Postoperative renal function after partial nephrectomy for renal cell carcinoma in patients with pre-existing chronic kidney disease: a comparison with radical nephrectomy.

We assessed whether adequately functioning parenchyma is preserved in patients with pre-existing chronic kidney disease (CKD) after partial nephrectomy (PN) compared with those who underwent radical nephrectomy (RN). A total of 95 patients with pre-existing CKD who underwent curative surgery for pathological T1a-T2N0M0 renal cell carcinoma with a follow-up period of 12 months or more were the subject of the present study. Of these, 51 patients underwent RN, and 44 PN. Renal function was assessed by using the estimated glomerular filtration rate (e-GFR). We classified the subjects into two groups according to the preoperative e-GFR: preoperative e-GFR 45-59 mL/min/1.73 m(2) (68 patients); and 30-44 mL/min/1.73 m(2) (27 patients). In the former group, the probability of freedom from new onset of e-GFR <45 mL/min/1.73 m(2) stemmed from the significant difference between the PN and RN groups (P = 0.006; PN: 2 years 64%; RN: 2 years 22%). In contrast, in the latter group, the probability of freedom from new onset of e-GFR <30 mL/min/1.73 m(2) was not associated with a significant difference between PN and RN group (P = 0.80). Overall survival and the number of the patients who went on to develop end-stage renal disease requiring renal replacement therapy between PN and RN were not significantly different in each group. Death from renal cell carcinoma was not noted in either group. PN could significantly prevent development to late-stage CKD in patients with preoperative e-GFR 45-59 mL/min/1.73 m(2) compared with RN. Patients with preoperative e-GFR 30-44 mL/min/1.73 m(2) should be reviewed in a more strict study.