 CEA is perhaps the most prominent tumor marker among malignancies of epithelial origin: colorectal carcinoma, with 60-94 of tumors positive in patients with advanced disease; breast carcinoma, with 30-60 of metastatic cases positive for CEA; and cancers of the lung, liver, pancreas, head and neck, bladder, cervix and prostate with 30 or more with CEA tumors. 