Carcinoembryonic Antigen (CEA) in Serum or Plasma

What Is Carcinoembryonic Antigen (CEA)?

Carcinoembryonic antigen (CEA) is a protein that can be found in small amounts in the blood of healthy people. It is produced by certain types of cells, including those in the digestive tract and some cancers. Elevated levels may indicate colorectal cancer or other conditions affecting the digestive system, though they can also appear in other cancers or non-cancerous conditions like chronic inflammation.

Why Might You Need This Test?

Doctors may order a CEA test to check for signs of cancer recurrence after treatment, monitor cancer progression in people with known cancer, or investigate symptoms like unexplained weight loss, abdominal pain, or changes in bowel habits. It can also be used as part of a screening in certain high-risk groups.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. The sample is sent to a lab where it is analyzed to measure the amount of CEA protein. The test can be done on either serum (liquid part of blood after clotting) or plasma (liquid part of blood without clotting).

What Do the Results Mean?

Results are not always definitive on their own. Elevated CEA levels can suggest cancer, but they can also be influenced by other factors like smoking, chronic liver disease, or other health conditions. Your doctor will consider your overall health, medical history, and symptoms when interpreting the results.