TAG-72

Tumor associated glycoprotein-72 (TAG-72) is a high molecular weight glycoprotein with mucus-like characteristic. It content is extremely low in the normal adult body, mainly existing in endometrial cells during secretory period. Some research found that TAG-72 is abnormally overexpressed in various adenocarcinomas, including gastric cancer, colorectal cancer, breast cancer, and ovarian cancer. It is not expressed in benign lesions and inflammatory tissues, so it becomes an excellent assisting diagnostic biomarker. Especially, it is expressed in lung adenocarcinoma but not in mesothelioma, which makes it commonly used in differential diagnosis. Meanwhile, the expression level of TAG-72 is negatively correlated with the degree of tumor differentiation and the overall survival of patients. Therefore, its high expression is considered as an independent risk factor for poor prognosis, but the specific mechanism is still unclear, speculated to be related to immune escape. In addition, some scholars pointed out that TAG-72 can be expressed in liver cancer, and its expression level is higher in advanced stage patients.