Prognostic significance of p27 Kip1 and Ki‐67 expression in carcinoma of the renal pelvis and ureter

OBJECTIVE: To determine the significance of p27(Kip1) (p27) for tumour behaviour and prognosis of patients with transitional cell carcinoma (TCC) of the renal pelvis and ureter. PATIENTS AND METHODS: Using immunohistochemical staining, the relationship was evaluated between p27 protein level (low < 50%, high > 50%) and the Ki-67 labelling index (low < 30%, high > 30%) and clinicopathological features of 37 consecutive Japanese patients with TCC of the renal pelvis and ureter. RESULTS: Low levels of p27 correlated with higher tumour stage (P < 0.05) and positive lymph node metastases (P < 0.05). There was no significant association between p27 staining and the grade and tumour proliferation as assessed by the Ki-67 index. A high Ki-67 index correlated with higher grade and stage (P < 0.05). Kaplan-Meier plots of survival rate in patients with low or high p27 staining showed that low levels correlated with a shorter disease-free and overall survival (P < 0.001 and P < 0.01, respectively). Similarly, patients with a high Ki-67 index had lower disease-free and overall survival than those with a low Ki-67 index (P < 0.01 and P < 0.05, respectively). The Cox proportional hazards model showed that a low level of p27 was an independent predictor of a shorter disease-free (P < 0.01) and overall survival (P < 0.05) on univariate analysis, but not of overall survival on multivariate analysis. A high Ki-67 index was an independent prognostic marker for shorter disease-free survival on univariate and multivariate analysis (P < 0.01) and for overall survival on multivariate analysis (P < 0.05). In those with a high Ki-67 index, increased p27 staining was associated with a better prognosis than decreased staining for disease-free and overall survival (log-rank test, P < 0. 01 and P < 0.05, respectively). CONCLUSIONS: The finding that a low level of p27 is associated with tumour invasion and unfavourable prognosis indicates that p27 may be a useful prognostic marker for survival in upper urinary tract cancer.