CEA Tumor Marker
CEA is an abbreviation of carcinoembryonic antigen, which is one of the most commonly used tumor markers. The tumor markers are substances occurring in the human body, whose increased concentration may be associated with presence of a certain malignant disease. Carcinoembryonic antigen is produced in human fetuses and its concentration after the birth quickly decreases. In adults, its serum concentration is minimal.
The CEA is associated mainly with cancers of the digestive tube and its concentration can be easily evaluated from a sample of venous blood.
Elevated CEA is mainly associated with presence of colon cancer and stomach cancer, but it is also present in pancreas cancer, lung cancer, thyroid cancer and breast cancer. It should be however noted the tumor markers should not be primarily used for diagnosis and it is better to check them in patients with already diagnosed malignant disease who undergo therapy. When CEA serum level decrease, the treatment is effective and when the concentration rises, the therapy is ineffective an the number of malignant cells rises.
As mentioned above, CEA is not very reliable and its high concentration may be present not only in tumors, but also in non-malignant diseases such as acute and chronic pancreatitis, liver cirrhosis, ulcerative colitis and Crohn's disease. Elevated CEA is also reported in chronic smokers. On the other hand, some people with advanced forms of aforementioned cancers may have normal levels of CEA.