Glomerular filtration rate measurement during platinum treatment for urothelial carcinoma: optimal methods for clinical practice.

BACKGROUND: We assessed the accuracy of four estimated glomerular filtration rate (eGFR) methods: MDRD, Cockcroft-Gault, CKD-EPI, and Wright. METHOD: The four methods were compared to measure GFR (mGFR) in patients with urothelial urinary tract cancer (T2-T4bNxMx) receiving platinum-based chemotherapy at Rigshospitalet, Copenhagen, from January 2019 to December 2021. Using standardized assays, creatinine values were measured, and mGFR was determined using Technetium-99 m diethylenetriaminepentaacetic acid (Tc-99 m-DTPA) or Cr-51-ethylenediaminetetraacetic acid (Cr-51-EDTA) plasma clearance. Patients (n = 146) with both mGFR and corresponding creatinine values available were included (n = 345 measurements). RESULTS: The CKD-EPI method consistently demonstrated superior accuracy, with the lowest Total Deviation Index of 21.8% at baseline and 22.9% for all measurements compared to Wright (23.4% /24.1%), MDRD (26.2%/25.5%), and Cockcroft-Gault (25.x%/25.1%). Bland Altman Limits of agreement (LOA) ranged from - 32 ml/min (Cockcroft-Gault) to + 33 ml/min (MDRD), with CKD-EPI showing the narrowest LOA (- 27 ml/min to + 24 ml/min and lowest bias (0.3 ml/min). Establishing an eGFR threshold at 85 ml/min-considering both the lower limit of agreement (LOA) and the minimum cisplatin limit at 60 ml/min-allows for the safe omission of mGFR in 30% of patients in this cohort. CONCLUSION: CKD-EPI equation emerged as the most suitable for estimating kidney function in this patient group although not meeting benchmark criteria. We recommend its use for initial assessment and ongoing monitoring, and suggest mGFR for patients with a CKD-EPI estimated GFR below 85 ml/min. This approach could reduce costs and decrease laboratory time for 30% of our UC patients.

Acute Kidney Injury Within 90Days of Radical Cystectomy for Bladder Cancer: Incidence and Risk Factors.

OBJECTIVE: To report incidence of acute kidney injury (AKI) following radical cystectomy (RC) for bladder cancer and evaluate risk factors for AKI as well as the impact of AKI on development of long-term renal insufficiency. METHODS: A retrospective analysis of patients undergoing RC between 2010 and 2020 at a high-volume tertiary referral center. AKI was graded according to the Kidney Disease Improving Global Outcome (KDIGO) criteria within 90days of surgery. Long-term renal insufficiency was defined as estimated glomerular function <45 mL/min. Cumulative incidence and Cox Proportional Hazards models were used to evaluate both short- and long-term loss of renal function and investigate their association with pre- and perioperative variables. RESULTS: AKI occurred in 332 out of 755 patients (44%) within 90days. Preoperative chronic hypertension and obesity were independent preoperative risk factors. Robot-assisted RC was associated with a higher risk of AKI compared to open RC in multivariable analyses. The absolute risk of developing long-term renal insufficiency was 8.7% (95%CI: 5.6-12) after 5years in patients without AKI and 26% (95%CI: 16-36) in patients with KDIGO-stage ≥2. In multivariable analysis, both KDIGO-stage 1 and ≥2 were independently associated with long-term estimated glomerular filtration rate <45 mL/min. CONCLUSION: A significant number of patients experienced AKI after RC, and even patients with KDIGO-stage 1 were at increased risk of long-term renal insufficiency. Recognizing pre- and perioperative risk factors can identify patients where close surveillance and early intervention may help minimize renal function decline following RC.