CA 19.9 is a circulating antigen associated with gastrointestinal cancer, especially the pancreas and colon.
This is detected in the serum antigen not normally present and produced by gastrointestinal tumor cells.
Sampling 5 mL of blood in a dry tube.
The assay is radioimmunoassay or enzyme immunoassay with double antibodies.
normal result: <40 U / mL.
The rate is high in digestive cancers: pancreatic primarily (over 80%), biliary tract (70%), against 30 to 40% for stomach and colon.
But high levels can also be observed in chronic pancreatitis, cirrhosis, gallstones and pulmonary fibrosis.
This marker is neither specific enough nor sensitive enough to be considered a review digestive cancer screening for subclinical stage.
However, it is very useful in monitoring cancer treatments.
B70 or B105.
This antigen is related to the blood and is thus absent in person Lewis negative (5% of the population).