Thyroglobulin - what is the postoperative threshold for the suspicion of thyroid cancer recurrence in the absence of anti-Tg antibody measurement?

• Published in: South African journal of surgery Vol. 49; no. 3; pp. 118 - 122
• Main Authors: Papageorgiou, M S, Liratzopoulos, N, Minopoulos, G, Manolas, K J
• Format: Journal Article
• Language: English
• Published: South Africa South African Sports Medicine Association 01.08.2011
• Subjects: Adolescent; Adult; Aged; Antibodies; Autoantibodies - blood; Carcinoma - blood; Carcinoma - pathology; Carcinoma - surgery; Care and treatment; Diseases; Female; Health aspects; Humans; Male; Middle Aged; Neoplasm Recurrence, Local - blood; Neoplasm Recurrence, Local - pathology; Physiological aspects; Predictive Value of Tests; Prognosis; Relapse; Retrospective Studies; Thyroglobulin; Thyroglobulin - blood; Thyroid cancer; Thyroid Neoplasms - blood; Thyroid Neoplasms - pathology; Thyroid Neoplasms - surgery; Thyroidectomy; Viral antibodies; Young Adult; South Africa
• ISSN: 0038-2361

Thyroglobulin (Tg) is used as a postoperative marker for the follow-up of patients with thyroid carcinoma, but there is no consensus regarding the value that may indicate possible recurrence. Aim. To evaluate Tg levels as a marker for recurrence of thyroid carcinoma. Demographics and survival of 80 patients who underwent total thyroidectomy for well-differentiated thyroid cancer were analysed and related to Tg levels. Tg measurements were performed when patients were euthyroid, after completion of treatment. The median Tg value was 1.3 ng/ml. Higher values were found in males, high-risk patients and patients with recurrent disease. Using the median Tg value as cut-off, patients were divided into two groups (group I ≤1.3 ng/ml and group II >1.3 ng/ml). There was a significant correlation between values >1.3 ng/ml and recurrence. When survival was related to Tg values, there was a tendency towards worse prognosis in group II. The best predictive cut-off value for recurrence was found to be 1.3 ng/ml, which had a sensitivity of 77% and a specificity of 57%. Although low, a cut-off Tg level of 1.3 ng/ml represents a simple indication for further investigation in patients receiving thyroxine after completion of treatment for thyroid cancer, in the absence of measurement of anti-Tg auto-antibodies.