CHILDHOOD THYROID-CANCER - CHARACTERISTICS AND LONG-TERM OUTCOME IN CHILDREN IRRADIATED FOR BENIGN CONDITIONS OF THE HEAD AND NECK

Objective: To determine the characteristics and long-term outcome of r adiation-induced thyroid cancer in children. Design: Retrospective rev iew of a cohort of 4296 irradiated patients who received childhood rad iation treatment to the head and neck area at the same hospital. Patie nts: Forty-one children who were younger than 20 years when thyroid ca ncer developed in them and 77 adults in whom thyroid cancer developed. All 118 cases were diagnosed before 1974 and were followed up for a m edian of 19.4 years. Results: Children presented with clinically palpa ble lymph nodes more often than adults (30.7% vs 15.1%, P=.05) and had more recurrences (39% vs 16%, P=.05). Despite these frequent recurren ces, only one patient (an adult) died of thyroid cancer. Seventy perce nt of the recurrences occurred during the first 10 years of follow-up, but recurrences continued after 20 years. The adults had previously i dentified factors that predicted the risk of recurrences, but none cou ld be identified in the children. Conclusion: The presentation and rel atively good outcome of radiation-induced thyroid cancer in children i s similar to that in nonirradiated children. Frequent and late recurre nces call for lifelong follow-up.