The Protective Role of Renal Parenchyma as a Barrier to Local Tumor Spread of Upper Tract Transitional Cell Carcinoma and its Impact on Patient Survival

Abstract

We investigated whether tumor location has independent prognostic significance in upper tract transitional cell carcinoma cases and which factor determines it. We reviewed data on 122 renal pelvis and 102 ureteral tumor cases, including the recurrence pattern. Tumor location and other clinicopathological variables were evaluated regarding cancer specific and recurrence-free survival. Stage pT3 tumors were stratified into those invading renal parenchyma or peripelvic/periureteral fat. Overall 5-year cancer specific survival and recurrence-free survival rates were 77.0% and 71.6%, respectively, at a mean followup of 60.7 months. Of the clinicopathological parameters T stage was the most significant prognosticator of the survival rate, while nodal involvement, high grade and ureteral tumor location were also significant for lower survival rates. Stratification analysis for matching pathological stage revealed that, while survival rates were similar in the renal pelvis and ureteral tumor groups at stage pT2 or less, renal pelvic tumors were associated with significantly higher survival rates than ureteral tumors for stage pT3. Specifically renal pelvic tumors invading the renal parenchyma were associated with a lower local failure rate, and higher cancer specific and recurrence-free survival rates than tumors invading peripelvic or periureteral fat, ie 77.5% vs 49.7% 5-year cancer specific survival and 75.6% vs 32.0% 5-year recurrence-free survival (p = 0.014 and 0.003, respectively). Tumor location is an independent prognostic factor for pT3 upper tract transitional cell carcinoma. The overall better prognosis of renal pelvic tumors was mainly attributable to pT3 tumor outcomes, specifically lesions invading the renal parenchyma. These findings may be due to the protective role of thick renal parenchyma against local tumor spread.