USEFULNESS OF THE TUMOR-MARKER CA 195 COMPARED TO CA 19-9 AND CEA IN COLORECTAL-CARCINOMA PATIENTS

The concentrations of the tumor markers CA 195, CA 19-9 and CEA were determined in sera of 50 healthy blood donors, 50 patients with benign diseases of the intestine, and 62 patients with colorectal cancer of various stages. Using the cut-off levels defined in the group of blood donors, sensitivity and specificity of each marker alone and combined with each other were calculated. Furthermore, serial determinations of all three markers over a mean period of 209 days were correlated with the clinical course of disease of 32 patients with colorectal cancer. The results of this study indicate, that CA 195 as well as CA 19-9 have no advantage over CEA as the marker of first choice in colorectal cancer. In contrast to the closely related antigen CA 19-9, the new marker CA 195 shows a high rate of false positive serum values in the group of benign diseases. Its sensitivity in colorectal cancer is superior to both other markers only in Dukes' stage D.