High Serum Thyrotropin Concentrations within the Reference Range: A Predictor of Malignancy in Nodular Thyroid Disease

Serum thyroid-stimulating hormone as a diagnostic marker for cancer in atypia of undetermined significance/follicular lesion of undetermined significance nodules

Background

Several studies have assessed the efficacy of thyroid-stimulating hormone (TSH) as a diagnostic marker of thyroid cancer (TC), with inconsistent findings. However, few studies have investigated its role in indeterminate thyroid nodules (TNs), particularly in those with atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS). The objective of this study was to evaluate preoperative TSH levels as a diagnostic marker for cancer in AUS/FLUS nodules.

Methods

A retrospective analysis was conducted on patients who underwent thyroidectomy with a primary cytological diagnosis of AUS/FLUS. The association between preoperative TSH levels and the final anatomopathological diagnosis (benign vs. differentiated TC) was examined.

Results

The analysis included 109 patients. The median TSH level was higher in patients with malignant nodules (2.32 mIU/L) than in those with benign pathology (1.60 mIU/L) (P=0.04). Receiver operating characteristic (ROC) curve analysis revealed that the TSH level was a potential indicator for the coexistence of thyroid malignancy, with a significant area under the curve of 0.61 (P=0.04). The optimal diagnostic cutoff point for TSH levels was ≥3.06 mIU/L.

Conclusions

This study demonstrated that TSH levels are an acceptable and useful marker to rule in rather than rule out TC in AUS/FLUS nodules.

Development and validation of an explainable machine learning model to predict Delphian lymph node metastasis in papillary thyroid cancer: a large cohort study

Background: The occurrence of papillary thyroid cancer (PTC) has risen substantially and tends to exhibit early-stage lymph node metastasis (LNM), increasing the risk of postoperative recurrence and decreasing survival. There is a lack of a machine learning (ML) model to predict delphian LNM (DLNM) in PTC. This investigation seeks to comprehensively assess the significance of standard clinical indicators for DLNM prediction, while constructing a dependable and widely applicable ensemble ML framework to support surgical planning and therapeutic decision-making. Methods: This investigation incorporated 1993 sequential PTC patients who underwent curative surgical procedures from 2020 to 2023. Based on the time to surgery, we divided the cohort into the training cohort (n=1395) and the validation cohort (n=598). The Boruta algorithm was applied to select feature variables, succeeded by the development of an innovative ML structure combining 12 ML techniques across 113 permutations to create a unified prediction model (DLNM index). ROC analysis, calibration curve, Bootstrapping, 10-fold cross validation, restricted cubic spline (RCS) regression, multivariable logistic regression, and subgroup analysis were utilised to evaluate the predictive accuracy and discriminative ability of the DLNM index. Model interpretation and feature impact visualisation were accomplished through the Shapley Additive Explanations (SHAP) methodology. Results: Based on 14 features via the Boruta algorithm selection, we integrated them into 12 ML approaches, yielding 113 permutations, from which we identified the superior algorithm to establish a consensus ML-derived diagnostic model (DLNM index). The DLNM index exhibited excellent diagnostic values with a mean AUC of 0.763 in two cohorts and discriminative ability, serving as an independent risk factor (P < 0.001). It performed better in predicting performance and yielded a larger net benefit than the published model (P < 0.05). Bootstrapping and 10-fold cross validation, and subgroup analysis showed that the DLNM index was generally robust and generalisable. SHAP explains the importance of ranking features (tumour size, right 4 region LN, FT4, TG, and T3) and visualises global and individual risk prediction. RCS regression suggested a nonlinear link between the DLNM index, TG, tumour size, FT3, and DLNM risk. Conclusion: An optimised explainable model (DLNM index) comprising 12 clinical features based on multiple ML algorithms was constructed and validated to provide an economical, readily available, and precise diagnostic instrument for DLNM in PTC, which has potential implications for clinical practice. The SHAP explanation and RCS regression quantify and visualise tumour size and FT4 as the most important variables that increase DLNM risk.

Tumor Size as a Predictive Indicator for Lymph Node Metastasis in Papillary Thyroid Carcinoma: An Inverted L-Shaped Curve Analysis Based on the SEER Database

BACKGROUND

Papillary thyroid carcinoma (PTC) frequently metastasises to lymph nodes, with lymph node metastasis (LNM) occurring with high frequency in small, early-stage tumors. The present study examines the inverse l-shaped relationship between tumor size and the likelihood of LNM in patients diagnosed with PTC.

METHODS

We performed a detailed retrospective cohort analysis of 48,021 cases of papillary thyroid cancer using data from the Epidemiology, and End Results (SEER) database from 1992 to 2019. Our study used various analytical methods, including logistic regression, spline curve fitting, and variable interaction assessment, to clarify the association between tumor size and LNM rates. We rigorously controlled for potential confounders such as patient age, sex, ethnicity, tumor size, extrathyroidal extension (ETE), histopathological characteristics and distant metastases. In addition, we thoroughly investigated and quantitatively assessed the relationship between adjusted tumor size measurements and the likelihood of LNM development.

RESULTS

The median tumor size among the 48,021 patients diagnosed with PTC was 1.3 cm. Among these patients, 12,365 (25.75%) had LNM, with a median tumor size of 1.9 cm in this group. A comparative analysis shows a significant difference in tumor sizes between PTC patients who were LNM-positive and those who were LNM-negative. The relationship between tumor size and the likelihood of LNM exhibits a distinct nonlinear pattern. Specifically, below a diameter threshold of 1.978 cm, the probability of LNM significantly increases with larger tumor sizes (odds ratio [OR] = 2.363, 95% confidence Interval [CI]: 2.214-2.523). Once this threshold is surpassed, the effect of tumor size on LNM incidence levels off (OR = 1.031, 95% CI: 1.003-1.061).

CONCLUSION

The results of this study confirm that tumor size significantly determines the likelihood of LNM in patients with PTC. We found an inverse l-shaped relationship between tumor size and the probability of LNM. As the tumor size increased below 1.978 cm, the likelihood of LNM increased, but not with tumor size above that threshold. These findings provide new insights into the complex relationship between tumor size and LNM in PTC.

Nomogram for predicting the risk of central lymph node metastasis in papillary thyroid microcarcinoma: a combination of sonographic findings and clinical factors

Background

A considerable controversy over performing thyroidectomy and central lymph node dissection in patients with papillary thyroid microcarcinoma (PTMC) remained. However, accurate prediction of central lymph node metastasis (CLNM) is crucial for surgical extent and proper management. The aim of this study was to develop and validate a practical nomogram for predicting CLNM in patients with PTMC.

Methods

A total of 1,029 patients with PTMC who underwent thyroidectomy and central lymph node dissection at Tangdu Hospital (the Second Affiliated Hospital of Air Force Medical University) and Xijing Hospital (the First Affiliated Hospital of Air Force Medical University) were selected. Seven hundred and nine patients were assigned to the training set and 320 patients to the validation set. Data encompassing demographic characteristics, ultrasonography results, and biochemical indicators were obtained. Stepwise backward selection and multiple logistic regression were used to screen the variables and establish the nomogram. Concordance index (C-index), receiver operating characteristic (ROC) curve analysis, and decision curve analysis (DCA) were employed to evaluate the nomogram's distinguishability, accuracy, and clinical utility.

Results

Young age, multifocality, bigger tumor, presence of microcalcification, aspect ratio (height divided by width) ≥1, loss of fatty hilum, high free thyroxine (FT4), and lower anti-thyroid peroxidase antibody (TPOAb) were significantly associated with CLNM. The nomogram showed strong predictive capacity, with a C-index and accuracy of 0.784 and 0.713 in the training set and 0.779 and 0.703 in the external validation set, respectively. DCA indicated that the nomogram demonstrated strong clinical applicability.

Conclusions

We established a reliable, cost-effective, reproducible, and noninvasive nomogram for predicting CLNM in patients with PTMC. This tool could be a valuable guidance for deciding on management in PTMC.

Serum TSH Level as a Simple Efficient Tool to Assess the Risk of Thyroid Malignancy in Euthyroid Patients with Indeterminate Cytology - A Cohort Study

Context

A significant number of fine-needle aspiration cytology (FNAC) for thyroid nodules is reported as indeterminate. Expensive molecular testing can give a clue to the possibility of malignancy in this group. The effectiveness of serum thyroid-stimulating hormone (TSH) levels as a diagnostic tool in euthyroid patients with indeterminate cytology has not been previously studied, especially in the Indian population.

Aims

This study was conducted to evaluate the predictive efficacy of serum TSH in the early diagnosis and treatment of malignancy.

Settings and Design

This is a retrospective cross-sectional study on a cohort of patients who presented to our department with complaints of thyroid swelling and underwent thyroidectomy.

Methods and Material

Euthyroid patients who underwent thyroid surgery for newly diagnosed thyroid nodules with FNAC reported as indeterminate cytology were included in our study. Based on the histopathological report, the patients were divided into two groups and into quartiles based on TSH values.

Statistical Analysis Used

The mean difference in the numerical variables between groups was compared using the independent two-sample 't' test for parametric data and Mann-Whitney 'u' test for non-parametric data. A logistic regression analysis was done with age, sex, TSH level and nodule size as dependant variables and malignancy as the independent variable.

Results

There were 211 patients in group A and 93 in group B. Patients with malignancy confirmed on final histopathology showed higher serum TSH levels compared to benign nodules (2.93 ± 1.067 vs 1.73 ± 1.051, P = <0.001). The mean TSH levels of all types of malignant nodules correlated with our test model (>2.185 mIU/L).

Conclusions

Serum TSH above 2.185 mIU/mL is a good predictor of malignancy in indeterminate nodules. It is an inexpensive, safe and reliable diagnostic screening test for the risk of malignancy in an indeterminate nodule.

Fish and the Thyroid: A Janus Bifrons Relationship Caused by Pollutants and the Omega-3 Polyunsaturated Fatty Acids

Benefits of the omega-3 polyunsaturated fatty acids (PUFA) on a number of clinical disorders, including autoimmune diseases, are widely reported in the literature. One major dietary source of PUFA are fish, particularly the small oily fish, like anchovy, sardine, mackerel and others. Unfortunately, fish (particularly the large, top-predator fish like swordfish) are also a source of pollutants, including the heavy metals. One relevant heavy metal is mercury, a known environmental trigger of autoimmunity that is measurable inside the thyroid. There are a number of interactions between the omega-3 PUFA and thyroid hormones, even at the level of the thyroid hormone transport proteins. Concerning the mechanisms behind the protection from/amelioration of autoimmune diseases, including thyroiditis, that are caused by the omega-3 PUFA, one can be the decreased production of chemokines, a decrease that was reported in the literature for other nutraceuticals. Recent studies point also to the involvement of resolvins. The intracellular increase in resolvins is associated with the tissue protection from inflammation that was observed in experimental animals after coadministration of omega-3 PUFA and thyroid hormone. After having presented data on fish consumption at the beginning, we conclude our review by presenting data on the market of the dietary supplements/nutraceuticals. The global omega-3 products market was valued at USD 2.10 billion in 2020, and was projected to go up at a compound annual growth rate of 7.8% from 2020 to 2028. Among supplements, fish oils, which are derived mainly from anchovies, are considered the best and generally safest source of omega-3. Taking into account (i) the anti-autoimmunity and anti-cancer properties of the omega-3 PUFA, (ii) the increasing incidence of both autoimmune thyroiditis and thyroid cancer worldwide, (iii) the predisposing role for thyroid cancer exerted by autoimmune thyroiditis, and (iv) the risk for developing metabolic and cardiovascular disorders conferred by both elevated/trendwise elevated serum TSH levels and thyroid autoimmunity, then there is enough rationale for the omega-3 PUFA as measures to contrast the appearance and/or duration of Hashimoto's thyroiditis as well as to correct the slightly elevated serum TSH levels of subclinical hypothyroidism.

Serum TSH as a predictor of malignancy in indeterminate thyroid nodules

INTRODUCTION

Thyroid nodules are lesions that are radiologically distinct from the thyroid parenchyma. Cervical ultrasound diagnoses 19-67% of nodules and is crucial in identifying those that lack cytological characterisation. Approximately 25% of biopsies reveal an indeterminate cytological result (Bethesda III), in which the risk of malignancy is variable (5-15%). The clinical importance of the diagnostic strategy used for thyroid nodules results from the need to exclude malignancy. The aim of this study was to evaluate the usefulness of serum thyroid-stimulating hormone (TSH) levels as a predictor of malignancy in cytologically indeterminate thyroid nodules.

METHODS

Our retrospective study included 40 patients with cytologically indeterminate thyroid nodules seen in our hospital between January 2013 and December 2017. Clinical parameters were reviewed, including age, gender, serum TSH levels, family history of thyroid carcinoma, radiation exposure and some sonographic features of the nodules. Statistical analysis was performed using SPSS. Statistical significance was defined as p<0.05.

RESULTS

Female gender was predominant (85%) and the mean (SD) age was 53.3 (15) years. Thyroid carcinoma was confirmed in 28% of patients. Median TSH levels were higher in patients with malignant (2.73µIU/ml) compared with benign (1.56µIU/ml) nodules (p<0.05). We demonstrated an increased risk of malignancy in patients with TSH levels of 2.68µIU/ml or above (p<0.05).

CONCLUSION

Higher serum TSH levels are associated with an increased risk of thyroid carcinoma in cytologically indeterminate nodules. TSH can become a fundamental diagnostic tool in stratifying the risk of malignancy and assist in diagnostic and therapeutic approaches to these nodules.

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.

Higher TSH Is Not Associated With Thyroid Cancer Risk in the Presence of Thyroid Autoimmunity

BACKGROUND

Higher-but-within-normal thyrotropin (thyroid-stimulating hormone, TSH) is associated with higher risk for differentiated thyroid cancer (DTC) in surgical series. Our recent clinical observations suggest that this is not the case in the presence of autoimmune thyroid disease (AITD). We designed the present study to clarify this controversy.

METHODS

We analyzed our prospectively collected database of patients referred for thyroid surgery at 2 tertiary care referral centers in Greece and the United States. We collected data for preoperative TSH, postoperative pathology, and thyroid peroxidase (TPO) antibodies titers. Subjects were subdivided into 2 groups, those with AITD (i.e., lymphocytic thyroiditis) and non-AITD. We excluded subjects with Graves disease, abnormal TSH (< 0.40 or > 4.50 mIU/mL), or recent use of levothyroxine. We compared the serum TSH among different groups using the Mann-Whitney test.

RESULTS

A total of 3973 subjects were screened; 1357 met exclusion criteria. After all exclusions, data from 1731 non-AITD subjects and 329 AITD subjects were included in the analysis. AITD subjects had higher TSH than non-AITD subjects (2.09 vs 1.48; P < 0.0001). TSH values were higher in DTC compared with benign histology only in non-AITD subjects (1.65 vs 1.40; P < 0.0001). Progressively higher TSH was associated with higher incidence of DTC only in non-AITD subjects (P < 0.0001). In AITD subjects, TSH was similar between groups with or without DTC (2.02 vs 2.14; P = 0.21).

CONCLUSIONS

TSH concentrations are not associated with the risk of developing DTC in the presence of thyroid autoimmunity, even though this seems to be the case for all other patients.

Could Serum TSH Levels Predict Malignancy in Euthyroid Patients Affected by Thyroid Nodules with Indeterminate Cytology?

BACKGROUND

Serum TSH levels in the upper-normal range were reported to be associated with increased risk of thyroid malignancy. However, measurement of TSH levels is currently not recommended for assessing the risk of malignancy in patients with newly diagnosed thyroid nodules.

OBJECTIVE

To evaluate a possible relationship between the serum levels of TSH and the histological outcome of patients undergoing thyroidectomy for thyroid nodules with indeterminate cytology.

MATERIALS AND METHODS

We collected the clinical data of all patients who had performed ultrasound-guided FNA of thyroid nodules with cytological diagnosis of indeterminate lesions (TIR3A and TIR3B) and serum TSH levels within the normal range. All patients had been submitted to thyroid surgery (hemi or thyroidectomy, as appropriate), and histological diagnosis had been performed.

RESULTS

A histological diagnosis of thyroid malignancy was rendered in 74/378 (19.6%) nodules. Patients with histologically proven thyroid malignancy were characterized by higher serum levels of TSH as compared to patients with histologically proven benign nodules (3.03 ± 1.16 vs. 2.37 ± 1.19 mIU/L, p < 0.001). To further analyze the role of serum TSH in predicting thyroid cancer, patients were stratified in 4 groups according to quartiles of TSH concentrations. The prevalence of malignancy was 12.2% for the first quartile and 50.0% for the last quartile. ROC curve analysis identified that a serum TSH level of ≥2.7 mIU/L predicted thyroid malignancy with a sensitivity of 61% and a specificity of 65%.

CONCLUSIONS

TSH levels in the upper-normal range are associated with an increased risk of thyroid malignancy in patients affected by thyroid nodules with indeterminate cytology at FNA. The measurement of serum TSH levels represents an easily performed additional tool for decision-making in patients with indeterminate cytological findings.