Carcinoembryonic antigen assay in thyroid screening.

CEA assay was incorporated into a screening program in which a high risk population for thyroid diseases due to previous irradiation for benign conditions in the head and neck areas were studied. Seven hundred eleven CEA determinations were available from 735 patients screened; 22 (3.1%) were found to have an elevated level. This is compared to 31 (1.7%) from 1875 healthy control subjects. Although the difference is statistically significant, we conclude the use of CEA assay in thyroid screening is not rewarding due to its lack of activity and specificity.