TPO and neoplasm: In multivariate analysis with adjusting the clinical factors that included age, tumour size, and anti-TPO, the subjects with preoperative Tg greater than 19.4 ng/mL exhibited an increased risk of detectable sTg 6–12 months after RAI ablation (OR: 2.604, 95% CI: 1.339 to 5.062, P = 0.005).