Data-Driven Thyroglobulin Cutoffs for Low- and Intermediate-Risk Thyroid Cancer Follow-Up: ITCO Real-World Analysis.

CONTEXT: The utility of thyroglobulin (Tg) in the follow-up of differentiated thyroid cancer (DTC) patients has been well-documented. Although third-generation immunoassays have improved accuracy, limitations persist (interfering anti-Tg antibodies and measurement variability). Evolving treatment strategies require a reevaluation of Tg thresholds for optimal patient management. OBJECTIVE: To assess the performance of serum Tg testing in two populations: patients receiving total thyroidectomy and radioiodine remnant ablation (RRA), or treated with thyroidectomy alone. DESIGN: Prospective observational study. Setting. Centers contributing to the Italian Thyroid Cancer Observatory (ITCO) database. PATIENTS: We included 540 patients with 5 years of follow-up and negative anti-Tg antibodies. INTERVENTIONS: Serum Tg levels assessed at 1-year follow-up visit. MAIN OUTCOME MEASURE: Detection of structural disease within 5 years of follow-up. RESULTS: After excluding 26 patients with structural disease detected at any time point, the median Tg did not differ between patients treated with or without radioiodine. Data-driven Tg thresholds were established based on the 97th percentile of Tg levels in disease-free individuals: 1.97 ng/mL for patients undergoing thyroidectomy alone (lower than proposed by the MSKCC protocol and ESMO Guidelines, yet demonstrating good predictive ability, with a negative predictive value (NPV) of 98%) and 0.84 ng/mL for patients receiving post-surgical RRA. High sensitivity and NPV supported the potential of these thresholds in excluding structural disease. CONCLUSIONS: This real-world study provides evidence for the continued reliability of 1-year serum Tg levels. The data-driven Tg thresholds proposed offer valuable insights for clinical decision-making in patients undergoing total thyroidectomy with or without RRA.

A Prospective Multicenter Study Examining the Relationship Between Thyroid Cancer Treatment Outcomes and the Presence of Autoimmune Thyroiditis.

Background: There is some controversy on the potential relationship between autoimmune processes and clinicopathologic features as well as prognosis of differentiated thyroid cancer (DTC), and the evidence is limited by its largely retrospective nature. We examined the relationship between the presence of autoimmune thyroiditis (AT) and 1-year thyroid cancer treatment outcomes in a large multicenter study using prospectively collected data. Methods: We included data from consecutive DTC patients enrolled in the Italian Thyroid Cancer Observatory (ITCO) database (NCT04031339). We divided the groups according to the presence (AT) or absence (no autoimmune thyroiditis [noAT]) of associated AT. We used propensity score matching to compare the clinical features and outcomes between the two groups at 1-year follow-up. Results: We included data from 4233 DTC patients, including 3172 (75%) females. The American Thyroid Association (ATA) risk levels were as follows: 51% (2160/4233) low risk, 41.3% (1750/4233) intermediate risk, and 7.6% (323/4233) high risk. There were 1552 patients (36.7%) who had AT. Before propensity score matching, AT patients were significantly younger and had a smaller and bilateral tumor (p < 0.0001). Patients with AT more frequently fell into the low- and intermediate-risk categories, while the ATA high risk was more frequent among noAT patients (p = 0.004). After propensity score matching, patients with AT more frequently showed evidence of disease (structural/biochemical incomplete response) versus excellent/indeterminate response, compared with patients without AT (7.3% vs. 4.5%, p = 0.001), with an odds ratio of 1.86 ([confidence interval: 1.3-2.6], p = 0.0001). However, when considering only structural persistence as the outcome, no statistically significant differences were observed between patients with or without AT (3.4% vs. 2.7%, p = 0.35). The elevated risk associated with the ATA intermediate and high risk at diagnosis remained consistently statistically significant. Conclusions: In this large prospective series, biochemical persistence was more frequent, at 1-year follow-up, in AT patients. However, there was no significant association between the presence of AT and structural persistence of disease. These findings may be explained by the presence of a residual thyroid tissue.

A Data-Driven Approach to Refine Predictions of Differentiated Thyroid Cancer Outcomes: A Prospective Multicenter Study.

CONTEXT: The risk stratification of patients with differentiated thyroid cancer (DTC) is crucial in clinical decision making. The most widely accepted method to assess risk of recurrent/persistent disease is described in the 2015 American Thyroid Association (ATA) guidelines. However, recent research has focused on the inclusion of novel features or questioned the relevance of currently included features. OBJECTIVE: To develop a comprehensive data-driven model to predict persistent/recurrent disease that can capture all available features and determine the weight of predictors. METHODS: In a prospective cohort study, using the Italian Thyroid Cancer Observatory (ITCO) database (NCT04031339), we selected consecutive cases with DTC and at least early follow-up data (n = 4773; median follow-up 26 months; interquartile range, 12-46 months) at 40 Italian clinical centers. A decision tree was built to assign a risk index to each patient. The model allowed us to investigate the impact of different variables in risk prediction. RESULTS: By ATA risk estimation, 2492 patients (52.2%) were classified as low, 1873 (39.2%) as intermediate, and 408 as high risk. The decision tree model outperformed the ATA risk stratification system: the sensitivity of high-risk classification for structural disease increased from 37% to 49%, and the negative predictive value for low-risk patients increased by 3%. Feature importance was estimated. Several variables not included in the ATA system significantly impacted the prediction of disease persistence/recurrence: age, body mass index, tumor size, sex, family history of thyroid cancer, surgical approach, presurgical cytology, and circumstances of the diagnosis. CONCLUSION: Current risk stratification systems may be complemented by the inclusion of other variables in order to improve the prediction of treatment response. A complete dataset allows for more precise patient clustering.

Minimal Extrathyroidal Extension in Predicting 1-Year Outcomes: A Longitudinal Multicenter Study of Low-to-Intermediate-Risk Papillary Thyroid Carcinoma (ITCO#4).

Background: The role of minimal extrathyroidal extension (mETE) as a risk factor for persistent papillary thyroid carcinoma (PTC) is still debated. The aims of this study were to assess the clinical impact of mETE as a predictor of worse initial treatment response in PTC patients and to verify the impact of radioiodine therapy after surgery in patients with mETE. Methods: We reviewed all records in the Italian Thyroid Cancer Observatory database and selected 2237 consecutive patients with PTC who satisfied the inclusion criteria (PTC with no lymph node metastases and at least 1 year of follow-up). For each case, we considered initial surgery, histological variant of PTC, tumor diameter, recurrence risk class according to the American Thyroid Association (ATA) risk stratification system, use of radioiodine therapy, and initial therapy response, as suggested by ATA guidelines. Results: At 1-year follow-up, 1831 patients (81.8%) had an excellent response, 296 (13.2%) had an indeterminate response, 55 (2.5%) had a biochemical incomplete response, and 55 (2.5%) had a structural incomplete response. Statistical analysis suggested that mETE (odds ratio [OR] 1.16, p = 0.65), tumor size >2 cm (OR 1.45, p = 0.34), aggressive PTC histology (OR 0.55, p = 0.15), and age at diagnosis (OR 0.90, p = 0.32) were not significant risk factors for a worse initial therapy response. When evaluating the combination of mETE, tumor size, and aggressive PTC histology, the presence of mETE with a >2 cm tumor was significantly associated with a worse outcome (OR 5.27 [95% confidence interval], p = 0.014). The role of radioiodine ablation in patients with mETE was also evaluated. When considering radioiodine treatment, propensity score-based matching was performed, and no significant differences were found between treated and nontreated patients (p = 0.24). Conclusions: This study failed to show the prognostic value of mETE in predicting initial therapy response in a large cohort of PTC patients without lymph node metastases. The study suggests that the combination of tumor diameter and mETE can be used as a reliable prognostic factor for persistence and could be easily applied in clinical practice to manage PTC patients with low-to-intermediate risk of recurrent/persistent disease.

Real-World Performance of the American Thyroid Association Risk Estimates in Predicting 1-Year Differentiated Thyroid Cancer Outcomes: A Prospective Multicenter Study of 2000 Patients.

Background: One of the most widely used risk stratification systems for estimating individual patients' risk of persistent or recurrent differentiated thyroid cancer (DTC) is the American Thyroid Association (ATA) guidelines. The 2015 ATA version, which has increased the number of patients considered at low or intermediate risk, has been validated in several retrospective, single-center studies. The aims of this study were to evaluate the real-world performance of the 2015 ATA risk stratification system in predicting the response to treatment 12 months after the initial treatment and to determine the extent to which this performance is affected by the treatment center in which it is used. Methods: A prospective cohort of DTC patients collected by the Italian Thyroid Cancer Observatory web-based database was analyzed. We reviewed all records present in the database and selected consecutive cases that satisfied inclusion criteria: (i) histological diagnosis of DTC, with the exclusion of noninvasive follicular thyroid neoplasm with papillary-like nuclear features; (ii) complete data of the initial treatment and pathological features; and (iii) results of 1-year follow-up visit (6-18 months after the initial treatment), including all data needed to classify the estimated response to treatment. Results: The final cohort was composed of 2071 patients from 40 centers. The ATA risk of persistent/recurrent disease was classified as low in 1109 patients (53.6%), intermediate in 796 (38.4%), and high in 166 (8.0%). Structural incomplete responses were documented in only 86 (4.2%) patients: 1.5% in the low-risk, 5.7% in the intermediate-risk, and 14.5% in the high-risk group. The baseline ATA risk class proved to be a significant predictor of structural persistent disease, both for intermediate-risk (odds ratio [OR] 4.67; 95% confidence interval [CI] 2.59-8.43) and high-risk groups (OR 16.48; CI 7.87-34.5). Individual center did not significantly influence the prediction of the 1-year disease status. Conclusions: The ATA risk stratification system is a reliable predictor of short-term outcomes in patients with DTC in real-world clinical settings characterized by center heterogeneity in terms of size, location, level of care, local management strategies, and resource availability.

Are Evidence-Based Guidelines Reflected in Clinical Practice? An Analysis of Prospectively Collected Data of the Italian Thyroid Cancer Observatory.

OBJECTIVES: The goal of evidence-based practice guidelines is to optimize the management of emerging diseases, such as differentiated thyroid cancer (DTC). The aim of this study was to assess therapeutic approaches for DTC in Italy and to see how closely these practices conformed to those recommended in the 2009 American Thyroid Association (ATA) guidelines. METHODS: The Italian Thyroid Cancer Observatory was established to collect data prospectively on thyroid cancers consecutively diagnosed in participating centers (uniformly distributed across the nation). Data on the initial treatment of all pathologically confirmed DTC cases present in the database from January 1, 2013 (database creation) to January 31, 2016, were analyzed. RESULTS: A total of 1748 patients (77.2% females; median age 48.1 years [range 10-85 years]) were enrolled in the study. Most (n = 1640; 93.8%) were papillary carcinomas (including 84 poorly differentiated/aggressive variants); 6.2% (n = 108) were follicular and Hürthle cell carcinomas. The median tumor diameter was 11 mm (range 1-93 mm). Tumors were multifocal in 613 (35%) and presented extrathyroidal extension in 492 (28%) cases. Initial treatments included total thyroidectomy (involving one or two procedures; n = 726; 98.8%) and lobectomy (n = 22; 1.2%). A quarter of the patients who underwent total thyroidectomy had unifocal, intrathyroidal tumors ≤1 cm (n = 408; 23.6%). Neck dissection was performed in 40.4% of the patients (29.5% had central compartment dissection). Radioiodine remnant ablation (RRA) was performed in 1057 (61.2%) of the 1726 patients who underwent total thyroidectomy: 460 (41.2%) of the 983 classified by 2009 ATA guideline criteria as low-risk, 570 (87.1%) of the 655 as intermediate-risk, and 82 (93.1%) of the 88 as high-risk patients (p < 0.001). RRA was performed in 44% of the cases involving multifocal DTCs measuring ≤1 cm. CONCLUSIONS: The treatment approaches for DTCs used in Italy display areas of inconsistency with those recommended by the 2009 ATA guidelines. Italian practices were characterized by underuse of thyroid lobectomy in intrathyroidal, unifocal DTCs ≤1 cm. The use of RRA was generally consistent with risk-stratified recommendations. However, its frequent use in small DTCs (≤1 cm) that are multifocal persists, despite the lack of evidence of benefit. These data provide a baseline for future assessments of the impact of international guidelines on DTC management in Italy. These findings also illustrate that the dissemination and implementation of guideline recommendations, and the change in practice patterns, require ongoing education and time.

A registry-based study of thyroid paraganglioma: histological and genetic characteristics.

The precise diagnosis of thyroid neoplasias will guide surgical management. Primary thyroid paraganglioma has been rarely reported. Data on prevalence, immunohistochemistry (IHC), and molecular genetics in a systematic series of such patients are pending. We performed a multinational population-based study on thyroid paraganglioma and analyzed prevalence, IHC, and molecular genetics. Patients with thyroid paraganglioma were recruited from the European-American-Head-and-Neck-Paraganglioma-Registry. Demographic and clinical data were registered. Histopathology and IHC were re-investigated. All patients with thyroid paraganglioma underwent molecular genetic analyses of the SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, RET, TMEM127, and MAX genes. Analyses included Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) for detection of large rearrangements. Of 947 registrants, eight candidates were initially identified. After immunohistochemical analyses of these eight subjects, 5 (0.5%) were confirmed to have thyroid paraganglioma. IHC was positive for chromogranin, synaptophysin, and S-100 and negative for calcitonin in all five thyroid paragangliomas, whereas the three excluded candidate tumors stained positive for pan-cytokeratin, a marker excluding endocrine tumors. Germline variants, probably representing mutations, were found in four of the five confirmed thyroid paraganglioma cases, two each in SDHA and SDHB, whereas the excluded cases had no mutations in the tested genes. Thyroid paraganglioma is a finite entity, which must be differentiated from medullary thyroid carcinoma, because medical, surgical, and genetic management for each is different. Notably, approximately 80% of thyroid paragangliomas are associated with germline variants, with implications for additional tumors and a potential risk for the family. As opposed to sporadic tumors, surgical management and extent of resection are different for heritable tumors, each guided by the precise gene involved.

Divergences in insulin resistance between the different phenotypes of the polycystic ovary syndrome.

CONTEXT/OBJECTIVE: Current diagnostic criteria for polycystic ovary syndrome (PCOS) have generated distinct PCOS phenotypes, based on the different combinations of diagnostic features found in each patient. Our aim was to assess whether either each single diagnostic feature or their combinations into the PCOS phenotypes may predict insulin resistance in these women. PATIENTS/DESIGN: A total of 137 consecutive Caucasian women with PCOS, diagnosed by the Rotterdam criteria, underwent accurate assessment of diagnostic and metabolic features. Insulin sensitivity was measured by the glucose clamp technique. RESULTS: Among women with PCOS, 84.7% had hyperandrogenism, 84.7% had chronic oligoanovulation, and 89% had polycystic ovaries. According to the individual combinations of these features, 69.4% of women had the classic phenotype, 15.3% had the ovulatory phenotype, and 15.3% had the normoandrogenic phenotype. Most subjects (71.4%) were insulin resistant. However, insulin resistance frequency differed among phenotypes, being 80.4%, 65.0%, and 38.1%, respectively, in the 3 subgroups (P < .001). Although none of the PCOS diagnostic features per se was associated with the impairment in insulin action, after adjustment for covariates, the classic phenotype and, to a lesser extent, the ovulatory phenotype were independently associated with insulin resistance, whereas the normoandrogenic phenotype was not. Metabolic syndrome frequency was also different among phenotypes (P = .030). CONCLUSIONS: There is a scale of metabolic risk among women with PCOS. Although no single diagnostic features of PCOS are independently associated with insulin resistance, their combinations, which define PCOS phenotypes, may allow physicians to establish which women should undergo metabolic screening. In metabolic terms, women belonging to the normoandrogenic phenotype behave as a separate group.

Body fat and insulin resistance independently predict increased serum C-reactive protein in hyperandrogenic women with polycystic ovary syndrome.

OBJECTIVE: Increased serum C-reactive protein (CRP), an independent predictor of coronary heart disease, was reported in women with polycystic ovary syndrome (PCOS). It remains unclear whether this finding is due to the association between PCOS and either insulin resistance, obesity, or androgen excess, which are all common features of this condition. The aims of this study were to assess whether increased serum CRP is a specific feature of PCOS and to investigate the mechanisms underlying this association. DESIGN AND METHODS: Serum high-sensitivity CRP (hs-CRP) was measured in 86 hyperandrogenic women (age 21.6+/-4.2 years, body mass index (BMI) 23.6+/-3.5 kg/m2), 50 with PCOS and 36 with idiopathic hyperandrogenism (HA). Thirty-five BMI-matched healthy women were also studied as controls. In these subjects, endocrine and metabolic profiles were assessed. In all hyperandrogenic subjects and 14 controls, insulin sensitivity was measured by the glucose clamp technique. Body fat was measured by bioelectrical impedance. RESULTS: Hs-CRP concentrations were higher in PCOS women (3.43+/-2.01 mg/l) than in HA subjects and healthy women (2.43+/-1.04, P<0.005; and 2.75+/-0.86 mg/l, P<0.05 respectively versus PCOS). In multiple regression analyses, increased serum hs-CRP was independently predicted by higher body fat and lower insulin sensitivity. However, in lean women, serum-free testosterone was an additional, negative, predictive variable. CONCLUSIONS: PCOS is accompanied by a low-grade chronic inflammation. Body fat appears the main determining factor of this finding, which is only partly explained by insulin resistance. At least in lean women, androgen excess per se seems to play an additional, possibly protective, role in this association.