Cancer Antigen (CA) 19-9

Alternate Name: Ca19-9

SAL Code:






Turn Around Time:

1 Day






Tumor Markers

Performing Laboratory:

Sherman Abrams Laboratory

Specimen Requirements:

Primary Tube:


Primary Substance:




Stable Ambient:

8 Hours

Stable Fridge:

2 Days

Stable Frozen:

28 Days

Rejection Criteria:

Gross hemolysis; lipemia; improper labeling

Clinical Info:

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.

Additional Information:

Cancer antigen 19-9 (CA 19-9) is to monitor treatment response and recurrence of gastrointestinal, pancreatic,liver, and colorectal cancers as well as to help differentiate between cancer of the pancreas and other conditions. CA 19-9 is a tumor marker with low level of sensitivity and specificity. The CA19-9 assay should not be used as the sole determining factor to make any diagnosis.

Sample Collection:

Collect patient samples using standard phlebotomy techniques. Click here for additional collection instructions.
Separate serum or plasma from cells within 45 minutes of collection.

Test Limitations:

Values obtained with different assay methodologies should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor a patient's course of therapy.
CA 19-9 may be absent in individuals with blood group Lewis Le(a-b-), as observed in approximately 5% of Caucasian and 20-25% of African American patients. CA 19-9 levels, regardless of value, should not be interpreted as absolute evidence of the presence or absence of disease.
Biotin may cause interference with this assay. Patients that are taking biotin supplements should cease taking any such supplements for 72 hours prior to sample collection.

Test Information: