Evaluation of the circulating glycoprotein CA549 in mammary cancer and other malignancies

A prospective study was carried out on a recent marker for breast cancer, CA549, a mucine-like acid glycoprotein present in the fat membranes of human milk. Fifty healthy control subjects and 91 with benign conditions, 103 mammary cancer patients and 256 patients with other types of malignancy were studied. For comparison, CEA and CA15-3 were also investigated. The CA549 cutoff was 11 U/ml. In breast cancer the marker was below the cutoff in 9 cases (92.8%); in malignancies other than breast cancer it was above the cutoff in 5 to 50% of patients. In breast cancer it was raised in 83.3% of cases (CA15-3 showed 82.9% and CEA 50%). In breast cancer after radical surgery, CA549 was normal in patients who were in TNM stage I but above the cutoff in 57.1% of those at more advanced stages. The follow-up study is ongoing among these patients. In all the study conditions, CA549 favorably compared to CA15-3 values, with sensitivity and specificity greater than CEA.