CA-549 serum levels in breast cancer monitoring.

CA-549 serum levels were assessed in 288 patients, 156 with early breast cancer (after surgery) and 132 with advanced breast cancer. CA-549 was abnormal (> 12 U/ml) in 25/156 patients (16%) without clinical signs of disease after surgery (median 9 U/ml), in 49/60 patients (82%) with disease in progression (P) (median 50 U/ml), in 19/27 patients (70%) with stationary disease (NC) (median 14 U/ml), in 25/33 patients (76%) with partial remission (PR) (median 18 U/ml) and in 4/12 patients (33%) with complete remission (CR) (median 9 U/ml). CA-549 serum levels correlated mainly with the extent of disease and secondarily with the prevalent metastatic site, higher values being observed in patients with visceral involvement (median 32.5 U/ml). CA-549 serum levels were also assessed in 51 patients at the start of treatment and at the time of objective evaluation: the results underline the concordance of CA-549 behavior with the clinical outcome in 71% of the cases. We conclude that CA-549 is a useful marker for monitoring breast cancer patients during the advanced stages of the disease.