Carbohydrate antigen 19-9 (CA 19-9)

Carbohydrate antigen 19-9 (CA 19-9) is a glycoprotein used as a marker for typing, monitoring and therapeutic response in many forms of gastrointestinal cancers. Increased values of CA 19-9 are also found in some cancers of the colon, stomach, pancreas and biliary tract. In addition, values may also be increased in some cases of benign conditions such as chronic pancreatitis or cirrhosis.