Vergleich der Tumormarker CEA und CA 19-9 in der kolorektalen Diagnostik

Endoscopic examination of the colon was performed in 405 patients (125 without, 217 with benign, and 63 with malignant colorectal diseases), and the serum levels of the tumour-associated antigens CEA and CA 19-9 were determined. On comparing both markers, the specificity of CA 19-9 (96% correctly normal values) was found to be higher in benign colorectal diseases than that of CEA (92% with a cut-off limit of 5 ng/ml for CEA). On the other hand, the sensitivity of CA 19-9 in colorectal carcinomas was only about 25% and thus much lower than that of CEA (52% correctly pathological values). The sensitivity of both markers was particularly low in the initial stages of carcinoma (in Dukes A: CEA 20%, CA 19-9 0%). If the cut-off limit for CEA was raised to 10 ng/ml, the specificity was increased to 99%, whereas the sensitivity was markedly reduced to 25%. The diagnostic accuracy of CEA in colorectal carcinomas was not surpassed by CA 19-9. There was no obvious advantage in simultaneous determination of CEA and CA 19-9.