Cancer Antigen CA 19-9


For: ,

Quest Diagnostics Test Code: 4698

A large percentage of patients with gastrointestinal tumors (such as pancreatic, liver, gastric, colorectal tumors) and some other malignancies have been shown to have elevated serum CA 19-9 levels. Serum CA 19-9 levels may be useful for monitoring disease activity or predicting relapse following treatment.

Cancer antigen (CA) 19-9 is a type of protein that can be found on the surface of some cancer cells. CA 19-9 is elevated in 70-95% of patients who have pancreatic cancer. Because of this, it is helpful in guiding the efficacy of treatment in those with pancreatic cancer. However, because this increase in CA 19-9 production is not present in all people with pancreatic cancer, and CA 19-9 can also be elevated in other types of cancer, it is not a useful screening tool or for diagnosis to detect pancreatic cancer. Therefore, the test is mainly used as a surveillance tool in people who already have a diagnosis and are on treatment to see if the treatment is effective.

This test is performed in following conditions such as:

• In people who already have pancreatic cancer diagnosed, this is to help determine cancer characteristics and treatment options
• In people with pancreatic cancer who are on treatment like radio or chemotherapy

Also Known As: Carbohydrate Antigen 19-9


CA 19-9 will be absent in a small percentage of the population with Blood Group Lewis Le(a-b-).


Specimen Collected
  • Blood
Estimated Time Taken

Turnaround time for the CA 19-9 test is typically 2-4 business days.