Carcinoembryonic antigen concentrations in undiagnosed patients.

Serum carcinoembryonic antigen (C.E.A.) levels were measured in 381 undiagnosed patients who presented with clinical problems commonly associated with gastrointestinal malignancy. The results were compared with the final diagnosis after follow-up for up to 5 years to see whether C.E.A.-testing added any useful information. Of 307 patients presenting with upper gastrointestinal symptoms, lower gastrointestinal symptoms, or irom deficiency anaemia, C.E.A. levels greater than 20 ng/ml indicated malignancy in 5 but in 3 of these malignancy was also diagnosed after routine investigation. Of 74 patients presenting with obstructive jaundice, hepatomegaly, or abnormal liver function, malignancy was diagnosed in 38. In 9 of these patients the diagnosis of malignancy could otherwise have been reached only by laparotomy. The serum-C.E.A. thus reached only by laparotomy. The serum-C.E.A. thus seems to be of value in the assessment of liver disease but not in patients with gastric or colonic symptoms or iron-deficiency anaemia.