Evaluation of recurrence risk in patients with papillary thyroid cancer through tumor-node-metastasis staging: A single-center observational study in Taiwan

Background: Many patients with papillary thyroid cancer (PTC) demonstrate satisfactory outcomes. However, 8%–28% of patients with PTC show tumor recurrence, which may affect prognosis. Therefore, identifying factors associated with tumor recurrence in patients with PTC may be helpful to refine therapeutic strategies. Methods: To identify factors associated with PTC recurrence, we retrospectively reviewed demographic features (sex and age), operation method, image character, serum thyroglobulin (Tg), accumulated radioactive iodine (I-131) therapeutic dose, I-131 uptake, and metastases at diagnosis in 829 patients with PTC. Patients were grouped into early (stage I and II; n = 698) and advanced (stage III and IV; n = 131) tumor-node-metastasis (TNM) stages. Recurrence rate, mortality rate, risk factors of recurrence, recurrent free survival and overall survival curve were compared between two groups. Results: Patients in the early stage demonstrated a lower recurrence rate (7.2%) than did those in the advanced stage (28.2%, p