Long-term renal function decline common following radical cystectomy for bladder cancer

Renal function considerably decreases over the long term for most bladder cancer patients who underwent radical cystectomy, a study has found.

The study included 670 patients who received radical cystectomy at a single centre in Denmark. Researchers collected patient data through national electronic medical records. They evaluated renal function by estimated glomerular filtration rate (eGFR) using pre- and postoperative creatinine measurements.

Of the patents, 537 (80.1 percent) received an ileal conduit urinary diversion, 76 (11.3 percent) an orthotopic neobladder, 37 (5.5 percent) a continent cutaneous reservoir, and the remaining 20 (3.0 percent) underwent a ureterocutaneostomy or permanent nephrostomy. At the time of radical cystectomy, 77 percent of patients had normal renal function (G1 and G2) while 8.9 percent had renal insufficiency (≥G3b).

Over a median follow-up of 6.2 years, 67 percent of the population had normal renal function while 19 percent had renal insufficiency, among whom 1.2 percent had end-stage renal failure (G5).

Of the 610 patients with a preoperative estimated glomerular filtration rate (eGFR) ≥45 mL/min/1.73m², 110 (18 percent) developed renal insufficiency within the follow-up period. In the same group, 47 patients (8 percent) progressed to grade 4 chronic kidney disease and 15 (3 percent) progressed to G5.

Cumulative incidence and Cox proportional hazards analyses showed that the absolute risk of renal function decline to CKD stage G3b or worse (eGFR <45 mL/min) was 17 percent at 5 years after radical cystectomy. Loss of renal function, however, had a null effect on all-cause mortality.

Lower preoperative eGFR, diabetes mellitus, prior pelvic radiation therapy, continent urinary diversion types, and postoperative ureteral stricture emerged as risk factors for renal function decline.

The findings underscore the importance of pinpointing preoperative risk factors that can identify patients who will benefit from enhanced renal surveillance or early intervention for modifiable factors to minimize renal insufficiency following radical cystectomy.