Stimulated Thyroglobulin and Pre-ablation Antithyroglobulin Antibody Product Can Predict the Response to Radioiodine Therapy in TgAb-positive Differentiated Thyroid Cancer Pa-tients: A Retrospective Study

Abstract

Objective We aimed to explore the predictive value of stimulated thyroglobulin(sTg) and pre-ablation antithyroglobulin (paTgAb) product to the effect of radioiodine therapy (RAIT) in TgAb-positive DTC patients.Methods We totally enrolled 265 patients with TgAb-positive DTC who underwent RAIT after total thyroidectomy (TT) in this study. Based on the last follow-up result, patients were divided into two groups, which were excellent response (ER) group and non-excellent response (NER) group. We analyzed the factors related to the effect of RAIT.Results The ER group was consisted of 197 cases. NER group was consisted of 68 cases. For the univariate analysis, we found that maximal tumor diameter, whether with extrathyroidal extension (ETE), bilateral or unilateral primary lesion, preop-TgAb, paTgAb, sTg×paTgAb and N stage showed significantly differently in ER group and NER group. ROC curves showed the cut-off value was 724.25 IU/ml, 424.00 IU/ml, and 59.73 for preop-TgAb, paTgAb, sTg×paTgAb, respectively. The multivariate logistic regression analysis results indicated that paTgAb, sTg×paTgAb and N stage were independent risk factors for NER. For the Kaplan-Meier analysis of DFS, the median DFS of patients with sTg×paTgAb<59.73 was significantly longer than patients with sTg×paTgAb ≥ 59.73 (48.59months vs. 50.27months, p = 0.041).Conclusion We found that sTg and paTgAb conduct is a good predictor of efficacy to RAIT in TgAb-positive DTC patients. It can play a very positive and important role in optimizing treatment, improving prognosis and reducing the burden of patients.