Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (777 page)

   Limitations

   CA 15-3 should not be used to diagnose breast cancer.

   Clinical sensitivity is 0.60, the specificity is 0.87, and the PPV is 0.91.

   It is considered equivalent to cancer antigen 27.29 mucin marker.

Suggested Reading

Duffy MJ, Duggan C, Keane R, et al. High preoperative CA 15-3 concentrations predict adverse outcome in node-negative and node-positive breast cancer: study of 600 patients with histologically confirmed breast cancer.
Clin Chem.
2004;50:559–563.

CANCER ANTIGEN 19-9 (CA 19-9)

   Definition

   CA 19-9 is a modified Lewis(a) blood group antigen and has been used as a tumor marker. It is shown to be elevated in sera of some patients with GI tumors.

   
Normal value:
<35 U/mL.

   Use

   Detection, diagnosis, and prognosis of pancreatic cancer

   Monitor response to therapy (e.g., postsurgical recurrence correlates with increased concentrations)

   May be a useful adjunct to CEA for diagnosis and to detect early recurrence of certain cancers

   May indicate development of cholangiocarcinoma in patients with primary sclerosing cholangitis

   Interpretation