Renal Cancer Surgery for Patients without Preexisting Chronic Kidney Disease: Is there a Survival Benefit for Elective Partial Nephrectomy?
Retrospective studies suggest that partial nephrectomy (PN) provides improved survival compared to radical nephrectomy (RN), even when performed electively. However, selection bias may be contributing and further investigation is required. We evaluated factors associated with non-renal cancer-related survival (NRCS) after PN or RN for patients with preoperative GFR ≥60ml/min/1.73m2.
Our study represents a single-center, retrospective evaluation of 3,133 patients (1997-2008) with preoperative GFR ≥60ml/min/1.73m2 managed with PN or RN, with PN performed in 1,732 (55%) cases. NRCS was analyzed by Kaplan-Meier in various cohorts based on functional parameters including preoperative GFR and new baseline GFR but also by procedure (PN versus RN). Cox proportional hazards assessed factors associated with NRCS among patients with new baseline GFR ≥45ml/min/1.73m2.
Median age was 59 years and 60% of patients were male. Median preoperative GFR was 85 ml/min/1.73m2 in both the PN and RN cohorts. New baseline GFR after RCS was 80 ml/min/1.73m2 for PN and 63 ml/min/1.73m2 for RN (p<0.001). Median follow-up was 9.3 years. NRCS at 10-years was 90.7% after PN and 85.8% after RN (p<0.001). NRCS was similar for all cohorts of patients with new baseline GFR ≥45 ml/min/1.73m<sup>2 (p=0.26) and only fell for patients with new baseline GFR below this level (p=0.001). Excluding patients with new baseline GFR<45ml/min/1.73m2 (n=290), NRCS at 10-years was still substantially improved after PN than RN (91.2% vs. 87.1%, p<0.001). For patients with new baseline GFR ≥45ml/min/1.73m<sup>2, age, gender, and procedure (PN versus RN) were associated with NRCS (all p≤0.001) on multivariable analysis. In contrast, increased new baseline GFR, as would be seen with PN, failed to associate with improved NRCS. Limitation includes retrospective design.
For patients with GFR ≥60ml/min/1.73m2 undergoing RCS, our data suggest priority for achieving new baseline GFR ≥45ml/min/1.73m2. For this cohort, PN associated with improved survival even though increased new baseline GFR failed to correlate. Given that the functional dividends of elective PN did not correlate with better survival, our study suggests that selection bias for procedure is the main factor impacting outcomes.