Carcinoembryonic Antigen (CEA)
The carcinoembryonic antigen (CEA) test measures the amount of this protein that may appear in the blood of some people who have certain kinds of cancers, especially cancer of the large intestine (colon and rectal cancer). It may also be present in people with cancer of the pancreas, breast, ovary, or lung.
CEA is normally produced during the development of a fetus. The production of CEA stops before birth, and it usually is not present in the blood of healthy adults.
Why It Is Done
The carcinoembryonic antigen (CEA) test is used to:
- Find how widespread cancer is for some types of the disease, especially colon cancer.
- Check the success of treatment for colon cancer.
- CEA levels may be measured both before and after surgery to evaluate both the success of the surgery and the person's chances of recovery.
- CEA levels may be measured during treatment with medicines to destroy cancer cells (chemotherapy). This provides information about how well the treatment is working.
- Check to see if cancer has returned after treatment.
How To Prepare
You do not need to do anything before you have this test.
Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results will mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).
How It Is Done
The health professional taking a sample of your blood will:
- Wrap an elastic band around your upper arm to stop the flow of blood. This makes the veins below the band larger so it is easier to put a needle into the vein.
- Clean the needle site with alcohol.
- Put the needle into the vein. More than one needle stick may be needed.
- Attach a tube to the needle to fill it with blood.
- Remove the band from your arm when enough blood is collected.
- Put a gauze pad or cotton ball over the needle site as the needle is removed.
- Put pressure to the site and then put on a bandage.