Management and outcome of pediatric metastatic Wilms' tumor at the National Cancer Institute, Egypt

Abstract

Background: Wilms' tumor (WT) is the most common renal malignant tumor of childhood. Metastatic WT has a worse prognosis than localized disease. This study aims to assess the clinical outcome and different prognostic factors that influence treatment outcome of pediatric metastatic WT cases treated at National Cancer Institute (NCI), Egypt, between January 2008 and December 2015. Medical records were retrospectively reviewed for clinical, radiological and histopathological data, treatment received, and survival outcome.

Results: In the specified study period, 24/103 (23.3%) patients with WT were metastatic at presentation. The mean age was 5.25 ± 2.87 years (range 2.0-12.7). Abdominal swelling/mass was the commonest presentation (70.8%). Only 3 patients (12.5%) had combined lung and liver metastases while 21 patients (87.5%) had pulmonary-only metastases. All patients had favorable histology tumors with no anaplasia. Nine patients (37.5%) underwent upfront nephrectomy. Majority of patients (91.7%) had local stage III disease. Surgical complications were reported in 4 patients; 3 of them had up-front nephrectomy. Only 7/21 patients achieved rapid complete response of pulmonary nodules after 6 weeks of chemotherapy (CTH), and they had a better survival outcome. Patients were followed up till December 2017. Thirteen patients (54.1%) experienced events during the study period including 5 relapses, 6 cases with disease progression, and 2 patients died out of sepsis. The 3-year event-free and overall survival rates were 48.2% and 54.2%, respectively.

Conclusion: Neo-adjuvant CTH followed by delayed nephrectomy seems more suitable approach in our institute. Pulmonary response to neo-adjuvant CTH appears to be a strong predictor for outcome.

Keywords: Metastatic; Nephroblastoma; Pediatric; Stage IV; Wilms’ tumor.