Clinical features associated with metastasis and recurrence of differentiated thyroid cancer in children, adolescents and young adults

OBJECTIVE Differentiated thyroid cancer (DTC), including papillary (PTC) an d follicular (FTC) variants, is unusual in children and accounts for only 1 0% of all cases, For that reason, knowledge of the clinical features which predict recurrence is limited. We reviewed 170 cases of childhood DTC to de termine if specific clinical or pathological findings were associated with increased risk of recurrence. DESIGN This was a retrospective study of children and adolescents with DTC registered in the Department of Defense Automated Centralized Tumor Registr y, PATIENTS We reviewed 137 cases of PTC and 33 cases of FTC diagnosed between 1953 and 1996 at less than or equal to 21 years of age. RESULTS In the PTC group (median follow-up 6.6 years, range 2 month - 39.5 years), only one patient died, but 21 developed local and 6 developed dista nt recurrence, By univariate analysis, recurrence was more common in patien ts with multifocal (odds ratio 7.5) or large tumours (odds ratio 4.1), and in those with palpable cervical lymphadenopathy (odds ratio 3.0) or metasta sis at diagnosis (odds ratio 2.8). By multivariate analysis focality was th e best predictor of recurrence (P=0.0019). In the FTC group (median follow- up 5 years, range 6 month 38.1 years), no patient died of disease, but 5 de veloped recurrence. As with PTC, recurrence was more likely in patients wit h multifocal tumours (odds ratio 22.0). CONCLUSIONS Differentiated thyroid cancer in children and adolescents has l ow mortality, but a high risk of recurrence, Young patients with large, mul tifocal tumours that are already metastatic at diagnosis have the greatest risk of recurrence.