Preoperative anti-thyroid antibodies predict malignancy risk in cytologically indeterminate thyroid nodules: a...

Cytologically indeterminate thyroid nodules (CITNs) are heterogeneous, and their assessment remains controversial. In this study, we examined the prognostic utility of anti-thyroid antibodies for predicting thyroid cancer (TC) in CITNs.

This prospective multicenter analysis included all patients with CITNs who were surgically treated between August 2023 and August 2024 at two hospitals in Saudi Arabia; preoperative anti-thyroid antibodies [thyroid peroxidase and thyroglobulin antibodies (TgAbs)], thyroid stimulating hormone (TSH), and a definitive histological diagnosis were required for inclusion. Multivariate analysis was used to identify independent predictors of TC.

This study included 76 individuals; 70/76 (92.1%) were women. Overall, 43/76 (56.6%) nodules had a cytological diagnosis of atypia of undetermined significance (AUS) (Bethesda III), whereas 33/76 (43.4%) were follicular neoplasms (FNs) (Bethesda IV). Pathological analysis revealed that 56/76 (73.7%) patients had benign nodules and 20/76 (26.3%) had malignant tumors. The coexistence of elevated levels of both antibodies and TSH demonstrated the highest odds ratio [3.10; 95% confidence interval (CI): 1.14-5.47], signifying a significant correlation with TC (P=0.003). Furthermore, high levels of one antibody along with elevated TSH levels resulted in an odds ratio of 2.25 (95% CI: 1.02-6.44), indicating a significant association with TC (P=0.04). The multivariate analysis identified Bethesda IV cytological diagnoses, the presence of Hashimoto's thyroiditis, and TSH levels >1 mIU/L as independent predictors of TC.

Elevated anti-thyroid antibody and TSH levels were effective predictors of TC in CITNs. These findings may help guide endocrine surgeons managing patients with these nodules.