Preoperative thyrotropin serum concentrations gradually increase from benign thyroid nodules to papillary thyroid microcarcinomas then to papillary thyroid cancers of larger size

The Relationship between Thyrotropin Serum Concentrations and Thyroid Carcinoma

Thyroid Stimulating Hormone (TSH) is a hormone secreted by the pituitary gland and plays a role in regulating the production and secretion of thyroid hormones by the thyroid gland. This precise feedback loop is essential for maintaining a harmonious balance of thyroid hormones in the body, which are vital for numerous physiological processes. Consequently, TSH serves as a significant marker in assessing thyroid function, and deviations from normal TSH levels may indicate the presence of a thyroid disorder. Thyroid cancer (TC) is the malignant tumor within the endocrine system. In recent years, numerous experts have dedicated their efforts to discovering efficacious biomarkers for TC. These biomarkers aim to improve the accurate identification of tumors with a poor prognosis, as well as facilitate active monitoring of tumors with a more favorable prognosis. The role of TSH in the thyroid gland underscores its potential influence on the occurrence and progression of TC, which has garnered attention in the scientific community. However, due to the limited scope of clinical research and the dearth of high-quality foundational studies, the precise impact of TSH on TC remains unclear. Consequently, we present a comprehensive review of this subject, aiming to offer a valuable reference for future research endeavors.

Association between thyroid stimulating hormone levels and papillary thyroid cancer risk: A meta-analysis

High thyroid stimulating hormone (TSH) levels may stimulate papillary thyroid cancer (PTC) cell proliferation; however, the relationship between TSH levels and PTC risk remains controversial. We aim to ascertain the association through a meta-analysis. Literature searches were conducted in PubMed, Embase, and Web of Science databases. After literature screening, the methodological quality was assessed using the Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality methods. Cochran's Q and I 2 tests were used to evaluate heterogeneity in the meta-analysis. Egger's test was applied to assess publication bias. A total of 12 eligible studies were included in this meta-analysis; all were of moderate and high methodological quality. The pooled results suggested that increased TSH levels were significantly associated with PTC risk; however, the included studies were significantly heterogeneous. Stratification analysis indicated that the heterogeneity might be from the area or type of control. Although significant publication bias existed among the studies, the trim-and-fill method and sensitivity analysis revealed that the combined results were stable and robust. TSH levels are significantly associated with the PTC risk; however, more high-quality studies in large sample sizes are recommended to verify the extrapolation of these findings.

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.

The associations between thyroid-related hormones and the risk of thyroid cancer: An overall and dose-response meta-analysis

Objective

Thyroid cancer (TC) is one of the most common malignant tumours of the endocrine system. Thyroid-stimulating hormone (TSH) is known as being a risk factor for TC, but other thyroid-related hormones are inconsistently associated with TC. The purpose of this study was to comprehensively evaluate the relationships between thyroid-related hormones and the risk of TC.

Methods

This study utilized searches of PubMed, Embase, Web of Science and Cochrane library up to the date of March 31st, 2022. Additionally, we performed a systematic review of related original studies combining overall and dose-response meta-analyses.

Results

A total of 30, 5 and 7 articles were included in the meta-analyses of TSH, Free triiodothyronine (FT3), free thyroxine (FT4) and TC risk with 58437, 6813 and 7118 participants respectively. An increased risk of TC was associated with high TSH exposure (OR=1.28, 95% CI: 1.19-1.37, P < 0.001) in the overall meta-analysis. For every 1 mU/L increase in TSH, the risk of TC increased by 16%. However, in those studies that used healthy subjects as controls, the association was not statistically significant(P=0.62). Additionally, high serum FT3 demonstrated a reduced risk of TC, with a combined OR of 0.86 in the fixed-effect model (95% CI: 0.81-0.90, P < 0.001). In addition, a statistically significant increase in TC risk was found when FT4 concentrations reached a certain threshold (approximately 2.2 ng/dL) in the dose-response meta-analysis.

Conclusions

Significant associations between thyroid-related hormones and the risk of TC were found in this study. Further research is needed to understand the underlying mechanisms.

Assessment of Preoperative TSH Serum Level and Thyroid Cancer Occurrence in Patients with AUS/FLUS Thyroid Nodule Diagnosis

Thyroid-stimulating hormone (TSH) is a growth factor associated with the initiation and progression of well-differentiated thyroid cancer (WDTC). Atypia of undetermined significance and follicular lesion of undetermined significance (AUS/FLUS) are the most uncertain cytological diagnoses of thyroid nodules. The aim of the study was to determine the association of histopathological diagnosis with preoperative serum TSH levels in patients with AUS/FLUS thyroid nodule diagnosis. Among 5028 individuals with thyroid nodules, 342 (6.8%) with AUS/FLUS diagnoses were analyzed. The frequency of all histopathology diagnoses was assessed for associations with preoperative serum TSH levels. The median TSH concentration was significantly higher in patients with AUS/FLUS diagnosis and histopathology of WDTC than in patients with the same cytology result and histopathology of a benign tumor (p < 0.0001). The diagnostic potential of serum TSH level was determined to evaluate risk of malignancy in patients with thyroid nodules classified into the Bethesda III category. ROC analysis showed the TSH concentration at a cutoff point of 2.5 mIU/L to be an acceptable prognostic factor for WDTC. For this optimal cutoff point, the AUC was 0.877, the sensitivity was 0.830, and the specificity was 0.902. Preoperative serum TSH levels in patients with AUS/FLUS thyroid tumor diagnosis should be taken into consideration in the decision-making process and clinical management.

Pattern analysis for prognosis of differentiated thyroid cancer according to preoperative serum thyrotropin levels

Serum thyrotropin (TSH) level after thyroid surgery affects the prognosis of differentiated thyroid cancer (DTC). However, the effects of preoperative serum TSH levels on the prognosis of DTC remain contradictory. In this study, to better understand the relationship between preoperative TSH levels and the prognosis of DTC, we performed pattern analysis of prognostic factors of DTC according to preoperative serum TSH levels. We retrospectively reviewed the clinical records of patients who were diagnosed and treated for DTC at the Samsung Medical Center, between 1994 and 2016. We reviewed preoperative serum TSH levels and performed a pattern analysis with prognostic risk factors for DTC. For pattern analysis, TSH was divided into 10 groups of equal fractions (TSH decile). We found a linear association between preoperative TSH levels and extra-thyroidal extension and lymph node metastasis. However, primary tumor size and initial distant metastasis showed a bimodal peak, which was similar to the pattern of overall and disease-specific death. We found that preoperative TSH range which showed the lowest mortality rate was about 0.8 to 1.59 mIU/L, which are slightly lower normal TSH levels. Although there was no linear trend, the primary tumor size, initial distant metastasis, and mortality of DTC were closely related with preoperative TSH decile and they showed a bimodal pattern. The results obtained in this study provide additional information for understanding the association between preoperative TSH levels and DTC prognosis.

Association between preoperative serum TSH and tumor status in patients with papillary thyroid microcarcinoma

Thyroid-stimulating hormone (TSH) is a growth factor affecting the initiation or progression of papillary thyroid cancer (PTC). However, the relationship between preoperative serum TSH and papillary thyroid microcarcinoma (PTMC) remains controversial. To investigate the relationship between preoperative serum TSH and tumor status of PTMC, a multicentered retrospective study was performed from January 2014 to December 2016. The cohort of this study consisted of 1997 patients who underwent thyroid surgery. Serum TSH concentrations were measured and PTMC was diagnosed based on the post-operation pathological report. Results showed that the preoperative serum TSH concentration was not related to age and gender but was positively associated with tumor size. Furthermore, higher TSH level was associated with extra-thyroidal extension and lymph node metastasis (LNM). These results indicated that TSH might not be involved in the development of PTMC but may be associated with PTMC progression. Preoperative serum TSH concentration should be considered as risk predictor for tumor progression in patients with PTMC.

The Effect of ThyroidߚStimulating Hormone on Stage of Differentiated Thyroid Carcinoma

Introduction

Thyroid cancer is the most common endocrine malignancy, and it has the fastest increase rate in incidence in both sexes, with a yearly increase of 3% over the last decade. Thyroid‐stimulating hormone (TSH) is the main driver for the thyroid gland to produce thyroid hormone. The main purpose of this study was to assess the relationship between serum TSH level and the stage of malignancy in patients with differentiated thyroid cancer.

Methods

This cross‐sectional study was performed on 77 patients with thyroid cancer. The demographic characteristics, TSH level and stage of malignancy were recorded for all patients in the data collection form. The data analysis was conducted by descriptive statistics using SPSS 20.0 software.

Results

The results show a significant relationship (p‐value = .025) between the malignancy stage and serum TSH level. The mean TSH level in patients of stage 3 (5.70 ± 2.03) was significantly higher than patients in stage 2 (2.58 ± 0.52) and stage 1 (2.33 ± 0.28). No significant relationship was observed between the age of patients and serum TSH level. Although the mean serum TSH level in men (3.61 ± 0.98) was higher than in women (2.52 ± 0.25), the difference was not statistically significant.

Conclusions

According to the results of this study, serum TSH level can be considered as a predictor of the stage of differentiated thyroid cancer. Therefore, it can be used to predict the likelihood of cancer and improve the outcome and extent of thyroidectomy in patients with thyroid cancer.

Thyroid‐stimulating hormone (TSH) is the main driver for the thyroid gland to produce thyroid hormone. The main purpose of this study is to assess the relationship between serum TSH level and the stage of malignancy in patients with differentiated thyroid cancer.

Risk Stratification of Thyroid Nodules with Bethesda III Category: The Experience of a Territorial Healthcare Hospital

Background The Bethesda System for Reporting Thyroid Cytolopathology (TBSRTC) is the standardized category-based reporting system for thyroid nodule (TN) aspirations; however, atypia of undetermined significance/follicular lesion of undetermined significance (Bethesda category III, AUS/FLUS) is the most controversial category. The aim of this study was to identify the degree of malignancy risk and the related risk factors in the surgical pathology of the Bethesda Category III thyroid nodules.  Methods A total of 4074 patients (15-90 years, 81.5% of females) were subjected to retrospective analysis, and a total of 463 nodules were classified as Bethesda Class III and included in the analysis. Once all the thyroid cytopathological slides and ultrasound (US) reports were reviewed, they were classified according to the Bethesda System for Reporting Thyroid Cytology, the American College of Radiology (ACR) and the Thyroid Imaging Reporting and Data System (TI-RADS). Results Among the 463 Bethesda class III nodules, 167 nodules were surgically excised, showing an overall malignancy of 27.6% (n = 46/167). Patients having thyroid-stimulating hormone (TSH) levels of >4.5 mIU/L (35%), TN <2 cm (34.6%), solid or nearly solid (28.7%), highly hypoechoic (58.3%), longer than wide (50%), lobulated (45.5%), punctate echogenic (48.6%), ACR TI-RAD 5 (55.2%) and falling under the ATA category of high suspicion (50%), displayed a higher risk of malignancy (ROM). The chi-square test revealed a strong association between the echogenicity, echogenic foci, ACR TI-RAD and American Thyroid Association (ATA) category between the malignant and benign nodules. The papillary thyroid carcinoma (PTC) follicular variant (39%) and PTC classical (27%) were identified, in this study population, as the commonest forms of thyroid cancer. Conclusion The nodules with AUS/FLUS cytology malignancy rate are comparable with the earlier estimations of other countries. The ACR TI-RAD displayed more accurate diagnostic performances in predicting malignancy in the Bethesda III nodules. However, to confirm the accuracy of the molecular marker tests in specific cytological scenarios, more extensive studies are required in the future.

Significance of CEP78 and WDR62 gene expressions in differentiated thyroid carcinoma: Possible predictors of lateral lymph node metastasis

OBJECTIVES

This study aimed at investigating the clinical significance of CEP78 and WDR62 in differentiated thyroid carcinoma (DTC). This study also aimed at finding predictors that help in detecting patients with DTC who have high risk for lateral lymph node metastasis (LNM).

METHODS

Quantitative real-time polymerase chain reaction (RT-qPCR) was performed to examine CEP78, and WDR62 mRNA expressions in 40 tissue specimens of DTC, and 40 goiter tissue specimens. Additionally, we reviewed clinical, ultrasound, laboratory, pathological data of patients to analyze the associations between these characteristics and lateral LNM.

RESULTS

Our results demonstrated that relative CEP78 mRNA levels were significantly decreased in thyroid cancer tissues than goiter tissues (P = 0.002). ROC curve analysis confirmed the diagnostic value of CEP78 mRNA expression, providing an AUC equals to 0.698 (95% confidence intervals (CI), 0.583-0.813; P = 0.002). The relative WDR62 mRNA expression was not statistically different in DTC tissues and goiter tissues (P = 0.686). Furthermore, the DTC patients had been included to examine risk factors for lateral LNM. In multivariate analysis, the significant factors for predicting lateral LNM were low CEP78 mRNA expression (cut off value ≤0.54; P = 0.03; OR = 19.62; 95% CI, 1.3-296.23), central LNM (P = 0.011; OR = 33.6; 95% CI, 2.24-503.6) and calcifications (P = 0.023; OR = 27.187; 95% CI, 1.57-469.5).

CONCLUSIONS

CEP78 can be used as a promising molecular biomarker for differentiation between DTC and goiter tissues, in addition it might serve as a predictor of lateral LNM in DTC along with central LNM and calcifications. Unlike CEP78, WDR62 mRNA expression was not statistically different in DTC and goiter.

Fasting serum glucose, thyroid-stimulating hormone, and thyroid hormones and risk of papillary thyroid cancer: A case-control study

BACKGROUND

This study was to investigate the association of fasting serum glucose (FSG), thyroid-stimulating hormone (TSH), and thyroid hormones with papillary thyroid cancer (PTC).

METHODS

A total of 649 participants were included in this case-control study. The associations of FSG, TSH, free triiodothyronine (FT3) and free thyroxine (FT4) with PTC were estimated using an unconditional logistic regression.

RESULTS

Compared with the lowest quintile of TSH levels, odds ratios (ORs) and 95% confidence intervals (CIs) for association between PTC risk and highest quintile of TSH levels were 1.67 (95% CI, 0.99-2.83). However, this risk correlation was more significant in PTC cases with ≤1.0 cm tumor size (adjusted OR, 1.95; 95% CI, 1.08-3.54; adjusted P-trend, 0.05). The PTC risk was also inversely associated with the serum FT3 level in all participants (adjusted P-trend, 0.001), but positively associated with the serum FT4 (adjusted P-trend, 0.001) and FSG (adjusted P-trend, 0.01) levels. Among the participants without diabetes, the individuals with high FSG levels and abnormal TSH concentration had an increased PTC risk (adjusted OR, 3.38; 95% CI, 1.78-6.42).

CONCLUSION

The current study provides evidence for the association of FSG, TSH, and thyroid hormones (FT3 and FT4) with PTC risk. However, larger relative studies are needed.

Human relevance of follicular thyroid tumors in rodents caused by non-genotoxic substances

Chronic stimulation of the thyroid gland of rodents by TSH leads to thyroid follicular hyperplasia and subsequently to thyroid follicular adenomas and carcinomas. However, the interpretations of rodent thyroid tumors are contradictory. The U.S. Food and Drug Administration (FDA) concluded that findings with drugs that lead to increased levels of thyroid-stimulating hormone (TSH) in rats are not relevant to humans, whereas the U.S. Environmental Protection Agency (US EPA) concluded that chemicals that produce rodent thyroid tumors may pose a carcinogenic hazard for humans although the thyroid of rodents appears to be more sensitive to a carcinogenic stimulus than that of humans. Meanwhile, based on the CLP Criteria of the European Chemicals Agency (ECHA), rodent thyroid tumors caused by the induction of uridine-diphosphate-glucuronosyl transferases (UDGT) were assessed as not relevant to humans. To clarify these discrepant positions, the function and regulation of the thyroid gland are described and the types of thyroid tumors and the causes of their development in humans and animals are examined. Based on these data and the evidence that so far, except radiation, no chemical is known to increase the incidence of thyroid tumors in humans, it is concluded that rodent thyroid tumors resulting from continuous stimulation of the thyroid gland by increased TSH levels are not relevant to humans. Consequently, compounds that induce such tumors do not warrant classification as carcinogenic.

Thyroid Nodule Management: Thyroid-Stimulating Hormone, Ultrasound, and Cytological Classification System for Predicting Malignancy

Background/objectives:

Thyroid nodule (TN) is a common thyroid disorder globally, and the incidence has been increasing in recent decades. The objective of this study was to determine the contribution of thyroid-stimulating hormone (TSH), ultrasound (US), and cytological classification system for predicting malignancy among the surgically excised nodules.

Design and methods:

A retrospective analysis was performed between January 2012 and December 2014, using data drawn from 1188 patients (15-90 years), who had 1433 TN and fine-needle aspiration in Prince Sultan Military Medical City, Saudi Arabia. After reviewing all the thyroid cytopathological slides and US reports, classification was done based on the Bethesda System for Reporting Thyroid Cytology and the Thyroid Imaging Reporting and Data System (TI-RADS).

Results:

A total of 1188 patients’ medical records were reviewed for this study, among them 311 patients had undergone surgical intervention (253 patients had single nodule and 58 had 2 nodules), with a total of 369 nodules. However, as 54 nodules on the US were either unavailable or unclear, the 315 remaining nodules were analyzed, revealing 30.2% (n = 95) malignancy overall. Patients with TSH values of >4.5 mIU/L (38.2%), TN <1 cm (48.8%), TI-RADS category 5 (75.6%), and Bethesda category VI (88.9%) revealed a higher percentage of malignancy. From the univariate analysis using the χ² test, significant relationship between the TSH, nodule size, TI-RADS, and the Bethesda category between the malignant and benign nodules emerged. The regression analysis showed that patients with a TSH value of 0.5 to 4.5 mIU/L (odds ratio [OR]: 2.96), TSH >4.5 mIU/L (OR: 6.54) had higher risk for malignancy than those with a TSH value of ≤0.4 mIU/L. Thyroid nodules with sizes of 1 to 1.9 cm (OR: 1.12), 2 to 2.9 cm (OR: 0.74), 3-3.9 cm (OR: 1.21), and ≥4 cm (OR: 0.52) were found to have no association with the risk of malignancy. Compared with TI-RADS 2 patients, those with categories 4B (OR: 1.35) and 5 (OR: 2.3) were found to be at higher risk of malignancy. Similarly, Bethesda IV (OR: 2.72), V (OR: 8.47), and VI (OR: 20; P < .02) category patients had a higher risk for malignancy than those in Bethesda class I. Among the study population, the papillary thyroid carcinoma was the most common type of thyroid cancer (86, 90.5%) followed by 7.4% (n = 7) of follicular thyroid carcinoma, 1.05% (n = 1) of anaplastic carcinoma, and 1.05% (n = 1) of medullary thyroid carcinoma.

Conclusions:

A predictive model for risk of malignancy using a combining characteristic of the TSH, US, and cytological classification systems could assist the clinicians in minimizing exposing the patients with TNs to nonessential invasive procedures.

Association between preoperative thyrotrophin and clinicopathological and aggressive features of papillary thyroid cancer

PURPOSE

We aimed to investigate the relation between preoperative serum thyrotrophin (TSH) and clinicopathological features in patients with papillary thyroid carcinoma (PTC) and microcarcinoma (PTMC).

METHODS

Patients who underwent thyroidectomy and diagnosed to have benign nodular disease or PTC/PTMC in our clinic were evaluated retrospectively. Patients with a previous history of thyroid surgery, patients using antithyroid medications or thyroid hormone and patients with tumors known to be unresponsive to TSH were excluded.

RESULTS

Data of 1632 patients were analyzed. Histopathological diagnosis was benign in 969 (59.4%) and malignant in 663 (40.6%) patients. Preoperative median serum TSH was significantly higher in malignant compared to benign group (1.41 IU/dL vs. 0.98 IU/dL, p < 0.001). Malignancy risk increased gradually as going from hyperthyroidism to euthyroidism and hypothyroidism (20, 40.6, and 59.1%, respectively, p < 0.05). Serum TSH was lowest in benign nodular disease, higher in PTMC and highest in PTC (p < 0.001). This was also true when patients with positive antithyroid peroxidase/antithyroglobulin and with lymphocytic thyroiditis were excluded from the analysis (p < 0.001). Serum TSH was higher in patients with bilateral tumor, capsular invasion and lymph node metastasis (LNM) compared to patients with unilateral tumor, without capsule invasion and without LNM, respectively (p = 0.036, p = 0.002, and p = 0.001, respectively). Patients with aggressive variant PTC had higher serum TSH than nonaggressive ones (p < 0.05).

CONCLUSION

Preoperative serum TSH is associated with PTMC, PTC and LNM. Serum TSH seems to be related with thyroid cancer regardless of autoimmunity. With the present study, for the first time, we showed an association between serum TSH and aggressive variants of PTC.

An overall and dose-response meta-analysis for thyrotropin and thyroid cancer risk by histological type

Thyrotropin (TSH) is thought as a risk factor for thyroid cancer. However, the effect of serum TSH might depend on histological types of thyroid cancer. We searched for related studies including serum TSH as an exposure and thyroid cancer as a result in PUBMED, EMBASE and Chinese National Knowledge Infrastructure up to April 21, 2016. This meta-analysis included 22 articles with 53,538 participants. When comparing all histological thyroid cancer, the pooled odds ratios of thyroid cancer in patients with nodules was found to increase significantly with higher serum TSH concentrations for differentiated thyroid carcinoma (1.88 vs .1.48, P = 0.0000) and papillary thyroid carcinoma (2.08 vs. 1.48, P = 0.0006). Each 1 mU/L increase of serum TSH was associated with 14% greater risk of thyroid cancer for all histological thyroid cancer, 16% for differentiated thyroid carcinoma and 22% for papillary thyroid carcinoma. In addition, high serum TSH was associated with a reduced risk for follicular thyroid carcinoma (OR = 0.73, 95% CI: 0.52, 1.02). This meta-analysis suggested high serum TSH concentration is risky for papillary thyroid carcinoma but not for follicular thyroid carcinoma.

Thyroid functional parameters and correlative autoantibodies as prognostic factors for differentiated thyroid cancers

To evaluate the effect of preoperative thyroid functional parameters and thyroid autoantibodies on aggressive clinicopathologic features and lymph node metastasis (LNM) of differentiated thyroid cancer patients. Four hundred twenty consecutive patients with initial surgery were enrolled from July 2010 to July 2015. The associations between aggressive clinicopathologic and LNM factors and thyroid functional & autoantibodies parameters were analyzed. Higher levels of TSH, TGAb or TMAb were found in patients with tumor size≥1 cm (all P<0.05), especially when TSH≥2.5 ulU/ml (P=0.03) and TGAb≥1 (P=0.01). Higher levels of TSH and TGAb and lower levels of T3 and T4 were found in patients with capsular invasion (all P<0.05), particularly when TSH≥2.5ulU/ml (P=0.03) and TGAb≥1 (P=0.005). The patients with multifocality had higher TAbs level (TAbs>1). Higher level of TSH was also found in patients with central LNM (P=0.001) and lateral LNM (P=0.002), especially with TSH≥2.5ulU/ml (P=0.003 and P=0.03). TGAb level was also found higher in patients with central LNM (P=0.02) and lateral LNM (P=0.01), especially with TGAb≥1 (P<0.05 and P=0.01). Higher level of TMAb was found in patients with lateral LNM (P<0.05). Moreover, multivariable analysis revealed that only TGAb was an independently predictive factor for primary tumor size≥1cm (P=0.01); and TSH level (P=0.01) and TGAb≥1 (P<0.05) were associated independently with central LNM. Thus, TSH level and TGAb≥1 were significantly independent predictors for central LNM, and might help make the decision of central neck dissection.

Thyroid-Stimulating Hormone, Thyroid Hormones, and Risk of Papillary Thyroid Cancer: A Nested Case-Control Study

Background: The effects of thyroid-stimulating hormone (TSH) and thyroid hormones on the development of human papillary thyroid cancer (PTC) remain poorly understood.Methods: The study population consisted of 741 (341 women, 400 men) histologically confirmed PTC cases and 741 matched controls with prediagnostic serum samples stored in the Department of Defense Serum Repository. Concentrations of TSH, total T3, total T4, and free T4 were measured in serum samples. Conditional logistic regression models were used to calculate ORs and 95% confidence intervals (CI).Results: The median time between blood draw and PTC diagnosis was 1,454 days. Compared with the middle tertile of TSH levels within the normal range, serum TSH levels below the normal range were associated with an elevated risk of PTC among women (OR, 3.74; 95% CI, 1.53-9.19) but not men. TSH levels above the normal range were associated with an increased risk of PTC among men (OR, 1.96; 95% CI, 1.04-3.66) but not women. The risk of PTC decreased with increasing TSH levels within the normal range among both men and women (P_trend = 0.0005 and 0.041, respectively).Conclusions: We found a significantly increased risk of PTC associated with TSH levels below the normal range among women and with TSH levels above the normal range among men. An inverse association between PTC and TSH levels within the normal range was observed among both men and women.Impact: These results could have significant clinical implications for physicians who are managing patients with abnormal thyroid functions and those with thyroidectomy. Cancer Epidemiol Biomarkers Prev; 26(8); 1209-18. ©2017 AACR.

WOMEN IN CANCER THEMATIC REVIEW: Thyroid-stimulating hormone in thyroid cancer: does it matter?

Differentiated thyroid cancer is the most common endocrine malignancy and the incidence is increasing rapidly worldwide. Appropriate diagnosis and post-treatment monitoring of patients with thyroid tumours are critical. Fine needle aspiration cytology remains the gold standard for diagnosing thyroid cancer, and although there have been significant refinements to this technique, diagnostic surgery is often required for patients suspected to have malignancy. Serum thyroid-stimulating hormone (TSH) is higher in patients with malignant thyroid nodules than in those with benign disease, and TSH is proportionally increased in more aggressive tumours. Importantly, we have shown that the pre-operative serum TSH concentration independently predicts the presence of malignancy in subjects presenting with thyroid nodules. Establishing the use of TSH measurements in algorithms identifying high-risk thyroid nodules in routine clinical practice represents an exciting, cost-efficient and non-invasive approach to optimise thyroid cancer diagnosis. Binding of TSH to receptors on thyrocytes stimulates a number of growth promoting pathways both in normal and malignant thyroid cells, and TSH suppression with high doses of levothyroxine is routinely used after thyroidectomy to prevent cancer recurrence, especially in high-risk tumours. This review examines the relationship between serum TSH and thyroid cancer and reflects on the clinical potential of TSH measurements in diagnosis and disease monitoring.

The Effect of Thyroid-Stimulating Hormone on Tumor Size in Differentiated Thyroid Carcinoma

We evaluated the correlation between serum thyroid-stimulating hormone (TSH) levels and tumor size and other invasiveness parameters of tumor in patients with differentiated thyroid carcinoma (DTC). Several clinical studies have reported that TSH may also have a role as a regulator of the development and function of the thyroid gland. It is currently not clear whether TSH is involved in the existence of thyroid cancer or progression of thyroid cancer or both. Patients with DTC who underwent thyroid surgery between 2003 and 2008 were included this study. Preoperative serum T3, T4, and TSH levels were compared with the size and invasiveness of cancer, retrospectively. DTC was observed in 110 patients over the 5-year period. Seventy-seven (70 %) of them were euthyroid and classified as the "normal-TSH group" (NTG), and 33 (30 %) have an overt or subclinical hyperthyroidism, classified as the "low-TSH group" (LTG). The mean tumor diameter in the LTG was found to be 8.91 ± 8.03 mm; however, it was found to be 18.19 ± 16.24 mm in the NTG. There were significantly differences among the groups related to the diameter of tumor (p = 0.001). Microcarcinoma was determined in 36 patients (46.8 %) in the NTG and 23 patients (69.7 %) in the LTG (p = 0.027). Although there were no significant differences, tumor capsule invasion (33.8 vs. 18.2 %, p = 0.099) and lymphovascular invasion (16.9 vs. 6.1 %, p = 0.130) rates were higher in the NTG. These findings suggest that TSH has effects on growing and proliferation of not only normal thyroid cells but also cancer cells in DTC. This study revealed that serum TSH level can be explored as an important factor that affects the size and invasiveness of tumor in DTC.

Thyroid Hormones, Autoantibodies, Ultrasonography, and Clinical Parameters for Predicting Thyroid Cancer

Our objective was to evaluate thyroid nodule malignancy prediction using thyroid function tests, autoantibodies, ultrasonographic imaging, and clinical data. We conducted a retrospective cohort study in 1400 patients with nodular thyroid disease (NTD). The thyroid stimulating hormone (TSH) concentration was significantly higher in patients with differentiated thyroid cancer (DTC) versus benign thyroid nodular disease (BTND) (p = 0.004). The receiver operating characteristic curve of TSH showed an AUC of 0.58 (95% CI 0.53-0.62, p = 0.001), sensitivity of 74%, and specificity of 57% at a cut-off of 1.59 mIU/L. There was an incremental increase in TSH concentration along with the increasing tumor size (p < 0.001). Thyroglobulin antibody (TgAb) concentration was associated with an increased risk of malignancy (p = 0.029), but this association was lost when the effect of TSH was taken into account (p = 0.11). Thyroid ultrasonographic characteristics, including fewer than three nodules, hypoechoic appearance, solid component, poorly defined margin, intranodular or peripheral-intranodular flow, and punctate calcification, can be used to predict the risk of thyroid cancer. In conclusion, our study suggests that preoperative serum TSH concentration, age, and ultrasonographic features can be used to predict the risk of malignancy in patients with NTD.

The Usefulness of Preoperative Thyroid-Stimulating Hormone for Predicting Differentiated Thyroid Microcarcinoma

OBJECTIVE

Thyroid-stimulating hormone (TSH) is a known thyroid growth factor, but the pathogenic role of TSH in thyroid tumorigenesis is controversial. The aim of this study is to examine the relationship between preoperative TSH and differentiated thyroid microcarcinoma (DTMC).

DATA SOURCES

We searched PubMed, EMBASE, Ovid, Web of Science, and the Cochrane Library from their inception to March 2015 and performed a systematic literature review of original studies.

REVIEW METHODS

Published studies that explored the relationship between preoperative TSH and DTMC were included for the review. We calculated odds ratio referring to different TSH concentrations between DTMC and control groups and used random effects model for the meta-analysis.

RESULTS

Nine eligible studies that included 6523 patients were identified. Meta-analysis revealed that DTMC was associated with high TSH concentration (odds ratio = 1.23, 95% confidence interval = 1.03-1.46, P = .001). Metaregression analysis indicated that the disparity of control groups was the possible factor resulting in heterogeneity among the studies.

CONCLUSIONS

The risk of DTMC increases significantly in parallel with TSH concentration. These results support the hypothesis that TSH is involved in tumorgenesis of differentiated thyroid cancer.

The Neutrophil-to-Lymphocyte Ratio Correlates with Age in Patients with Papillary Thyroid Carcinoma

AIM

The aim of this study is to explore the relationship between the neutrophil-to-lymphocyte ratio (NLR) and clinicopathological features in patients with papillary thyroid carcinoma (PTC).

METHODS

We performed an analysis of 843 patients, including 321 patients with PTC, 83 patients with thyroid adenoma and 439 patients with nodular goiter (NG). Thyroglobulin and thyrotropin were measured in each patient. Neutrophils, lymphocytes, and platelets were counted. Statistical analysis was used to correlate the NLR with demographic and histopathologic characteristics of the patients.

RESULT

Age correlated with NLR and lymphocyte number in patients with PTC and NG. In patients aged >45 years, those with PTC had a higher NLR and a lower lymphocyte count than those with NG. Patients with PTC aged <45 years had a higher leukocyte count and a lower NLR than those aged ≥45 years. Patients with clinical stage I/II PTC had a lower NLR and a higher lymphocyte count than patients with stage III/IV.

CONCLUSIONS

Younger patients with PTC had a higher lymphocyte count but a lower NLR than older patients with PTC. The NLR and lymphocyte counts were associated with the clinical stage. Thus, a higher NLR and a lower lymphocyte count may be prognostic for stratifying patients with thyroidal goiters and are risk factors of PTC for older patients.

Coexistence of thyroglobulin antibodies and thyroid peroxidase antibodies correlates with elevated thyroid-stimulating hormone level and advanced tumor stage of papillary thyroid cancer

The correlation between thyroglobulin antibodies (TgAb) or thyroid peroxidase antibodies (TPOAb) and papillary thyroid cancer (PTC) remains controversial. This histological study aimed to explore the correlation between thyroid autoantibodies (TAb), thyroid-stimulating hormone (TSH), and PTC in patients with thyroid nodules (TN). This was a retrospective study. 2,132 non-autoimmune thyroid diseases (AITD) patients who underwent thyroidectomy were subdivided into: TgAb or TPOAb single positive (TgAb+ or TPOAb+) TN group; TgAb and TPOAb double positive or negative (TAb+ or TAb-) TN group. PTC patients showed a higher rate of TAb+ TN (10.24 vs. 4.89 %; P = 0.000) and a higher TSH level (1.83 ± 0.07 vs. 1.39 ± 0.03 mIU/L; P = 0.000) than patients with benign nodules. TAb+ TN patients showed a higher TSH level and PTC frequency than those with TAb- TN (1.91 ± 0.17 vs. 1.47 ± 0.03 mIU/L; P = 0.011) (41.35 vs. 22.08 %; P = 0.000). In PTC, TAb+ TN patients showed a higher TSH level (2.57 ± 0.35 vs. 1.79 ± 0.07 mIU/L; P = 0.032), a greater frequency of lymph node metastasis (52.73 vs. 36.51 %, P = 0.026), and a lower micro-PTC frequency (16.36 vs. 39.51 %; P = 0.001) than TAb- TN patients. PTC was correlated with TgAb+ TN (OR = 1.921, CI 1.431-2.580; P = 0.000), TPOAb+ TN (OR = 1.945, CI 1.195-3.165; P = 0.007), TAb+ TN (OR = 2.393, CI 1.635-3.501; P = 0.000), and serum TSH >1.35 mIU/L (OR = 1.742, CI 1.089-2.786; P = 0.021). Serum positive TgAb or TPOAb is an independent predictor for PTC regardless of AITD. The coexistence of TgAb and TPOAb confers a greater risk for PTC than isolated positive TgAb or TPOAb, and is correlated with elevated TSH level and advanced PTC stage.

Hashimoto's thyroiditis as a risk factor of papillary thyroid cancer may improve cancer prognosis

OBJECTIVE

Hashimoto's thyroiditis (HT) has been associated with an elevated risk of papillary thyroid cancer (PTC). To investigate the possible influence of HT on the prognosis of PTC patients, we assessed the related clinical factors linking these conditions, especially serum thyroid-stimulating hormone (TSH) concentration.

STUDY DESIGN

Case-control study.

SETTING

The First Hospital of China Medical University.

SUBJECTS AND METHODS

The demographic and histological characteristics of 2478 patients who underwent thyroidectomy at our center from 2004 to 2012 were analyzed.

RESULTS

Compared with patients with benign thyroid nodular disease, patients with PTC showed a significantly higher prevalence of HT (18.8% vs 7.2%, P < .001), mean TSH concentrations (2.02 ± 1.76 vs 1.46 ± 1.21 mIU/L, P < .001), and positivity rates for anti-thyroglobulin antibodies (TGAB; 40.0% vs 20.4%, P < .001) and anti-thyroid peroxidase antibodies (24.8% vs 12.5%, P < .001). These differences remained after excluding all HT patients. The TSH concentrations were significantly higher in PTC patients with HT than in those without HT (2.54 ± 2.06 vs 1.90 ± 1.66 mIU/L, P = .001). Patients with PTC and HT were younger, with a female predominance, and had smaller sized tumors with less advanced TNM stage compared with those without HT, indicating a better prognosis. Multivariate analysis showed that HT, higher TSH concentration, male sex, and TGAB positivity were independent risk factors for PTC development.

CONCLUSION

Histologically confirmed HT is associated with a significantly higher risk of PTC, due primarily to the higher serum TSH concentrations resulting from the tendency to hypothyroidism in HT. Autoimmunity is another independent risk factor for PTC but may be associated with a better prognosis.

Risk of malignancy in follicular thyroid neoplasm: predictive value of thyrotropin

The cytological diagnosis of follicular neoplasm is a common finding in fine needle aspiration cytology (FNAC) of thyroid nodules and includes benign disease as well as differentiated thyroid cancer. The aim of the study is to determine if thyrotropin is a predictive factor for a malignant nature of follicular neoplasm.

PATIENTS, METHODS

The records of 119 patients with follicular neoplasm on FNAC, who underwent surgery for final diagnosis, were reviewed retrospectively. The predictive value of serum parameters including thyrotropin, thyroglobulin, and anti-thyroid antibodies, ultrasonographic criteria and clinical variables was evaluated by univariate analysis and logistic regression analysis.

RESULTS, DISCUSSION

Patients with malignant nodules showed a higher thyrotropin concentration compared to patients with benign nodules (median 1.6 mU/l, interquartile range 1.4-3.0 mU/l vs. median 1.2 mU/l, interquartile range 0.8-1.6 mU/l, p < 0.01). ROC-analysis of thyrotropin revealed an optimal cut off value to differentiate benign and malignant nodules of 1.34 mU/l. The incidence of malignancy was 30.3% for a thyrotropin concentration higher than 1.34 mU/l compared to 6.4% for a thyrotropin concentration lower than or equal to 1.34 mU/l. On univariate analysis thyroglobulin higher than 300 ng/ml, positive anti-thyroid antibodies, hypoechogenicity, and ill-defined margins, respectively, were also significantly associated with malignancy. On logistic regression analysis higher thyrotropin concentrations, ill-defined margins, and thyroglobulin higher than 300 ng/ml, respectively, were independent predictive factors for malignancy (OR 20.0, 10.7, and 22.7, respectively).

CONCLUSION

Higher thyrotropin concentrations are predictive for a malignant nature of follicular neoplasm.

Serum TSH and risk of papillary thyroid cancer in nodular thyroid disease

CONTEXT

TSH is the main factor involved in the control of proliferation of thyrocytes. Recently, a strong relationship between serum TSH and risk of thyroid malignancy has been reported.

OBJECTIVES

The aim was to review published papers about the relationship between serum TSH and frequency of differentiated thyroid cancer.

EVIDENCE ACQUISITION

PubMed was used to identify studies focused on the relationship between TSH and differentiated thyroid cancer.

EVIDENCE SYNTHESIS

In patients with nodular thyroid disease, the risk of thyroid malignancy increases with serum TSH, and even within normal ranges, higher TSH values are associated with a higher frequency and more advanced stage of thyroid cancer. The likelihood of papillary thyroid carcinoma is reduced when TSH is lower, as in thyroid autonomy, and increased when TSH is higher, as in thyroid autoimmunity. Treatment with l-thyroxine (LT4), which reduces serum TSH, is associated with significantly lower risk of developing clinically detectable thyroid cancer.

CONCLUSIONS

TSH plays a key role in the development of clinically detectable thyroid cancer, and LT4 treatment reduces the risk of thyroid malignancy in patients with nodular thyroid disease. According to the guidelines of the main scientific societies, LT4 therapy is not currently recommended for the treatment of patients with nodular goiter. Even if the available data are not sufficient to advise LT4 treatment in all patients with nodular goiter with the aim of reducing the risk of papillary thyroid carcinoma, we propose that this indication should be reconsidered, taking into account recent evidence reported in the literature.

Mouse models of follicular and papillary thyroid cancer progression

A significant number of well-differentiated thyroid cancers progress or recur, becoming resistant to current therapeutic options. Mouse models recapitulating the genetic and histological features of advanced thyroid cancer have been an invaluable tool to dissect the mechanisms involved in the progression from indolent, well differentiated tumors to aggressive, poorly differentiated carcinomas, and to identify novel therapeutic targets. In this review, we focus on the lessons learned from models of epithelial cell-derived thyroid cancer showing progression from hyperplastic lesions to locally invasive and metastatic carcinomas.