Normal CEA (Carcinoembryonic Antigen) in a blood test

Each laboratory must establish its own normal range for CEA (Carcinoembryonic Antigen) in a blood test. These ranges depend on the makeup of the local population, the technologies used and the accuracy of the measurement. There may be also slight differences in the normal levels according to age, gender, race or ethnic origin, geographic region, diet, type of sample and other relevant status.

Your doctor will study the results along with your medical record, screenings, physical condition, symptoms and any other relevant information about your situation.

Tobacco increases Carcinoembryonic antigen (CEA). Heavy Smokers, as a group, have higher than normal baseline concentration of CEA. Therefore, in smokers normal range may be up to 10 ng/ml.

In addition, there are different procedures to measure CEA in the blood. It can be measured by immunoradiometric analysis (IRMA) or immunochemiluminometric assays (ICMA) so the values may differ from one laboratory to another. Therefore, to monitor patient with colorectal cancer, tests should be performed in the same lab with the same procedure.

Carcinoembryonic antigen (CEA) is an oncophetal glycoprotein with a molecular weight of 180 kDa. The carcinoembryonic antigen (CEA) protein belongs to the immunoglobulin superfamily and is coded on the long arm of chromosome 19.

CEA is localized to the luminal surface, an arrangement that suggests that it contributes to spatial orientation of colonocytes and that it may also function to preserve the adult gut mucosal barrier. In tumor cells, however, CEA is irregularly distributed throughout the cell membrane.

Carcinoembryonic antigen (CEA), a glycoprotein that circulates at a high level during fetal life, is detectable in only tiny amounts in the blood of healthy adults.

Carcinoembryonic antigen (CEA) is a tumor marker. It means that it raises in the presence of a malignant tumor. CEA is the most widely used marker for gastrointestinal cancer. CEA is elevated in colonic cancer and metastatic breast disease.

Although the CEA is primarily associated with colorectal cancers, other malignancies that can cause elevated levels of CEA include breast, lung, stomach, pancreas, ovary and other organs.

Benign conditions that cause significantly higher than normal levels include liver diseases (cirrhosis, pancreatitis, etc.) or in inflammatory bowel disease (ulcerative colitis, diverticulitis, etc.).

CEA is helpful but not conclusive and is thus of little value in a diagnostic evaluation for cancer of the colon because:

• Not all people with cancer of the colon show elevated CEA levels.
• Several conditions other than colonic cancer may cause elevated CEA levels.

Although CEA may be used as part of a diagnostic evaluation for cancer of the colon, it is most useful as a marker to determine the effectiveness of treatment. For example, CEA levels usually return to normal about 4- 6 weeks after a malignant tumor of the colon is surgically removed. If it does not return to normal range, it may be a sign of incomplete resection or metastasis.

If it increases again after a while, it may suggest a new recurrence of the cancer. Therefore, the CEA test should be performed every three months in patients who has previously suffered from colonic cancer.

The following values are considered to be normal values:

IMPORTANT: These levels are expressed in ng/ml. They are an example of a healthy non-smoker man/woman of about 40 years old with no known disease and not taking any medication. The ranges can be different depending on the laboratory or on your personal circumstances.