RECEIVER OPERATING CHARACTERISTIC (ROC) CURVE ANALYSIS OF THE TUMOR-MARKERS CEA, CA-19.9 AND CA-195 IN GASTROINTESTINAL CANCERS - RESULTS FROM A RETROSPECTIVE FRENCH MULTICENTER EVALUATION

The serum values of the tumour markers carcinoembryonic antigen (CEA), cancer-associated carbohydrate antigens CA 19.9 and CA 195 were evalu ated in 630 patients with gastrointestinal cancer and in 98 patients w ith benign gastrointestinal disorders by Receiver Operating Characteri stic (ROC) curve analysis, in order to compare their accuracy in oesop hageal (n = 38), gastric (n = 219), colorectal (n = 343), hepatic (n = 55) and pancreatic (n = 77) cancer, and to define optimal cut-off lev els for serum values of these tumour markers in the diagnosis of gastr ointestinal cancer. The ROC analysis showed a low diagnostic ability o f these three markers : - in oesophagus cancer, with Areas Under the C urve (AUG) of 0.55 for CEA, 0.43 for CA 19.9 and 0.52 for CA 195, -in stomach cancer, with AUC of 0.52 for CEA, 0.63 for CA 19.9, 0.59 for C A 195, in colon cancer with AUC of 0.73 for CEA, 0.55 for CA 19.9 and 0.52 for CA 195, -in rectum cancer, with AUC of 0.73 for CEA, 0.55 for CA 19.9, 0.52 for CA 195, - in hepatic cancer, with AUC of 0.54 for C EA, 0.63 for CA 19.9 and CA 195. in pancreatic cancer, CA 19.9 and CA 195 with AUC of 0.87 and 0.83, compared to an AUC of 0.67 for CEA, sho wed a good diagnostic accuracy. Overall CA 195 and CA 19.9 showed a co mparable diagnostic ability.