Over-expression of Her-2 in colorectal cancer tissue, but not in serum, constitutes an independent worse prognostic factor

Background: Currently, conflicting information exists regarding Her-2 over-expression and its clinicopathological implications in colorectal cancer (CRC). This study was undertaken to determine Her-2 over-expression in both serum and tumor tissue of CRC patients, and to assess its clinicopathological and targeted therapeutic implications. Methods: Ninety five CRC patients and sixty healthy controls were prospectively enrolled. Her-2 expression status in serum and CRC tissue were examined by chemiluminescent immunoassay and immunohistochemical staining, respectively. The results were confirmed using fluorescent in situ hybridization. Clinicopathological parameters were analyzed according to Her-2 expression status. Results: Serum Her-2 levels were found to be increased in CRC patients as compared to those of healthy controls. However, serum Her-2 levels were not found to be significantly associated with prognostic parameters. Her-2 expression analysis of CRC tissues revealed Her-2 over-expression in 23 patients (25%), i.e., 13 patients (14%) showed moderate over-expression and 10 patients (11%) showed strong over-expression. The overall survival of patients negative for Her-2 expression was significantly better than that of patients positive for Her-2 expression (P = 0.018). The disease-free survival of patients with Her-2 over-expression was significantly shorter than that of patients with no Her-2 expression (P = 0.021). Conclusions: Her-2 over-expression in CRC tissue, but not in serum, acts as a significant independent worse prognostic factor. Assessment of Her-2 expression status may be valuable for the targeted therapeutic management of CRC.