To monitor a person's response to pancreatic cancer treatment and/or cancer progression
To watch for pancreatic cancer recurrence
CA 19-9 can only be used as a tumor marker if the cancer is producing elevated amounts of it. Since CA 19-9 is elevated in about 65% of those with bile duct (hepatobiliary) cancer, it may be ordered to help evaluate and monitor people with this type of cancer.
If CA 19-9 is initially elevated in pancreatic cancer, then it may be ordered several times during cancer treatment to monitor response and on a regular basis following treatment to help detect recurrence.
CA 19-9 may sometimes be ordered when a doctor suspects hepatobiliary cancer and/or bile duct obstruction. Non-cancerous causes of bile duct obstruction can cause very high CA 19-9 levels, which fall when the blockage is cleared. In these cases, it is a good idea to wait at least a week or two after the blockage is removed to re-check CA 19-9 levels.
Low amounts of CA 19-9 can be detected in healthy people, and many conditions that affect the liver or pancreas can cause temporary elevations.
Moderate to high levels are found in pancreatic cancer, other cancers, and in several other diseases and conditions. The highest levels of CA 19-9 are seen in cancer of the exocrine pancreas. This cancer arises in the tissues that produce food-digesting enzymes and in the ducts that carry those enzymes into the small intestine. About 95% of pancreatic cancers are of this type.
Serial measurements of CA 19-9 may be useful during and following cancer treatment. Rising or falling levels may give the doctor important information about whether the treatment is working, whether all of the cancer was removed successfully during surgery, and whether the cancer is recurring.
This article was last reviewed on November 29, 2012. | This article was last modified on February 24, 2015.
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