Cytoplasmic expression of p27kip1 is associated with a favourable prognosis in colorectal cancer patients

AIM: To evaluate the prognostic significance of p27(kip1) in colorectal cancer patients. METHODS: Cytoplasmic and nuclear 27(kip1) expression was evaluated in 418 colorectal cancers using tissue microarrays. Data were associated with known patient and tumor variables and long-term patient outcomes, providing further insight into the mechanisms by which p27(kip1) may influence tumor development. RESULTS: Nuclear and cytoplasmic 27(Kip1) expressions were detected in 59% and 19% of tumors respectively. Cytoplasmic p27(Kip1) was almost invariably associated with positive nuclear p27(Kip1) expression. Neither case correlated with known clinical or pathological variables, including tumor stage, grade or extramural vascular invasion. Furthermore, nuclear p27(kip1) expression had no impact on survival. However, we identified a significant correlation between expression of cytoplasmic 27(kip1) and longer disease-specific survival times. On multivariate analysis, TNM stage and extramural vascular invasion were highly significant independent prognostic factors, with positive cytoplasmic p27 expression showing a trend towards improved patient survival (P = 0.059). CONCLUSION: These findings support the recent evidence that cytoplasmic p27(kip1) has a distinct and important biological role that can influence tumor outcome. (c) 2006 The WJG Press. All rights reserved.