Significance of a Biomarkers Immunohistochemistry Panel for Survival Prognostic in Patients with Sporadic Colorectal Cancer

Objective: to evaluate the prognostic power of survival of a biomarkers panel formed by p53, VEGF, Bcl-2, Ki-67, and EGFR in subjects with sporadic colorectal adenocarcinoma subjected to radical surgical treatment. Methods: 114 post-surgical subjects with colorectal adenocarcinoma were studied and followed for 3 to 5 years at FundaçãoPio XII – Hospital de Câncer de Barretos. The study was conducted in paraffin-embedded tumor tissue whose slides were stained using the hematoxylin-eosin technique. The tissue microarray slides, as well as the immunohistochemical staining, were examined by two pathologists, blinded to the evaluations. The statistical analyses were conducted using mean, median, minimum, maximum, and number of valid observations for the descriptive analysis of the numeric variable, global survival. The comparison of the expression of EGFR, VEGF, Ki-67, p53, and Bcl-2 biomarkers was conducted through the Chi-square test or, when required, Fisher’s exact test. The Cox regression model was used for global survival analysis with a panel of markers and for uni and multivariate global survival analyses. Results: Isolated expression correlation results of the markers with the variables: age, differentiation degree, venous invasion, perineural invasion, TNM (I+II) x (III+IV), and survival showed statistically significant differences in the EGFR expression with venous invasion, TNM classification, and global survival; the expression of the VEGF marker has showed significant correlation with the perineural invasion; the Ki-67 marker, with age, venous invasion, and TNM; expression of p53 was significantly related with age, venous invasion, TNM, and global survival; the Bcl-2 marker did not show significant correlation with any of the variables analyzed. The survival analysis, using the markers panel, has significantly showed lesser time of survival in surgical species with 60% or more over-expression. Conclusion: over expression of the selected tumor markers panel is related with lesser time of survival in those suffering from sporadic colorectal adenocarcinoma submitted to radical surgical treatment.