CA 15-3 in human breast cancer. Comparison with tissue polypeptide antigen (TPA) and carcinoembryonic antigen (CEA).

CEA, TPA, CA 15-3 were assayed in 238 patients in follow-up for breast cancer after surgery. CA 15-3 showed the best sensitivity and specificity; the predictive value of a positive CA 15-3 test was three times higher than CEA and TPA. No association was found between marker positivity and the number of organs involved by metastases. CA 15-3 positivity was significantly associated with visceral rather than soft tissue recurrences; no significant similar association was observed for CEA and TPA. CA 15-3 serum levels were early predictors of relapse in four out of nine patients within a 6-12 month follow-up period.