What is CA-GI, CA 19-9?
This test measures the amount of a protein called CA 19-9 (cancer antigen19-9), a type of tumor marker in the blood. This test is primarily used in the diagnosis of pancreatic cancer as well as during the treatment of pancreatic cancer.
Healthy people can have small amounts of CA 19-9 in their blood. The levels of CA 19-9 are found to be elevated in other cancers as well, such as gallbladder and cholangiocarcinoma (bile duct cancer), colorectal cancer, ovarian cancer, gastric cancer, liver cancer, lung cancer.
Sometimes elevated levels of CA 19-9 might also indicate inflammation of the pancreas, cirrhosis, gallstones and thyroid disease.
Why is CA-GI, CA 19-9 done?
The CA 19-9 test is done during the treatment of pancreatic cancer. However, it can also be done following the treatment of pancreatic cancer.
What does CA-GI, CA 19-9 Measure?
CA 19-9 test measures the levels of CA 19-9 in the blood. CA 19-9 is a protein that exists on the surface of certain cancer cells and does not cause cancer. CA 19-9 is shed by the tumor cells.
CA 19-9 can be measured in the blood which makes this test very helpful as a tumor marker. It is useful to follow the course of cancer. Its levels get raised in about 70% - 95% of patients with advanced pancreatic cancer.
The levels of CA 19-9 are found to be elevated in other cancers such as gallbladder and cholangiocarcinoma (bile duct cancer), colorectal cancer, ovarian cancer, gastric cancer, liver cancer, lung cancer, obstruction of bile duct, inflammation of the pancreas, cystic fibrosis, disease of thyroid, and disease of the liver.
In healthy people, CA 19-9 is found in small amounts in the blood. CA 19-9 cannot be used by itself for screening or diagnosis as it is not specific for pancreatic cancer.
Interpreting CA-GI, CA 19-9 results
%age positivity of CA 19-9
40 - 50
30 - 50
10 - 20
Benign gastrointestinal diseases
10 - 20