Surgical management of bilateral synchronous kidney tumors: Functional and oncological outcomes

Purpose: We evaluated renal functional and oncological outcomes after sequential partial nephrectomy and radical nephrectomy in patients with bilateral synchronous kidney tumors. Materials and Methods: A total of 220 patients treated from June 1994 to July 2008 were included in the study. Estimated glomerular filtration rate, and overall, cancer specific and recurrence-free survival were assessed. Results: Patients underwent sequential partial nephrectomy (134), partial nephrectomy followed by radical nephrectomy (60) or radical nephrectomy followed by partial nephrectomy (26). Final estimated glomerular filtration rate after bilateral surgery was 59, 36 and 35 ml/minute/1.73 m² in these 3 groups, respectively (p <0.001). The order in which partial nephrectomy and radical nephrectomy were conducted did not affect functional outcomes. Overall survival of patients with bilateral cancer was 86% at 5 years and 71% at 10 years, cancer specific survival was 96% at 5 and 10 years, and recurrence-free survival was 73% at 5 years and 44% at 10 years. Overall survival was decreased in patients with tumors larger than 7 cm (p = 0.003). Patients with postoperative stage III or greater chronic kidney disease had decreased overall survival due to noncancer causes (p = 0.007). Conclusions: Patients treated with sequential surgery for bilateral synchronous kidney tumors have 5 and 10-year oncological outcomes comparable to those of patients with unilateral kidney cancer. Decreased overall survival was significantly associated with tumor size larger than 7 cm and postoperative stage III or greater chronic kidney disease. Nephron sparing surgery should be conducted for all amenable bilateral kidney masses given the negative impact of renal functional decline on overall survival.