Receiver operating characteristic (ROC) curve analysis of the tumor markers CEA, CA 19-9 and CA 72-4 in gastric...

Pre-surgery serum levels of CA 72-4, CEA and CA 19-9 were quantified by the enzyme immunoassay method in 167 patients with histological diagnosis of gastric adenocarcinoma and in 92 patients with an endoscopic diagnosis of benign gastric pathology. CA 72-4 showed a better correlation between its serum levels and the different clinical stages of the disease than CEA and CA 19-9. At the individual study of stages I-II, CA 72-4 proved positive in 36.9% of patients while CEA and CA 19-9 appeared positive in 10.8% and 8.6%, respectively. In the ROC curve, at a specificity of 95%, the sensitivities of CA 72-4, CEA and CA 19-9 were 59.8%, 21% and 26.3% respectively. The discriminatory capacity of the test (area under the ROC curve +/- SD) was 0.86 +/- 0.03 in the case of CA 72-4, 0.52 +/- 0.03 for CEA and 0.58 +/- 0.03 for CA 19-9. In conclusion, in our series and with regard to CEA and CA 19-9, CA 72-4 shows better sensitivity and discriminatory capacity. CEA and CA 19-9 do not provide significant benefits when combined with CA 72-4 due to the good results obtained with the later marker alone.