Thyroid Research Thyroid Research Archive Thyroid Cancer

High serum antithyroglobulin concentrations after initial therapy predict recurrence in patients with thyroid carcinoma

(November 2002)

The background of the study. Some patients with thyroid carcinoma have high serum antithyroglobulin antibody concentrations after surgical and radioiodine therapy. In this study the relationship between high serum antithyroglobulin antibody concentrations after initial treatment and outcome in patients with thyroid carcinoma was evaluated.

How the study was done. The study subjects were 226 patients with thyroid carcinoma treated by surgery and radioiodine who subsequently had no detectable thyroid tissue and serum thyroglobulin concentrations <1 ng/ml. Serum antithyroglobulin antibodies were measured then and during follow up in each patient, and the patients were studied for recurrent tumor.

The results of the study. The initial serum antithyroglobulin antibody concentrations were <100 U/ml (negative) in 175 patients (77 percent), of whom 6 patients (3 percent) had a recurrence during follow up. Serum antithyroglobulin antibody concentrations were ≥100 U/ml in 51 patients (23 percent), of whom 25 (49 percent) had a recurrence after a mean disease-free interval of 52 months, and 26 (51 percent) had no recurrence during a mean follow-up period of 25 months.

In the 51 patients with high serum antithyroglobulin antibody concentrations, the initial values were higher in the 25 patients who had a recurrence than in the 26 patients who did not. Fourteen of the 25 patients responded to therapy; serum antithyroglobulin antibody concentrations decreased in 10 and did not change or increased in 4. Serum antithyroglobulin antibody concentrations decreased in 19 of the 26 patients (73 percent) (to values <100 U/ml in 12 patients) who did not have a recurrence during follow-up.

The conclusions of the study. In patients with thyroid carcinoma, those who have high serum antithyroglobulin antibody concentrations after initial therapy are more likely to have recurrent carcinoma than those with low concentrations.

The original article. Chung JK, Park YJ, Kim TY, So Y, Kim SK, Park DJ, Less DS, Lee MC, Cho BY. Clinical significance of elevated level of serum antithyroglobulin antibody in patients with differentiated thyroid cancer after thyroid ablation. Clin Endocrinol 2002;57:215-21.