Preoperative CA 15-3 concentrations predict outcome of patients with breast carcinoma

BACKGROUND, CA 15-3 is a breast-associated mucin that is elevated in the ma jority of breast carcinoma patients with distant metastases. Currently, the main application of this marker is in monitoring and detecting recurrences in patients with diagnosed breast carcinoma. METHODS. Preoperative serum concentrations (prior to excision of the primar y tumor) of CA 15-3 were measured in 368 patients undergoing potentially cu rative surgical treatment for early breast carcinoma. These results were co mpared with prospectively recorded clinicopathologic characteristics and pa tient outcome data. RESULTS. A weak but significant positive association was found between CA 1 5-3 concentrations and both tumor stage and the number of involved axillary lymph nodes but not between CA 15-3 concentrations and estrogen receptor s tatus. Patients with high concentrations of CA 15-3 had a significantly wor se prognosis than patients with low concentrations. Using an optimum cutoff value of 30.38 U/mL, the probability of disease free survival at 5 years w as 44% in patients with high CA 15-3 levels compared with 65% in patients w ith low CA 15-3 levels (P = 0.002, Mantel-Cox log rank test). The correspon ding probabilities for overall survival were 67% and 83%, respectively (P < 0.001). The association of preoperative CA 15-3 levels with outcome was ma intained in multivariate survival analysis and was not explained by the ass ociation between CA 15-3 and tumor size or lymph node burden. The relation between CA 15-3 and outcome also was found within some patient subgroups id entified by traditional prognostic factors (axillary lymph node positive pa tients, patients with primary tumors >2 cm in greatest dimension, and patie nts with estrogen receptor positive tumors). CONCLUSIONS, Preoperative serum concentrations of CA 15-3 appear to have a significant relation to outcome in patients with early breast carcinoma and may have a role in the rational selection of patients for appropriate adju vant treatments. To the authors' knowledge, CA 15-3 thus is one of the firs t circulating markers shown to be an independent prognostic indicator in pa tients with breast carcinoma. Cancer 1998;83:2521-7. (C) 1998 American Canc er Society.