[Nephron-sparing surgery is superior to radical nephrectomy in preserving renal function outcome in tumors larger...

The objective of the present study was to analyse whether nephron-sparing surgery (NSS) was superior to radical nephrectomy (RN) in preserving renal function outcome in tumors larger than 4cm.

The data from 888 patients who had been operated upon at eight french university hospitals were retrospectively analyzed. Glomerular filtration rate (GFR) pre- and post-surgery was calculated with the abbreviated Modification of Diet in Renal Disease (MDRD) equation. For a fair comparison between the two techniques, all imperative indications for NSS and all GFR<30 mL/min/1.73 m(2) were excluded from analysis. A shift to a less favorable DFG group following surgery was considered clinically significant.

Seven hundred and thirty patients were suitable for comparison. Median age at diagnosis was 60 years (19-88). Tumors measuring more than 4cm represented 359 (49.2%) cases. NSS and RN were performed in 384 (52.6%) and 346 (47.4%) patients, respectively. In univariate analysis, patients undergoing NSS had a smaller risk than RN of developing significant GFR change following surgery. This was true for tumors≤4cm (P=0.0001) and for tumors>4cm (P=0.018). In multivariate analysis, the following criteria were independent predictive factors for developing significant postoperative GFR loss: the use of RN (P=0.001), decreased preoperative DFG (P=0.006), increased age at diagnosis (P=0.001) and increased ASA score (P=0.004).

The renal function benefit offered by elective NSS over RN persists even when expanding NSS indications beyond the traditional 4 cm cut-off.