Prospective Analysis of Ki-67 as an Independent Predictor of Oncologic Outcomes in Patients with High Grade Upper Tract Urothelial Carcinoma

Abstract

We determined the association of the proliferation marker Ki-67 with pathological parameters and oncologic outcomes in patients with high grade upper tract urothelial carcinoma. Immunohistochemical staining for Ki-67 was done prospectively in 101 consecutive patients undergoing radical nephroureterectomy/ureterectomy for high grade upper tract urothelial carcinoma. Data were compared based on Ki-67 status (normal vs over expressed). Survival was assessed by the Kaplan-Meier method. Cox regression analysis was done to identify independent predictors of time dependent outcomes. Median patient age was 70.0 years and median followup was 22.0 months (range 1 to 77). Overall, 30.2% of the population experienced recurrence and 24.8% died of upper tract urothelial carcinoma. Organ confined disease (T2 or less and lymph node negative), lymphovascular invasion and sessile architecture were present in 56.3%, 33.3% and 20.8% of patients, respectively. Ki-67 was over expressed in 73.3% of patients and associated with adverse pathological features. Patients with over expressed Ki-67 had significantly worse recurrence-free survival (43.2 vs 69.0 months, p = 0.006) and cancer specific survival (48.9 vs 68.9 months, p = 0.031) than patients with normal Ki-67. Patients with nonmetastatic disease similarly had worse recurrence-free survival (40.7 vs 71.8 months, p = 0.003) and cancer specific survival (41 months vs not attained, p = 0.008) for over expressed vs normal Ki-67. After adjusting for the effects of organ vs nonorgan confined disease Ki-67 over expression was an independent predictor of recurrence-free survival in the total cohort (HR 4.3, p = 0.05) and in patients with nonmetastatic disease (HR 8.5, p = 0.038). Ki-67 over expression was associated with adverse pathological features in cases of upper tract urothelial carcinoma. It was also an independent predictor of recurrence-free survival in patients with high grade upper tract urothelial carcinoma.