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Imperative and elective indications for nephron-sparing surgery for renal tumors: long-term oncological follow-up.

INTRODUCTION
Nephron-sparing surgery (NSS) is mandatory for patients with renal tumors in both kidneys or in a solitary kidney in order to preserve renal function (imperative indication). NSS has also become the gold standard (elective indication) for small unilateral renal tumors (< 4 cm) with a normal contralateral kidney. We report the oncological long-term follow-up of NSS of our own series and discuss the results of the current literature.


PATIENTS AND METHODS
From 1979 until 2006, a total of 851 patients was treated at our institution by NSS. The mean tumor diameter was 3 cm (0.5-11 cm) for elective cases and 4.2 cm (1.2-11 cm) for imperative cases. The median follow-up for elective cases is 4.7 years (0.1-24.1 years) and imperative cases 8 years (0.1-25.8 years). Cancer-specific survival (CSS) and local recurrence-free survival (RFS) were estimated.


RESULTS
Estimated CSS at 5 and 10 years for elective indications were 98.5% and 96.7% and for imperative indications (solitary kidney) 89.6% and 76%. RFS after 5 and 10 years for elective indications were 98.3% and 95.7%; and for imperative indications (solitary kidney) 89.4% and 79.9%. Chronic renal failure requiring haemodialysis developed after NSS in a solitary kidney in nine patients (11.2%).


CONCLUSION
NSS can be performed with oncologically safe and good functional results in imperative indications. In elective indications the resectability of a tumour rather than size and location is the limiting factor.