What is CEA (Carcino Embryonic Antigen)?
Also Known As:
Carcinoembryonic Antigen Test CEA Blood Test Carcinoembryonic Antigen Assay CEA Assay
Carcinoembryonic antigen (CEA) is a protein that is primarily associated with certain types of cancer. The most common way to measure CEA is through a blood test, although other bodily fluids may be tested as well.
CEA testing is not used to diagnose cancer, but it may assist doctors in predicting how a person’s cancer may be likely to progress, determining treatment effectiveness, and assessing whether or not cancer has returned after treatment.
The purpose of a CEA test is to measure the presence and amount of CEA in a patient’s test sample. CEA is a type of tumor marker. A tumor marker is a substance found in the body that may be a sign of cancer or other health conditions.
Testing may be performed for several purposes:
- Estimating cancer prognosis: Prognosis is a prediction of the expected course or outcome of a disease. Doctors may use CEA levels along with other factors such as the stage or extent of a person’s cancer to estimate their prognosis.
- Monitoring cancer treatment: An increase or decrease of CEA levels during treatment for specific types of cancer may reflect whether treatment is working effectively. In the case of cancers of the colon and rectum, for example, a CEA level will generally be taken as a baseline measurement after diagnosis so that it can be compared to future CEA levels taken during treatment.
- Detecting cancer recurrence: Doctors often monitor CEA levels after treatment for some cancers as a way of trying to determine whether cancer has returned. For example, patients with earlier-stage colon and rectal cancer have CEA testing every 3 to 6 months for several years after receiving initial treatment.
In addition to colon and rectal cancer, CEA testing may be done in relation to the following types of cancer:
- Breast cancer
- Lung cancer
- Thyroid cancer
- Pancreatic cancer
- Head and neck cancer
- Cancers of the urinary or reproductive tracts
CEA testing is not used for screening, which is looking for cancer in people who have no symptoms. It is also not used for cancer diagnosis because other, noncancerous conditions can cause CEA levels to increase and because not all cancers cause CEA levels to rise.
Noncancerous conditions that can cause CEA levels to rise include stomach ulcers, pancreatitis, smoking, lung infection, inflammatory bowel diseases like ulcerative colitis or diverticulitis, liver scarring, and gallbladder inflammation
What does the test measure?
CEA testing evaluates how much carcinoembryonic antigen is in the blood, spinal fluid, or peritoneal fluid.
CEA is a protein that is normal in developing fetuses but drops to low or nonexistent levels after birth. Because CEA isn’t typically found in adults, its detection can be related to certain cancers or other health problems.