淋巴结转移对分化型甲状腺癌手术及^(131)I治疗后血清甲状腺球蛋白抗体转阴的影响

Effect of Lymph Node Metastasis on Change of Positive Thyroglobulin Antibody in Differentiated Thyroid Carcinoma after Initial Treatment

目的探讨淋巴结转移对分化型甲状腺癌患者经手术及^(131)I治疗后阳性甲状腺球蛋白抗体(TgAb)转阴情况的影响。方法回顾性分析98例^(131)I治疗前TgAb阳性(≥115 IU/ml)患者,所有患者均行全或近全甲状腺切除+淋巴结清扫术。经过^(131)I"清甲"治疗后中位随访21个月,根据TgAb是否转阴分为转阴组(n=83)和未转阴组(n=15),采用单因素方差分析、χ~2检验、Kruskal-Wallis秩和检验比较2组患者的年龄、淋巴结转移数及转移率、淋巴结分期、^(131)I治疗剂量等因素,通过多因素分析探讨影响TgAb转阴的预测因素,并应用受试者工作特征曲线评估影响TgAb转阴因素的预测价值及最佳界值点。结果未转阴组N1a及N1b比例及淋巴结转移率均显著高于转阴组(Mann-Whitney U,Z=-3.498,P=0.000),且未转阴组中无N0患者(Fisher's Exact Test,P=0.032)。受试者工作特征曲线显示,淋巴结转移率预测TgAb转阴界值点为24%,对应的灵敏度为71.4%。多因素分析显示,淋巴结分期可作为预测患者TgAb转阴的独立危险因素(OR=3.183,P=0.038)。结论淋巴结侵犯及转移率影响TgAb的转阴,淋巴结分期是TgAb转阴的独立预测因素。以24%作为淋巴结转移率的最佳界值点,对预测TgAb转阴具有较高的灵敏度和特异性。

Objective To investigate the influence of lymph node metastasis on the change of positive thyroglobulin antibody（Tg Ab） in differentiated thyroid carcinoma after initial treatment.Methods We retro-spectively analyzed the clinical data of 98 differentiated thyroid carcinoma patients with positive Tg Ab（≥115 IU/ml） before radioiodine（RAI） therapy.All of whom underwent total or near total thyroidectomy,neck lymph node dissection,and subsequent RAI therapy.Patients were divided into negative group（n=83） and non-negative group（n=15） according to the disappearance of positive Tg Ab or not after a mean follow-up of 21.0 months.Analysis of variance,χ~2 test,and Mann-Whitney rank-sum test were applied to compare the basic clinical features including number of metastatic lymph nodes,lymph node metastasis rate and node stage,and dose of RAI ablation.The receiver operating characteristic curves were employed to evaluate the predictive values of Tg Ab levels（negative or positive） and optimal cut-off points.Multivariate analyses were further performed to explore the independent indicators for persistent positive Tg Ab.Results Compared with the negative group,the proportions of N1a and N1b in the non-negative group were significantly higher,with no N0 in the non-negative group（Fisher＇s Exact Test,P=0.032）.The median metastatic lymph node rate was also significantly higher in the non-negative group（Mann-Whitney U=-3.498,P=0.000）.The cut-off value for metastatic lymph node rate to predicting disappearance of positive Tg Ab was 24%,and its sensitivity was 71.4%.The multivariate analysis showed that only lymph node stage（OR=3.183,P=0.038） was the independent indicator for persistent positive Tg Ab.Conclusions Lymph node stage was an independent indicator for the disappearance of positive Tg Ab.A metastatic lymph node rate of higher than 24% may be predictive for the disappearance of positive Tg Ab.