Safety and efficacy of mini-margin nephron-sparing surgery for renal cell carcinoma 4-cm or less

OBJECTIVES To explore whether mini-margin nephron-sparing surgery (NSS) is clinically safe and effective for renal cell carcinoma (RCC) of 4 cm or less with a normal contralateral kidney. METHODS A total of 115 patients with sporadic, pathologically confirmed RCC of 4 cm or less (Stage T1a), with a normal contralateral kidney, were treated by NSS using a mini-margin of less than 5 mm from 1998 to 2006. The surgical margin status was evaluated by both frozen and permanent paraffin section studies. The patients were followed up, and the data were analyzed. RESULTS The mean and median tumor diameter was 3.3 and 3.5 cm (range 1.0 to 4.0). None of the patients had positive surgical margins detected at either frozen section or final paraffin section analysis. The mean margin width was 2.2 mm (median 2.0, range 0 to 6). Of the 115 patients, 114 had margins of 5 mm or less (99.1%), 97 (84.3%) had margins of 3 mm or less, and 26 had margins of 0 mm (22.6%). At a mean follow-up of 65 months (median 66, range 9 to 105), all patients were alive. No distant metastasis was detected. Local recurrence was detected in I patient (0.9%) at a different site in the kidney. No major surgical complications, such as hemorrhage or urinary leakage/urinoma requiring reoperation, occurred. Considering only the 97 patients with follow-up of more than 3 years in the analysis, the mean and median follow-up time was 73 and 69 months (range 37 to 105), respectively. All 97 patients were alive with no evidence of disease at the last visit. CONCLUSIONS The results of our study have shown that mini-margin NSS is a safe and effective approach for treating early localized RCC of 4 cm or less.