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Comparison of the Surgical Outcome and Renal Function between Radical and Nephron-sparing Surgery for Renal Cell Carcinomas

We retrospectively evaluated the outcomes of a matched comparison of nephron-sparing surgery(NSS) and radical nephrectomy(RN) for renal cell carcinoma(RCC) that was less than 4cm in size and the renal function after surgery. Materials and Methods: Between January 1995 and February 2004, 92 and 200 patients with unilateral RCC and a normal contralateral kidney underwent NSS and RN, respectively. A total 56 patients in each cohort were matched according to the size of tumor, the pathological T stage, the pathological grade and the follow-up time. The Kaplan-Meier method was used to estimate the overall survival, the disease-free survival and the cancer-specific survival. Ninety-seven and 317 patients underwent NSS and RN during the same period, and their impaired renal function after surgery was evaluated. Postoperatively, the impaired renal function was defined as a serum creatinine value greater than 1.6mg/dl. The risk factors for impaired renal function, including diabetes, hypertension, age and the operative method were compared between the two groups. Chi-square tests and Student's t-tests were used to compare the two groups for their renal function after surgery. Multivariate logistic regression analysis was used to evaluate the preoperative risk factors for impaired renal function after surgery. Results: There was no significant difference observed between NSS and RN with respect to overall survival(p=0.63), disease-free survival(p=0.18) and cancer-specific survival(p=0.98). Postoperatively, the impaired renal function was significantly different between the two groups(p=0.045, chi-square). The only preoperative risk factor for impaired renal function after surgery was diabetes(p=0.044). Conclusions: The surgical outcomes for renal cell carcinoma that's less than 4cm in size were comparable between NSS and RN. The only preoperative risk factor for impaired renal function after surgery was diabetes.