Endocrine Abstracts (2017) 49 EP1409 | DOI: 10.1530/endoabs.49.EP1409

Does the delayed risk stratification system help to evaluate the risk of unfavorable clinical outcome in pT1aN0/Nx stage patients with differentiated thyroid cancer treated without radioactive iodine?

Danuta Gasior-Perczak1, Iwona Palyga1, Monika Szymonek1, Agnieszka Walczyk1, Janusz Kopczynski1, Anna Sluszniak1, Ryszard Mezyk1, Stanislaw Gozdz1,2 & Aldona Kowalska1,2

1Holycross Cancer Centre, Kielce, Swietokrzyskie, Poland; 2Jan Kochanowski University, Kielce, Swietokrzyskie, Poland.

Introduction: In ATA recommendations (2016) a delayed risk stratification (DRS) system proposed by D.P. Momesso et al. was accepted as a diagnostic tool for the risk stratification of unfavorable clinical outcome and for monitoring the clinical outcome in differentiated thyroid cancer (DTC) patients treated without radioactive iodine (RAI).

The aim of the study: To evaluate the DRS system in patients with low clinical stage (pT1aN0/Nx).

Material: 304 patients after total thyroidectomy (n=202) or lobectomy (n=102) without adjuvant RAI therapy, with a follow-up period of at least 24 months, treated at a single center were enrolled to the study. The median age was 50.5 years, 91.1% were women, 100% at baseline had a low risk according to ATA, the median follow-up was 4 years (2–24).

Methods: DRS of the treatment response was conducted, based on the medical records, according to the criteria by Momesso et al. The course of the disease was evaluated (recurrence, death) as well as the status on 31.12.2016, which is the end of the follow-up (remission, persistent disease). The relationship between unfavorable outcome and the DRS system was evaluated.

Results: The response to initial therapy was excellent in 272 patients (89.5%), intermediate in 31 patients (10.2%) and biochemically incomplete in 1 patient (0.3%) (increased concentration of TgAb). There was a recurrence in 2 patients from the excellent response group at 6 and 7 years of follow-up (after lobectomy). No patients with intermediate and biochemically incomplete response were diagnosed with the structural disease and none of the patients died during the follow-up.

Conclusions: The DRS system did not prove useful in predicting the risk of unfavorable clinical outcome and cannot be used to personalize the monitoring method of the disease in patients at pT1aN0/Nx, not treated with RAI.