Analysis of survival for patients with chronic kidney disease primarily related to renal cancer surgery.

OBJECTIVES: To evaluate predictors of long-term survival for patients with chronic kidney disease primarily due to surgery (CKD-S). Patients with CKD-S have generally good survival that approximates patients who do not have CKD even after renal cancer surgery (RCS), yet there may be heterogeneity within this cohort. PATIENTS AND METHODS: From 1997 to 2008, 4 246 patients underwent RCS at our centre. The median (interquartile range [IQR]) follow-up was 9.4 (7.3-11.0) years. New baseline glomerular filtration rate (GFR) was defined as highest GFR between nadir and 6 weeks after RCS. We retrospectively evaluated three cohorts: no-CKD (new baseline GFR of ≥60 mL/min/1.73 m2 ); CKD-S (new baseline GFR of <60 mL/min/1.73 m2 but preoperative GFR of ≥60 mL/min/1.73 m2 ); and CKD due to medical aetiologies who then require RCS (CKD-M/S, preoperative and new baseline GFR both <60 mL/min/1.73 m2 ). Analysis focused primarily on non-renal cancer-related survival (NRCRS) for the CKD-S cohort. Kaplan-Meier analysis assessed the longitudinal impact of new baseline GFR (45-60 mL/min/1.73 m2 vs <45 mL/min/1.73 m2 ) and Cox regression evaluated relative impact of preoperative GFR, new baseline GFR, and relevant demographics/comorbidities. RESULTS: Of the 4 246 patients who underwent RCS, 931 had CKD-S and 1 113 had CKD-M/S, whilst 2 202 had no-CKD even after RCS. Partial/radical nephrectomy (PN/RN) was performed in 54%/46% of the patients, respectively. For CKD-S, 641 patients had a new baseline GFR of 45-60 mL/min/1.73 m2 and 290 had a new baseline GFR of <45 mL/min/1.73 m2 . Kaplan-Meier analysis showed significantly reduced NRCRS for patients with CKD-S with a GFR of <45 mL/min/1.73 m2 compared to those with no-CKD or CKD-S with a GFR of 45-60 mL/min/1.73 m2 (both P ≤ 0.004), and competing risk analysis confirmed this (P < 0.001). Age, gender, heart disease, and new baseline GFR were all associated independently with NRCRS for patients with CKD-S (all P ≤ 0.02). CONCLUSION: Our data suggest that CKD-S is heterogeneous, and patients with a reduced new baseline GFR have compromised survival, particularly if <45 mL/min/1.73 m2 . Our findings may have implications regarding choice of PN/RN in patients at risk of developing CKD-S.

Long-Term Renal Function Recovery following Radical Nephrectomy for Kidney Cancer: Results from a Multicenter Confirmatory Study.

PURPOSE: We sought to confirm the findings from a previous single institution study of 572 patients from Memorial Sloan Kettering Cancer Center in which we found that 49% of patients recovered to the preoperative estimated glomerular filtration rate within 2 years following radical nephrectomy for renal cell carcinoma. MATERIALS AND METHODS: A multicenter retrospective study was performed in 1,928 patients using data contributed from 3 independent centers. The outcome of interest was postoperative recovery to the preoperative estimated glomerular filtration rate. Data were analyzed using cumulative incidence and competing risks regression with death from any cause treated as a competing event. RESULTS: This study demonstrated that 45% of patients had recovered to the preoperative estimated glomerular filtration rate by 2 years following radical nephrectomy. Furthermore, this study confirmed that recovery of renal function differed according to preoperative renal function such that patients with a lower preoperative estimated glomerular filtration rate had an increased chance of recovery. This study also suggested that larger tumor size and female gender were significantly associated with an increased chance of renal function recovery. CONCLUSIONS: In this multicenter retrospective study we confirmed that in the long term a large proportion of patients recover to preoperative renal function following radical nephrectomy for kidney tumors. Recovery is more likely among those with a lower preoperative estimated glomerular filtration rate.