Upfront Nephrectomy for the Treatment of Wilms Tumor: Outcomes and Predictors of Complications

Wilms tumor (WT) is the most common kidney tumor in children. Upfront nephrectomy and preoperative chemotherapy, the two different treatment strategies, have not shown considerable differences in the outcomes. Research focus has turned into decreasing the incidences of posttreatment morbidity. The aim of this study is to determine the existence of prognostic factors and the predictors of surgical complications with upfront surgery following COG protocol. Medical records of patients with WT treated with upfront surgery between 2003 and 2013 were retrospectively reviewed focusing on surgical aspects and complications. Forty-five patients were identified. The mean age at diagnosis was 3.8 years (2-154 months). Thirteen of them had stage I disease (28.9%), 12 stage II (26.7%), 15 stage III (33.3%), and 5 stage IV (11.1%). Mean follow-up was 4.5 years (2-132 months). The 4-year overall survival (OS) and event-free survival (EFS) was 100 and 91.1%, respectively. There were 4 cases of disease progression (3 lung disease and 1 locoregional relapse). We had two cases of intraoperative tumor rupture (4.4%), one partial colectomy, and a distal pancreatectomy. The most common complication was associated with blood transfusion (44.4%). The existence of anaplasia was a risk factor for progression ( p =0.01). Clinical stage and tumor size positively correlated with transfusion ( p =0.001); this relationship was not observed for other complications. Clinical stage and tumor size are predictors of surgical complications and anaplasia for progression. Standardized surgical complications scales such as Clavien-Dindo should be used to properly compare surgical outcomes between different treatment approaches.