Multivariate analysis of prognostic factors for differentiated thyroid carcinoma in children

At most centres, the standard treatment for differentiated thyroid cancer ( DTC) comprises total thyroidectomy, radioiodine treatment and thyroid-stimu lating hormone (TSH) suppressive therapy. There is, however, considerable d isagreement over the appropriate treatment for DTC in children. Some disput e the use of total thyroidectomy and/or question the routine application of iodine-131 therapy in children. The aim of this study was to perform a ret rospective analysis of treatment results and prognostic factors for DTC in children treated at our centre. The study included 109 children with DTC (a ged 6-17 years). The primary treatment comprised total thyroidectomy in 81 cases, radioiodine therapy in 85 cases and TSH suppressive therapy with L-t hyroxine in all patients. Uni- and multivariate analysis of prognostic fact ors for disease-free survival was performed using the Cox regression method . The actuarial survival rate was 100%, and the 5- and 10-year actuarial di sease-free survival rates were 80% and 61% respectively. Univariate analysi s revealed that older age, total thyroidectomy and radioiodine treatment ha d a positive impact on disease-free survival whereas there were no statisti cal differences with regard to the child's sex, histological type of cancer or lymph node status. On multivariate analysis, radical surgery was estima ted to be the most significant factor (P=0.007) for disease-free survival, while less than total thyroidectomy increased the relative risk of relapse by a factor of 10, Radioiodine treatment decreased the relative risk of rel apse by a factor of 5, but with borderline significance (P=0.07). Permanent postoperative complications were observed in 17% of children: in 11 laryng eal palsy occurred, in six there was hypoparathyroidism, and one suffered f rom both. It is concluded that total thyroidectomy and radioiodine treatmen t significantly improve recurrence-free survival in children and should be routinely applied even in young children as the primary treatment of DTC.