Children and adolescents with differentiated thyroid cancer from 1998 to 2018: a retrospective analysis.

Objectives: This study aims to investigate the clinical features of differentiated thyroid carcinoma (DTC) in children and adolescents under 18 years and assess the impact of surgery combined with thyroid hormone and radioactive iodine (RAI) on their prognosis.

Methods: A retrospective observational study was conducted, involving children/adolescents with DTC who underwent surgery at the Head and Neck Department of Tianjin Medical University Cancer Institute and Hospital from January 1998 to December 2018.

Results: Among 198 patients, 130 (65.7 %) were female. According to the American Thyroid Association guidelines, cases were categorized as low (106, 53.5 %), intermediate (54, 27.3 %), and high (38, 19.2 %) risk. The follow-up duration ranged from 3 to 23 years. Local recurrence and distant metastasis were identified in 21 (10.6 %) and 14 (7.1 %) cases, respectively. All patients received levothyroxine, while RAI therapy was administered to intermediate- and high-risk patients. The local recurrence and distant metastasis rates in these two groups were 33.3 and 39.5 %, respectively, with no recurrence or metastasis in the low-risk group. Persistent without structural evidence of disease were 0.9, 3.7, and 26.3 % at end of follow-up for the low-, intermediate-, and high-risk groups, respectively. The overall survival rates for all three groups were 100 %, while disease-free survival rates were 99.1, 63.0, and 34.2 % for the low-, intermediate-, and high-risk groups, respectively.

Conclusions: Children/adolescents with low-risk DTC exhibited a favorable prognosis even without RAI. However, intermediate- and high-risk DTC patients, despite RAI and levothyroxine treatment, showed elevated rates of persistent disease, local recurrence, and distant metastasis.