Matched comparison of radical nephrectomy vs. nephron-sparing surgery in patients with unilateral renal cell carcinoma and a normal contralateral kidney.

Abstract

Objective: To report the long-term follow-up of a matched comparison of radical nephrectomy (RN) and nephron-sparing surgery (NSS) in patients with single unilateral renal cell carcinoma (RCC) and a normal contralateral kidney. Patients and Methods: Between August 1966 and March 1999, 1492 and 189 patients with unilateral RCC and a normal contralateral kidney underwent RN and NSS, respectively. Patients with renal impairment, previous nephrectomy, bilateral or multiple RCCs, metastasis, and familial cancer syndromes were excluded. A total 164 patients in each cohort were matched according to pathological grade, pathological T stage, size of tumor, age, sex, and year of surgery. The Kaplan-Meier method and stratified Cox proportional hazards model were used to estimate and compare overall, cancer-specific, local recurrence-free, and metastasis-free survival and survival free of chronic renal insufficiency. The 2 groups were evaluated for early (⩽30 days) complications and proteinuria at last follow-up. Results: At last follow-up, 126 RN patients (77%) and 130 NSS patients (79%) were alive with no evidence of disease. There was no significant difference observed between patients who had RN and those who had NSS with respect to overall survival (risk ratio, 0.96; 95% confidence interval [CI], 0.52–1.74; P = .88) or cancer-specific survival (risk ratio, 1.33; 95% CI, 0.30–5.95; P = .71). At 10 years, similar rates of contralateral recurrence (0.9% for RN vs 1% for NSS) and metastasis (4.9% for RN vs 4.3% for NSS) were seen in each group, whereas the rate of ipsilateral local recurrence for patients who underwent RN and NSS was 0.8% and 5.4%, respectively ( P = .18). There was no significant difference in the early complications between the RN and NSS groups. However, patients who underwent RN had a significantly higher risk for proteinuria as defined by a protein/osmolality ratio of 0.12 or higher (55.2% vs 34.5%; P = .01). At 10 years, the cumulative incidence of chronic renal insufficiency (creatinine > 2.0 mg/dL at least 30 days after surgery) was 22.4% and 11.6%, respectively, for the RN and NSS groups (risk ratio, 3.7; 95% CI, 1.2–11.2; P = .01). Conclusions: This retrospective study of patients with unilateral RCC and a normal contralateral kidney suggests that NSS is as effective as RN for the treatment of RCC on long-term follow-up. The increased risk of chronic renal insufficiency and proteinuria after RN supports use of NSS. Commentary Data from several studies have shown that nephron-sparing surgery (NSS) and radical nephrectomy provide equally effective curative treatment for patients with a single, small (⩽ 4 cm), unilateral, localized renal cell carcinoma (RCC) and a normal opposite kidney [1,2]. A recent study from Memorial Sloan Kettering reported a 10-year cancer free survival rate of 97% following elective partial nephrectomy in 70 such patients [3]. Other studies have further shown that the cost of NSS is equivalent to that of radical nephrectomy [4] and that quality of life is improved following NSS in this setting [5]. Notwithstanding the above data, there has been controversy concerning the renal functional advantage of performing NSS when the contralateral kidney is anatomically and functionally normal. Long-term follow-up after live donor nephrectomy operations has failed to demonstrate any significant adverse sequela in terms of proteinuria, hypertension or renal failure. However, patients undergoing surgical treatment for localized RCC represent a different population who are generally older and often have co-morbid medical conditions. This is the likely explanation for the findings in this important study from the Mayo Clinic which suggest an increased risk of chronic renal insufficiency and proteinuria after radical nephrectomy (compared to NSS) in patients with a normal contralateral kidney. A similar observation was recently reported in a study from Memorial Sloan Kettering presented at the 2001 annual AUA meeting. These emerging beneficial renal functional data enhance the argument in favor of elective NSS in patients with a solitary small (⩽ 4 cm) RCC and a normal contralateral kidney. Andrew C. Novick, M.D.