Cyclin D1 and Rb protein expression and their correlation with prognosis in patients with colon cancer

Abstract

Background: Cyclin DI plays a major role as a potential contributor to the multistep process of oncogenesis; nevertheless its prognostic significance in colon cancer has already been examined in a few studies and needs to be further delineated. The aim of this study was to assess the expression of cyclin DI and pRb and to correlate them with tumor histological stage and grade, proliferative capacity (Ki-67 labeling index) and clinical parameters, in order to delineate their impact on prognosis. Methods: One hundred and eleven patients, who underwent surgical resection of the colon for colon cancer constituted the group of our study. The immunohistochemical expression of cyclin DI, Rb and Ki-67 proteins was examined and correlated with clinico-pathological parameters and survival. Results: The 5-years survival rate of patients presenting cyclin DI positive tumors was 54%, while that of cyclin DI negative ones was 67% (P = > 0.05). The survival rate of patients with pRb positive tumors was similar to that of pRb negatine ones. Significant association was observed between Ki-67 and cyclin DI positivity (P = 0.045). Univariate analysis revealed worse survival in advanced stage patients presenting cyclin DI positive tumors (P = 0.025). Additionally, the survival of patients aging less than 70 years old was correlated to cyclin DI positivity (P = 0.009). Multivariate survival analysis revealed statistical significance for stage and hepatic metastasis. Conclusion: Even though cyclin DI and pRb have not disclosed any clear association with shorter survival, cyclin DI positivity may be a useful predictor of subgroup patients with colon cancer being in advanced stage and early age. © 2006 Kouraklis et al; licensee BioMed Central Ltd