SIMPLE METHOD FOR COMPARING RELIABILITY OF 2 SERUM TUMOR-MARKERS IN BREAST-CARCINOMA

Aims-To compare the two breast tumour markers, CA15-3 and mucinous-lik e carcinoma associated antigen (MCA), using Receiver Operating Charact eristic (ROC) curve analysis. Methods-One hundred and ninety six patie nts ''presenting'' with breast carcinoma had serum CA15-3 and MCA conc entrations measured. Results-Using these markers as indicators of stag e IV disease at the recommended laboratory level, true positive rates (TPR) and false positive rates (FPR) were obtained as follows: CA15-3 TPR = 75%, FPR = 7.4%, MCA TPR = 80%, FPR= 59.1%. By increasing the CA 15-3 cutoff level to 45 U/ml, a TPR and FPR of 75% and 0.6%, respectiv ely were obtained. By increasing the MCA cutoff level to 23 U/ml, a TP R and FPR of 65% and 2.3%, respectively, were obtained. Conclusions-Us ing ROC curve analysis shows that CA15-3 is a superior indicator of me tastatic breast disease than MCA at recommended laboratory levels, and by altering the cutoff points, the specificity and sensitivity for bo th these markers can be improved.