Prognostic value of serum Tg and TgAb in patients with differentiated thyroid carcinoma treated with ii I after' resection Baya". Zulayati Kuerban, Nazi Yilihamu': Xie Bin, Liu Lishui. " Department of Nuclear Medicine, The First Aftlia.ted Hospital of Xinjiang Medical Unwersity, Xinjiang Province , Urumgi 830054 , ChinaCorresponding author: Baya  E-mail :yasser216 163. comFunding program : Natural Science Foundation of Xinjang Uygur Autonomous Region ( 2017D01 C354)

Abstract：

Objective To analyze the predictive value of serum thyroglobulin(Tg) and thyroglobulin antibody(TgAb) on the prognosis of patients with differentiated thyroid carcinoma treated with ¹³¹I after resection. Methods One hundred and ninety-one patients with differentiated thyroid cancer were treated by thyroid surgery in the First Affiliated Hospital of Xinjiang Medical University from January 2017 to December 2019. They received ¹³¹I treatment after surgery and were followed up for 1 year after treatment. According to the follow-up results, the patients were divided into two groups: the group with good prognosis and the group with poor prognosis. The clinical data of the patients in the two groups were compared, and the indexes of thyroid function [triiodothyronine(T₃), thyroxine(T₄) Free triiodothyronine(FT₃), free thyroxine(FT₄), thyrotropin(TSH), Tg, TgAb], neutrophil gelatinase-associated lipid carrier protein(NGAL) and imaging indicators(lymph node metastasis, multi-focus metastasis, size of metastasis, number of metastasis). The factors affecting the prognosis of patients were analyzed by using multivariate logistic regression model, The predictive value of the prognostic indicators of patients was analyzed by the ROC. Results During the follow-up, 8 patients were lost and 183 patients were eventually included, including 127 patients with good prognosis and 56 patients with poor prognosis. In the poor prognosis group, the tumor stage Ⅲ to Ⅳ, multiple metastasis, the proportion of lesions>1 cm, and the serum Tg, TgAb, NGAL levels were higher than those in the good prognosis group [χ²(t)/P=12.601/<0.001, 4.165/0.042, 7.741/0.005, 10.657/<0.001, 10.592/<0.001, 8.586/<0.001];There was no significant difference between the two groups in T₃, T₄, FT₃, FT₄, TSH, lymph node metastasis and the number of metastatic foci(P>0.05). Multivariate logistic regression analysis showed that high Tg, high TgAb, high NGAL level and multifocal metastasis were independent risk factors for the prognosis of patients [OR(95% CI)=1.114(1.060-1.172), 1.016(1.007-1.025), 1.108(1.042-1.178), 68.700(2.712-1 740.439)], while tumor stage I-II was an independent protective factor for the prognosis of patients [OR(95% CI)=0.026(0.001-0.696)]. The ROC curve showed that the area under the curve(AUC) of serum Tg, TgAb, NGAL and their combination to predict the prognosis of patients were 0.908, 0.852, 0.805 and 0.977, respectively. The combined predictive value of the three indicators was higher than that of single indicators(Z=3.329, 4.013, 4.881, P<0.001). Conclusion The combination of serum Tg and TgAb can effectively predict the prognosis of patients with differentiated thyroid cancer undergoing ¹³¹I treatment after operation, which has high diagnostic value and diagnostic efficacy.

Thyroid carcinoma,differentiated;                    Thyroglobulin;                    Thyroglobulin antibody;                    ¹³¹I treatment;                    Prognosis;