A multicentre evaluation of tumour marker determinations using the automatic Enzymun-Test Systems ES 300 and ES 600/700

A multicentre evaluation of the determination of carcinoembryonic antigen (CEA), the cancer antigens CA 15-3, CA 19-9, CA 72-4 and CA 125 (II generation), the cytokeratin 19 marker Cyfra 21-1 and alpha-foetoprotein (AFP) using the Enzymun-Test System (ES 300 and ES 600/700) was performed in 23 laboratories. The tumour markers were measured in a total of 4266 human serum samples. The intra-assay precision was less than 5% in 80% of all serum samples investigated and in 95% of the serum samples at or above the cut-off level of the tumour markers. Inter-assay precision was less than 10% in 86% of the marker determinations. The interlaboratory survey also showed high reproducibility for the determination of all the tumour markers. In 3 laboratories the results of CA 15-3 in 283 serum samples were compared with the IRMA method of CIS bio international. The regression coefficient, r, was 0.967. In 4 laboratories the results of CEA in 312 samples were compared with the results obtained on the IMx analyser. The regression coefficient, r, was 0.967. In benign gynaecological diseases, CA 125 (II) was most frequently elevated in endometriosis. In gastrointestinal diseases it was proven that CEA is still the marker with the highest sensitivity as compared with CA 19-9 and CA 72-2 (59% with healthy controls as the reference group and 44% with patients having benign gastrointestinal disease as the control group). In pancreatic cancer CA 19-9 showed the highest sensitivity (78% and 62% respectively). In gastric cancer the three markers did not show statistically different results. When the gastric cancer patients were divided according to stage, CA 72-4 appeared to be more sensitive than CA 19-9 only in stage IV.