CEACAM5 and breast cancer: Similar observations have also been made in breast cancer, where studies have shown ALCAM to perform as well or better than cancer antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) [31–33] and in epithelial ovarian cancer, where correlations between serum ALCAM and cancer antigen 125 (CA125) were noted [34].