CEA test: normal range and what a raised result means

Carcinoembryonic antigen (CEA) is a protein that is found in the blood of a healthy adult in very small amounts or not at all. The amount of CEA can rise in various cancers — most often of the colon, and also in cancer of the thyroid, the rectum, the lung, the breast, the liver, the pancreas and the ovary. That is why CEA is not used as a screening or diagnostic test in a healthy person — its value is that, when a cancer is already known about, the test makes it possible to follow how the body is responding to treatment, and later helps to notice a possible return of the disease after treatment. It is important to know that CEA can be raised without cancer too — because of gastritis, a stomach ulcer, chronic obstructive pulmonary disease (COPD), liver diseases, cirrhosis, diverticulitis, diabetes mellitus or autoimmune and inflammatory diseases. Smoking also raises the CEA level, which is why a slightly higher norm applies to people who smoke. For these reasons a CEA result always has to be assessed together with a doctor and other tests, and not on its own.

• When a cancer is already known about (most often of the colon or the rectum) — to learn more about the course of the disease
• During treatment (chemotherapy, surgery, radiotherapy) — to follow whether the body is responding to the treatment given
• After cancer treatment has been completed — checking periodically whether the disease has returned
• When a doctor, taking other tests or symptoms into account, wants additional information about the oncological condition

How to prepare

• No special preparation is needed for the routine blood test
• If you smoke, your doctor may ask you not to smoke before the test, because smoking can temporarily raise the amount of CEA

A raised CEA

According to MedlinePlus, a raised CEA is considered significant, but it does not point to cancer alone. It is associated with cancer of the colon, the thyroid, the rectum, the lung, the breast, the liver, the pancreas or the ovary. However, it can also rise because of gastritis, a stomach ulcer, COPD, liver diseases, cirrhosis, diverticulitis, diabetes mellitus, inflammatory bowel diseases, lung infections or pancreatitis. Smoking also raises the value.

• Oncological diseases — most often cancer of the colon, and also of the thyroid, the rectum, the lung, the breast, the liver, the pancreas or the ovary
• Gastritis or a stomach ulcer
• Chronic obstructive pulmonary disease (COPD) or lung infections
• Liver diseases and cirrhosis
• Diverticulitis
• Diabetes mellitus
• Inflammatory bowel diseases and other autoimmune or inflammatory conditions
• Pancreatitis
• Smoking — temporarily raises the amount of CEA

What to discuss with a doctor

• Whether the person smokes at the time of the test — this can temporarily raise the result
• Comparison of the result with earlier tests — in order to assess the response to treatment or a possible return of the disease
• Other tests and imaging methods that a doctor will order, depending on the clinical context
• Non-cancer causes (gastritis, liver disease, COPD and others), if no oncological history is known

A low CEA result

A very low or undetectable amount of CEA in the blood is typical of a healthy adult — it is considered an ordinary result rather than a deviation that would need explaining. However, according to MedlinePlus, a normal CEA does not rule out cancer: it can be normal even in a cancer that usually raises CEA.

Related pages: CA 19-9, CA 125, AFP, CYFRA 21-1, fecal occult blood test and how to read blood test results.