Metastatic Differentiated Thyroid Cancer Survival Is Unaffected by Mode of Preparation for 131I Administration

Abstract

Background and Objective Recombinant human thyrotropin (rhTSH) is currently not FDA-approved for the treatment of high-risk patients with differentiated thyroid cancer (DTC). The goal of our study was to compare the outcomes in higher risk patients with metastatic DTC prepared for radioiodine (RAI) therapy with rhTSH versus thyroid hormone withdrawal (THW). Methods Retrospective chart review of patients with metastatic DTC in follow-up at MedStar Washington Hospital Center and MedStar Georgetown University Hospital from 2009 to 2017. Patients were divided according to their preparation for RAI therapy, with assessment of progression free survival (PFS) and overall survival (OS). Results Fifty-five patients with distant metastases (16 men, 39 women) were prepared for RAI therapy exclusively either with rhTSH (n= 27) or with THW (n= 28). There were no statistically significant differences between the groups regarding clinicopathological features and history of RAI therapies. The median follow-up time for patients with rhTSH-aided therapies was 4.2 yr (range 3.3 – 5.5 yr) and for patients with THW-aided therapies was 6.8 yr (range 4.2- 11.6 yr) (p=0.002). Multivariate analysis showed that the method of TSH stimulation was not associated with a difference in PFS or OS. Conclusion As has been shown previously for low-risk DTC, this study indicates that the mode of preparation for RAI therapy does not appear to influence the outcomes of patients with metastatic DTC. PFS and OS were similar for patients with THW-aided or rhTSH-aided RAI therapies.

Strategies for Radioiodine Treatment: What’s New

“…However, due to the well-known drawbacks and potential health risks of THW, rhTSH has been explored as an alternative protocol for metastatic patients [ 107 ]. Some studies showed benefits and the same effectiveness of rhTSH preparation compared with THW [ 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 ]. However, most of these cohorts are small and retrospective, and the follow-up of the patients treated with rhTSH is most often significantly shorter than that of the patients treated after THW, preventing any reliable conclusions ( Table 4 ).…”

Letter to the Editor From Zandee and Links: “Metastatic Differentiated Thyroid Cancer Survival Is Unaffected by Mode of Preparation for 131I Administration”

“…We read with great interest the by paper by Christiane Gomes-Lima and colleagues, titled “Metastatic Differentiated Thyroid Cancer Survival Is Unaffected by Mode of Preparation for 131 I Administration” [ 1 ].…”

“…The study describes 55 patients with metastatic differentiated thyroid carcinoma (DTC) who were treated with radioactive iodine (RAI) and compares the outcomes of patients prepared solely with recombinant human thyrotropin (rhTSH) or with thyroid hormone withdrawal (THW). The authors conclude that the mode of preparation for RAI therapy does not decisively affect the outcome of RAI therapy of patients with metastatic DTC [ 1 ].…”

Response to Letter to the Editor from Zandee and Links: “Metastatic Differentiated Thyroid Cancer Survival Is Unaffected by Mode of Preparation for 131I Administration”

“…In our view, there is little doubt that use of recombinant human thyrotropin (rhTSH) has proved of significant benefit to patients with low- or intermediate-risk differentiated thyroid cancer (DTC). And in their communication regarding our study [ 1 ], Zandee and Links [ 2 ] present compelling arguments with which we fully agree on the importance and merits of also establishing that preparation by rhTSH for radioiodine (RAI) therapy of higher risk or metastatic DTC would be equally efficacious to preparation by thyroid hormone withdrawal. Insofar as our study did reach this conclusion, they express concern that we may have overstated that the results achieved by the 2 approaches were equivalent due to underpowering of the study.…”