TAG-72 expression has no clinical significance in colorectal cancer

Purpose: To determine the expression patterns of TAG-72 and its association with factors as an index of its clinical significance and function in the etiology of colorectal cancer (CRC). Methods: This retrospective study involved histopathological reports, archival blocks, and slides of patients with CRC at King Abdulaziz University Hospital. Immunohistochemistry procedures were carried out utilizing TAG-72 monoclonal antibody and tissue microarray (TMA) slides of 155 CRC cases and 33 specimens of normal colon tissue. Results: TAG-72 was found in 55 (35.5 %) of CRC cases, out of which 13 (8.1 %) cases showed weak immunostaining, while 8 (24.2 %) of the 33 normal colon mucosal specimens showed diffuse-to-moderate TAG-72 levels. Cytoplasmic staining was seen in each positive case in CRC and healthy colon mucosa. However, no correlation was noted between TAG-72 and any of the parameters. The Kaplan-Meier survival curves and Cox proportional hazards model did not show differences in survival behavior. Conclusion: TAG-72 has no association with clinicopathological parameters of CRC, and has no diagnostic and prognostic values in CRC.