CA19-9

Immunology

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Description

The main application of all tumour markers is monitoring for relapse or progression. Use as a diagnostic aid requires care and knowledge of the test limitations. Opportunistic screening is discouraged. Guidelines for the use of tumour markers suggest that the best validated marker for pancreatic cancer is CA19-9. Inadequate sensitivity and specificity limit the use of CA19-9 in the early diagnosis of pancreatic cancer, however it is of use in predicting prognosis and when deciding on a treatment plan [1,2]. CA19-9 is a high molecular weight mucin containing a sialyated pentasaccharide epitope, which represents a component of the Lewis A blood group antigen [6]. Elevated levels can be seen in patients with pancreatic, gastrointestinal and hepatobiliary carcinoma. Levels may also be raised in patients with pancreatitis, but it rarely exceeds 60kU/L in these cases. Other benign causes of raised CA19-9 include cholecystitis, primary biliary cirrhosis, hepititis and obstructive jaundice [4,5]. In coloretal carcinoma CA19-9 concentrations rise with advancing disease, the diagnostic sensitivity and specificity for colorectal cancer can be improved by also measuring CEA [5]. In appropriate clinical situations CA19-9 can be used to aid the diagnosis of pancreatic carcinoma [3,5]. CA19-9 has a role in determining the most appropriate treatment for pancreatic cancer, such as surgery, and monitoring response to therapy [3].

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Indications

Monitoring of pancreatic, colorectal (with CEA) & hepatobiliary cancer.

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Sample Type

2mL Serum (Gel 5mL Yellow tube), or 2mL Heparin (Lithium or Sodium) or 2mL EDTA Plasma.
Requests from outside Sheffield: transport at ambient temperature via Royal Mail or Courier.

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Reference Range

Normal range: 0-35 kU/L.

Reference range established by manufacturer and verified in house.

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Turnaround Time

Within 2 days

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Testing Frequency

Daily

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References

Sturgeon CM and Diamandis EP. Use of tumour markers in clinical practice: Quality requirements. The National Acadamy of Clinical Biochemistry. Laboratory medicine practice guidelines. 2009. [Ref 1]
Sturgeon CM, et al. Serum Tumour Markers:How to order and interpret them. British Medical Journal. 2009; 339; 852-858.
Duffy MJ, et al. Tumour markers in pancreatic cancer: a European group on Tumour markers (EGTM) status report. Ann Onc. 2009. (In press) [Ref 2]
Balzano G and Di Carlo V. Is CA 19-9 useful in the the management of pancreatic cancer. Lancet Onc. 2008. 9:89-91. [Ref 3]
Hess V, et al. CA 19-9 tumour-marker response to chemotherapy in patients with advanced pancreatic cancer enrolled in a randomised controlled trial. The Lancet: Oncology. 2008. 9(2):89-91. [Ref 4]
PRU handbook of clinical immunochemistry. 9th Edition. 2007. [Ref 5]
Magnani JL, et al. Identification of the gastrointestinal and pancreatic cancer associated antigen detected by monoclonal antibody 19-9 in the sera of patients as a mucin. Canc Res. 1983. 43:5489-5492. [Ref 6]

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.