(UroToday.com) The 37th Annual European Association of Urology Congress held in Amsterdam, the Netherlands between July 1st, and 4th 2022 was host to an abstract session regarding new insights in the management of upper tract urothelial cancer (UTUC). Dr. Clara Cerrato presented results from the Radical Nephroureterectomy Outcomes (RaNeO) registry evaluating renal function variations after radical nephroureterectomy (RNU) for UTUC.
The aim of this study was to evaluate the frequency and predictors of renal function variations after RNU for UTUC. This study from the RaNeO registry included patients with available perioperative clinical data undergoing RNU at 17 centers between 1994 and 2020. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI equation. Renal function variation was evaluated at three time points: postoperative day 1 (POD 1), six and 12 months postoperatively. The variations in eGFR were defined as follows:
- Δ1: POD1 eGFR - baseline eGFR
- Δ2: 6 months eGFR - POD1 eGFR
- Δ3: 12 months eGFR - 6 months eGFR
An acute kidney injury (AKI) on POD 1 was defined as an increase in serum Cr by ≥ 0.3 mg/dl or a 1.5-1.9 fold increase in serum Cr from baseline (Acute Kidney Injury Network definition). The effect of clinical variables on eGFR variations and their interaction during follow-up was evaluated using the linear mixed models.
This retrospective cohort analysis included 576 patients. Median age was 72 years (IQR: 64-79), BMI was 26.2 kg/m2 (IQR: 24.0-29.0), 71% were male, 57.5% were current/former smokers, and 46.5% had unilateral hydronephrosis. Median pre-operative eGFR was 62.2 ml/min/1.73m2 (IQR: 48.1 – 79.9). pT2 disease was present in 50.8% of patients and 4.6% had positive surgical margins.
The following renal function variations were noted:
- Δ1: -10.2 (-25.9: -2.2)
- Δ2: 1.37 (-6.2; 9.0)
- Δ3: 0.9 (-3.6; 5.2).
On univariable linear mixed models, positive eGFR variations after RNU were noted in:
- Elderly patients (ß =0.3±0.09, p=0.03)
- Patients with hydronephrosis (ß = 9.5±1.9, p<0.001)
Conversely, RNU had a clinically meaningful detrimental effect on those with POD 1AKI (ß:-32.6±1.7; p<0.001). During follow-up, the eGFR recovery was more pronounced in those with preoperative hydronephrosis (ß interaction: -3.4±0.9; p<0.001) and in those who experienced POD 1 AKI (ß interaction: 13.9±0.8; p<0.001). Elderly patients were less likely to recover compared to their younger counterparts (ß interaction: -0.1±0.04, p=0.006).
Predictors of eGFR variation post-operatively on multivariable analysis included:
- Age (ß 0.3 ± 0.1, p=0.002)
- Hydronephrosis (ß: 3.7±1.8, p=0.039)
- POD 1 AKI (ß: -31.6±1.8, p<0.001)
All models confirmed a positive eGFR variation during follow-up as the expression of contralateral kidney adaptation (ß: 10.3±2.9, p<0.001).
Dr. Cerrato concluded as follows:
- eGFR variations post-RNU are associated with age, pre-operative hydronephrosis and POD 1 AKI
- Although elderly patients experience less pronounced post-operative eGFR declines, eGFR in younger patients recovers better during follow up
Presented by: Dr. Clara Cerrato, MD, Resident Physician, Department of Urology, University of Verona, Verona, Italy
Written by: Rashid Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 2022 European Association of Urology (EAU) Annual Hybrid Meeting, Amsterdam, NL, Fri, July 1 – Mon, July 4, 2022.