Abstrac Context Rates of pediatric differentiated thyroid cancer (DTC) in the United States have been increasing while studies on this population remain limited by inconsistent age cut-offs, short follow-up periods, or relative lack of clinical data. Objective To report long-term outcomes in patients diagnosed with DTC at age 20 years old and younger. Methods A retrospective study was conducted of patients diagnosed with DTC at age 20 years old or younger with long-term follow-up. Results 155 patients were included with a median age at diagnosis of 17 years (9 to 20 years). The frequency of distant metastasis and larger tumor size were inversely related to age at diagnosis (overall stage p = 0.045, T-stage (size of the primary tumor ± invasion) p = 0.001). The median duration of follow-up was 16 years (1 to 63 years) and at last follow-up, 52.3% of patients had excellent response and disease specific mortality was 0%. There was no difference in response to therapy based on histologic subtype or birth sex; however, younger age at diagnosis was associated with worse response (p = 0.046). Patients with over 50 years of follow-up (n = 9) had median of 36 years of stability, with progression occurring in 6 out of 9 (67%) patients. Conclusions Patients diagnosed with DTC as children or young adults have outstanding long-term survivorship, but may experience disease progression later in life, suggesting that long-term follow-up might be appropriate for this population. Younger age at diagnosis was identified as a risk factor for distant metastases and poorer response to therapy.
Valenciaga et al. (Thu,) studied this question.