When is a tumor marker a laboratory test?
Galen, R.S.
Annals of Clinical and Laboratory Science 7(1): 51-56
1977
ISSN/ISBN: 0091-7370 PMID: 65149 Document Number: 121533
No matter how carefully the upper limits of normal are defined for tumor markers, the overlapping frequency distribution of results in patients with cancer and patients with high risk conditions prohibits the use of these markers as useful screening procedures as suggested by Vaitukaitis. In clinical settings, when these tests can be of greatest value (ulcerative colitis, cirrhosis, etc.), the false-positive rate was unacceptably high. At the present time, CEA have no role in cancer screening and have an extremely limited role in hepatoma diagnosis. Their usefulness in the management of patients under treatment for known cancer was not considered in this review. As research proceeds in the area of tumor markers, more specific antigens may be identified so that the resulting assays will have high predictive values and low false positive rates. The specificity of tumor markers must be improved if they are to be used effectively as laboratory screening or diagnostic tests.