Overall survival and development of stage IV chronic kidney disease in patients undergoing partial and radical nephrectomy for benign renal tumors

Abstract

Background: Although partial nephrectomy (PN) has been associated with improved renal function compared with radical nephrectomy (RN) for renal cell carcinoma, the impact on overall survival (OS) remains controversial.

Objective: To evaluate comparative OS and renal function in patients following PN and RN for a renal mass where malignancy was not a confounding factor.

Design, setting, and participants: Using the Mayo Clinic Nephrectomy Registry, we retrospectively identified 442 patients with unilateral sporadic benign renal masses treated surgically with PN or RN between 1980 and 2008.

Outcome measurements and statistical analysis: The primary outcome measures were OS and the incidence of new-onset stage IV chronic kidney disease (CKD), determined using the Kaplan-Meier method. Cox models were used to test the association of nephrectomy type with these outcomes.

Results and limitations: Overall, 206 and 236 patients with benign renal masses were surgically treated with RN and PN, respectively. Patients who underwent RN were older (median age: 67 vs 64 yr; p=0.02) and had larger tumors (median size: 5.0 vs 2.7 cm; p<0.001). Median follow-up for patients still alive at last follow-up was 8.3 yr (range: 0.1-27.9 yr). Estimated OS (95% confidence interval [CI]) rates at 10 and 15 yr were 69% (62-76%) and 53% (45-62%) for RN compared with 80% (73-87%) and 74% (65-83%) following PN (p=0.032). After adjusting for covariates of interest, patients treated with RN were significantly more likely to die from any cause (hazard ratio [HR]: 1.75; 95% CI, 1.08-2.83; p=0.023) or develop stage IV CKD (HR: 4.23; 95% CI, 1.80-9.93; p<0.001) compared with patients who underwent PN. Limitations include the retrospective design, selection bias for surgical approach, and referral bias to a tertiary care facility.

Conclusions: Our data suggest that PN may confer a clinical benefit for improved renal function and better OS compared with RN after excluding the confounding effect of malignancy.

Keywords: Chronic kidney disease; Partial nephrectomy; Radical nephrectomy; Renal cell carcinoma.