Pathology Associates Of Lexington, P.A.

CA 19-9 Test, Blood

CA 19-9 antigen, serum

This is one of the "mucin-type glycoproteins" carbohydrate (cancer) antigens which may circulate in the blood of patients with pancreatic and other adenocarcinomas...casually considered to be a "pancreatic cancer marker". An ovarian cancer (OC19-9) cell line is cultivated and maintained to produce cancer cells which are injected into mice to produce antibodies against the OC19-9 cells. The murine (mouse) lymphocytes are harvested and grown to produce the antibodies at commercial volumes².It can be helpful in the initial evaluation of a newly discovered mass of the pancreas. If this test is really high in such a case, then the odds are very high that it is a non-resectable cancer. One would then perform a fine-needle biopsy to prove the malignant diagnosis. Whether or not to perform exploratory surgery for the possibility of performing a Whipple procedure to remove the tumor would depend on many additional factors.

Conditions Causing Elevations (>40U/mL) of this Marker:

pancreatic cancer 72-79%

but, 200g., 6cm SCC of pancreas with clear margins but growing into gastric wall (AJC stage IVA) preop. only 71 (nl<37)[LMC-01-4430]

biliary cancers 67%-73%

gastric cancers 42-62%

colorectal cancers 19-41%; when elevated preoperatively, this is a good follow-up marker for early evidence of recurrence

benign multicystic mesothelioma of peritoneum (BMMP)

may see a moderate elevation associated with collagen diseases, diabetes mellitus, alcoholic or non-alcoholic liver disease, and acute or chronic pancreatitis & combination CA125 & CA19-9 pretty specific for advanced fibrosis or cirrhosis ⁴.

other [warning]

situations wherein the level is not elevated:

some...particularly when small and curatively resectable...pancreatic cancers are present without elevation.
non-adenocarcinomatous malignant tumors of the pancreas
benign pancreatic tumors

PAM4 is another extra-hepatic, pancreaticobiliary antigen getting attention in late 2011 and early 2012⁵. But, even combined with CA19-9, it does not really help that much in early detection of treatable disease. It has false positives and negatives.

References:

Seminars in Oncology, vol. 20, #3, page 255 June 1993
The Handbook of Clinical Pathology [text], McKenna & Keffer, 2nd Ed., 2000.
Interpretation of Diagnostic Tests, Wallach, 2000, 7th Ed.
Etxagibel A, et. al., "Drug-induced hepatitis superimposed on the presence of anti-SLA antibody: a case report", J Med Case Reports 2:25, 2008.
Medscape commentary (PAM4) January 2012 HERE.

Synonyms:

pancreatic cancer antigen, carbohydrate antigen 19-9

(posted 7 April 2002; latest addition 13 February 2012)