Down-regulation of p27 is a significant predictor of poor overall survival and may facilitate metastasis in colorectal carcinomas.

The p27 gene product has been shown to have prognostic significance in a range of tumors. Down-regulation of p27 has also been implicated in loss of cell adhesion in tumor cells. Our study aimed to investigate whether p27 expression was significantly correlated with overall survival of colorectal carcinoma patients in the Singapore population, which is predominantly Chinese. Staining was performed on 136 paraffin-embedded specimens collected between 1991 and 1992 using an anti-p27 monoclonal antibody. Follow-up of patients was until time of death or for 5 years. There was a significant association between overall survival and p27 expression for all specimens. However, there was no significant correlation between p27 expression and other clinical features such as gender, age, tumor stage, differentiation, and site. When stratified by tumor stage, patients whose tumors exhibited higher metastatic potential (stage III/IV) but had strong p27 expression had a median survival that was 23 months longer than stage III/IV patients whose tumors had no or weak p27 expression. Our results thus suggest that one potential mechanism of action of p27 is to suppress metastasis possibly through its involvement in cell adhesion. Copyright 2000 Wiley-Liss, Inc.