Clausi Cristina, Censi Simona, Zanin Emma, Messina Giulia, Piva Ilaria, Basso Daniela, Merante Boschin Isabella, Bertazza Loris, Torresan Francesca, Iacobone Maurizio, Battheu Fiammetta, Barollo Susi, Arnone Jacopo Maria, Mian Caterina
Department of Medicine (DIMED), University of Padua, Padova, Italy.
Endocrinology Unit, University Hospital of Padova, Padova, Italy.
Clin Endocrinol (Oxf). 2025 Oct;103(4):587-595. doi: 10.1111/cen.15287. Epub 2025 Jun 4.
Calcitonin (CT) represents the most important biochemical marker of medullary thyroid cancer (MTC), but has certain limits. Procalcitonin (ProCT) has been recognized as an alternative or additional marker for MTC. The aim of the study is to evaluate prospectively the role of ProCT combined with CT in the identification of MTC.
Patients and measurements: 478 patients undergoing thyroidectomy in Padua between January 2023 and June 2024 were enrolled to investigate ProCT levels in comparison with CT for MTC diagnosis. Serum levels of ProCT and CT were dosed preoperatively.
At histological diagnosis, 23/478 (4.8%) patients tested positive for MTC. CT with a cut-off > 10 pg/mL performed as follows: sensitivity 0.91, specificity 0.98, positive predictive value (PPV) 0.7, negative predictive value (NPV) 0.99. CT with a cut-off > 10 pg/mL performed better than ProCT both using the cut-off of 0.04 ng/mL (sensitivity 0.87; specificity 0.96; PPV 0.56; NPV 0.99) and the cut-off of 0.07 ng/mL (sensitivity 0.78; specificity 0.98; PPV 0.72; NPV 0.99). Within the sample of patients with a CT value between 10 and 100 pg/mL, 17/21 (80.9%) patients would have been correctly identified as MTC or non-MTC based on a positive or negative ProCT using the 0.04 ng/mL cut-off.
CT is more sensitive than ProCT as a diagnostic marker for MTC. However, a two-step approach using ProCT as a supplementary marker can help to refine the diagnosis avoiding overtreatment, particularly when CT serum levels lie between 10 and 100 pg/mL.
降钙素（CT）是甲状腺髓样癌（MTC）最重要的生化标志物，但有一定局限性。降钙素原（ProCT）已被视为MTC的替代或补充标志物。本研究旨在前瞻性评估ProCT联合CT在MTC诊断中的作用。
患者与测量：纳入2023年1月至2024年6月在帕多瓦接受甲状腺切除术的478例患者，研究ProCT水平并与CT用于MTC诊断进行比较。术前检测血清ProCT和CT水平。
组织学诊断时，478例患者中有23例（4.8%）MTC检测呈阳性。CT临界值>10 pg/mL时表现如下：敏感性0.91，特异性0.98，阳性预测值（PPV）0.7，阴性预测值（NPV）0.99。CT临界值>10 pg/mL时，无论是使用0.04 ng/mL的临界值（敏感性0.87；特异性0.96；PPV 0.56；NPV 0.99）还是0.07 ng/mL的临界值（敏感性0.78；特异性0.98；PPV 0.72；NPV 0.99），其表现均优于ProCT。在CT值介于10至100 pg/mL的患者样本中，基于ProCT使用0.04 ng/mL临界值的阳性或阴性结果，17/21（80.9%）的患者能够被正确诊断为MTC或非MTC。
作为MTC的诊断标志物，CT比ProCT更敏感。然而，采用两步法将ProCT作为补充标志物有助于优化诊断，避免过度治疗，尤其是当CT血清水平介于10至100 pg/mL之间时。
