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.
Data-driven Thyroglobulin Cutoffs for Low- and Intermediate-risk Thyroid Cancer Follow-up: ITCO Real-world Analysis / Grani, G., D'Elia, S., Puxeddu, E., Morelli, S., Arvat, E., Nervo, A., Spiazzi, G., Rolli, N., Zatelli, M.C., Ambrosio, M.R., Ceresini, G., Marina, M., Mele, C., Aimaretti, G., Santaguida, M.G., Virili, C., Crescenzi, A., Palermo, A., Rossetto Giaccherino, R., Meomartino, L., et al.. - In: THE JOURNAL OF CLINICAL ENDOCRINOLOGY AND METABOLISM. - ISSN 0021-972X. - 110:5(2025), p. 1377. [10.1210/clinem/dgae559]
Data-driven Thyroglobulin Cutoffs for Low- and Intermediate-risk Thyroid Cancer Follow-up: ITCO Real-world Analysis
Porcelli, Tommaso;
2025
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
