CA-19.9 (Cancer Agent – 19.9) is a protein present in the blood. This test measures the level of this protein present in your bloodstream. 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 in the body.
High levels of CA 19-9 are often a sign of pancreatic cancer. But sometimes, high levels can indicate other types of cancer or certain noncancerous disorders, including cirrhosis and gallstones.