P27Kip1 and Ki-67 expression analysis in transitional cell carcinoma of the bladder

P27Kip1 protein is a cell cycle inhibitor which blocks the transition of cells from G1 to S phase, while Ki-67 is the most specific marker of proliferative activity. Both proteins are independent predictors of clinical outcome in various neoplasms. The aim of the study was to assess the prognostic value of p27Kip1 and Ki-67 expression in urothelial bladder tumours. P27Kip1 and Ki-67 expressions were evaluated immunohistochemically in archival samples of 45 superficial and 26 invasive transitional cell carcinomas obtained by a transurethral resection. In the patients with superficial tumours, disease-free survival (DFS) was positively influenced by good histological differentiation as well as by concurrent high p27Kip1 and low Ki-67 expression. Multivariate analysis has confirmed that tumour grade and p27Kip1/Ki-67 status were independent predictors of DFS (p=0.028 and p=0.029, respectively). P27Kip1 or Ki-67 expressions did not influence overall survival. We conclude that a variable combined of p27Kip1 and Ki-67 expressions is a better predictor of DFS in superficial bladder tumours than either protein alone.