Renal function outcomes in patients treated with nephron sparing surgery for bilateral Wilms tumor.

PURPOSE: Management of bilateral Wilms tumor represents a particular challenge in the consideration of long-term renal function for affected patients. Aggressive surgical resection to prevent recurrence must be balanced with the desire to preserve renal function. We evaluated our institutional experience with nephrological outcomes in patients treated with nephron sparing surgery for bilateral Wilms tumor.

MATERIALS AND METHODS: We identified all patients with synchronous bilateral Wilms tumors presenting to St. Jude Children's Research Hospital between October 1987 and February 2004. We also included patients with Wilms tumor involving a solitary kidney presenting during the same period. A total of 17 patients were identified who underwent nephron sparing surgery, including 16 with bilateral tumors and 1 with tumor in a solitary kidney. Institutional review board approval was obtained to retrospectively review records and analyze outcomes based on long-term renal function, hypertension, proteinuria, need for dialysis and indications for renal transplantation.

RESULTS: Eight of the 17 patients initially underwent bilateral nephron sparing surgery and 9 initially underwent a combination of nephrectomy and contralateral nephron sparing surgery. Two patients were eventually rendered anephric following further resections secondary to local recurrence. Before the initiation of therapy all patients had normal baseline creatinine clearance, which was calculated using the Schwartz formula. At a median followup from diagnosis of 72 months (range 15 to 207) 1 patient had renal insufficiency and another 3 had renal failure requiring dialysis. One of the 3 patients on dialysis died of metastatic Wilms and 2 await renal transplantation. None of the remaining patients had evidence of proteinuria. Ten of the 17 patients (58.8%) had hypertension at diagnosis and 9 (52.9%) required antihypertensive medications at the most recent followup. The overall survival rate in this group of patients was 88.2% with no evidence of disease in survivors at the most recent followup.

CONCLUSIONS: When combined with adjuvant radiation and/or chemotherapy, nephron sparing surgery provides an opportunity to preserve renal function, while maintaining excellent long-term oncological outcomes for patients with bilateral Wilms tumor.