Carcino Embryonic Antigen (CEA)

General Information

Carcino Embryonic Antigen (CEA) is a 200 kDa glycoprotein which appears to have a role in cell adhesion and inhibition of apoptosis. It can be elevated in any advanced adenocarcinoma, i.e., where distant metastases are present. CEA is almost never elevated in early malignancy.

In addition, slight to moderate elevations (i.e. > 10 ug/L) of CEA can be seen in 20-50% of benign diseases of the intestine, the pancreas, the liver, the kidney and the lungs (e.g. hepatitis, cirrhosis, alcoholic liver disease, obstructive jaundice, ulcerative colitis, Crohn’s disease, pancreatitis, bronchitis, emphysema and renal disease). Slight elevations may also occur in apparently healthy individuals who smoke.

CEA is primarily used for the monitoring of patients with colorectal carcinoma. Specifically:

• In surveillance following curative resection of colorectal cancer.
• In monitoring therapy in advanced colorectal cancer. This is especially important when disease cannot be evaluated by standard criteria.

Caution should be used when interpreting increasing CEA concentrations during the early phase of systemic treatment as certain treatments (e.g., 5-fluorouracil and levamisole; oxaliplatin) can cause transient elevations in CEA levels in the absence of disease progression.

CEA should not be used to screen for colorectal cancer.