TERT promoter mutations and recurrence patterns in differentiated thyroid carcinoma.

Telomerase reverse transcriptase promoter mutations (TERT) are known prognostic factors associated with poor outcomes in differentiated thyroid carcinoma (DTC). We analyzed differences in DTC recurrence patterns over time according to TERT. A retrospective review was conducted on DTC patients who achieved remission after total thyroidectomy and/or radioactive iodine treatment at Samsung Medical Center between 1994 and 2004. The sites and patterns by time of recurrence in the patients were reviewed. In total, 367 patients with a median follow-up of 14 years (interquartile range, 12-17 years) were included. Recurrence occurred in 91 patients, wherein 56 had lymph node recurrence and 35 had either local or distant recurrence. TE RT and tumor size <2 cm were independent factors for recurrence in the Cox proportional hazards analysis. In cases of TERT-wild type (WT), the recurrence rate decreased significantly over time after diagnosis, whereas in TERT-mutant type (MT), a consistently high recurrence rate was observed. In the Kaplan-Meier analysis, TERT-MT exhibited a significantly poorer disease-free survival, with continuous recurrence over time, whereas in TERT-WT, the curve showed a gradual decline. Further analysis of the overall survival among the 91 patients revealed that TERT-MT was significantly associated with a higher risk of mortality, whereas TERT-WT exhibited a slowly decreasing curve. In conclusion, TERT-MT was a significant adverse prognostic factor wherein continuous recurrence necessitates long-term follow-up. For TERT-WT, the recurrence rate decreased compared to TERT-MT, and even in cases of recurrence, the treatment outcomes are favorable.