Minimally invasive nephrectomy for Wilms tumors in children - data from SIOP 2001.

PURPOSE: To analyse the surgical and oncological outcome of minimally invasive surgery (MIS) for tumor nephrectomy in Wilms tumor (WT) patients. METHODS: WT patients from the SIOP 2001 trial, undergoing MIS for tumor nephrectomy were analyzed with regard to demographic characterization, surgical specifications, complications, and outcome. RESULTS: There were 24 children matching the inclusion criteria. Median age at operation was 40.35 months (14.3-65.4). All patients received preoperative chemotherapy. Median tumor volume was 177.5 ml at diagnosis (46.5-958) and 73.0 ml at surgery (3.8-776). There was one surgical complication (splenic injury), no intraoperative tumor rupture occurred. Abdominal stage was I in 14, II in 7, and III in 3 patients. Adequate lymph node sampling was performed in only 2 patients. One local relapse occurred. Event-free survival was 23/24, overall survival was 24/24, median follow up was 47 months (2-114). CONCLUSIONS: We present the largest series so far of minimally invasive nephrectomies for nephroblastoma based on a multinational trial. Treatment results were comparable to those of open surgery; however, experience of operating surgeons was generally high. Discipline of lymph node sampling was inadequate. Based on this analysis a prospective study on MIS in nephroblastoma is planned by the SIOP Renal Tumor Study Group