TOTAL AND LIPID-BOUND SERUM SIALIC-ACID IN BENIGN AND MALIGNANT BREAST DISEASE

Elevation in the total sialic acid (TSA), TSA/total protein (TSA/TP) a nd lipid-bound sialic acid (LASA) concentration in serum occurs in bre ast cancer and we have studied the applicability of the assays in clas sification of undefined breast tumors. Sialic acid was determined by H PLC and the statistical evaluation included the receiver operating cha racteristic (ROC) and Youden's index analyses. In cancer patients, the serum LASA and TSA concentration was significantly higher (p<0.05) th an in patients with benign breast disease and all the markers were sig nificantly higher (p<0.0001) than in normal controls. All the markers had a low accuracy (AUCs<0.75) in differentiating between breast cance r and benign breast disease and at the specificity level of 0.95 the c orresponding sensitivities were 0.32 (TSA), 0.14 (TSA/TP) and 0.23 (LA SA). The results indicate that both breast cancer and benign breast di sease cause elevation of TSA, TSA/TP and LASA values in serum and do n ot provide reliable classification of undefined breast tumors.