Carcinoembryonic Antigen CEA
Also Known as: CEA assay, CEA blood test, carcinoembryonic antigen test
What is a CEA Blood Test?
CEA (Carcinoembryonic Antigen) is a protein found in a developing baby's tissues. After birth, CEA levels in the blood usually become very low or disappear entirely. CEA, a type of tumor marker, usually is present in the body of healthy people in tiny quantities, if at all. Malignant cells and normal cells produce tumor markers in response to cancer in the body. This test determines how much CEA is present in the blood and other bodily fluids. A CEA test cannot tell you what type of cancer you have or if you have it. As a result, the test is not used for cancer detection or screening. If you have already been diagnosed with cancer, a CEA test can help you track how well your therapy is working or determine if the disease has spread to other parts of your body.
What is the Test used for?
A CEA test is used to determine the presence and level of CEA in a patient's blood sample. CEA test can be used for a variety of purposes, including:
- Monitoring treatment for individuals with certain types of cancers such as cancers of the colon, rectum, prostate, ovary, lung, thyroid, and liver. CEA levels may rise or fall during treatment for specific types of cancer, indicating whether the treatment is effective. For example, in the case of cancers of the colon and rectum, a CEA level will typically be taken as a baseline measurement following diagnosis so that future CEA levels can be compared during treatment.
- Finding out the cancer stage and determining the tumor's size and the extent to which cancer has spread.
- I was checking to see if cancer has reappeared following treatment. For example, patients with early-stage colon and rectal cancer receive CEA testing every 3 to 6 months for several years following therapy.
CEA testing can also be done for the following types of cancers in addition to colon and rectal cancer:
- Breast cancer
- Lung cancer
- Thyroid cancer
- Pancreatic cancer
- Cancer of the head and neck
- Urinary and reproductive tract cancers
CEA testing is not used for cancer screening, which usually looks for cancer in patients with no symptoms. It is also not used to diagnose cancer because other non-cancerous conditions can cause CEA levels to rise, for example, stomach ulcers, pancreatitis, smoking, lung infection, ulcerative colitis or diverticulitis, liver scarring, and inflammation of the gallbladder.
Why and when do you need this test?
If you have been diagnosed with cancer, you may need this test. Your health care provider may test you before you begin the treatment and then frequently during your treatment. This can assist your doctor in determining how effective your treatment is going. You may also require to have CEA tests after the treatment to monitor prognosis or check to see if cancer has reappeared following treatment.
What kind of sample is required for the test?
A small needle will be used by a healthcare professional to obtain a blood sample from a vein in your arm. A small amount of blood will be collected into a test tube or vial once the needle is inserted. When the needle goes in or out, it may sting a little. It usually takes less than five minutes to complete this process.
Do you need to prepare for the test?
A CEA blood test does not require any specific preparation. If there are any special instructions to follow, your health care provider will inform you.
Are there any risks to this test?
Having a blood test carries relatively little risk. You may experience minor pain or bruising where the needle gets inserted, but most symptoms disappear quickly.
What do the test results mean?
If you were tested before starting cancer treatment, your results could show:
CEA at a Low level: This could indicate that the tumor is tiny and has not migrated to other parts of your body.
CEA at a High level: This could indicate that the tumor is large or that cancer has spread.
If you are being treated for cancer, you may be tested several times during your treatment. The results could show:
CEA levels started high and remained high: This could indicate that the cancer is resistant to treatment.
CEA levels were first high but then dropped: This could indicate that the treatment is working.
CEA levels dropped but then increased again: This could indicate that cancer has returned following treatment.