Childhood and adolescent thyroid carcinoma.

OBJECTIVES: This analysis was performed to evaluate the influence of clinical and treatment factors on local tumor control, control of distant metastasis, survival, and complications in children and adolescents with thyroid carcinoma.

METHODS: The records of 56 children and adolescents with papillary and follicular carcinoma of the thyroid were reviewed. They ranged in age from 4 to 20 years. There were 43 females and 13 males. At diagnosis, 15 (27%) patients had disease confined to the thyroid, 34 (60%) had additional lymph node metastasis to the neck or upper mediastinum, and 7 (13%) also had lung metastasis. Treatment consisted of a total thyroidectomy in 48 patients, a subtotal thyroidectomy in 4 patients, and a lobectomy in 4 patients. All 56 patients received postoperative thyroid hormone suppressive therapy. (131)I was administered to 82% (46 of 56) of patients after their initial surgery.

RESULTS: The overall survival rate was 98% with a follow-up of 0.6-30.7 years (with a median follow-up of 11.0 years). The one death that occurred in this patient population was the result of a congenital heart defect and was unrelated to thyroid carcinoma. The 10-year progression-free survival rate was 61%. Nineteen patients (34%) experienced a recurrence of their thyroid carcinoma. The time to first recurrence of disease ranged from 8 months to 14.8 years (mean, 5.3 years). None of those with disease confined to the thyroid developed recurrent disease. The recurrence rate was 50% (17 of 34) in patients with lymph node metastasis and 29% (2 of 7) in patients with lung metastasis (P = 0.02). Tumor characteristics were evaluated for time to first recurrence utilizing the logistic likelihood ratio test to predict disease recurrence. Thyroid capsule invasion (P = 0.02), soft tissue invasion (P = 0.03), positive margins (P = 0.006), and tumor location at diagnosis (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02) were significant for developing recurrent disease. Patients younger than 15 years old at diagnosis were more likely to have more extensive tumor at diagnosis than patients who were 15 years and older (thyroid only vs. thyroid and lymph nodes vs. thyroid, lymph nodes, and lung metastasis, P = 0.02).

CONCLUSION: Carcinoma of the thyroid in children and adolescents has little risk of mortality but a high risk of recurrence. Younger patients present with a more advanced stage of disease and are more likely to have disease recurrence. Total thyroidectomy and lymph node dissection, followed by postoperative (131)I therapy, thyroid hormone replacement (suppressive) administration, and diligent surveillance are warranted.