1. CA 72-4 assay detects the mucine-like tumor-associated glycoprotein TAG 72 in serum. This assay serves as an aid in the therapeutic monitoring of carcinomas of the stomach, and ovaries. CA 72-4 may be elevated in other carcinomas, such as mammary, colon, non-small cell pulmonary, pancreas and endometrium. Diagnostic sensitivities of post-operative relapse increases when combined markers are used, e.g. CA 72-4 and CEA for colorectal carcinoma, CA 72-4 and CA 125 for mucinal ovarian carcinoma. An advantage of this marker is that it has a high diagnostic specificity for benign illnesses. These include, pancreatitis, liver cirrhosis, rheumatic illness, pulmonary disease, benign gynecological and ovarian disease, breast disease, and benign gastrointestinal disorders. Therefore, because of the high frequency of positive results associated with benign conditions, if used as a screening test, care must be taken in the interpretation of the results.
2. Falsely decreased results may be seen in patients on high doses of biotin (i.e. > 5mg/day). Samples should only be collected from these patients at least 8 hours following the last biotin administration so as to avoid potential interference.