Comparative evaluation of four tumor markers, CA 242, CA 19/9, TPA and CEA in carcinomas of the colon.

At present there is at least one optimal tumor marker and/or optimal marker combination available for the most frequent carcinomas. For colorectal carcinomas (CRC) the general consensus is that CEA is the best single marker, however, other markers, like CA 19/9, TPA and more recently CA 242 were reported to be just as useful. Since CA 242 is a relatively new marker we decided to assess comparatively the value of the four markers in CRCs. Although 308 sera from patients with CRCs, benign digestive diseases (n = 128) and healthy controls (n = 45) were analyzed using commercially available testkits. None of the mean values of the four markers were elevated above their respective cut-off levels in the controls. CEA was the most sensitive marker in early stage cancer, while CA 19/9 was the least sensitive marker, and hence should not be used for the study of this kind of malignancy. However, it remains usefull for carcinomas of the pancreas. As regards specificity, CA 242 was the most specific marker in hepatobiliary diseases. Used concomitantly, CEA and TPA and CEA plus CA 242 augmented the sensitivity markedly, hence these combinations can be recommended. CEA remains the most reliable marker for the follow-up of colon cancer patients, the novel marker CA 242 has a similar performance, the combination of the two markers ameliorates the specificity of CEA used as a single marker.