THE ROLE OF CA-15-3 EXPRESSION IN SERUM AND TISSUE OF BREAST-CANCER PATIENTS

CA 15-3 is today a well established tumor marker used mainly for breas t cancer patients. The aim of this study was to compare CA 15-3 expres sion in tissue and serum and both to Estrogen Receptor status of these patients. The main question was whether tissue expression may give pr ognostic information in addition to serum levels. CA 15-3 serum levels were correlated to disease activity: active disease, recurrence or un responsiveness to treatment were associated with CA 15-3 increases. in contrast, non active disease and response to therapy, were associated with CA 15-3 serum decreases. CA 15-3 sera values predicted recurrenc e of malignancy from 4 to 12 months prior to clinical signs. Breast ti ssues (benign or malignant), ovary tissues, as well as other tissues w ere stained by CA 15-3. We conclude that CA 15-3 is present in almost all breast tissues and not specific. Serum CA 15-3 levels depend on st age of breast tumor and tumor activity. Therefore, there is no correla tion between tissue and serum expression. Positive Estrogen Receptor s tatus was associated with high CA 15-3 tissue expression. Tissue CA 15 -3 expression seems not to be very useful for clinical decisions. In c ontrast, serum CA 15-3 is a very reliable tumor marker for breast canc er.