Comparative results of treatment of children and adolescents with thyroid cancer at St. Petersburg Endocrine Surgery Centre and Mayo Clinic

Introduction. Thyroid cancer (TC) is the most often malignant tumor in childhood and made 1.5-3.0 % of all children population or 45.3 % of pediatric endocrine epithelial cancers. A lot of questions concerning to volume of thyroid surgery, postoperative radioiodine therapy needs to be discussed. Material and methods. During 1970-2011 in the Center (1 group) were operated 105 TC children and adolescent (up to 18 yeas) and in Mayo Clinic - 188 (2 group) in period 1940-2000. Since of 80-s in those clinics were used the same perioperative examinations, like TSH, T4, T3 blood levels, USG, fine needles aspiration biopsy, CT and morphological examinations. Results and discussion. Average age of the Center and Rochester patients was the same and achieve 16.3 ± 0.3 and 16.0 ± 0.5, accordingly. In both groups has prevailed girls: in the 1 group they made 73.3 % (M : F 1 : 2.7) and in the 2 - 70.7 % (M : F 1 : 2.4). Childhood differentiated TC were associated with aggressive behavior: regional metastases were found in 53.0 % and 81.4 %, extrathyroid TC spreading - in 9.6 and 19.7 %, distant metastases - in 9.6 and 4.8 %, accordingly. In our Center we have performed hemithyroidectomies and subtotal thyroidectomies in 58.1 % with ipsilateral central neck dissection (CND). In Mayo Clinic in all TC cases were performed thyroidectomy (TE) since 1950. TC relapses we have no observed in 1 group and they have place in 6.9 % 2 group patients, recurring lymphatic metastases - in 8.4 % and 20.7 %, accordingly. Radioiodine therapy (RIT) has performed in 21.1 % and 25.5 % operated children. In 1 group 95 (96.0 %) of 99 operated were alive during 5-36 years, in the 2 - only in two cases reason of death was TC, but in 14 - other malignant tumor. Conclusion. Childhood TC is associated with more locally aggressive and more frequent distant disease than its adult counterpart. Recurrence rates tend to be higher in children, but cause-specific mortality remains low. Optimal initial treatment of childhood TC should include TE and CND. RIT in childhood has increased possibility of others malignant tumor in follow up period.