Proceedings: Carcinoembryonic antigen. Report of a screening study.

Abstract

Originally described as a specific marker for colonic carcinomas, carcinoembryonic antigen (CEA) has recently been demonstrated in elevated titers in patients with a variety of non-neoplastic diseases, especially in patients with serious metabolic disorders and in patients with inflammatory bowel disease. We are reporting results of CEA screening in 576 patients undergoing barium enema examination. None were known to have cancer, previously diagnosed or recurrent. Of this group, 23 were discovered to have primary or recurrent colonic cancers. CEA-radioimmunoassays by the Zirconyl phosphate gel method of Hansen were positive (>2.5 ng/cc) in 18 and greater than 5 ng cc in 15. However, in 4 of 13 early stage colonic carcinomas, CEA values were normal. Of the remaining 553 patients, none had proven cancer. Ninety-eight (18%) of them had elevated CEA values, but only 18 of these were greater than 5 ng/cc. Forty-six of these CEA positive patients had acute inflammatory bowel disease, acute gastrointestinal disorders, collagen diseases, or serious chronic metabolic diseases. Repeat CEA sampling in a third of the “false” positive group produced normal results in most. To date only 1 of the 98 “false” positive group is known to have developed a diagnosable cancer within the year. Of the CEA negative group, none have reported development of cancer. Caution is advised against interpreting a single elevated CEA value as synonymous with colonic cancer, and against dismissing the possibility of early colonic cancer in the face of a normal CEA value.