Disease outcome in patients with low stage renal cell carcinoma treated with nephron sparing or radical surgery.

PURPOSE: We investigated the outcome of nephron sparing surgery in patients with low grade and low stage (Robson stage II or less) renal cell carcinoma.

MATERIALS AND METHODS: We retrospectively reviewed the records of 185 patients treated with nephron sparing surgery and 209 matched for patient age and sex, and tumor stage and grade who were treated with radical nephrectomy. Kaplan-Meier survival curves were constructed for progression and survival end points. Multivariate analysis was performed to determine the tumor characteristics independently correlated with progression and cancer death.

RESULTS: No significant difference was observed with respect to progression-free, crude or cancer specific survival between the nephron sparing surgery and radical nephrectomy groups. Less than 5% of the patients treated with conservative nephron sparing surgery had local recurrence. Tumor size was a strong independent predictor of outcome, whereas Robson stage was not. Patients treated with radical nephrectomy had a significant cancer specific and progression-free survival advantage when controlling for tumor diameter and grade. However, no difference was observed in patients with primary tumor diameters of 4 cm. or less.

CONCLUSIONS: Robson staging is inaccurate in predicting tumor behavior. Patients with tumors larger than 4 cm. and a normal contralateral kidney may be best served by radical nephrectomy rather than elective nephron sparing surgery. However, nephron sparing surgery may result in an outcome similar to that of radical nephrectomy for low grade, low stage renal cell carcinomas of 4 cm. or smaller.