Background:

The risk of recurrence (RR) stratification system has been proposed as a useful tool for stablishing the frequency of the structural incomplete and excellent response-to-treatment in patients with differentiated thyroid cancer (DTC). However, the available information at diagnosis could be insufficient to accurately determine the initial RR. We called this situation “the broken chair”. Although many studies have shown that the initial response to treatment usually predicts the final outcome, it is not clear if the final outcome could be different in the distinctive responses to treatment, if we analyze it together with the initial RR.

Purpose:

To investigate the outcomes of patients by comparing both situations: the initial RR and the initial response to treatment with the final outcome to establish if there was a different frequency of structural incomplete response at the end of follow-up.

Methods:

Retrospective review of 340 DTC patients followed up for at least 3 years after initial total thyroidectomy and radioactive iodine ablation (RAI). We assessed the initial response as the best response to therapy during the first 2 years, and the final response to therapy as the status at the end of follow-up, according to the definitions of the 2015 ATA guidelines.

Conclusions:

An excellent response to treatment during the first two years of follow-up can fix the “broken chair” in patients treated with DTC who received remnant ablation and it is independent of the initial RR.

Results:

None of the patients that achieved an initial excellent response to treatment (n=122, 36%), showed structural evidence of disease in the entire follow-up despite their initial RR.