Differentiated thyroid carcinoma in childhood and adolescence—clinical course and role of radioiodine†

Background Differentiated thyroid carcinoma (DTC) in childhood has a good prognosis despite a high incidence of relapse. The use of radioactive iodine (RAI) has not been well established. Procedure This is a review of 60 patients less than 21 years of age; mean follow-up was 14 years. Results Patients had a higher relapse rate with papillary thyroid carcinoma (PTC) than with follicular thyroid carcinoma (FTC): 24.5 vs. 9.1%. Compared with 997 patients with age ≥ 21, patients <21 years of age had a higher female to male ratio (7.6 vs. 3.9), higher incidence of nodal metastasis (45 vs. 28%), and lung metastasis (15 vs. 7.8%), and improved 10-year cause-specific survival (CSS) (98.3 vs. 89.5%). The 10-year rates of CSS, local-regional failure-free survival (LRFFS), and distant metastasis failure-free survival (DMFFS) for the young patients were 98.3, 79.3, and 90.7%, respectively. In patients with no distant metastasis at presentation, RAI improved 10-year LRFFS (71.9 vs. 86.5%; P = 0.04). At last follow-up, 10 of 12 patients (80%) with local-regional (LR) relapse and five of nine patients (55.6%) with distant metastasis were rendered disease-free. No patient has experienced a second malignancy. Conclusions Prognosis of DTC in young patients was good. Patients with LR relapse and distant metastasis had a high rate of remission after treatment. RAI treatment can reduce the rate of LR relapse in patients with no distant metastasis and result in complete remission in half of those with distant metastasis. No patient experienced a second malignancy. © 2003 Wiley-Liss, Inc.