Does the Distance to Normal Renal Parenchyma (DTNRP) in Nephron-sparing Surgery for Renal Cell Carcinoma have an Effect on Survival?

Abstract

Background: The effect of the distance to normal renal parenchyma (DTNRP) on survival after nephron-sparing surgery (NSS) for renal cell cancer (RCC) was analyzed. Additionally, the role of T-classification, tumor diameter and tumor grading was considered. Patients and Methods: NSS was performed on 126 patients with RCC between 1988 and 2000. Eighty-six patients were submitted to annual follow-up. These 86 patients were sub-classified into statistical groups according to the distance to normal renal parenchyma (≤ 2mm; > 2mm - ≤ 5mm; >5 mm), T-classification, tumor diameter (≤ 20mm; > 20mm - ≤ 30 mm; >30 mm - ≤ 50mm; >50mm) and tumor grading. The effect of belonging to one of these groups on survival was analyzed using the Log-Rank-Test (SPSS; version 11.0) and the Kaplan and Meier survival data. The level of significance was set at p<0.05. Results: During the follow-up period, 4 patients died related to RCC and 15 patients died from other causes. The tumor-specific survival was 95.4%. At the end of 2002, the mean follow-up time was 5.5 years (range 0.1 - 14.7). None of the variables which had been analyzed in our statistical groups had an effect on the overall survival. Conclusion: The distance to normal renal parenchyma does not influence survival, suggesting an additional resection to be unnecessary even in cases where the DTNRP is reported by frozen section to be less than 2 mm. RCC up to 5 cm in tumor diameter can be safely removed by NSS, even in the presence of a functional intact contralateral kidney.