Prognostic significance of changes in serum thyroglobulin antibody levels of pre- and post-total thyroidectomy in thyroglobulin antibody-positive papillary thyroid carcinoma patients

Although postoperative serum thyroglobulin (Tg) is a prognostic indicator for papillary thyroid carcinoma (PTC), it is unreliable when Tg antibody (TgAb) is positive. We evaluated the prognostic significance of changes in serum TgAb levels of pre- and post-total thyroidectomy in TgAb-positive PTC patients. We reviewed our medical charts of 225 TgAb-positive PTC patients in whom TgAb levels were measured before and 1–2 years after total thyroidectomy, performed between April 2002 and March 2007. We divided them into 3 groups based on changes in TgAb levels. Postoperative serum TgAb levels decreased by ≥50% in 181 patients (80.4%) (Group 1), by