Version July 2025
Please read the Disclaimer at the end of this page.
What is a carcinoembryonic antigen test? —
This measures the amount of carcinoembryonic antigen, or "CEA," in the blood.
Different things can make the CEA level increase, including cancer. CEA can be produced by certain types of cancer, such as ovarian, thyroid, colon, or rectal cancer.
A person's CEA level can also be affected by smoking, inflammation, or certain other health conditions. Small amounts of CEA are sometimes found in the large intestine of healthy adults.
Rarely, your doctor might do a CEA test on other body fluids besides blood.
Why might I get a CEA test? —
Your doctor might order this test to:
●Help figure out if you have cancer
●Check how cancer treatment is working
●Check if cancer comes back after treatment
How do I prepare for a CEA test? —
You need to get a "blood draw." Your doctor or nurse will tell you where to go for this.
It might help to wear a short-sleeve shirt to your blood draw appointment. This makes it easier for the person drawing your blood to get to your arm.
What happens during a blood draw? —
A needle is used to take a small amount of blood from your arm (figure 1). Collecting the blood only takes a few minutes. The blood is then tested in a lab.
Tell the person who takes your blood:
●If you take "blood thinner" medicines or have a bleeding problem – They will make sure your bleeding is under control before you leave.
●If you have a latex allergy – Some of the supplies used for blood draws might contain latex.
●If you have a preferred arm to use
Most of the time, getting blood taken does not cause problems. You might have a little soreness or bruising where the needle went in.
What do my results mean? —
Your doctor or nurse will tell you when to expect your results, and will contact you with the results. Or if you use an online "patient portal," you might get an alert there when your results are ready.
If the test shows your CEA level is high, your doctor or nurse will talk to you about what to do next. They might need to do more tests to figure out the cause.
If you do have a health problem, your doctor will work with you to come up with a treatment plan.
Patient education: Ovarian cancer (The Basics)
Patient education: Thyroid cancer (The Basics)
Patient education: Colon and rectal cancer (The Basics)
Patient education: Ovarian cancer diagnosis and staging (Beyond the Basics)
Patient education: Treatment of ovarian cancer (Beyond the Basics)
Patient education: Colon and rectal cancer (Beyond the Basics)
