THE USEFULNESS OF CA15.3, MUCIN-LIKE CARCINOMA-ASSOCIATED ANTIGEN ANDCARCINOEMBRYONIC ANTIGEN IN DETERMINING THE CLINICAL COURSE IN PATIENTS WITH METASTATIC BREAST-CANCER

Levels of mucin-like carcinoma-associated antigen (MCA), CA15.3 and ca rcinoembryonic antigen (CEA) were measured in consecutive serum sample s of 40 women with metastatic breast cancer. A change in antigen level of more than 25%, either an increase or a decrease, was considered to predict progressive or responsive disease respectively. A change of l ess than 25% was considered to predict stable disease. MCA, CA15.3 and CEA were elevated in the serum of 68%, 76% and 48% of the patients re spectively (P < 0.05). The overall prediction of clinical course was s imilar for all three markers. A more than 25% increase of MCA, CA15.3, and CEA was observed in 61%, 54% and 36% respectively. The predictive value of a more than 25% increase was high for all three markers: 94% , 94%, 83%. Changes in marker levels were correlated with each other. Logistic regression analysis showed that combining MCA and CA15.3 did not improve the prediction further. In conclusion, these tumour marker s may help in evaluating the disease course and there is no advantage in combining MCA and CA15.3.