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Test Code CA19 Carbohydrate Antigen 19-9 (CA 19-9), Serum

Reporting Name

Carbohydrate Ag 19-9, S

Useful For

As a potential adjunct for diagnosis and monitoring of pancreatic cancer

 

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

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Specimen Required


Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.6 mL

Collection Instructions:

1. Within 2 hours of collection, serum gel tubes should be centrifuged.

2. Within 2 hours of collection, red-top tubes should be centrifuged, and the serum aliquoted into a plastic vial.


Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 7 days
  Frozen  90 days
  Ambient  8 hours

Reference Values

<35 U/mL

Day(s) Performed

Monday through Saturday

Test Classification

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

86301

Clinical Information

Carbohydrate antigen 19-9 (CA 19-9) is a modified Lewis(a) blood group antigen. CA 19-9 may be elevated in patients with gastrointestinal malignancies such as cholangiocarcinoma, pancreatic cancer, or colon cancer.

 

Benign conditions, such as cirrhosis, cholestasis, and pancreatitis, also result in elevated serum CA 19-9 concentrations, but in these cases, values are usually below 1000 U/mL.

 

Individuals that are Lewis antigen negative (5%-7% of the population) do not express CA 19-9 due to the lack of the enzyme fucosyltransferase needed for CA 19-9 production. In these individuals, a low or undetectable serum CA 19-9 concentration is not informative regarding cancer recurrence.

Report Available

1 to 3 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross Icterus OK

Forms

If not ordering electronically, complete, print, and send Oncology Test Request (T729)

Method Name

Immunoenzymatic Assay