CA 15-3, mucin-like carcinoma-associated antigen and tissue polypeptide-specific antigen: correlation to disease state and prognosis in breast cancer patients.

Serum testing for the tumor markers CA 15-3 and mucin-like carcinoma-associated antigen (MCA) was performed in 144 patients with breast cancer. Of those patients, 127 were also tested for a third tumor marker, tissue polypeptide-specific antigen (TPS). At the time of testing, 73 patients (51%) were without evidence of disease and 71 patients (49%) had active disease. Mean follow-up time was 16 months. Positivity rates were: 29.8% for CA 15-3, 47.2% for MCA, and 58.3% for TPS. Mean value for patients with no evidence of disease as compared to patients with active disease was 21 U/ml and 117 U/ml for CA 15-3 (P = 0.001), 10.2 kU/l and 22.6 kU/l for MCA (P = 0.001), and 148 U/l and 310 U/l for TPS (P = 0.02). Two year actuarial survival, according to values below and above an established cutoff for CA 15-3 were 80% and 31% (P < 0.001), 75% and 45% for MCA (P < 0.01), and 82% and 50% for TPS (P < 0.01). We conclude that CA 15-3, MCA and TPS values reflect disease state and prognosis in breast cancer patients.