Renal function in bladder cancer patients after trimodality therapy: Long-term results of a large institutional experience.

Abstract

453 Background: Maintenance of renal function following treatment of bladder cancer presents an ongoing challenge. The decline following radical cystectomy is well documented. However, in patients undergoing trimodality bladder-sparing therapy consisting of transurethral resection (TURBT) and concurrent chemoradiation followed by adjuvant chemotherapy, renal function is poorly understood. Methods: We performed a retrospective review of 178 patients with muscle-invasive bladder cancer who underwent bladder-sparing therapy between 2001 and 2013 and collected nadir creatinine values in the month preceding TURBT and at 1, 3, 5, 7, and 9 years post treatment initiation. Wilcoxon signed-rank test and mixed effects analysis were performed to compare the pre-treatment and post-treatment levels of creatinine and EGFR and to analyze their temporal change. Results: Median follow-up was 48 months (range: 1 to 162 months). The mean pre-treatment creatinine and EGFR were 1.12 mg/dl and 71 mg/dl, respectively. Cr increased to 1.21 mg/dl and EGFR decreased to 65 mg/dl at 1 year following treatment initiation (p = 0.001, p = 0.002). All post-treatment values were also significantly different from pre-treatment values (all p values < 0.002), but there was no significant difference between the post-treatment values over time. Conclusions: Following bladder-sparing therapy for muscle invasive bladder cancer, renal function was generally well preserved in the long term. Although there was a modest yet statistically significant decrease in renal function that occurred during the first year, there was no further decline up to 9 years. While this initial decrease in function is of unknown clinical significance, the lack of further decline after 1 year is different from similar studies following cystectomy.