Normal levels for CA 19-9 blood tests are under 37 units per milliliter, states University of Rochester Medical Center. Higher results sometimes indicate pancreatic, liver, gallbladder, lung, colon or stomach cancer. Abnormal scores below 75 potentially signal gallbladder or pancreatic infection. Liver disease, gallstones or cystic fibrosis are also possibilities.
The CA 19-9 blood test is just one step in the diagnosis process, UR Medical Center explains. Physicians order CA 19-9 when cancer is suspected or there is a family history of the disease. Patients with cancer are sometimes tested weekly to monitor the progression of treatment. It is also used to look for a recurrence of the disease. CA 19-9 is most effective when used for pancreatic cancer.