ESPE Abstracts

Introduction and Purpose: Differentiated thyroid cancer in children is rare. However, its incidence has increased recently. It differs from adult thyroid cancer in terms of clinical, molecular and pathologic features. Pediatric patients present with advanced disease at the time of diagnosis. They have an excellent prognosis and a 5-year survival rate that reaches 100%. The aim of this study was to record and statistically analyze data from children diagnosed with thyroid cancer during the last 15 years of operation of a pediatric endocrinology clinic in Crete.

Patients and Methods: This retrospective study included 36 patients (14 boys, 22 girls), with ages at diagnosis ranging from 7.25 to 18.5 years and examined associations between the disease and age, gender, BMI, genetic background, autoimmune thyroiditis, positive family history, histological type, tumor size, disease stage, type of surgery, postoperative complications, adjuvant radioactive iodine therapy and 5-year survival rates. Additionally, the potential increase in the incidence of the disease over the past 5 years was investigated.

Results: Girls (61.1%) were more than boys (38.9%). The mean age of onset was 14.1 years. Based on BMI, 55.6% of patients were classified as normal, 22.2% as overweight and 11.1% as obese. 58.3% had Hashimoto's disease, 2 had a RET, 1 a NRAS and 4 a BRAF gene mutation. 34% had a first-degree relative with thyroid disease and 1/3 of patients had a family history of thyroid cancer. 91.7% had papillary carcinoma. 47.2% had focal cancer, while 50% multifocal. 70.2% had tumor diameter less than 1 cm. 97.2% underwent total thyroidectomy, while 63.9% also underwent lymphadenectomy. 63.9% underwent adjuvant radioactive iodine therapy. In 13.9% permanent hypoparathyroidism occurred postoperatively. The 5-year survival was 100% in all (55.6%) who had completed 5 years from diagnosis. Finally, there was an increase in annual incidence, as 47.2% were diagnosed in the last 5 years.

Conclusion: Thyroid cancer was more common in adolescent girls, with a significant association with family history and autoimmune thyroiditis. Papillary carcinoma was the most common histological type. In the majority, the disease was advanced, despite tumor size < 1cm. Almost all patients underwent total thyroidectomy and some concomitant lymphadenectomy. The percentage of patients with permanent hypoparathyroidism postoperatively was not negligible. Most of them required adjuvant radioactive iodine therapy. The prognosis was excellent, with a 5-year survival rate of 100%. An increased incidence of thyroid cancer over the last 5 years was observed. These findings are aligned with the literature.