EBM Consult

Lab Test: CA 19-9 Level

    Lab Test
    • CA 19-9 measurement
    • Measurement of carbohydrate antigen 19-9 in serum for the evaluation and treatment of malignant disease, such as pancreatic or hepatobiliary cancer.
    • Used for evaluation of response to treatment and surveillance.
    Reference Range
    • Adults:  0-37 units/mL (0-37 kunits/L)
    Indications & Uses
    • Suspected malignant tumor of ampulla of Vater (Note: Levels can correlate with tumor size and can help predict prognosis.)
    • Suspected malignant tumor of biliary tract
    • Suspected malignant tumor of colon (Note: Elevated level may be associated with colorectal cancer, but currently is not recommended for evaluation, diagnosis, or monitoring of this condition.)
    • Suspected malignant tumor of pancreas (Note: Best used as a diagnostic adjunct in the monitoring of disease in patients with pancreatic cancer)
    Clinical Application

    CA 19-9 is a carbohydrate cell-surface antigen that exists on the surface of some cancer cells.  It is estimated that ~70% of patients with pancreatic carcinoma and 65% of patients with hepatobiliary cancer have elevated levels of CA 19-9. In patients with pancreatic or biliary cancer and who have a good response to surgery, chemotherapy, or radiation therapy, there should be a notable decline in serum levels of CA 19-9 will confirm this response.  A rapid rise in levels may be associated with recurrent or progressive tumor growth. Because of its lack of sensitivity and specificity, CA 19-9 is not effective in screening for pancreatobiliary tumors in the general population. 

    • Increased levels may indicate:
      • Pancreatic carcinoma
      • Cholecystitis
      • Colorectal cancer
      • Hepatobiliary carcinoma
      • Cirrhosis, gallstones
      • Pancreatitis
      • Gastric cancer
      • Lung cancer
      • Inflammatory bowel disease
      • Rheumatoid disease
    Related Tests

    Carcinoembryonic antigen - tumor marker that is elevated in patients with pancreatobiliary cancer.

    Test Tube Needed
    • Red top tube
    • Collect a venous blood sample. 
    • The blood may be sent to a central diagnostic laboratory for CA 19-9 determinations.  The results may not be available for 7 to 10 days.
    • Apply pressure or a pressure dressing to the venipuncture site and observe the site for bleeding.
    Storage and Handling
    • Serum is stable at 2 to 8°C for up to 24 hours; for longer periods, freeze serum at -20°C.
    • Plasma should be fresh, not frozen or thawed.
    What To Tell Patient Before & After
    • Explain the procedure to the patient.
    • Tell the patient that no fasting is required.
    • LaGow B et al., eds. PDR Lab Advisor. A Comprehensive Point-of-Care Guide for Over 600 Lab Tests.  First ed. Montvale, NJ: Thomson PDR; 2007.
    • Pagana K, Pagana TJ eds. Mosby's Manual of Diagnostic and Laboratory Tests. 5th Ed.  St. Louis, Missouri. 2014.

MESH Terms & Keywords

  • CA 19-9