CA 19-9 Blood Test (Pancreatic Cancer)

A CA 19-9 test measures the amount of a protein called CA 19-9 (cancer antigen 19-9) in a sample of your blood. CA 19-9 is a type of tumor marker. Tumor markers are substances made by cancer cells or by normal cells in response to cancer.

High levels of CA 19-9 can be a sign of certain cancers of the digestive tract. These include cancers of the: Pancreas.; Bile duct.; Colon and rectum.; Stomach.; Ovaries.; Bladder.; However, high CA 19-9 levels can also be a sign of other conditions, including: Gallstones, which can block your bile ducts.; Cholangitis, which is an infection of the bile ducts.; Pancreatitis, which is inflammation of the pancreas.; Cirrhosis (or scarring) of the liver.; Bile duct disease, including a blockage or infection.; Liver disease.; Cystic fibrosis.; Because high levels of CA 19-9 can mean different things, health care providers don't use the results from a CA 19-9 test alone to screen for or diagnose cancer or other diseases. To do this, your provider will have to consider the results of a CA19-9 test as well as the results of other tests.

Why this test is done

You may need a CA 19-9 blood test if you:

• Have been diagnosed with any of the types of cancer associated with CA 19-9.
• Are going through cancer treatment. Your provider may test you on a regular basis to see if your treatment is working.
• Have completed cancer treatment. Your provider may test you to see if your CA 19-9 levels stay low. If they rise, it could be a sign that your cancer has returned.

Your provider may also order this test if you have symptoms of the cancers associated with high CA 19-9 levels. These can include:

• Jaundice (yellowing of the skin).
• Weight loss.
• Abdominal (belly) pain.
• Weakness.
• Swollen gallbladder or liver.

How to prepare

Usually, you don't need any special preparations for a CA 19-9 blood test. But ask your provider to be sure. If you take certain vitamins, you may need to stop them before the test.

Sample type

Blood

Other names for this test

cancer antigen 19-9, carbohydrate antigen 19-9, CA 19-9 measurement, CA 19-9 radioimmunoassay (RIA)