Cancer antigen 19-9 (CA 19-9)
CA 19-9 is a tumour-associated glycoprotein mucin that bears a specific carbohydrate epitope, the sialylated Lewisa blood group antigen. The assay is based upon a monoclonal antibody, 1116-NS-19-9 which recognises this carbohydrate antigenic determinant. Approximately 7 % of the population who have the phenotype Lewisa negative are prevented by their genetic constitution from synthesising CA 19-9 antigen. Serum CA 19-9 concentrations are elevated in 70-92 % of patients with pancreatic carcinomas. This marker may also prove helpful in monitoring treatment response in other CA 19-9 positive carcinomas.
CA 19-9 may be elevated in cancers, including hepatocellular, gastric, colorectal, lung and gall bladder cancers. A variety of conditions, including biliary obstruction, cholestasis, cholangitis, hepatic cirrhosis, cystic fibrosis, acute and chronic pancreatitis, may also cause elevation of CA 19-9.
Pancreatic cancer
Diagnosis: since CA 19-9 may be elevated in benign conditions it is not recommended for screening purposes and diagnostic utility should be limited to case finding in symptomatic patients in conjunction with pancreatic imaging.
Prognosis and staging: baseline CA 19-9 can be used to guide treatment and follow-up and may have a prognostic value in absence of cholestasis. CA 19-9 carries independent predictive value for successful resection of pancreatic cancer and overall survival.
Treatment monitoring: CA 19-9 measurements are recommended in conjunction with imaging to monitor response to therapy.
Surveillance: studies have indicated that CA19-9 has high sensitivity for detection of relapse following pancreatectomy.
<37 kIU/L
Abbott Alinity
Please note: This test is now also available at Hillingdon, but UKAS accreditation for this site is pending.
Record last updated
September 5, 2025
Sample Container
5ml SST Vacutainers (Gold / Yellow top)
Sample Container
6ml Plain Vacutainers (Red top)
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Test Results
Yes, we have a Pathology User Guide
Yes. Please email your request to Imperial.nwlpcustomerservice@nhs.net
Results are communicated to clinical staff and are normally not communicated direct to patients either on telephone requests or in written report. If you need to contact us please click here to view the contact details page
Please contact the Customer Service Team Monday to Friday from 8:30am – 6:00pm on 0203 313 5353. Alternatively, see the Pathology User Guide for how to contact the relevant department. If advice is not urgent you can also email your query to Imperial.nwlpcustomerservice@nhs.net
Additional tests may be added by discussion with the relevant laboratory. The time limit for adding additional tests to a sample already received in the laboratory will depend on the type of sample and the department it was sent to.
Information on the repertoire of tests performed by pathology, including reference ranges, turnaround times and specimen requirements, can be found in the test directory.
Phlebotomy services are not managed by NWLP. For further information please see:
Imperial College Healthcare Trust Phlebotomy services
Chelsea and Westminster Hospital NHS Foundation Trust Phlebotomy services
NWLP operates UKAS accredited medical laboratories as per the references below. The current scope of accreditation for all NWLP’s laboratories can be found on the UKAS website.
See the following UKAS ref numbers:
- Clinical Biochemistry Ref: 8673
- Haematology and Blood Transfusion Ref: 8674
- Infection & Immunity Sciences (Including Immunology, Virology, Microbiology and Histocompatibility and Immunogenetics ) Ref: 8659
- Cellular Pathology (Including Histopathology, Cytology and Molecular Pathology) Ref: 9615
If you require copies of our certificate of accreditation and associated documentation please contact Imperial.nwlpcustomerservice@nhs.net.
UKAS requires the laboratories to be accredited for a particular repertoire/scope (ISO15189), any changes or additions to repertoire require assessment by UKAS (extension to scope).
The BD Hospital Tube Guide, BD GP Tube Guide and BD Paediatric Tube Guide provide visual references to the correct tube types and collection instructions.
Home testing
INSTRUCTION SHEET FOR BLOOD SAMPLE COLLECTION
We also have two instruction videos available (one with subtitles and one without) – please click on the links to view the videos on Google.
Our accreditations
Upholding excellence in diagnostic standards
Our laboratories are accredited by the UK Accreditation Service (UKAS) against the international standard ISO15189:2022. UKAS is the accreditation body for the UK that assesses medical laboratories.
Find out more about our accreditations on the UKAS website.
UKAS website