Appropriate and mindful measurement of serum calcitonin in patients with thyroid nodules. A white paper.

Medullary thyroid carcinoma (MTC) is an infrequent thyroid malignancy that is often diagnosed at advanced stage with consequent poor prognosis. Thus, the earlier the diagnosis of MTC, the better the prognosis. Unfortunately, the preoperative detection of MTC remains challenging in clinical practice. In fact, while ultrasound and fine-needle aspiration cytology have suboptimal performance in this context, measuring serum calcitonin (Ctn), fully recognized as the most reliable test to detect MTC, is not universally accepted as routine test in all patients with thyroid nodule(s). The authors of this paper reappraise critically the matter of Ctn measurement in view of the recent advancements in the literature to point out the essential information to be known, and then to prepare an easy-to-use guide for clinicians to appropriately consider the measurement of serum Ctn during clinical practice.

Is the 1mg-dexamethasone suppression test a precise marker of glucocorticoid excess and cardiometabolic risk in patients with adrenal incidentalomas?

AIM: To analyze if the 1mg-dexamethasone suppression test (DST) is a reliable marker of glucocorticoid excess and cardiometabolic risk in patients with adrenal incidentalomas (AIs). METHODS: Cross-sectional study of patients with nonfunctioning adrenal incidentalomas (NFAIs, defined by cortisol post-DST ≤ 1.8 µg/dL) and patients with autonomous cortisol secretion (ACS, defined by cortisol post-DST > 1.8 µg/Dl). The urinary steroid profile (USP) was determined by gas chromatography coupled to mass spectrometry. Both groups were matched by sex, age and body mass index. RESULTS: Forty-nine patients with AIs (25 with ACS and 24 with NFAI) were included. As a whole, AIs showed a high excretion of ß-cortolone, tetrahydro-11-deoxycortisol (THS), α-cortolone, α-cortol, tetrahydrocortisol (THF) and tetrahydrocortisone (THE). A positive yet modest correlation between post-DST cortisol and total excretion of glucocorticoid metabolites (r = 0.401, P = 0.004) was observed, with the stronger being observed with total THS (r = 0.548, P < 0.001) and THF (r = 0.441, P = 0.002). Some of the metabolites that were elevated in patients with AIs, were higher in patients with ACS-related comorbidities than in those without comorbidities. Post-DST cortisol showed a fair diagnostic accuracy for the prediction of ACS-related comorbidities (AUC 0.767 [95% CI 0.634-0.882]). However, post-DST diagnostic accuracy improved when combined with urinary cortisone, α-cortol, THS and serum DHEAS (0.853 [0.712‒0.954]). CONCLUSION: The DST has a positive, but modest, correlation with urinary glucocorticoid excretion. Similarly, the diagnostic accuracy of the DST for the prediction of ACS-related comorbidities is only fair, but it may be improved if combined with the results of the USP and serum DHEAS. SIGNIFICANCE STATEMENT: This is the first study aimed to evaluate if 1mg-dexamethasone suppression test (DST) is a reliable marker of glucocorticoid excess and cardiometabolic risk in patients with adrenal incidentalomas (AIs) and if urinary steroid profile was measured by GS-MS could improve such a prediction. We found a positive yet modest correlation between post-DST cortisol and total excretion of glucocorticoid metabolites, with the stronger being observed with total tetrahydro-11-deoxycortisol (THS) and tetrahydrocortisol. Post-DST cortisol showed a fair diagnostic accuracy for the prediction of ACS-related comorbidities (AUC 0.767). However, post-DST diagnostic accuracy improved when combined with urinary cortisone, α-cortol, THS and serum DHEAS (0.853).

Prevalence and incidence of type 2 diabetes mellitus in patients with adrenal incidentalomas: a study of 709 cases.

AIM: To evaluate the prevalence and incidence of type 2 diabetes in patients with nonfunctioning adrenal incidentalomas (NFAI) or adrenal incidentalomas (AI) with autonomous cortisol secretion (ACS). METHODS: In this single-center retrospective study, all patients with adrenal incidentalomas ≥1 cm and ACS or NFAI studied between 2013 and 2020 were included. ACS was defined by a post-dexamethasone suppression test (DST) serum cortisol concentration ≥1.8 µg/dl, in the absence of signs of hypercortisolism, and NFAI was defined as a DST < 1.8 µg/dl without biochemical evidence of hypersecretion of other hormones. RESULTS: Inclusion criteria were met by 231 patients with ACS and 478 with NFAI. At diagnosis, type 2 diabetes was present in 24.3% of patients. No differences were found in the prevalence of type 2 diabetes (27.7 vs. 22.6%, P = 0.137) between patients with ACS and NFAI. However, fasting plasma glucose values and glycated hemoglobin levels were significantly higher in patients with ACS than with NFAI (112 ± 35.6 vs. 105 ± 29 mg/dl, P = 0.004; and 6.5 ± 1.4 vs. 6.1 ± 0.9%, P = 0.005, respectively). Furthermore, patients with type 2 diabetes had higher urinary free cortisol (P = 0.039) and late-night salivary cortisol levels (P = 0.010) than those without type 2 diabetes. After a median follow-up of 28 months, no differences were found in the incidence of type 2 diabetes between the groups (HR 1.17, 95% 0.52-2.64). CONCLUSION: Type 2 diabetes was present in one fourth of our cohort. We found no differences in its prevalence or incidence between the groups. However, glycemic control might be worse among diabetic patients with ACS. Higher concentrations of urinary and salivary cortisol were found in patients with than without type 2 diabetes.

Clinical value of molecular markers as diagnostic and prognostic tools to guide treatment of thyroid cancer.

OBJECTIVE: Advances in our understanding of the molecular biology of thyroid tumours is being rapidly translated into their clinical management. This review summarizes the current use of molecular testing in thyroid tumours, focusing on their usefulness as diagnostic and prognostic tools to guide treatment with consideration of present limitations. DESIGN: Considerations about molecular testing applications for the diagnosis and treatment of thyroid tumours are divided into four sections/roles: (1) evaluating cytologically indeterminate thyroid nodules; (2) guiding extent of surgery in indeterminate thyroid nodules; (3) completing histological characterization of thyroid tumours and (4) identifying actionable mutations in advanced progressive thyroid cancers. RESULTS: Genomic testing can improve the presurgical malignancy risk assessment in indeterminate thyroid nodules. However, a prior in-depth analysis of institutional quality and outcomes of sonographical, cytological and histological characterization of thyroid tumours is necessary. Presently, it remains uncertain whether knowing the molecular profile of a cytologically indeterminate thyroid nodule might be advantageous to modify the extent of initial surgery. Molecular characterization of thyroid tumours can be a valuable adjunct to morphological diagnosis in some challenging cases, such as in low-risk follicular cell-derived neoplasms, or rare tumours. Finally, as selective kinase inhibitors are available, molecular testing in locally advanced/metastatic progressive thyroid cancers should also be integrated into the institutional clinical management pathway to improve outcomes and limit toxicity. CONCLUSIONS: Molecular testing needs to be implemented into the local evidence-based clinical management thyroid nodule/cancer pathways to improve its diagnostic and prognostic value and to optimize cost-effectiveness.

Evaluation of Body Composition in Patients With and Without Adrenal Tumors and Without Overt Hypersecretory Syndromes.

OBJECTIVE: To compare body composition between patients with autonomous cortisol secretion (ACS), those with nonfunctioning adrenal incidentalomas (NFAIs), and control subjects without adrenal tumors. METHODS: A cross-sectional study was performed, incluidng the following 3 groups: patients with ACS (cortisol post-dexamethasone suppression test [DST] >1.8 µg/dL), NFAIs (cortisol post-DST ≤ 1.8 µg/dL), and patients without adrenal tumors (control group). Patients of the 3 groups were matched according to age (±5 years), sex, and body mass index (±5 kg/m2). Body composition was evaluated by bioelectrical impedance and abdominal computed tomography (CT) and urinary steroid profile by gas chromatography mass spectrometry. RESULTS: This study enrolled 25 patients with ACS, 24 with NFAIs, and 24 control subjects. Based on CT images, a weak positive correlation between the serum cortisol level post-DST and subcutaneous fat area (r = 0.3, P =.048) was found. As assessed by bioelectrical impedance, lean mass and bone mass were positively correlated with the excretion of total androgens (r = 0.56, P <.001; and r = 0.58, P <.001, respectively); visceral mass was positively correlated with the excretion of glucocorticoid metabolites and total glucocorticoids (r = 0.28, P =.031; and r = 0.42, P =.001, respectively). Based on CT imaging evaluation, a positive correlation was observed between lean mass and androgen metabolites (r = 0.30, P =.036) and between visceral fat area, total fat area, and visceral/total fat area ratio and the excretion of glucocorticoid metabolites (r = 0.34, P =.014; r = 0.29, P =.042; and r = 0.31, P =.170, respectively). CONCLUSION: The urinary steroid profile observed in adrenal tumors, comprising a low excretion of androgen metabolites and high excretion of glucocorticoid metabolites, is associated with a lower lean mass and bone mass and higher level of visceral mass in patients with adrenal tumors.

Predictive model for autonomous cortisol secretion development in non-functioning adrenal incidentalomas.

PURPOSE: We aimed to develop a predictive model able to stratify patients with non-functioning adrenal incidentalomas (AIs), according to their risk for developing autonomous cortisol secretion (ACS) during follow-up. METHODS: This was a retrospective study of patients with non-functioning AIs consecutively evaluated at a single institution between 2013 and 2019 in whom hormonal follow-up information was available for at least 1 year. Clinical, biochemical, and radiological features were used to build a multivariate Cox regression model using the estimation of all possible equations. RESULTS: We included 331 patients with non-functioning AIs. ACS (post-dexamethasone suppression test (DST) serum cortisol > 1.8 µg/dL) developed in 73 patients during a median follow-up time of 35.7 months [range 12.8-165.4]. The best predictive model for ACS development during follow-up combined age, post-DST serum cortisol, and bilaterality at presentation and showed good diagnostic accuracy (AUC-ROC 0.70 [95% CI 0.65-0.75]). The lowest risk for ACS development was found among patients < 50 years old with cortisol post-DST values < 0.45 µg/dL and with unilateral tumors (risk 2.42%). Baseline post-DST serum cortisol levels at diagnosis were the most important factor for the development of ACS during follow-up (hazard ratio 3.56 for each µg/dL, p < 0.001). The rate of ACS development was associated with post-DST cortisol levels, being 19.2, 32.3, and 68.1 cases/10,000 person-years for patients with baseline post-DST cortisol < 0.9 µg/dL, 0.9-1.3 µg/dL, and > 1.3 µg/dL, respectively. CONCLUSION: After ruling out malignancy, follow-up visits for patients < 50 years old with unilateral non-functioning AIs and post-DST serum cortisol < 0.45 µg/dL are considered unnecessary given the low risk of developing ACS during follow-up.

Characterisation of the urinary steroid profile of patients with nonfunctioning adrenal incidentalomas: A matched controlled cross-sectional study.

AIM: To identify alterations in steroid metabolism in patients with nonfunctioning adrenal incidentalomas (NFAIs) through the analysis of their urinary steroid profile (USP). METHODS: Cross-sectional study with one study group (NFAIs, cortisol post dexamethasone suppression test [DST] ≤ 1.8 µg/dl [49.7 nmol/L]) and 2 control groups: patients with autonomous cortisol secretion (ACS group, cortisol post-DST > 1.8 µg/dl (49.7 nmol/L) and patients without adrenal tumours (healthy-adrenal group). Twenty-four-hour urine collections for USP measurement (total and free fraction of 51 24 h-urine specimens) were obtained from 73 participants (24 with NFAIs, 24 without AIs, and 25 with ACS). USP was determined by gas chromatography coupled to mass spectrometry. Patients of the three groups were matched according to sex, age (±5 years-old) and body mass index (±5 kg/m2 ). RESULTS: Compared to healthy-adrenal controls, patients with NFAIs had a lower excretion of androgen metabolites (230.5 ± 190.12 vs. 388.7 ± 328.58 µg/24 h, p = .046) and a higher excretion of urinary free cortisol (UFC) (54.3 ± 66.07 vs. 25.4 ± 11.16 µg/24 h, p = .038). UFC was above the reference range in 20.8% of patients in the NFAI, compared to 0% in the healthy-adrenal group (p = .018). Patients with ACS had a higher prevalence of hypertension, dyslipidemia, and diabetes than patients with NFAIs or the control group. A lower excretion of androgen metabolites (218.4 ± 204.24 vs. 231 ± 190 µg/24 h, p = .041) and a nonsignificant higher excretion of glucocorticoid metabolites (2129.6 ± 1195.96 vs. 1550.8 ± 810.03 µg/24 h, p = .180) was found in patients with ACS compared to patients with NFAIs. CONCLUSION: NFAIs seem to secrete a subtle, yet clinically relevant, excess of glucocorticoids. Future studies are needed to confirm our findings; and to identify metabolic alterations associated with an increased cardiometabolic risk.

Predictive model of pheochromocytoma based on the imaging features of the adrenal tumours.

The purpose of our study was to develop a predictive model to rule out pheochromocytoma among adrenal tumours, based on unenhanced computed tomography (CT) and/or magnetic resonance imaging (MRI) features. We performed a retrospective multicentre study of 1131 patients presenting with adrenal lesions including 163 subjects with histological confirmation of pheochromocytoma (PHEO), and 968 patients showing no clinical suspicion of pheochromocytoma in whom plasma and/or urinary metanephrines and/or catecholamines were within reference ranges (non-PHEO). We found that tumour size was significantly larger in PHEO than non-PHEO lesions (44.3 ± 33.2 versus 20.6 ± 9.2 mm respectively; P < 0.001). Mean unenhanced CT attenuation was higher in PHEO (52.4 ± 43.1 versus 4.7 ± 17.9HU; P < 0.001). High lipid content in CT was more frequent among non-PHEO (83.6% versus 3.8% respectively; P < 0.001); and this feature alone had 83.6% sensitivity and 96.2% specificity to rule out pheochromocytoma with an area under the receiver operating characteristics curve (AUC-ROC) of 0.899. The combination of high lipid content and tumour size improved the diagnostic accuracy (AUC-ROC 0.961, sensitivity 88.1% and specificity 92.3%). The probability of having a pheochromocytoma was 0.1% for adrenal lesions smaller than 20 mm showing high lipid content in CT. Ninety percent of non-PHEO presented loss of signal in the "out of phase" MRI sequence compared to 39.0% of PHEO (P < 0.001), but the specificity of this feature for the diagnosis of non-PHEO lesions low. In conclusion, our study suggests that sparing biochemical screening for pheochromocytoma might be reasonable in patients with adrenal lesions smaller than 20 mm showing high lipid content in the CT scan, if there are no typical signs and symptoms of pheochromocytoma.

Predictors of Tumour Growth and Autonomous Cortisol Secretion Development during Follow-Up in Non-Functioning Adrenal Incidentalomas.

PURPOSE: To assess the risk of developing autonomous cortisol secretion (ACS) and tumour growth in non-functioning adrenal incidentalomas (NFAIs). METHODS: Multicentre retrospective observational study of patients with NFAIs. ACS was defined as serum cortisol >1.8 µg/dL after 1 mg-dexamethasone suppression test (DST) without specific data on Cushing's syndrome. Tumour growth was defined as an increase in maximum tumour diameter >20% from baseline; and of at least 5 mm. RESULTS: Of 654 subjects with NFAIs included in the study, both tumour diameter and DST were re-evaluated during a follow-up longer than 12 months in 305 patients. After a median follow-up of 41.3 (IQR 24.7-63.1) months, 10.5% of NFAIs developed ACS. The risk for developing ACS was higher in patients with higher serum cortisol post-DST levels (HR 6.45 for each µg/dL, p = 0.001) at diagnosis. Significant tumour growth was observed in 5.2% of cases. The risk of tumour growth was higher in females (HR 10.7, p = 0.004). CONCLUSIONS: The frequency of re-evaluation with DST in NFAIs during the initial 5 years from diagnosis can probably be tailored to the serum cortisol post-DST level at presentation. Re-evaluation of NFAIs with imaging studies, on the other hand, seems unnecessary in most cases, particularly if the initial imaging demonstrates features specific to typical adenoma, given the low rate of significant tumour growth.

Diagnostic accuracy of the different hormonal tests used for the diagnosis of autonomous cortisol secretion.

To evaluate the diagnostic accuracy of the different tests commonly used in the evaluation of adrenal incidentalomas (AIs) for the identification of autonomous cortisol secretion (ACS) and comorbidities potentially related to ACS. In a retrospective study of patients with AIs ≥ 1 cm, we evaluated the diagnostic reliability and validity of the dexamethasone suppression test (DST), urinary free cortisol (UFC), ACTH, late-night salivary cortisol (LNSC), and dehydroepiandrosterone-sulphate (DHEAS) for the diagnosis of comorbidities potentially related to ACS. Diagnostic indexes were also calculated for UFC, ACTH, LNSC, and DHEAS considering DST as the gold standard test for the diagnosis of ACS, using three different post-DST cortisol thresholds (138 nmol/L, 50 nmol/L and 83 nmol/L). We included 197 patients with AIs in whom the results of the five tests abovementioned were available. At diagnosis, 85.9% of patients with one or more AIs had any comorbidity potentially related to ACS, whereas 9.6% had ACS as defined by post-DST cortisol > 138 nmol/L. The reliability of UFC, ACTH, LNSC, and DHEAS for the diagnosis of ACS was low (kappa index < 0.30). Of them, LNSC reached the highest diagnosis accuracy for ACS identification (AUC = 0.696 [95% CI 0.626-0.759]). The diagnostic performances of these tests for comorbidities potentially related to ACS was poor; of them, the DST was the most accurate (AUC = 0.661 [95% CI 0.546-0.778]) and had the strongest association with these comorbidities (OR 2.6, P = 0.045). Patients presenting with increased values of both DST and LNSC had the strongest association with hypertension (OR 7.1, P = 0.002) and with cardiovascular events (OR 3.6, P = 0.041). In conclusion, LNSC was the test showing the highest diagnosis accuracy for the identification of ACS when a positive DST was used as the gold standard for its diagnosis. The DST test showed the strongest association with comorbidities potentially related to ACS. The definition of ACS based on the combination of elevated DST and LNSC levels improved the identification of patients with increased cardiometabolic risk.

Outcomes of repeat fineneedle aspiration biopsy for AUS/FLUS thyroid nodules.

OBJECTIVE: To determine the proportion of aspirates reclassified into each Bethesda category and to assess the rates of malignancy in each of them on repeat fine-needle aspiration biopsy (RFNA) following an AUS/FLUS diagnosis. DESIGN: Systematic review and meta-analysis. METHODS: On February 2019, Pubmed/MEDLINE, EMBASE, WoS, and the Cochrane Library were searched for articles published from January 1, 2007. All studies published in English describing RFNA outcomes in AUS/FLUS nodules were included. PRISMA and MOOSE guidelines were followed. Five investigators independently assessed the eligibility of the studies. Two investigators extracted summary data and assessed the risk of bias. Data were pooled using a random-effects model. The rate of malignancy was calculated on resected nodules only (upper limit of true value); and considering all unresected nodules were benign (lower limit of true value). The protocol was registered in PROSPERO (CRD42019123114). RESULTS: Of 2937 retrieved studies, 27 were eligible. The meta-analysis was conducted on summary data of 3932 AUS/FLUS thyroid nodules with RFNA. RFNA cytology would reclassify into categories I through VI of Bethesda: 4% (3%, 5%), 48% (43%, 54%), 26% (20%, 32%), 4% (3%, 6%), 5% (3%, 6%), and 2% (1%, 2%) of AUS/FLUS nodules. Malignancy rates of resected nodules were 24% (9%, 38%), 4% (1%, 7%), 40% (28%, 52%), 37% (27%, 47%), 79% (69%, 90%), and 99% (95%, 100%) for categories I through VI of Bethesda. There was high heterogeneity in these data. CONCLUSIONS: RFNA reclassified two-thirds of the AUS/FLUS specimens into a more definitive cytological category, with a benign call rate of nearly 50% and a negative predictive value greater than 96%.

Accuracy of the dexamethasone suppression test for the prediction of autonomous cortisol secretion-related comorbidities in adrenal incidentalomas.

PURPOSE: The aim of this study was to evaluate the diagnostic accuracy of the 1 mg dexamethasone suppression test (DST) for the prediction of autonomous cortisol secretion (ACS)-related comorbidities in patients with adrenal incidentalomas (AIs). METHODS: This was a retrospective multicenter study. We recruited patients with AI/s ≥ 1 cm, excluding those who, during the study, were found during the extension study of an extra-adrenal cancer, with a known diagnosis of hereditary syndromes characterized by adrenal tumors, those presenting with overt hormonal excess syndromes, and those in whom the DST results were missing. RESULTS: A total of 823 patients met the inclusion criteria. Based on the 1.8, 3.0, and 5.0 µg/dl post-DST cortisol thresholds, the prevalence of ACS was 33.5%, 13.7%, and 5.6%, respectively. The prevalence of hypertension (OR = 1.8, 95% CI = 1.3-2.4), diabetes (OR = 1.6, 95% CI = 1.2-2.2), and dyslipidemia (OR = 1.4, 95% CI = 1.0-1.9) was higher with cortisol post-DST ≥ 1.8 µg/dl; the prevalence of hypertension (OR = 2.1, 95% CI = 1.4-3.3) and diabetes (OR = 1.7, 95% CI = 1.1-2.6) was higher with values ≥ 3.0 µg/dl; and the prevalence of hypertension (OR = 2.0, 95% CI = 1.0-3.7) was higher with levels ≥ 5.0 µg/dl. However, the diagnostic accuracy of the DST for the prediction of cardiometabolic comorbidities in patients with AIs was poor, with areas under the ROC curve < 0.61. CONCLUSIONS: The DST is a poor predictor of cardiometabolic comorbidities in patients with AIs regardless of the cortisol cut-off values applied. This finding suggests that the diagnosis of ACS should not be based solely on the results of the DST. Other clinical, metabolic, or imaging markers showing a better performance for the prediction of the development and progression of cardiometabolic comorbidities in AIs need to be identified.

Molecular Determinants of Thyroid Nodules with Indeterminate Cytology and RAS Mutations.

Background:RAS gene family mutations are the most prevalent in thyroid nodules with indeterminate cytology and are present in a wide spectrum of histological diagnoses. We evaluated differentially expressed genes and signaling pathways across the histological/clinical spectrum of RAS-mutant nodules to determine key molecular determinants associated with a high risk of malignancy. Methods: Sixty-one thyroid nodules with RAS mutations were identified. Based on the histological diagnosis and biological behavior, the nodules were grouped into five categories indicating their degree of malignancy: non-neoplastic appearance, benign neoplasm, indeterminate malignant potential, low-risk cancer, or high-risk cancer. Gene expression profiles of these nodules were determined using the NanoString PanCancer Pathways and IO 360 Panels, and Angiopoietin-2 level was determined by immunohistochemical staining. Results: The analysis of differentially expressed genes using the five categories as supervising parameters unearthed a significant correlation between the degree of malignancy and genes involved in cell cycle and apoptosis (BAX, CCNE2, CDKN2A, CDKN2B, CHEK1, E2F1, GSK3B, NFKB1, and PRKAR2A), PI3K pathway (CCNE2, CSF3, GSKB3, NFKB1, PPP2R2C, and SGK2), and stromal factors (ANGPT2 and DLL4). The expression of Angiopoietin-2 by immunohistochemistry also showed the same trend of increasing expression from non-neoplastic appearance to high-risk cancer (p < 0.0001). Conclusions: The gene expression analysis of RAS-mutant thyroid nodules suggests increasing upregulation of key oncogenic pathways depending on their degree of malignancy and supports the concept of a stepwise progression. The utility of ANGPT2 expression as a potential diagnostic biomarker warrants further evaluation.

Urine steroid profile as a new promising tool for the evaluation of adrenal tumors. Literature review.

PURPOSE: To review the literature assessing the diagnostic performance of urinary steroid profiling (USP) by high-performance liquid chromatography (LC-MS) or gas chromatography (GC) coupled to mass spectrometry (MS) in the evaluation of adrenal lesions, both in terms of functionality and malignancy. RESULTS: The evaluation of adrenal incidentalomas (AI) aims to rule out malignancy and hormone excess. Current diagnostic protocols have several limitations and include time consuming and relatively complicated multi-step processes in most cases. On the contrary, USP by LC-MS/MS or LC-GC/MS offer an easy, comprehensive and non-invasive assessment of adrenal steroid secretion. USP complements current workups used in the evaluation of AIs by improving our ability to identify malignancy and/or autonomous hormone secretion. CONCLUSIONS: Urine steroid profiling by LC-MS/MS and GC-MS allows a thorough, non-invasive, assessment of adrenal steroidogenesis as a whole which complement the current evaluation of AIs, and holds a promising role in the diagnosis of autonomous cortisol secretion, primary aldosteronism, and adrenal malignancy.

Thyroid Cancer Incidence Trends in the United States: Association with Changes in Professional Guideline Recommendations.

Background: Overdiagnosis is the leading factor contributing to the rapid increase in thyroid cancer incidence of the last decades. During this period, however, thyroid cancer incidence has not been increasing at a constant pace. We hypothesized that changes in the slope of the incidence trends curve, called joinpoints, could be associated with changes in clinical practice guideline recommendations. Methods: Data were obtained from the initial nine registries of the Surveillance, Epidemiology, and End Results (SEER) Program. Thyroid cancer incidence was analyzed from 1975 to 2016. Joinpoints in thyroid cancer incidence trends and clinical variables were correlated with significant changes in clinical practice recommendations. Results: Incidence rate trends of medullary and anaplastic thyroid cancer were constant during the study period. Among papillary thyroid cancers (PTCs), three main joinpoints were identified, mainly driven by changes in incidence trends of smaller cancers. First, acceleration followed by two deceleration periods in thyroid cancer incidence coincident in time with the release of American Thyroid Association guidelines in 1996, 2009, and 2015. In 1996, the use of thyroid ultrasound and fine needle aspiration biopsy for the evaluation of thyroid nodules was described; and in 2009 and 2015, higher size thresholds for the biopsy of thyroid nodules were set. For the follicular variant of PTC, a joinpoint was observed around 1988, when the histological diagnosis of this entity was revised in the World Health Organization classification; and another one in 2015 coinciding with the proposal to remove the term carcinoma from noninvasive follicular-pattern tumors with papillary-like nuclear features which contributed to drive down the overall thyroid cancer incidence. Follicular thyroid cancer incidence was affected as well by changes in the guidelines, but to a lesser extent, and it was fairly stable during the study period. Conclusions: This study suggests that thyroid cancer incidence trends have been shaped, in large part, but not completely, by changes in professional guideline recommendations.

Ultrasound characterization for thyroid nodules with indeterminate cytology: inter-observer agreement and impact of combining pattern-based and scoring-based classifications in risk stratification.

BACKGROUND: The American Thyroid Association (ATA) sonographic patterns stratify the risk of malignancy of cytologically indeterminate thyroid nodules (ITNs). This study aimed to (1) assess inter-observer agreement for sonographic features and patterns; (2) identify potential sources of disagreement; and (3) evaluate whether the number of suspicious features risk-stratifies non-ATA and high-suspicion patterns. METHODS: Three observers independently reviewed the ultrasound images of 463 ITNs with histological follow-up consecutively evaluated between October 2008 and June 2015 at an academic cancer center. Each observer evaluated individual sonographic features. ATA sonographic patterns were derived from the interpretation of sonographic features. Nodules not fitting into any of the proposed patterns were clustered into a non-ATA pattern. RESULTS: The inter-observer agreement for ATA sonographic patterns and echogenicity was fair, moderate for margins, good for composition and echogenic foci, and very good for extrathyroidal extension and lymph node metastasis. The interpretation of each sonographic feature was significantly different between observers, and there was complete disagreement in at least one of the features in 104 (22%) nodules. A total of 169 nodules (37%) were classified into the non-ATA pattern. The number of suspicious features allowed risk stratifying nodules with non-ATA and high-suspicion sonographic patterns. Most Non-invasive Follicular Thyroid Neoplasms with Papillary-like Nuclear Features had 0-1 suspicious features and none had >2. CONCLUSIONS: Echogenicity interpretation was the greatest source of disagreement. The number of suspicious features risk-stratifies ITNs with non-ATA or high-suspicion patterns. Future studies attempting to objectivize the interpretation of echogenicity and heterogeneity are needed.

Comparison of Postmarketing Findings vs the Initial Clinical Validation Findings of a Thyroid Nodule Gene Expression Classifier: A Systematic Review and Meta-analysis.

IMPORTANCE: In the United States, the most used molecular test for the evaluation of cytologically indeterminate thyroid nodules is the Afirma gene expression classifier (GEC). OBJECTIVE: To evaluate the GEC's diagnostic performance through a novel approach to assess whether the findings of the initial validation study are consistent with the results of postmarketing studies. DATA SOURCES: PubMed was systematically searched from inception through October 26, 2017, using the terms gene expression classifier or Afirma or GEC and thyroid. STUDY SELECTION: Studies included were those in which the GEC diagnostic performance could be calculated on consecutively resected cytologically indeterminate thyroid nodules. DATA EXTRACTION AND SYNTHESIS: Two observers independently assessed study eligibility and risk of bias using the quality assessment tool for observational cohort and cross-sectional studies of the National Heart, Lung, and Blood Institute. Summary data were extracted by a reviewer and reviewed independently by another. Study authors were contacted if missing data were needed. Data were pooled using a random-effects model. PRISMA and MOOSE guidelines were followed. MAIN OUTCOMES AND MEASURES: Evaluation of the linear correlation between the benign call rate (BCR) and the positive predictive value (PPV). RESULTS: Of the 137 retrieved titles, 19 (13.9%) were included, comprising a total of 2568 thyroid nodules. Based on a simulation using the sensitivity and specificity reported in the initial validation study, the observed BCR and PPV values in postmarketing studies would have to be explained by different underlying prevalence rates of cancer (15% vs 30%), which is an impossible event. Furthermore, the overall correlation between BCR and PPV for independent studies fell outside the PPV 95% CI of the initial validation study (95% CI, 0.17-0.32) at the BCR of pooled independent studies (0.45) and was just at the limit of the BCR 95% CI of the initial validation study (95% CI, 0.32-0.45) at the PPV of pooled independent studies (0.45). The diagnostic performance was statistically significantly better for atypia or follicular lesions of undetermined significance (diagnostic odds ratio [DOR], 5.67; 95% CI, 4.23-7.60) compared with follicular neoplasms (DOR, 2.24; 95% CI, 1.45-3.47). CONCLUSIONS AND RELEVANCE: The findings suggest that the initial validation study cohort was not representative of the populations in whom the GEC has been used, calling into question its reported diagnostic performance, including its negative predictive value.

Interinstitutional variation in predictive value of the ThyroSeq v2 genomic classifier for cytologically indeterminate thyroid nodules.

BACKGROUND: The ThyroSeq v2 next-generation sequencing assay estimates the probability of malignancy in indeterminate thyroid nodules. Its diagnostic accuracy in different practice settings and patient populations is not well understood. METHODS: We analyzed 273 Bethesda III/IV indeterminate thyroid nodules evaluated with ThyroSeq at 4 institutions: 2 comprehensive cancer centers (n = 98 and 102), a multicenter health care system (n = 60), and an academic medical center (n = 13). The positive and negative predictive values of ThyroSeq and distribution of final pathologic diagnoses were analyzed and compared with values predicted by Bayes theorem. RESULTS: Across 4 institutions, the positive predictive value was 35% (22%-43%) and negative predictive value was 93% (88%-100%). Predictive values correlated closely with Bayes theorem estimates (r2 = 0.84), although positive predictive values were lower than expected. RAS mutations were the most common molecular alteration. Among 84 RAS-mutated nodules, malignancy risk was variable (25%, range 10%-37%) and distribution of benign diagnoses differed across institutions (adenoma/hyperplasia 12%-85%, noninvasive follicular thyroid neoplasm with papillary-like nuclear features 5%-46%). CONCLUSION: In a multi-institutional analysis, ThyroSeq positive predictive values were variable and lower than expected. This is attributable to differences in the prevalence of malignancy and variability in pathologist interpretations of noninvasive tumors. It is important that clinicians understand ThyroSeq performance in their practice setting when evaluating these results.