CEA
At a Glance
Why Get Tested?
To help determine whether cancer is present in the body, although it is not recommended as a general population screening test; to monitor cancer treatment, including response to therapy and recurrence; to help in staging of cancer
When to Get Tested?
When your doctor thinks your symptoms suggest the possibility of cancer; before starting cancer treatment as well as at intervals during and after therapy
Sample Required?
A blood sample drawn from a vein in the arm
The Test Sample
What is being tested?
Carcinoembryonic antigen (CEA) is a protein that is found in embryonic tissues. By the time a baby is born, detectable levels in the blood disappear. In adults, CEA is normally present at very low levels in blood. When the concentration of CEA is elevated, it may indicate that a cancer is present. However, an increase in CEA may also be due to benign conditions.
How is the sample collected for testing?
A blood sample is taken by needle from a vein in the arm.
NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.
Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.
Is any test preparation needed to ensure the quality of the sample?
No test preparation is needed.
The Test
How is it used?
CEA is used mainly to monitor the treatment of cancer patients, especially those with colon cancer. Following surgery, CEA values are helpful in monitoring the response to therapy and in determining whether the disease has recurred. CEA is also used as a marker for other forms of cancer, including cancers of the rectum, lung, breast, liver, pancreas, stomach, and ovary. Not all cancers produce CEA, and a positive CEA test is not always due to cancer. Therefore, CEA is not used for screening the general population.
When is it ordered?
A CEA test may be ordered when your symptoms suggest the possibility of cancer. In patients who have been diagnosed with certain types of cancer, a CEA level is also measured before and after therapy, to evaluate the success of treatment.
What does the test result mean?
On initial testing, patients with smaller and early-stage tumors are likely to have normal or only slightly elevated CEA values. Patients with more advanced tumors or tumors that have spread throughout the body are more likely to have high CEA values. When CEA levels decrease after therapy, it means that most or all of the CEA-producing tumor has been removed. A steadily rising CEA level is often the first sign of tumor recurrence.
Increased CEA levels can indicate some non-cancer-related conditions, such as inflammation, cirrhosis, peptic ulcer, ulcerative colitis, rectal polyps, emphysema, and benign breast disease.
Since not all cancers produce CEA, it is possible to have cancer but also have a normal CEA level.
Is there anything else I should know?
Individuals who smoke cigarettes tend to have higher CEA levels than non-smokers.
When cancer spreads to other organs, CEA may be present in other bodily fluids besides blood. For example, if CEA is detected in cerebrospinal fluid, this may indicate a central nervous system metastasis.
Common Questions
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Article Sources
NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Sources Used in Current Review
Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Pp 244-245.
Pagana K, Pagana T. Mosby's Manual of Diagnostic and Laboratory Tests. 3rd Edition, St. Louis: Mosby Elsevier; 2006 pp 161-162.
MedlinePlus Medical Encyclopedia: CEA. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/003574.htm. Accessed February 2009.
