Endocrine Abstracts

Background: Telomerase reverse transcriptase (TERT) promoter mutation is a poor prognostic factor in differentiated thyroid carcinoma(DTC). It is thought to play a role in the transformation process to undifferentiated thyroid carcinoma(UTC), but its role as a prognostic factor in UTC is unclear. Therefore, in this study, we investigated whether the TERT promoter mutation acts as as an independent poor prognostic factor in UTC.

Methods: Among patients diagnosed with UTC from 1995 to 2020 at Samsung Medical Center, 28 patients who underwent TERT promoter mutation test were enrolled. Clinical features, including survival rate, were compared between patients with positive and negative in TERT promoter mutations. The overall survival(OS) was verified by the Kaplan-Meier method, and the evaluation of factors affecting survival was verified by the multiple regression analysis method [HR (95% CI)].

Results: The median age of 28 patients with UTC was 68.5 years (50.0~79.0), and 19 patients (67.9%) were female. In 16 patients (57.1%), there was coexistence or history of DTC. The median tumor size was 4.5 cm (0.8~11.0). There was no patient with stage IVA, whereas 12 patients(42.9%) with IVB, and 16 patients(57.1%) with IVC. Aggressive treatment (combination of surgery, radiotherapy and systemic treatment including tyrosine kinase inhibitor) was performed in 10 patients (35.7%). The median OS was 6.9 months (0.4~39.5), the 1-year OS was 32.1%, the 2-year OS was 21.4%, and the 3-year OS was 14.3%. TERT promoter mutations were found in 10 patients (35.7%). There was no difference in the clinical characteristics (age, gender, coexistence or history of DTC, tumor size, stage, pathological findings, etc.) between the TERT promoter mutation positive group and the negative group. However, more active treatment was performed in the TERT promoter mutation positive group. (60.0% vs. 22.2%, P = 0.04). The average survival time of the TERT promoter mutation positive group, which received more active treatment, was 9.1 months (0.4 to 39.5). It was longer than that of the negative group (6.1 months (0.4 to 39.0)), but was not a significant difference (P = 0.43). The 1-year survival rate was 40% in the TERT promoter mutation positive group, higher than 28% in the negative group, but it was not a significant difference. When multiple regression analysis was performed to find prognostic factors affecting OS, age [2.60 (1.08–6.26)], lymph node metastasis [5.72 (1.58–20.70)], and distant metastasis [2.59 (1.06–6.32)] came out as significant prognostic factors (P < 0.05), whereas TERT promoter mutation was not [0.89 (0.27–2.93)].

Conclusion: In this study, unlike DTC, TERT promoter mutation was not an independent poor prognostic factor in UTC.