Carcinoma of the Thyroid in Children After X-Ray Therapy in Early Childhood

Carcinoma of the thyroid in children is being diagnosed with increasing frequency. Several explanations have been offered to help explain this. Among these is the formerly prevalent use of x-ray therapy for benign childhood conditions. If a carcinogenic mechanism is involved we should expect a decrease in the incidence of this neoplasm in the future, as the practice of using irradiation for benign conditions in children is being abandoned. Also, if such a mechanism exists, it probably operates most strongly during infancy. Thyroid cancer after irradiation in adults is a rarity. Of 357 children with reported thyroid carcinomas, approximately one-third had received prior radiation therapy to the pharynx, neck, or chest for nonmalignant conditions. Further studies are needed before definite conclusions are reached, and until that time children should be protected from ionizing radiation in the treatment of benign conditions.