Differentiated Thyroid Cancer in Adolescents: Single Center Experience and Considerations for Surgical Management and Radioiodine Treatment.

BACKGROUND: Differentiated thyroid cancer (DTC) in adolescents is a rare disease with favorable outcome, despite higher rates of cervical lymph node and pulmonary metastasis compared to adults. Aim of this study was to critically evaluate its treatment.

METHODS: Patients receiving postoperative radiojodine treatment (RAIT) for DTC between 2005 and 2020 at our institution were screened to identify adolescents according to the WHO definition (10-19 years of age). Demographics, clinico-pathologic characteristics, treatment and outcome were analyzed.

RESULTS: Among 1897 DTC patients 23 (1.3%) were adolescents (median age 16 years, range 10-18). The female to male ratio was 3.6:1. Classic papillary thyroid cancer was seen in 60%, follicular variant in 40% of cases, which is higher than reported in the literature (15-25%) for this age group. pT-status was pT1 in 9 (39.2%), pT2 in 8 (34.8%), pT3 in 3 (13%) and pT4 status in 3(13%) patients. In 19 (82.6%) patients, central lymphadenectomy was performed revealing metastasis in 57%. All patients received RAIT with an initial activity of 1.2 (n=1, 4.3%), 2 (n=12, 52.2%) or 3.7 GBq (n=10, 43.5%). Eighteen (78.2%) patients are free of biochemical and radiologic disease in a median follow-up of 60.7 months. Second-line surgery of lymph nodal relapse was necessary in 3 (13%) cases. There was one disease-associated death.

CONCLUSION: Despite high rates of metastasis, most patients were cured, and second-line surgery was rarely required. Further prospective studies are needed to determine whether less aggressive surgical management or omitting adjuvant RAIT are feasible in limited stages.