Thyroid cancer in children and adolescents--consequences in later life.

Thyroid cancer is rare below the age of 16 years, with an annual incidence of 0.02-0.3 cases per 100,000. Papillary and follicular thyroid cancer in childhood and adolescence is more advanced upon presentation than in adults, as evident from a higher frequency of extra-thyroidal spread. The recurrence rate is also higher. Nevertheless, the prognosis for survival in children and adolescents is better than in adults; why this is so remains unclear. An approximately 30-fold increase in the incidence of thyroid cancer has been observed in children exposed to the fallout of the Chernobyl accident, especially in the age group of <1 year at the time of the disaster. Medullary thyroid cancer in childhood and adolescence occurs mainly as part of the MEN2 syndrome. Early detection by DNA mutation analysis and treatment by prophylactic thyroidectomy results in a potential normal life expectancy. Consequences in adult life relate to long-term complications of thyroid surgery, 131I treatment and TSH-suppressive doses of L-T4.