Hydronephrosis in children with abdominal and pelvic neoplasms: Outcome and survival analysis of a single center pediatric oncology series

Purpose: We ascertained the incidence and outcome of hydronephrosis related to abdominal or pelvic neoplasms and survival in pediatric patients. Materials and Methods: We retrospectively reviewed our institutional oncology database between January 1995 and November 2009. We reviewed the charts of all children with intra-abdominal (nonrenal) and pelvic neoplasms. Results: Of the 366 patients whose charts were reviewed 66 (18%) had hydronephrosis at some point during treatment, including 12 with hydronephrosis that was not caused by the neoplasm and 1 who was lost to followup, leaving 53 with malignant obstruction. Of the remaining patients hydronephrosis resolved in 34 (64%) with treatment for the primary neoplasm alone while in 19 (36%) hydronephrosis persisted after primary oncological treatment. Univariate analysis revealed that patients with persistent hydronephrosis (p = 0.025), those with urological intervention (p = 0.05) and those with high stage disease (p <0.001) had statistically significantly worse overall survival. On Cox multivariate analysis only disease stage remained statistically significant (p = 0.004). Conclusions: Analysis of this group revealed that pediatric nonrenal abdominal and pelvic tumors are associated with hydronephrosis in about 20% of cases. Approximately 60% of these cases resolved with treatment for the primary tumor alone while 13% required specific urological intervention for urinary tract involvement or compression. Patients with pediatric malignant ureteral obstruction had a 20% 5-year mortality rate. The main predictive factor was primary disease stage.