TAG-72 expression and its role in the biological evaluation of human colorectal cancer.

Immunohistochemical studies showed that TAG-72 is expressed in more than 80% of colorectal carcinomas, but is rarely expressed in normal epithelium and benign diseases. TAG-72 can also be found in the body fluids of patients with adenocarcinomas, and its direct measurement can be used in conjunction with immunocytochemical analysis to help in discriminating benign from malignant effusions. The evaluation of TAG-72 in serum of colorectal carcinoma patients showed a sensitivity of approximately 40%, comparable to that of the widely used CEA. TAG-72 serum levels correlate with the stage of disease, suggesting its utility in discriminating between early-stage versus late-stage colon carcinoma. Longitudinal studies demonstrated that TAG-72 serum levels may be used as a predictive marker of recurrences. Moreover, the simultaneous measurement of TAG-72 and CEA serum markers improves the monitoring of recurrent disease. Therefore, these data suggest that TAG-72 is a well suitable marker for colorectal cancer.