Low-level Ki-67 expression as an independent predictor of bladder tumour recurrence in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy

Objective: To evaluate the association of molecular markers and conventional clinicopathological factors with bladder tumour recurrence in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy. Methods: The expressions of Ki-67 and P53 were measured by immunohistochemical staining prospectively in 115 consecutive patients with primary upper tract urothelial carcinoma from March 2004 to February 2014. The Cox proportional hazards regression model was used to identify independent predictors. The association between Ki-67 expression and clinicopathological variables was assessed by the chi(2) test. Results: Intravesical recurrence occurred in 13 out of 115 (11.3%) patients with a mean follow-up of 54.2 months (range: 7-130). Low-level Ki-67 expression (P = 0.010), older age (> 65, P = 0.040) and lower ureter tumour (P = 0.001) were independent predictors of bladder tumour recurrence in Cox regression analysis. Ki-67 expression was elevated with the progression of tumour grade (P = 0.004) but not with stage (P = 0.186). Ki-67 overexpression was also significantly higher in aggressive pathological types (P = 0.008), but only shows an inclination towards poor oncologic outcomes in the cancer-specific survival rate (P = 0.107) and the overall survival rate (P = 0.063). Conclusions: Low-level Ki-67 expression was an independent predictor for bladder tumour recurrence, while Ki-67 overexpression was associated with adverse clinicopathological parameters and poor prognosis in patients with primary upper tract urothelial carcinoma after radical nephroureterectomy.