The Efficacy Of ¹³¹I Therapy For Postoperative Differentiated Thyroid Carcinoma And Significance Of TgAb In Monitoring And Evaluating The Prognosis

IntroductionThyroid carcinoma is the most common malignancy of the endocrine system.Well-differentiated thyroid cancers(DTC)account for a percentage of 90%thyroid cancer,primarily papillary(PTC)and follicular carcinomas(70%-75%and15%-20%,respectively).Therapeutic approach for DTC is multifactorial,including surgery and thyroid hormone suppressive therapy,often followed by radioactive 131I treatment.It has been considered that surgery is the most important part of the treatment process and can directly affect the subsequent 131I and TSH suppression treatment of DTC,and has a close relationship with the prognosis.Moreover,131I treatment plays an important role in the postoperative treatment of DTC.Postoperative 131I treatment includes 131I thyroid ablation therapy and 131I ablating thyroid remnant(or known or suspected persistent neoplastic foci)treatment.The first 131I thyroid ablation therapy is critical;131I ablating thyroid remnant also plays an important role in the prognosis of DTC.At present,research reports on the efficacy and influencing factors of 131I are not the same.In this study,we retrospectively analyzed the clinical data of 131I treatment of DTC and explored the curative effect of 131I and its influencing factors.After surgery and 131I removal of residual thyroid gland,serum thyroglobulin(Tg)is a specific tumor marker of DTC,which has important clinical value in monitoring DTC recurrence and metastasis.The detection of Tg is affected by thyroglobulin antibody(TgAb)in the serum.Therefore,serum Tg should be taken into account as an indicator of disease monitoring and therapeutic efficacy.TgAb should be considered in the serum.Therefore,Tg is only measured in TgAb-negative patients.For TgAb-positive patients,the presence of TgAb may also reflect the persistence of DTC lesions and may be used as a surrogate marker for Tg.At present,the diagnostic value of TgAb is not perfect.In this study,the level of TgAb was monitored during follow-up to further explore its value in the evaluation of prognosis.ObjectiveTo investigate the efficacy and influential factors of post-resection 131I therapy in DTC patients with residual thyroid tissue and metastasis can not be removed by surgery.Meanwhile,it is also essential to explore the significance of TgAb monitoring and evaluating the prognosis.MethodsDTC patients(119 males,316 females;age range 14~77 years)from April2011 to December 2016 in Henan Province People's Hospital were retrospectively analyzed.All patients underwent 131I therapy,and the therapeutic effect was assessed.The case datas were as detail as possible.435 patients were treated with131I ablation for thyroid remnant,126 patients were treated with adjuvant therapy,107 TgAb-positive patients,328 TgAb-negative patients.The clinical information of the patient's gender,age,surgical procedures,with or without Hashimoto thyroiditis(HT),histological type,TNM stage,with or without lymph node and(or)distant metastasis,time interval between first 131I therapy and thyroidectomy,131I dose,the value of thyroid stimulating hormone(TSH)before 131I therapy,stimulated serm thyroglobulin(sTg)and thyroglobulin antibody(TgAb)were collected.Univariate analysis(?~2 test,rank sum test)and the Logistic regression analysis were performed to select the influential factors for treatment effect.In addition,the cases were followed up and monitored.According to the change of TgAb during the follow-up,the value of the study on the monitoring and evaluation of the disease recurrence/metastasis was analyzed.ResultsThe initial 131I therapy ablation success rate was 75.4%(328/435).Univariate analysis factors of 131I therapy showed that age,with or without HT,TNM staging,the preablation sTg level and with/without metastases were influential factors for the initial postoperative 131I therapy(?~2 value:2.678?9.709?10.157?-4.678?49.375;all P<0.05).Logistic regression analysis showed that with/without metastases was an independent influential factor for 131I therapy on patients with residual thyroid tissue(P<0.05).The effective rate of 131I therapy on treatment of metastasis was 72.2%(91/126).Univariate analysis factors of 131I therapy showed that the sTg level and with/without metastases were influential factors for the 131I treatment of metastasis(?value:-2.575;?~2 value:12.591;both P<0.05).Logistic regression analysis showed that with/without metastases were independent influential factors for 131I therapy on patients with metastasis(P<0.05).The difference between TgAb-negative and TgAb-positive patients in DTC recurrence/metastasis was statistically significant(?~2=13.094,P=0.001).There were statistically significant difference in tumor size,whether extrathyroidal extension,risk stratification,and concurrent with Hashimoto's thyroiditis between TgAb-positive patients with recurrence/metastasis and without recurrence/metastasis(?~2=6.860?7.067?25.369?16.581,all P<0.05).There were statistically significant difference in tumor size,whether extrathyroidal extension and risk stratification between TgAb-negative patients with recurrence/metastasis and without recurrence/metastasis(?~2=6.086?187.924?108.873,all P<0.05).The difference between the TgAb-negative patients and the TgAb-positive patients in the recurrence/metastasis of disease was statistically significant.TgAb persistent negative group,positive to negative group,persistent positive group in disease recurrence/metastasis difference was statistically significant(?~2=64.217,P<0.001)ConclusionThe curative effect of 131I after the operation of DTC was obvious.The success rate of initial 131I therapy ablation was 75.4%,and the effective rate of 131I therapy on treatment of metastasis was 72.2%.The metastasis situation is a good predictor to predict the curative effect of remnant ablation.The success rate of remnant ablation combined with metastases is lower than those without metastases.The site of metastasis is an predictive marker for the curative effect of the treatment on metastasis,and the efficacy of distant metastases is less than that of cervical lymph nodes.In TgAb-positive patients,the larger tumor size,the presence of extrathyroidal invasion,and the higher the risk stratification,the higher the prognosis may be,but the prognosis of the merger with Hashimoto may be better.In TgAb-negative patients,the larger tumor size,the presence of extrathyroidal invasion,and the higher the risk stratification,the worse the prognosis may be.Patients with positive TgAb and elevated levels during follow-up have a high rate of recurrence/metastasis in DTC patients.