In the presence of certain cancers, CEA may be used to monitor the effect of treatment and recurrence of disease
Carcinoembryonic Antigen (CEA)
Before starting cancer treatment as well as at intervals during and after therapy
A blood sample taken from a vein in the arm
No test preparation is needed
CEA is a protein that is normally not detected in the blood of a healthy person. When certain types of cancer are present, CEA may be produced by the cancer cells. CEA may then be detected in blood, but it will not indicate which kind of cancer is present. CEA is often used to monitor patients with cancers of the gastrointestinal (GI) tract such as bowel (colorectal) cancer. It may be raised in other cancers, such as ovarian and breast cancers, but can also be raised in benign conditions such as liver disease and inflammatory bowel disease (Crohns disease or ulcerative colitis).
How is it used?
CEA is most useful to monitor treatment of cancer patients. It is used for patients who have had surgery, to measure response to therapy and to monitor whether the disease has recurred. In 2011, NICE (National Institute for Health and Care Excellence) published guidelines for the diagnosis and management of bowel cancer (CG131) that are currently referred to by the British Society of Gastroenterology. Their recommendations are that bowel surgery is followed up with regular CEA blood testing (at least every 6 months in the first 3 years). A blood test for CEA in this circumstance is used as a tumour marker, i.e. an indicator of whether the cancer is present or not.
CEA is used as a marker for bowel cancer in particular, but may be measured where other forms of cancer are present. It has been found helpful in monitoring some patients with cancer of the rectum, lung, breast, liver, pancreas, stomach, and ovary. Not all cancers produce CEA, and a level within the given reference range does not guarantee that cancer (even the kinds known to produce CEA) is not present, therefore the CEA test is not used for screening the general population.
When is it requested?
What does the test result mean?
The concentration of CEA in the blood does not accurately reflect tumour size, however on initial testing, patients with smaller and early-stage tumours are likely to have low, if not normal, CEA concentrations, while patients with more advanced tumours, or tumours that have spread throughout the body, are likely to have initially high CEA concentrations. When CEA decreases to "normal" concentrations after therapy, it means that the CEA-producing tumour has been removed. A steadily rising CEA result may be the first sign that the cancer has returned.
Is there anything else I should know?
CEA is a protein that is found in developing tissues of babies. By the time a baby is born, detectable levels in the blood disappear.
Increased CEA concentrations can indicate some non-cancer-related conditions, such as liver disease, and inflammatory bowel disease. Also, smokers tend to have higher concentrations in the blood than non-smokers.
If my CEA results rise and indicate cancer, what are my treatment options?
If I am a smoker, does an elevated CEA result mean I have cancer?