The Prognostic Value of G1 Cyclins, p21 and Rb Protein in Patients With Colon Cancer.

Abstract

Cyclins D1 and E play different roles in the cell cycle. Cyclin E promotes chromosome instability, whereas cyclin D1 regulates apoptosis of cells. This study evaluated the prognostic significance of G1 cyclins, p21 and pRb in tumor proliferation. A total of 102 patients with colon cancer were operated on and staged according to TNM. Follow-up was 2 to 68 months (mean 38.3±16.7 months). Expression of cyclin E and D1 were evaluated using immunohistochemistry. Levels of cyclin E expression were correlated with cyclin D1 expression (p=0.038), p21 expression (p=0.047), and pRb expression (p=0.004). The 5-year survival rate along with prognosis of patients with advanced stage (III, IV) colon cancer and cyclin D1 positive tumors, were significantly worse (p=0.009). Statistically significant association was observed between tumor proliferative capacity Ki-67, cyclin D1 (p=0.009), pRb (p=0.031) and p21 (p=0.050). Cyclin D1 is highly expressed in advanced stage colon cancer patients, implying a potential prognostic value.