CIRCULATING CA-549 AND OTHER ASSOCIATED ANTIGENS IN BREAST-CANCER PATIENTS

The new marker CA 549 was determined in the serum of 258 breast cancer patients, classified according to TNM (148 at diagnosis and 110 at re lapse), using a RIA method (cut-off: 10 U/ml). CEA, CA 15-3 and MCA we re also evaluated. At diagnosis, CA 549 was more sensitive than the ot her markers, and cut-off values of 11 and 12 U/ml did not significantl y reduce sensitivity. No significant correlation existed between the m arkers, except for CA 15-3 and CA 549 (r = 0.65). A new quantitative a pproach to the four markers was effected in the relapsed patients: an X value was calculated for each marker by dividing serum concentration by its cut-off. In these patients, grouped according to the area invo lved, marker sensitivities were similar except in locoregional relapse , where CA 549 and MCA were the most sensitive. From the data obtained , the more defined cut-off and the good specificity, it is suggested t hat CA 549 be routinely determined in the follow-up of the disease.