Abstract
IN 1950 it was first suggested that there might be some relationship between irradiation of the thymus gland and cancer of the thyroid (1). In a survey of the cases of thyroid cancer seen at the Memorial Hospital in New York from 1932 to 1948, 28 patients were found to have histologic evidence of thyroid cancer before the age of 18 years. Ten of these 28 had been irradiated over the chest in infancy for symptoms thought to be due to enlarged thymus. The authors stated at that time that “to propose a cause-and-effect relationship between thymic irradiation and the development of cancer would be quite unjustified on the basis of data at hand when one considers the large number of children who have had irradiation to an ‘enlarged thymus.’ However, the potential carcinogenic effects of irradiation are becoming increasingly apparent, and such relationships as those of thymic irradiation in early life and the subsequent development of thyroid or thymic tumors might be profitably explored.” This is a review of clinical and experimental work, developed since the initial report, which confirms and extends the observation that there is a relationship between irradiation in infancy and childhood and the subsequent development of thyroid cancer.