: Group A (tumour free), Group B (uncertain), Group C (incomplete biochemical response), and Group D (structural disease). The patient demographics, tumour characteristics, operations, pathology reports, and all serological biomarkers were reviewed and compared, and the prognostic efficacy of TgAb was evaluated.

RESULTS

Among all 1,686 patients, 393 (23.65%) were TgAb positive (>40 IU/ml) preoperatively. The TgAb level in Group A decreased significantly after surgery and ¹³¹I therapy and stabilised at a low level after 1-2 years of ¹³¹I therapy. However, in the other three groups, the decrease in TgAb was not significant after treatment. Conversely, TgAb declined slowly and remained stable or increased. The variations in TgAb relative to the preoperative level of Group A were significantly larger than those of Groups B, C, and D at most time points of follow-up (p < 0.001). By receiver operating characteristic (ROC) analyses, the variations of TgAb > -77.9% at 6 months after ¹³¹I therapy (area under the curve (AUC) = 0.862; p < 0.001) and TgAb > -88.6% at 2 years after ¹³¹I therapy (AUC = 0.901; p < 0.001) had good prognostic efficacy in tumour-free survival. When the variation in TgAb > -88.6% at 2 years after ¹³¹I therapy was incorporated as a variable in the American Thyroid Association (ATA) categories, both intermediate- and high-risk patients also had a significantly increased chance of being tumour free (from 75.68% to 93.88% and 42.0% to 82.61%, respectively).

CONCLUSIONS

For preoperative TgAb-positive DTC patients, variations in TgAb > -77.9% at 6 months after ¹³¹I therapy and TgAb > -88.6% at 2 years after ¹³¹I therapy had good prognostic efficacy. Their incorporation as variables in the ATA risk stratification system could more accurately predict disease-free survival.

Molecular Markers Guiding Thyroid Cancer Management

The incidence of thyroid cancer is rapidly increasing, mostly due to the overdiagnosis and overtreatment of differentiated thyroid cancer (TC). The increasing use of potent preclinical models, high throughput molecular technologies, and gene expression microarrays have provided a deeper understanding of molecular characteristics in cancer. Hence, molecular markers have become a potent tool also in TC management to distinguish benign from malignant lesions, predict aggressive biology, prognosis, recurrence, as well as for identification of novel therapeutic targets. In differentiated TC, molecular markers are mainly used as an adjunct to guide management of indeterminate nodules on fine needle aspiration biopsies. In contrast, in advanced thyroid cancer, molecular markers enable targeted treatments of affected signalling pathways. Identification of the driver mutation of targetable kinases in advanced TC can select treatment with mutation targeted tyrosine kinase inhibitors (TKI) to slow growth and reverse adverse effects of the mutations, when traditional treatments fail. This review will outline the molecular landscape and discuss the impact of molecular markers on diagnosis, surveillance and treatment of differentiated, poorly differentiated and anaplastic follicular TC.