Carcinoembryonic Antigen

Function

Carcinoembryonic Antigen (CEA) is a glycoprotein involved in cell adhesion. It is normally produced in gastrointestinal tissue during fetal development, but production stops or drops to very low levels after birth. In adults, elevated levels of CEA are often associated with certain types of cancer, particularly those originating in the digestive tract.

Why it is Ordered

CEA is not typically used as a general cancer screening tool for asymptomatic individuals because many non-cancerous conditions can raise its levels. Instead, it is used for:

• Monitoring Cancer Treatment: Assessing the response to surgery, chemotherapy, or radiation.
• Recurrence Surveillance: Following up with patients after successful treatment to catch early signs of cancer returning.
• Staging: Helping to determine the extent of disease in patients already diagnosed with cancer.

Associated Conditions

• Colorectal Cancer: The most common association.
• Other Malignancies: Pancreatic, gastric, lung, breast, and ovarian cancers.
• Benign Conditions: Inflammation of the gut (IBD), cirrhosis, pancreatitis, and heavy smoking.