MCA PERFORMANCE IN PREOPERATIVE BREAST-CANCER PATIENTS

Mucin-like carcinoma-associated antigen (MCA) is a new tumor associate d antigen expressed on breast cancer cells independent of histological type and recognized by a two-site sandwich EIA (Roche) ruing the Mab b-12 as capture and detection antibody and a MCA cut-off of 11 U/ml. M CA serum levels were determined in 409 breast cancer patients and in 1 00 pts with benign breast disease histologically confirmed and staged according to UICC. The sensitivity of MCA regarding the stage of disea se was elevated only in metastatic patients (89%) and the MCA values o f this group were significantly different compared to those of patient s with early or locally advanced breast cancer. In the group of benign patients, the specificity was 81%. The correlation between MCA values and number of involved axillary lymphnodes showed significant differe nces ill the O versus 4-10 node subgroup (p < 0.001), in O versus > 10 and in 1-3 versus 4-10 node subgroup (p < 0.05); elevated MCA sensiti vity was found in the 4-10 and > 10 subgroups. In our experience, the determination of MCA is not useful for early diagnosis of breast cance r nor does it indicate the extent of lymphnode involvement. With regar d to the prediction of tumor recurrence in postoperative patients free of disease, MCA levels increased concomitantly with the clinical evid ence of relapse. These findings suggest that the MCA assay is highly s ensitive only in patients with metastatic breast cancer; therefore one of the most promising test application seems to be for monitoring the clinical course of advanced disease patients.