Relationship Between Urinary Iodine Concentration and the Prevalence of Thyroid Nodules and Subclinical Hypothyroidism.

The aim of the study was to investigate the iodine intake in the resident population in Xi'an and analyze the relationship between iodine nutritional status and the prevalence of subclinical hypothyroidism and thyroid nodules (TNs). A total of 2507 people were enrolled in Xi'an. Venous serum thyroid stimulating hormone (TSH), thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb), urinary iodine concentration (UIC), and thyroid ultrasonography were collected. Patients with abnormal TSH were checked for free thyroxine (FT4) and triiodothyronine (FT3). Adults in Xi'an had median UICs of 220.80 µg/L and 178.56 µg/l, respectively. A sum of 16.78% of people had subclinical hypothyroidism. Both iodine excess and iodine deficit increased the frequency of subclinical hypothyroidism. The lowest was around 15.09% in females with urine iodine levels between 200 and 299 µg/l. With a rate of 10.69%, the lowest prevalence range for males was 100-199 µg/l. In Xi'an, 11.37% of people have TNs. In comparison to other UIC categories, TN occurrences were higher in females (18.5%) and males (12%) when UIC were below 100 µg/l. In conclusion, iodine intake was sufficient in the Xi'an area, while the adults' UIC remains slightly higher than the criteria. Iodine excess or deficiency can lead to an increase in the prevalence of subclinical hypothyroidism. Patients with iodine deficiency are more likely to develop TNs.

Adjusted association between type 2 immunity and low risk thyroid nodules: a retrospective cohort study.

BACKGROUND: Immune responses, especially type 2 immunity, might be related to the prevalence of thyroid nodules, while the key regulators and potential pathways are remaining largely unknown. In addition, the immune status of individuals could be affected by mixed metabolic background. Herein our aim was to investigate the adjusted association between ultrasound-diagnosed low risk thyroid nodules and immune responses, excluding the interference of metabolic effects on immunity. METHODS: We retrospectively enrolled 1764 subjects who underwent a thorough thyroid ultrasound examination. To eliminate the interference of confounders, we used propensity score matching (PSM) to match age, gender, cigarette smoking and alcohol drinking, parameters that are related with metabolic syndrome (MetS). Then the potential effectors of immune responses involved in the laboratorial assays were evaluated. Binary logistic regression analysis was used to assess the independent predictors of thyroid nodules in a multivariate manner. RESULTS: The 1172 subjects were remained after PSM, and differences of demographic background between subjects with and without thyroid nodules were eliminated. Metabolic parameters comprising blood pressure, fasting blood glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein and serum uric acid were shown no significant difference between post-PSM subjects with and without thyroid nodules. Among the biochemistry and hematological parameters, white blood cell count and the positive rate of eosinophil percentage were increased in subjects with thyroid nodules than in those without thyroid nodules. In contrast, the positive rate of basophil percentage was lower in subjects with thyroid nodules than in those without thyroid nodules. In addition, the thyroid function test results showed that subjects with thyroid nodules had higher positive rates of antithyroglobulin antibody (TgAb) and antithyroid peroxidase antibody (TPOAb) than subjects without thyroid nodules. The logistic regression analysis indicated that the positive value of TgAb as well as high level of white blood cell count and BMI could serve as independent risk factors of thyroid nodules. CONCLUSIONS: The type 2 immune responses mediated by increased level of eosinophils, along with positive value of TgAb and TPOAb were associated with the presence of thyroid nodules. In addition, the potential role of basophils in protecting against thyroid nodules and the pathogenesis of immune-metabolic status remains to be elucidated.

Clinical challenges with calcitonin-negative medullary thyroid carcinoma: three case reports and a review of the literature.

Medullary thyroid carcinoma (MTC) is relatively rare, and has the main feature of calcitonin (Ct) secretion. However, a few cases of MTC with negative serum calcitonin have been reported in the literature, so the diagnosis and follow up of Ct-negative MTCs are still a challenge. Here we present three cases of Ct-negative MTCs, illustrating the rarity of the disease and challenges in managing it, together with a review of the literature of 39 MTCs with negative serum Ct.

Preoperative thyroid-stimulating hormone associated risk of differentiated thyroid cancer in patients with thyroid nodules.

In an assessment of risk for differentiated thyroid cancer (DTC) in individuals with human papillary thyroid cancer (PTC) and thyroid nodules a cohort prospective study was undertaken to establish the significance of preoperative thyroid-stimulating hormone (TSH) levels. Confirmed histologically PTC cases in one tertiary care center, and matched healthy individuals were tested for TSH, T3, T4 and T4 free total. The ORs and 95% confidence intervals have been calculated using conditional logistic regression models (CI). The blood TSH levels were related to the higher risk of PTC for men (OR,0,09; 95% Ci, 04-0,21, 95% CI and women) compared with the middle tertile of the TSH levels in the normal range (OR,0,07; 95 percent CI, 0,04-0,1). Over the normal range of TSH levels, an elevated PTC risks were connected amongst women (OR 0,09; 95% CI, 0,04-0,21) but not amongst men (OR,0,07; 95% CI, 0,04-0,1). With an increase in TSH level in the normal range between men and women, the risk for PTC reduced (Ptrend=0.041 and 0.0001). The risk of PTC related to TSH levels has been dramatically elevated above  the normal range for men  and TSH values below the normal range for women.

Changes in thyroid antibody and T lymphocyte subsets after radiofrequency ablation of thyroid nodules in patients with autoimmune thyroiditis.

SETTINGS AND DESIGN: The aim was to study the changes in thyroid antibody and T lymphocyte subsets after radiofrequency ablation (RFA) of thyroid nodules in patients with autoimmune thyroiditis. SUBJECTS AND METHODS: Patients (n = 135) with autoimmune thyroiditis and thyroid nodules were treated by RFA. The indices of thyroid function and thyroid antibody and T lymphocyte subsets were examined preoperation and on the 1st day and the 1st month after ablation. Any complications were recorded. STATISTICAL ANALYSIS: The software SPSS 17.0.0 (version: 2008-8-23) running under Windows 8 was used for statistical analysis. The measurement data were expressed as x ± s, with P < 0.01 indicating a significant difference in the statistical data. RESULTS: Levels of free triiodothyronine, free thyroxine, and thyroid-stimulating hormone were in the normal range before ablation, and no significant changes occurred on the 1st day or in the 1st month after ablation. The change in the percentage of CD8+T cells and the absolute value of B cells were not statistically significant (P > 0.01), and the values were in the normal range. Compared with values recorded preoperation, the value of TG-Ab, TPO-Ab, CD4+/CD8+, the percentage of CD4+T cells, the absolute values of lymphocytes, T cells, CD4+T cells, and CD8+T cells decreased significantly at the 1st day after ablation (P < 0.01) and then recovered to preoperative levels during the first 30 days after ablation (P > 0.01). Within 1 month after ablation, none of the patients had complications such as active bleeding, infection, recurrent laryngeal nerve injury, parathyroid gland injury, skin scald, and so on. CONCLUSIONS: After RFA of thyroid nodules in patients with autoimmune thyroiditis, thyroid function is not affected and no serious complications occurred. TG-Ab and TPO-Ab levels can be significantly decreased, and the distribution of T lymphocyte subsets can be changed in the short term after ablation.

Distinguishing Benign and Malignant Thyroid Nodules and Identifying Lymph Node Metastasis in Papillary Thyroid Cancer by Plasma N-Glycomics.

Background: Biomarkers are needed for patient stratification between benign thyroid nodules (BTN) and thyroid cancer (TC) and identifying metastasis in TC. Though plasma N-glycome profiling has shown potential in the discovery of biomarkers and can provide new insight into the mechanisms involved, little is known about it in TC and BTN. Besides, several studies have indicated associations between abnormal glycosylation and TC. Here, we aimed to explore plasma protein N-glycome of a TC cohort with regard to their applicability to serve as biomarkers. Methods: Plasma protein N-glycomes of TC, BTN, and matched healthy controls (HC) were obtained using a robust quantitative strategy based on MALDI-TOF MS and included linkage-specific sialylation information. Results: Plasma N-glycans were found to differ between BTN, TC, and HC in main glycosylation features, namely complexity, galactosylation, fucosylation, and sialylation. Four altered glycan traits, which were consecutively decreased in BTN and TC, and classification models based on them showed high potential as biomarkers for discrimination between BTN and TC ("moderately accurate" to "accurate"). Additionally, strong associations were found between plasma N-glycans and lymph node metastasis in TC, which added the accuracy of predicting metastasis before surgery to the existing method. Conclusions: We comprehensively evaluated the plasma N-glycomic changes in patients with TC or BTN for the first time. We determined several N-glycan biomarkers, some of them have potential in the differential diagnosis of TC, and the others can help to stratify TC patients to low or high risk of lymph node metastasis. The findings enhanced the understanding of TC.

Evaluation of serum insulin-like growth factor 1 and its significance in thyroid cancer: An observational study.

ABSTRACT: Serum insulin-like growth factor 1 (IGF-1) is elevated in different cancers. However, relationships between serum IGF-1 and thyroid cancer (TC) are scarce. The present study aimed to investigate the clinical significance of serum IGF-1 in TC.Serum was collected from 124 TC patients, 50 patients with benign nodules, and 50 healthy controls. Serum IGF-1 levels were measured and compared. Relationships were investigated between IGF-1 and clinical characteristics. A receiver operating characteristic (ROC) curve was plotted to explore the diagnostic value of IGF-1 in TC.Serum IGF-1 levels were significantly higher in TC than that of healthy controls and benign nodules (P = .003; P < .001). Serum IGF-1 levels were higher in TC patients with advanced stage than early stage (P = .029). Higher serum IGF-1 levels were found in patients with lymph node metastasis present and (tumor size >1 cm) than that of patients without lymph node metastasis (P = .018) and (tumor size ≤1 cm) (P = .031). Serum IGF-1 levels were higher in patients with a solitary nodule than multinodular nodules (P = .043). The serum IGF-1 cutoff value for a TC diagnosis was 216 ng/mL with a sensitivity of 53.2%, a specificity of 74.0%, a positive predictive value (PPV) of 83.5%, and an area under the curve was of 0.71.Serum IGF-1 was significantly correlated with tumor stage, size, and lymph node metastasis. Serum IGF-1 shows great potential as a laboratory marker for TC.

Plasma Cell-Free DNA to Differentiate Malignant from Benign Thyroid Nodules.

BACKGROUND: Molecular testing is increasingly used to identify malignancy in thyroid nodules (especially indeterminate category). Measurement of cell-free DNA (cfDNA) levels from plasma has been useful in diagnosis of cancers of other organs/tissues; herein we analyze cfDNA levels in patients with thyroid nodules to explore the possibility of establishing a cutoff for identification of malignancy. METHODS: Patients underwent ultrasonography (USG) and USG-guided fine needle aspiration as well as surgery, where indicated. Cell-free DNA was extracted from plasma and quantified. In initial analysis (determination of cutoff), cfDNA levels were compared between Bethesda 2 and Bethesda 5 &6 to establish a cutoff value that could differentiate malignant from benign nodules. In the subsequent analysis, the aforementioned cutoff was applied (validation of cutoff) to those with indeterminate nodules to check ability to predict malignancy. RESULTS: Fine needle aspiration (n = 119) yielded patients with Bethesda 2 (n = 69) Bethesda 5 & 6 (n = 13) who underwent histopathological confirmation. Cell-free DNA levels in these 2 groups were 22.85 ±â€…1.27 and 96.20 ±â€…8.31 (ng/mL) respectively. A cfDNA cutoff of 67.9 ng/mL, with area under the curve of 0.992 (95% CI, 0.97-1.0) with 100% sensitivity and 93% specificity was established to identify malignant lesions. Indeterminate group (Bethesda 3 & 4) underwent surgery (malignant n = 24), (benign n = 13), and using the previously identified cutoff for cfDNA, we were able to identify malignant lesions with a sensitivity of 100% and specificity of 92.3%. There was a very strong agreement between cfDNA-based classification with histopathology-based classification of benign and malignant nodules (Cohen's kappa 0.94; P < 0.001). CONCLUSION: Plasma cfDNA estimation could help differentiate malignant from benign thyroid nodules.

Identifying benign and malignant thyroid nodules based on blood serum surface-enhanced Raman spectroscopy.

The aim of this study is to evaluate the feasibility of using blood serum surface-enhanced Raman spectroscopy (SERS) to identify benign and malignant thyroid nodules. Blood serum samples collected from three different groups including healthy volunteers (n = 22), patients with benign nodules (n = 19) and malignant nodules (n = 22) were measured by SERS. The spectral analysis results demonstrate that biomolecules in serum, such as amino acids, adenine and nucleic acid bases, change differently due to the different progression of nodules. By further combining with partial least square analysis and linear discriminant analysis (PLS-LDA) method, diagnostic accuracies of 93.65% and 82.93%, sensitivities of 92.68% and 81.82% and specificities of 95.45% and 84.21% can be achieved for differentiating healthy versus thyroid nodular groups and benign versus malignant groups, respectively. The above results have suggested that the blood serum SERS technique is helpful for precise diagnosis and timely treatment for patients with thyroid nodules.

MiRNA let-7 from TPO(+) Extracellular Vesicles is a Potential Marker for a Differential Diagnosis of Follicular Thyroid Nodules.

BACKGROUND: The current approaches to distinguish follicular adenomas (FA) and follicular thyroid cancer (FTC) at the pre-operative stage have low predictive value. Liquid biopsy-based analysis of circulating extracellular vesicles (EVs) presents a promising diagnostic method. However, the extreme heterogeneity of plasma EV population hampers the development of new diagnostic tests. We hypothesize that the isolation of EVs with thyroid-specific surface molecules followed by miRNA analysis, may have improved diagnostic potency. METHODS: The total population of EVs was isolated from the plasma of patients with FA (n = 30) and FTC (n = 30). Thyroid peroxidase (TPO)-positive EVs were isolated from the total populations using immune-beads. The miRNA from the TPO(+)EVs obtained from the plasma of FA and FTC patients was assayed by RT-PCR. The diagnostic potency of the selected miRNAs was estimated by the receiver operating characteristic (ROC) analysis. RESULTS: TPO(+)EVs can be efficiently isolated by immunobeads. The analysis of Let-7 family members in TPO(+)EVs allows one to distinguish FA and FTC with high accuracy (area under curve defined by ROC = 0.77-0.84). CONCLUSION: The isolation of TPO(+)EVs, followed by RT-qPCR analysis of Let-7 family members, may present a helpful approach to manage follicular nodules in the thyroid gland.

Serum Adiponectin and Progranulin Level in Patients with Benign Thyroid Nodule or Papillary Thyroid Cancer.

BACKGROUND: Obesity is associated with thyroid cancer risk. Adiponectin has insulin-sensitizing and anti-inflammatory effects, while progranulin is associated with inflammation and tumorigenesis. We investigated serum adiponectin and progranulin levels in patients with benign thyroid nodule (benign group) and papillary thyroid cancer (PTC; PTC group). The associations between these levels and the clinicopathological features of PTC were evaluated. METHODS: We included 157 patients who underwent thyroid surgery (17% of benign and 83% of PTC group). Clinicopathological features including size, lymph node metastasis, extrathyroidal extension (ETE), multifocality, American Thyroid Association risk stratification were evaluated. RESULTS: The age was 42.0 years, and 69% were female. Serum adiponectin and progranulin levels were 6.3 µg/mL and 101.5 ng/mL in the benign group and 5.4 µg/mL and 106.1 ng/mL in the PTC group, respectively (P=0.6 and P=0.4, respectively). Serum adiponectin levels showed no significant differences according to clinicopathological features of PTC. The proportions of patients with primary tumor size >1 cm were 3%, 5%, 8%, and 8% according to serum progranulin level quartiles, respectively (P=0.03). The proportions of patients with microscopic/gross ETE were 8%/0%, 9%/1%, 11%/1%, and 11%/2% according to serum progranulin level quartiles, respectively. Median serum progranulin level was significantly higher in patients with PTC >1 cm than in patients with papillary thyroid microcarcinoma (P=0.04, 115.3 ng/mL and 104.7 ng/mL, respectively). CONCLUSION: Serum adiponectin and progranulin levels showed no significant difference between benign and PTC groups. Increased serum progranulin levels were significantly associated with PTC >1 cm and microscopic and gross ETE.

The Role of Vitamin D, Platelet-Derived Growth Factor and Insulin-Like Growth Factor 1 in the Progression of Thyroid Diseases.

BACKGROUND: Thyroid cancer (TC) is a common malignant tumor, however the role of total vitamin D: 25(OH)D, Platelet Derived Growth Factor (PDGF) and Insulin Like Growth Factor 1 (IGF-1) in the development of TC is still unclear. AIM: To assess the roles of 25(OH)D, PDGF and IGF-1 in the progression of thyroid diseases. METHODS: The serum levels of 25(OH)D, PDGF and IGF-1 were assessed in 70 patients with papillary thyroid cancer (PTC), 60 patients with benign thyroid nodules (BN) compared to 60 normal controls (NC) using ELISA technique. RESULTS: There was a significant decrease in the serum level of 25(OH)D in TC patients compared to NC (P<0.001) and BN patients (P=0.006). There was a significant increase in the serum levels of PDGF and IGF-1 in TC patients (P<0.001), and BN patients (P<0.001) compared to NC, while there were no significant differences between TC and BN (P=0.087, and 0.258; respectively). PDGF correlated significantly with IGF-1 (r=0.412, P<0.001), TSH (r=0.146, P=0.045), and inversely correlated with 25(OH)D (r= -0.156, P=0.013) and FT4 (r=-0.178, P=0.014). There was a significant inverse correlation between the serum levels of IGF-1 and FT4 (r=-0.172, P=0.017). Sensitivity and specificity for assessment of TC patients were (65.7% and 58.3%, P= 0.001) for 25(OH)D, (65.7% and 58.3%, P=0.021) for IGF-1, and (68.6% and 61.7%, P=0.006) for PDGF. Multivariate analysis demonstrated that serum 25(OH)D (OR=0.578, 95%CI= 0.426-0.783), IGF-1 (OR=1.019, 95%CI= 1.010-1.029) and PDGF (OR=1.007, 95%CI= 1.004-1.009) were considered independent risk factors for thyroid cancer (P<0.001, for all). CONCLUSION: 25(OH) D, IGF-1 and PDGF are significantly different in TC and BN cases compared to control. They have an important role in the progression of TC. However, these data should be validated on a larger sample size.
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The Association Between Hyperhomocysteinemia and Thyroid Nodule Prevalence in an Adult Population.

Background: Thyroid nodule is the most common disorder of thyroid. Metabolic syndrome was regarded as an important factor for the prevalence of thyroid nodule. Homocysteine has been shown to be related to metabolic syndrome, inflammation, and several common cancers. In this study, we aimed to investigate the relationship between serum homocysteine and the prevalence of thyroid nodule. Materials and Methods: This was a cross-sectional study that included 2040 adults in a health checkup population in Beijing Chao-yang hospital. Thyroid ultrasound data, together with anthropometric characteristics, metabolic parameters, and serum homocysteine, were recorded respectively. Results: Hyperhomocysteinemia (defined as serum homocysteine ≥15 µmol/L) was detected in 452 participants (21.91%). Thyroid nodule prevalence was significantly higher in hyperhomocysteinemia participants than in normal homocysteine participants (52.57% vs. 45.16%, P = 0.006). Logistic regression analysis revealed that age [odds ratio (OR) 1.054; P < 0.001], female gender (OR 2.242; P < 0.001), body mass index (OR 1.050; P < 0.001), and serum homocysteine level (OR 1.022; P = 0.001) were the independent risk factors for thyroid nodule. Conclusions: Subjects with hyperhomocysteinemia have significantly higher thyroid nodule prevalence. Homocysteine is an independent risk factor for thyroid nodule. It implies that individuals with hyperhomocysteinemia have higher susceptibility to thyroid nodule.

Hyperactive thyroid nodules treated by radiofrequency ablation: a Dutch single-centre experience.

BACKGROUND: Hyperactive thyroid nodules (HTN) are usually treated with radioactive iodine (RAI). However, as RAI is associated with a 30-60% long-term risk of permanent hypothyroidism, radiofrequency ablation (RFA) may be a good alternative. Primary aim of this study was to assess the percentage of patients achieving euthyroidism after RFA. PATIENTS AND METHODS: Patients with a symptomatic HTN were treated by ultrasound-guided RFA, using the trans-isthmic approach and moving-shot technique, in an outpatient setting under local anaesthesia. RESULTS: Twenty-one patients were included, ranging in age from 37-75 years. Follow-up was at least one year. All patients had a suppressed serum thyroid-stimulating hormone (TSH), with free thyroxine (FT4) and free triiodothyronine (FT3) concentrations mildly elevated in 33% and 43% of cases, respectively. RFA was not associated with clinically meaningful adverse effects. TSH normalisation was achieved in 11/21 patients (52%) after first RFA. A partial response, defined as a normalisation of FT4 and FT3, but incomplete improvement of TSH, was observed in 6/21 patients (29%). Three patients had no response (14%), and one patient developed mild, asymptomatic subclinical hypothyroidism. Five patients underwent a second RFA and this led to TSH normalisation in four, thereby raising the rate of complete remission to 71%. Recurrence of TSH suppression did not occur during the study period. CONCLUSION: These data suggest that RFA is a safe and promising treatment for symptomatic hyperactive thyroid nodules, with a low risk of permanent hypothyroidism. Long-term studies are needed to identify the recurrence risk of hyperthyroidism.

Thyroglobulin can be a functional biomarker of iodine deficiency, thyroid nodules, and goiter in Chinese pregnant women.

BACKGROUND AND OBJECTIVES: Thyroglobulin (Tg) is considered a sensitive indicator of iodine status for children and adults, but its usefulness for pregnant women is unknown. The aim of this study was attempting to explore the relationship between Tg and iodine status and the association between elevated Tg and thyroid diseases. METHODS AND STUDY DESIGN: A total of 2163 pregnant women were recruited in this study. The ratio of urine iodine concentration and urine creatinine concentration (UI/Cr) was measured in spot urine samples. Serum thyroid hormones and thyroglobulin were measured. Thyroid nodules and thyroid volume were diagnosed by ultrasound. RESULTS: The geometric mean of serum Tg was significantly higher in the UI/Cr <100 µg/g group (10.94 [2.47] µg/L) and the UI/Cr >500 µg/g group (11.48 [2.35] µg/L) than in the 150-249 µg/g group (9.64 [2.32] µg/L). The generalized linear model analysis showed that Serum log(10) Tg concentration was much higher in the UI/Cr <100 µg/g group (ß=0.052, p=0.026) than in the 150-249 µg/g group. Multivariate logistic regression models demonstrated that elevated Tg may be a risk factor for both goiter (OR=8.30) and thyroid nodules (OR=2.73). CONCLUSIONS: Pregnant women with UI/Cr <100 µg/g have a higher Tg, and those with elevated Tg concentrations have a higher risk of thyroid nodules and goiter. Tg can be a functional biomarker of iodine deficient, thyroid nodules and goiter.

Usefulness of Serum Calcitonin in Patients with Thyroid Nodules ≤ 1 cm Without an Indication for Fine-Needle Aspiration.

Fine-needle aspiration (FNA) is not necessary in adults with nodules ≤ 1 cm without apparent extrathyroidal extension (ETE) or lymph node (LN) involvement on ultrasonography (US). In the absence of FNA and serum calcitonin (Ctn) measurement, medullary thyroid microcarcinomas (microMTC) are not diagnosed. The aim of this prospective study was to evaluate Ctn levels in adults with a low clinical risk of MTC and nodules ≤ 1 cm without ETE or LN involvement on US. A total of 506 consecutively seen adults who had nodules with two or more suspicious features were included. Patients with elevated basal Ctn underwent a calcium stimulation test and FNA. Basal Ctn was normal in 490 patients (96.8%). In the 16 patients with elevated basal Ctn, FNA revealed MTC in only one patient and MTC was not suspected in the 15 patients with elevated basal Ctn. Three patients with stimulated Ctn<100 pg/ml and benign cytology were not submitted to surgery. MTC was excluded by histology in three patients with stimulated Ctn<100 pg/ml and indeterminate or suspicious cytology and in eight patients with stimulated Ctn>100 pg/ml. One patient with stimulated Ctn>100 pg/ml had MTC. Ctn was undetectable 6 months after surgery in two patients with MTC. Although uncommon, even subjects without a suspicious history and with nodules ≤ 1 cm without ETE or LN involvement on US, but with suspicious findings, can have microMTC. The measurement of Ctn permits the diagnosis of these cases.

Calcitonin testing for detection of medullary thyroid cancer in people with thyroid nodules.

BACKGROUND: Thyroid nodules are very common in general medical practice, but rarely turn out to be a medullary thyroid carcinoma (MTC). Calcitonin is a sensitive tumour marker for the detection of MTC (basal calcitonin). Sometimes a stimulation test is used to improve specificity (stimulated calcitonin). Although the European Thyroid Association's guideline advocates calcitonin determination in people with thyroid nodules, the role of routine calcitonin testing in individuals with thyroid nodules is still questionable. OBJECTIVES: The objective of this review was to determine the diagnostic accuracy of basal and/or stimulated calcitonin as a triage or add-on test for detection of MTC in people with thyroid nodules. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and Web of Science from inception to June 2018. SELECTION CRITERIA: We included all retrospective and prospective cohort studies in which all participants with thyroid nodules had undergone determination of basal calcitonin levels (and stimulated calcitonin, if performed). DATA COLLECTION AND ANALYSIS: Two review authors independently scanned all retrieved records. We extracted data using a standard data extraction form. We assessed risk of bias and applicability using the QUADAS-2 tool. Using the hierarchical summary receiver operating characteristic (HSROC) model, we estimated summary curves across different thresholds and also obtained summary estimates of sensitivity and specificity at a common threshold when possible. MAIN RESULTS: In 16 studies, we identified 72,368 participants with nodular thyroid disease in whom routinely calcitonin testing was performed. All included studies performed the calcitonin test as a triage test. Median prevalence of MTC was 0.32%. Sensitivity in these studies ranged between 83% and 100% and specificity ranged between 94% and 100%. An important limitation in 15 of the 16 studies (94%) was the absence of adequate reference standards and follow-up in calcitonin-negative participants. This resulted in a high risk of bias with regard to flow and timing in the methodological quality assessment. At the median specificity of 96.6% from the included studies, the estimated sensitivity (95% confidence interval (CI)) from the summary curve was 99.7% ( 68.8% to 100%). For the median prevalence of MTC of 0.23%, the positive predictive value (PPV) for basal calcitonin testing at a threshold of 10 pg/mL was 7.7% (4.9% to 12.1%). Summary estimates of sensitivity and specificity for the threshold of 10 pg/mL of basal calcitonin testing was 100% (95% CI 99.7 to 100) and 97.2% (95% CI 95.9 to 98.6), respectively. For combined basal and stimulated calcitonin testing, sensitivity ranged between 82% and 100% with specificity between 99% and 100%. The median specificity was 99.8% with an estimated sensitivity of 98.8% (95% CI 65.8 to 100) . AUTHORS' CONCLUSIONS: Both basal and combined basal and stimulated calcitonin testing have a high sensitivity and specificity. However, this may be an overestimation due to high risk of bias in the use and choice of reference standard The value of routine testing in patients with thyroid nodules remains questionable, due to the low prevalence, which results in a low PPV of basal calcitonin testing. Whether routine calcitonin testing improves prognosis in MTC patients remains unclear.

The impact of concurrent Hashimoto thyroiditis on thyroid nodule cytopathology assessed by ultrasound-guided fine-needle aspiration cytology.

Objective: Thyroid nodules are highly prevalent and a common clinical problem worldwide. How to identify the nature of a nodule is a major concern of clinicians. Fine needle aspiration cytology (FNAC) has an established role and is well-utilized in nodule management. However, the unsatisfactory nondiagnostic and indeterminate rates limit its usage and lead to some unnecessary surgery. Hashimoto thyroiditis (HT) is prevalently found concurrent with thyroid nodules. Whether HT can influence the accuracy of cytopathological diagnosis of nodules is still controversial. Methods: We collected medical records of 1,063 patients with thyroid nodules who had done FNAC in our hospital from 2015 to 2016. Thyroid function, anti-thyroid autoantibody levels, thyroid ultrasound records, and cytological and histopathological results of nodules were reviewed to analyze the impact of HT on FNAC outcome. Results: A total of 1,063 patients with an average age of 44 ± 13 years old were retrospectively reviewed for pathological and clinical data. Patients with different cytological diagnoses had comparable positive rates of anti-thyroid autoantibodies. One hundred patients were confirmed to have concurrent HT by histopathology after surgery. The overall nondiagnostic and indeterminate cytology rates were 11.9% and 25% respectively. No statistical difference was found either in the rate of a nondiagnostic cytology results or in the rate of indeterminate cytology results between patients with positive anti-thyroid autoantibodies and patients with negative test for anti-thyroid autoantibodies (P > 0.05). The same was true between patients with histopathologically confirmed HT and HT-negative ones (P > 0.05). Conclusions: The presence of concurrent HT, whether clinically implied with positive anti-thyroid autoantibodies or pathologically confirmed, is unlikely to predispose an FNAC diagnosis of thyroid nodules to be non-diagnostic or indeterminate.

Early Diagnosis of Medullary Thyroid Cancer: Are Calcitonin Stimulation Tests Still Indicated in the Era of Highly Sensitive Calcitonin Immunoassays?

Background: Measurements of both basal (b) calcitonin (CT) and calcium (Ca)-stimulated CT (Ca-sCT) levels are performed to identify medullary thyroid cancer (MTC) at an early stage when used as part of the diagnostic workup of thyroid nodules (CT screening). Novel immunochemiluminometric assays, which are highly sensitive and specific for monomeric CT and avoid cross-reactivity, have been introduced over the past decade. No prospectively generated data have so far become available to answer the frequently raised question as to whether Ca-sCT in contrast to bCT alone is helpful and, therefore, still indicated for the early detection of MTC. Methods: Ca-stimulation tests were performed in 149 consecutive patients with thyroid nodules and elevated bCT. Regardless of Ca-sCT levels, all patients had an operation applying a uniform surgical protocol, including thyroidectomy and systematic lymph node dissection. Recently published sex-specific cutoff levels for the differentiation of MTC and other C-cell pathologies (C-cell hyperplasia [CCH]) were used to compare the diagnostic performance of bCT or Ca-sCT alone and in combination using receiver-operating characteristic (ROC) analysis. In addition, CT cutoff levels to predict lateral lymph node metastasis were evaluated for bCT compared with Ca-sCT. Follow-up for all patients was documented and correlated with initial CT levels. Results: MTC was identified in 76 (50.1%) patients, in 21/76 (27.6%) with lymph node and in 4 (5.3%) with distant metastasis. Using predefined cutoff levels, patients could effectively be subdivided into a group above the cutoff level with definitive diagnosis of MTC (100%) and below (gray zone) with a significant overlap of CCH and MTC (all classified as pT1a; males: 19/58 [37.5%], females: 7/41 [17.1%]). The areas under the ROC curve (AUC) were excellent for the diagnosis of MTC in all tests. Determination of bCT proved to be superior for both diagnosing MTC in males (AUC for bCT: 0.894; AUC for Ca-sCT: 0.849) and females (bCT: 0.935; Ca-sCT: 0.868) and also for diagnosing lymph node metastasis in the lateral compartment (males: bCT: 0.925; Ca-sCT: 0.810; females: bCT: 0.797; Ca-sCT: 0.674). Combining both tests did not improve diagnostic accuracy. Using a cutoff level of >85 pg/mL for females and >100 pg/mL for males, the sensitivity for diagnosing lateral neck lymph node metastasis was 100%. Below these cutoff levels, no patient showed persistent or recurrent disease (median follow-up: 46 [ ± 27] months). Conclusions: Predefined sex-specific bCT cutoff levels are helpful for the early detection of MTC and for predicting lateral neck lymph node metastasis. Ca-sCT did not improve preoperative diagnostics. bCT levels >43 and >100 pg/mL for males and of >23 and >85 pg/mL for females are relevant for advising patients and planning the extent of surgery.