Prognostic factors of a good response to initial therapy in children and adolescents withdifferentiated thyroid cancer

ABSTRACT

BACKGROUND: Therapeutic approaches in pediatric populations are based on adult data because there is a lack ofappropriate data for children. Consequently, there are many controversies regarding the proper treatment ofpediatric patients.OBJECTIVE: The present study was designed to evaluate patients with differentiated thyroid carcinoma diagnosedbefore 20 years of age and to determine the factors associated with the response to the initial therapy.METHODS: Sixty-five patients, treated in two tertiary-care referral centers in Rio de Janeiro between 1980 and 2005were evaluated. Information about clinical presentation and the response to initial treatment was analyzed andpatients had their risk stratified in Tumor-Node- Metastasis; Age-Metastasis-Extracapsular-Size; distant Metastasis-Age-Completeness of primary tumor resection-local Invasion-Size and American-Thyroid-Association classificationRESULTS: Patients ages ranged from 4 to 20 years (median 14). The mean follow-up was 12,6 years. Lymph nodemetastasis was found in 61.5% and indicated a poor response to initial therapy, with a significant impact on time forachieving disease free status (p = 0.014 for response to initial therapy and p,0,0001 for disease-free status in followup).Distant metastasis was a predictor of a poor response to initial therapy in these patients (p = 0.014). The riskstratification systems we analyzed were useful for high-risk patients because they had a high sensitivity andnegative predictive value in determining the response to initial therapy.CONCLUSIONS: Metastases, both lymph nodal and distant, are important predictors of the persistence of diseaseafter initial therapy in children and adolescents with differentiated thyroid cancer.(AU)