分化型甲状腺癌^(131)I治疗前刺激性Tg动态变化与远处转移的关系

Relationship between Variation of Pre-ablation Stimulated Thyroglobulin and Distant Metastasis in Patients with Differentiated Thyroid Cancer

目的探讨分化型甲状腺癌(DTC)131 I治疗前未服或停服甲状腺激素状态下测定的刺激性甲状腺球蛋白(s Tg)的动态变化及其与远处转移的关系。方法远处转移组(M1)38例和非远处转移组(M0)130例。动态监测131I治疗前s Tg及相应促甲状腺激素(TSH)值(首次记为Tg1、TSH1,末次记为Tg2、TSH2)。比较两组Tg1、Tg2、s Tg变化值(ΔTg)及s Tg随TSH变化比值(ΔTg/ΔTSH)有无差异。用ROC曲线及最佳诊断界值点(DCP)评估以上指标对远处转移的预测价值。结果 M1组Tg1和Tg2均显著高于M0组(P均<0.001),ROC曲线下面积分别为0.921和0.942,其中Tg2对远处转移预测准确性更高,达85.71%(DCP=24.30 ng/ml,灵敏度92.11%,特异度83.85%)。两组间ΔTg及ΔTg/ΔTSH差异均有统计学意义(P均<0.01);△Tg/△TSH对远处转移预测准确性及特异度均优于Tg2(分别为87.50%和86.92%)。结论131I治疗前动态监测s Tg有助于提高DTC远处转移预测的准确性和特异度,△Tg/△TSH所反映的s Tg随TSH变化比值可作为DTC远处转移有效的预测指标。

Objective To investigate the relationship between the dynamic variation of pre-ablation stimulated thyroglobulin（ s Tg） and distant metastasis in patietns with differentiated thyroid cancer（ DTC）.Methods DTC patients after total or near total thyroidectomy were divided into two groups as M1 group（ n =38） and M0 group（ n = 130） according to the presence of distant metastases or not. Clinical data including preablation s Tg and the corresponding thyrotropin（ TSH） values were dynamically measured. The pre-ablation s Tg and corresponding TSH collected at the first time were defined as Tg1 and TSH1,while as Tg2 and TSH2 at thelast time. χ2test was used to compare the variation tendency of s Tg between these two groups. Tg1,Tg2,preablation s Tg variation（ ΔTg）,and ΔTg / ΔTSH ratio between M0 and M1 were compared by Mann-Whitney ranksum test. The receiver operating characteristic（ ROC） curves and diagnostic critical point（ DCP） were employed to evaluate the predictive values of the above indicators. Results Both Tg1 and Tg2 of M1 were significantly higher than those of M0（ the Mann-Whitney rank-sum test： Tg1 P〈0. 001,Tg2 P〈0. 001）. The corresponding areas under the ROC curve（ AUC） to differentiate the two groups were 0. 921 and 0. 942,respectively. The cut-off value of Tg2,which was more accurate in predicting distant metastasis,was 24. 3 ng / ml with a sensitivity of 92. 11% and a specificity of 83. 85%. Both ΔTg and ΔTg / ΔTSH between these two groups were significantly different（ the Mann-Whitney rank-sum test： ΔTg P = 0. 002,ΔTg / ΔTSH P〈0. 001）. ΔTg / ΔTSH worked better than Tg2 in predicting distant metastasis with both higher accuracy（ 87. 50%） and higher specificity（ 86. 92%）. Conclusions Dynamically tracing pre-ablation s Tg may improve the accuracy and specificity of distant metastases prediction in DTC patients. ΔTg / ΔTSH,which means the ratio of s Tg variation to TSH variation,may be a useful diagnostic marker for predicting distant metastases in DTC.