TG and neoplasm: According to the univariate Cox analysis in the training cohort, capsular invasion (HR = 2.824, 95%CI = 1.486–5.365, P = 0.002), tumor size (HR = 1.062, 95%CI = 1.044–1.081, P < 0.001), ETE (HR = 3.335, 95%CI = 1.565–7.104, P = 0.002), LN metastasis (HR = 3.553, 95%CI = 1.787–7.064, P < 0.001), preoperative Tg (HR = 1.004, 95%CI = 1.002–1.006, P < 0.001) were identified as risk factors for recurrence in PTC patients.