Treatment Approach, Surveillance, and Outcome of Well-Differentiated Thyroid Cancer in Childhood and Adolescence

Background: Well-differentiated thyroid carcinoma in children and adolescents is a rare disease with favorable prognosis despite regional and distant metastasis at presentation in many patients. Treatment recommendations are varied and there is little consensus on follow-up guidelines for these patients. Methods: Medical records of patients less than 22 years of age treated at our institution were reviewed. One hundred twelve patients treated between 1969 and 2009 were selected for further analysis. Effects of patient and tumor characteristics on progression-free survival (PFS) were evaluated along with the predictive value of whole-body I-131 scintigraphy in the follow-up setting. Results: Overall survival at 20 years and 30 years was 100% and 94.4%, respectively. PFS at 10, 20, and 30 years was 71%, 62%, and 55%, respectively. Although male patients and younger patients presented with more advanced disease, sex, and age at diagnosis had no effect on risk of PFS. Additionally, neither the presence of vascular invasion, capsular extension, positive margins, nor soft tissue invasion had an effect on PFS. Mean time to recurrence in patients who underwent immediate postoperative I-131 therapy was 3.8 years compared to 14.1 years in patients who either never received I-131 therapy or were treated in the salvage setting (p < 0.0001). Negative posttreatment whole-body I-131 scintigraphy was strongly predictive for decreased risk of recurrence, especially in patients with three consecutive negative scans. Conclusions: Pediatric patients are more likely to present with advanced disease and for this reason, the majority of patients treated at our institution receive postoperative I-131. Long-term surveillance is required in this population because of the risk of late recurrences. Whole-body I-131 scintigraphy is useful for risk stratification; after three consecutive negative scans, the risk of recurrence is low.