CA 19.9 is a tumor marker used especially for pancreatic cancer but also useful in diagnosing hepatic, oesophageal and colorectal cancers.
The measured CA 19-9 value of a patient’s sample can vary depending on the testing procedure used. CA 19-9 values determined on patient samples by different testing procedures cannot be directly compared with one another and could be the cause of erroneous medical interpretations. The determination of CA 19-9 cannot be used for the early detection of pancreatic carcinoma.1 Three percent to 7% of the population have the Lewis a-negative/b-negative blood group configuration and are unable to express the mucin with the reactive determinant CA 19-9. Patients known to be genotypically negative for Lewis blood group antigens will be unable to produce the CA 19-9 antigen even in the presence of malignant tissue. Phenotyping for the presence of the Lewis blood group antigen may be insufficient to detect true Lewis antigen-negative individuals. Even patients who are genotype positive for the Lewis antigen may produce varying levels of CA 19-9 as the result of gene dosage effect. This must be taken into account when interpreting the findings.2 As the mucin is excreted exclusively via the liver, even slight cholestasis can lead to clearly elevated CA 19-9 serum levels in some cases. In patients receiving therapy with high biotin doses (ie,>5 mg/day), no sample should be taken until at least eight hours after the last biotin administration.1 As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes.1 In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.1 The test contains additives, which minimize these effects. For diagnostic purposes, the results should always be assessed in conjunction with the patient’s medical history, clinical examination, and other findings.
Detecting pancreatic, hepatic, oesopahgeal, colorectal cancer and monitoring therapy for them.
No special preparation is necessary prior to blood sample collection.
Estimated Turn Around For Results:
2-10 Business Days
For an exact turnaround time for results, please contact us at Personalabs and we will contact the lab on your behalf as turnaround times vary depending on testing location or lab testing provider.