The DTCC 2nd will follow DTCC 1st and observe the long-term efficacy of initial management including surgery treatment, 131I therapy and TSH suppression therapy. It will involve nine hospitals which have participated in the first stage, and continually to observe the DTC patients who were recruited. The patients with more than 5 years long-term follow-up from the date of signing the informed consent form (ICF) in DTCC 1st to signing ICF in DTCC 2nd will be collected data retrospectively. For those follow-up less than 5 years, in addition to the retrospective data collection, one prospective visit will be conducted.~Primary endpoint(s)~1.Five-year accumulated recurrence rate~Secondary endpoint(s)~Disease-free survival (DFS)~Overall survival (OS)~Response to therapy~Re-operation rate~Time weighted TSH level (TW-TSH)~Adverse events related to L-T4 therapy (ADRs)~Median follow-up years
To find out the gap between real-world clinical practice and guideline recommendations in initial management of DTC patients~To observe the characteristics of patients who achieved and did not achieve TSH target value after five year follow-up~To assess response to initial therapy in patients who undergo total or neartotal thyroidectomy and RAI remnant ablation after five year follow-up (according to an modified dynamic risk stratification system)~To observe the recurrence status after five year follow-up