Is Adrenalectomy Necessary during Unilateral Nephrectomy for Wilms Tumor? a Report from the Children’s Oncology Group

PURPOSE To determine whether performing adrenalectomy at the time of nephrectomy for unilateral Wilms tumor impacts clinical outcome. METHODS We reviewed information on all patients enrolled on National Wilms Tumor Study-4 and -5. Data were abstracted on patient demographics, tumor characteristics, surgical and pathologic status of the adrenal gland, and patient outcomes. The primary endpoints were intraoperative spill and five-year event-free survival (EFS) in patients who did or did not undergo adrenalectomy. RESULTS Of 3825 patients with complete evaluable data, the adrenal was left in situ in 2264 (57.9%) patients, and was removed completely in 1367 patients (36.7%) or partially in 194 patients (5.2%). Of the adrenal glands removed, 68 (4.4%) contained tumor. Adrenal involvement was more common in patients with stage 3 (9.8%) than stage 2 disease (1.9%; p < 0.0001). After controlling for stage and histopathology, five-year EFS was similar whether or not the adrenal gland was removed (p = 0.48), or involved with tumor (p = 0.81); however, intraoperative spill rates were higher in patients undergoing adrenalectomy (26.1% vs 15.5%, p < 0.0001), likely due to larger tumor size or technical factors. No patient had clinical evidence of adrenal insufficiency or tumor recurrence in the adrenal gland during follow-up (median 9.9 years). CONCLUSIONS Sparing the adrenal gland during nephrectomy for unilateral Wilms tumor was not associated with a higher incidence of intraoperative spill and was associated with a similar oncologic outcome, on a per-stage basis, with cases where the adrenal was removed. Thus, adrenalectomy should not be considered mandatory during radical nephrectomy for Wilms tumor.