Impact of worsening surgically induced chronic kidney disease (CKD-S) in preoperative CKD-naïve patients on survival in renal cell carcinoma.

ABSTRACT

OBJECTIVES: To evaluate effects of worsening surgically induced chronic kidney disease (CKD-S) on oncological and non-oncological survival outcomes in renal cell carcinoma (RCC). PATIENTS AND METHODS: We performed a retrospective analysis of patients who underwent partial (PN) or radical nephrectomy (RN) and were free of preoperative CKD (estimated glomerular filtration rate [eGFR] ≥60 mL/min/1.73 m2 ). Patients were stratified by CKD stage at last follow-up no CKD-S (eGFR ≥60 mL/min/1.73 m2 ), de novo CKD-S 3a (eGFR 45-59 mL/min/1.73 m2 ), CKD-S 3b (eGFR <45 and ≥30 mL/min/1.73 m2 ) and CKD-S 4 (eGFR <30 and ≥15 mL/min/1.73 m2 ). The primary outcome was all-cause mortality (ACM). Secondary outcomes included non-cancer mortality (NCM), cancer-specific mortality (CSM) and de novo CKD-S Stage 3/4. Multivariable analysis (MVA) was utilised to identify risk factors for outcomes. Kaplan-Meier analysis (KMA) was utilised to evaluate overall (OS), non-cancer (NCS), and cancer-specific survival with respect to CKD-S categories. RESULTS: We analysed 3239 patients. The mean preoperative and last-follow-up eGFRs were 87.4 and 69.5 mL/min/1.73 m2 , respectively. On last follow-up, 57.9% (n = 1876) had no CKD-S, 18.7% (n = 606) had CKD-S 3a, 15.1% (n = 489) had CKD-S 3b and 8.3% (n = 268) had CKD-S 4. On MVA, de novo CKD-S 3b and 4 were independently associated with ACM (hazard ratios [HRs] 1.3-2.1, P = 0.003-0.001) and NCM (HRs 1.5-2.8, P = 0.021-0.001), but not CSM (P = 0.219-0.909); de novo CKD-S 3a was not predictive for any mortality outcomes (P = 0.102-0.81). RN was independently associated with CKD-S 3-4 (HRs 1.78-1.99, P < 0.001-0.035). Comparing no CKD-S, CKD-S 3a, CKD-S 3b and CKD-S 4, KMA demonstrated worsening outcomes with progressive CKD-S stage 5-year OS 84% vs 78% vs 71% vs 60% (P < 0.001) and 5-year NCS 93% vs 87% vs 83% vs 72% (P < 0.001). CONCLUSION: Development of CKD-S Stage 3b and 4, but not 3a, was associated with worsened ACM and NCM. The decision to proceed with nephron preservation via PN should be individualised based on oncological risk and risk of functional decline to CKD-S 3b or 4, and not CKD-S 3a.