Thyroglobulin levels measured at the time of remnant ablation to predict response to treatment in differentiated thyroid cancer after thyroid hormone withdrawal or recombinant human TSH

Abstract

The objective of our study was to evaluate the prognostic value of stimulated thyroglobulin levels at the moment of remnant ablation for predicting an initial excellent or a structural incomplete response to treatment according to the risk of recurrence in patients with differentiated thyroid cancer. Patients were divided into two groups according to the preparation mode for remnant ablation (thyroid hormone withdrawal or recombinant human TSH). We included 219 patients followed-up for at least for 24 months after remnant ablation. The primary endpoint was the best response to initial therapy assessed in the first 9-18 months of follow-up. An excellent response was observed in 45.1 % of patients prepared after recombinant human TSH compared to 44.6 % of patients prepared after thyroid hormone withdrawal (P = NS). The cutoff value of thyroglobulin level after recombinant human TSH for predicting an excellent response was 8 ng/ml (n = 51), with a sensitivity of 73.9 %, and a positive predictive value of 61 %. It was similar for patients with low vs. intermediate to high risk of recurrence. This cutoff value for thyroglobulin level after thyroid hormone withdrawal was 22 ng/ml (n = 168), with a sensitivity of 94.7 % and a positive predictive value of 61.7 %. In the thyroid hormone withdrawal group the thyroglobulin cutoff level was 12 ng/ml for low-risk patients compared to 16 ng/ml for those with intermediate to high risk of recurrence (P = 0.003). The cutoff value of the thyroglobulin level for predicting a structural incomplete response to initial treatment was 20 ng/ml after rhTSH, with a negative predictive value of 91.4 %. This level was higher in thyroid hormone withdrawal group, and it was established at 25 ng/ml, with a negative predictive value of 97.7 %. The stimulated Tg level seems to be different depending on the preparation mode (rhTSH or THW) for RA. It has a high NPV to predict the absence of a structural incomplete response and it is also a good predictor of the initial excellent response and the NED status at the end of follow-up.

BRAF V600E Status and Stimulated Thyroglobulin at Ablation Time Increase Prognostic Value of American Thyroid Association Classification Systems for Persistent Disease in Differentiated Thyroid Carcinoma

“…Therefore, it is possible to identify a subset of thyroid cancer with poor uptake from the first radioiodine treatment by combining high A-hTg levels with absent or reduced uptake at WBS postradioiodine treatment. We did not find any significant difference regarding the performance of AUC cut-off of stimulated A-hTg ablation prepared by THW or Thyrogen in comparison with the work of Pitoia et al [19] and Ciappuccini et al [18]. In addition, the modality of preparation for radioiodine treatment (THW vs. Thyrogen) was not significant in the Cox regression analysis with respect to persistent disease.…”

“…Recently, some authors have proposed a value of ablation hTg (A-hTg) lower than 10 ng/ml as a favourable factor on the subsequent disease-free status [16]. Additionally, different retrospective studies have confirmed this predictive prognostic value [17–19].…”

Efficacy and Affecting Factors of 131I Thyroid Remnant Ablation After Surgical Treatment of Differentiated Thyroid Carcinoma

“…It is well known that the main factors affecting the thyroglobulin level include the amount of residual thyroid tissue or cancer lesion, TSH level, the time after the operation, and the thyroid hormone withdrawal time (39). These affecting factors can be closely related to each other.…”

Recombinant human TSH stimulated thyroglobulin levels at remnant ablation predict structural incomplete response to treatment in patients with differentiated thyroid cancer

“…At follow-up, there was no significant difference in treatment response whether under rhTSH-aided or THW-aided. In recent study by Pitoia et al [20] , 62.7% of patients under rhTSH-aided RA showed no evidence of disease and 15.7% of patients showed SIR. Although the characteristics of study population was different and the number of high-risk patients was relatively smaller in our study, it is likely that prophylactic CND yields better response profiles, probably at the cost of increased incidence of complications like hypoparathyroidism in our study.…”