Carcinoembryonic antigen (CEA) is a glycoprotein, which is present in normal mucosal cells but increased amounts are associated with adenocarcinoma, especially colorectal cancer. CEA therefore has a role as a tumour marker. Sensitivity and specificity are low, however, so it is of more use for monitoring and is not useful as a diagnostic or screening test.
This is a companion discussion topic for the original article at https://patient.info/doctor/carcinoembryonic-antigen-cea