Background: Cell-cycle control is important in carcinogenesis and cancer progression. p27 and cyclin E are cell-cycle regulators, which control the G1-S phase transition. Recently, these two factors were found to be affected in many human cancers. The aim of the study was to examine the expression of p27 and cyclin E in gastric cancer and to evaluate their prognostic implication.
Materials and methods: Paraffin blocks of 56 samples of advanced gastric cancer, 15 samples of early gastric cancer, and 17 samples of normal gastric mucosa were studied. Expression of p27 and cyclin E was analyzed by immunohistochemistry. The relationship between the expression and clinicopathological data was examined.
Results: Expression of p27 was reduced in 89% of advanced cancer samples, 44% of early cancer samples, and 12% of normal mucosa samples (P<0.0001). Among the cancers, reduced expression of p27 was associated with a large tumor size, increased cancer invasion, nodal metastases, and the presence of residual tumor after operation. No significant difference in cyclin E expression was found. Kaplan-Meier plots of survival showed tumors with low p27 were associated with poorer survival than those with high p27 expression (RR, 5.3; CI = 1.6-17.4; P = 0.005). Tumors with low p27 and high cyclin E expression were associated with the highest mortality expression (RR, 9.8; CI = 1.2-80; P = 0.03).
Conclusions: Gastric cancer with low expression of p27 is associated with aggressive characteristics and a poorer outcome.
Copyright 2000 Academic Press.