Serum carcinoembryonic antigen in clinical disorders.

Carcinoembryonic antigen (CEA) levels have been measured in the serum of 490 patients and 93 normal controls using the double antibody radioimmunoassay technique. Levels were elevated in 71 of patients with carcinomata of the gastrointestinal tract and in 42% with other types of malignancy. In patients with non-neoplastic disease of the gastrointestinal tract and liver, elevated levels were found in 14 and 66% respectively. In general the CEA level tends to be higher in cancer patients with haematogenous dissemination. Following complete surgical removal of a tumour, levels fall to normal within 14 days in the majority of patients. Of 33 patients studied during follow up, elevated levels were found in 12, 10 of whom had evidence of recurrence. The significance of these findings and the possible application of CEA assay in clinical practice are discussed.