Partial Versus Radical Nephrectomy for 4 to 7 cm Renal Cortical Tumors

Purpose: Recent observations suggest that partial nephrectomy for small renal tumors may be associated with improved survival compared with radical nephrectomy. We evaluated survival in patients with 4 to 7 cm renal tumors in a bi-institutional collaboration. Materials and Methods: By combining institutional databases from Mayo Clinic and Memorial Sloan-Kettering Cancer Center we identified 1,159 patients with 4.1 to 7.0 cm sporadic, unilateral, solitary, localized renal masses who underwent radical or partial nephrectomy between 1989 and 2006. Patient outcome was compared using Cox proportional hazards regression models. Results: Of the 1,159 patients 873 (75%) and 286 (25%) were treated with radical and partial nephrectomy, respectively. Patients treated with partial vs radical nephrectomy were significantly more likely to have a solitary kidney (10% vs 0.2%) and chronic kidney disease (15% vs 7%, each p <0.001). Median followup in survivors was 4.8 years (range 0 to 19). There was no significant difference in overall survival in patients treated with radical vs partial nephrectomy (p = 0.8). Of 943 patients with renal cell carcinoma those treated with radical nephrectomy were significantly more likely to die of renal cell carcinoma than those treated with partial nephrectomy (HR 2.16, 95% CI 1.04-4.50, p = 0.039) but this only approached statistical significance on multivariate analysis (HR 1.97, 95% CI 0.92-4.20, p = 0.079). Conclusions: Results suggest that overall and cancer specific survival is not compromised when partial nephrectomy is done for 4 to 7 cm renal cortical tumors. With the benefit of preserving renal function our results support partial nephrectomy when technically feasible for renal tumors up to 7 cm.