Diagnostic value of mucin-like carcinoma-associated antigen (MCA) in breast cancer

The diagnostic value of mucin-like carcinoma-associated antigen (MCA) was compared to that of carcinoembryonic antigen (CEA) and/or CA 15.3 in patients with breast cancer. A total of 368 patients with breast cancer were studied, of whom 253 were free of metastases, whereas 94 had either skeletal or visceral metastases or diffuse metastatic disease. The diagnostic sensitivity of MCA proved to be comparable to that of CA 15.3 and superior to that of CEA in patients with metastatic breast cancer. In contrast, the specificity of MCA was superior to that of CA 15.3. Finally, the diagnostic sensitivity of each of the tested tumour markers, i.e. MCA, CEA and CA 15.3, could be improved by their combined use. We conclude that MCA, either alone or in combination with CA 15.3 and CEA, can improve the monitoring of disease progression in patients with metastatic breast cancer.