Abstract
A fundamental and clinical study of a new tumor marker BCA225 was cnducted. The concerntrations of BCA225 of healthy individuals show a logarithmic regularity distribution. The cut-off value was set 160U/ml, when the sensitivity was 72.5%, and specificity was 94.0%. In an assessment clinical utility of BCA225, it was found that the frequency of positive response to BCA225 rose with a progress of the disease, from 6.2% in Stage I, 24.1% in Stage II, 29.4% in Stage III-IV primary breast cancers and 66.7% in recurrent breast cancers. The positive test rate with BCA225 was comparable to or higher than that with CA15-3 or CEA, which were simultaneously examined. The results were further improved by using combination assay. Particularly in recurrent breast cancers, the positive test rate was 77.8% with BCA225 and/or CA15-3 and/or CEA. Though BCA225 lacks specificity to the organ involved in recurrence, the high sensitivity of BCA225 assay to recurrent breast cancer can be put to good use in the postoperative follow up or assessment of a effects of the treatment. The antigen recognized by BCA225 seems to be a glycoprotein, that is essential to the galactopoietic function of mammary cells and makes itself known when these cells are transformed.
