Laboratory Services

Carbohydrate Antigen 19-9 (CA 19-9), Serum

Print this page

Updated Test Information:

Test Description
Carbohydrate Antigen 19-9 (CA 19-9), Serum
Synonym(s)

CA 19-9 (Carbohydrate Antigen 19-9); Cancer Antigen 19-9 (CA 19-9); GI Cancer Antigen

Test ID
CA19
General Information

Useful for: 



  • Potentially for diagnosis and monitoring of pancreatic cancer

  • Potentially differentiating patients with cholangiocarcinoma and primary sclerosing cholangitis (PSC) from those with PSC alone

Specimen Type

Serum

Specimen Requirements

  • Preferred: Serum Gel

  • Acceptable: Red Top

Specimen Collection / Processing Instructions

  • Patient Preparation: For 12 hours before specimen collection do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins

  • Serum gel tubes should be centrifuged within 2 hours of collection.

  • Red-top tubes should be centrifuged and aliquoted within 2 hours of collection

Minimum Sample Volume

0.5 mL

Stability

  • Refrigerated (preferred): 7 days

  • Frozen: 90 days

  • Ambient: 8 hours

Unacceptable Specimen Conditions

Gross hemolysis

Limitations

  • Carbohydrate antigen 19-9 (CA 19-9) is neither specific nor sensitive enough to be used as a cancer screen

  • Some individuals do not express CA 19-9. Consequently low values in these individuals are not informative regarding cancer recurrence

  • Do not interpret serum CA 19-9 levels as absolute evidence of the presence or the absence of malignant disease. Use serum CA 19-9 in conjunction with information from the clinical evaluation of the patient and other diagnostic procedures

  • Some patients who have been exposed to animal antigens, either in the environment or as part of treatment or imaging procedures, may have circulating anti-animal antibodies present. These antibodies may interfere with the assay reagents to produce unreliable results

Methodology

Immunoenzymatic Assay

Estimated TAT

1-3 days

Testing Schedule

Mon-Sat

Retention

3 months

CPT Code(s)

86301

Reference Range

< 35 U/mL

Performing Lab

Mayo

LOINC Code(s)

83084-4

Additional Information