Prognostic significance of p27(kip1) protein expression and spontaneous apoptosis in patients with colorectal adenocarcinomas.

Tumor cell apoptosis, proliferation and p27 expression using an in situ apoptosis detection kit, anti-Ki67 antibody and anti-p27 antibody were investigated in 171 colorectal adenocarcinoma specimens, together with the assessment of mutated p53 expression. No apparent association was observed among p27 expression, mutated p53 accumulation, the Ki67 labeling index and the apoptotic index (AI). In the multivariate analysis using the median values as the cut-off points (46.8% for p27 expression and 0.89% for AI), p27 expression was identified as an independent and significant predictor for overall survival. When the present series of patients were dichotomized by these cut-off points to categorize the cases into 4 subgroups, the patients in the group with low p27 expression and a low AI had the poorest prognosis. The assessment of p27 expression and AI therefore may prove valuable in identifying patients with colorectal adenocarcinoma who may have a poor prognosis.