Prognostic significance of fascin expression in advanced colorectal cancer: an immunohistochemical study of colorectal adenomas and adenocarcinomas

Background: Fascin is an actin bundling protein with roles in the formation of cell protrusions and motility of mesenchymal and neuronal cells. Fascin is normally low or absent from epithelia, but is upregulated in several epithelial neoplasms where it may contribute to an invasive phenotype. Here, we report on the prevalence and potential clinical significance of fascin expression in relation to the progression of colorectal adenocarcinoma and to tumor cell proliferation as measured by Ki67 index. Methods: Conventional tissue sections of 107 colorectal adenomas and 35 adenocarcinomas were analyzed by immunohistochemistry for fascin and Ki67 expression. Fascin expression and Ki67 proliferation index were also investigated by use of a tissue microarray containing cores from a further 158 colorectal adenocarcinomas and 15 adenomas linked to a CCF, IRB-approved database with a mean of 38 months of clinical follow-up. Survival analysis was carried out by the Kaplan-Meier and Cox regression methods. Results: Fascin was not expressed by the normal colonic epithelium. In conventional sections, 16% of adenomas and 26% of adenocarcinomas showed fascin expression in greater than 10% of the tumor cells. In the clinically-annotated tumors, fascin immunoreactivity was more common in tumors located in the proximal colon (p = 0.009), but was not associated with age, gender, or TNM stage. Patients with stage III/IV adenocarcinomas (n = 62) with strong fascin immunoreactivity had a worse prognosis than patients with low or absent fascin, (3-year overall survival of 11% versus 43% for fascin-negative patients; p = 0.023). In adenomas, fascin and Ki67 tended to be inversely correlated at the cellular level; this trend was less apparent in adenocarcinomas. Conclusion: Fascin is upregulated in a proportion of adenomas, where its expression is often focal. Strong and diffuse expression was seen in a subset of advanced colorectal adenocarcinomas that correlated with shorter survival in stage III and IV patients. Fascin may have prognostic value as an early biomarker for more aggressive colorectal adenocarcinomas.