Treatment of Pulmonary Metastases in Children With Stage IV Nephroblastoma With Risk-Based Use of Pulmonary Radiotherapy

Abstract

Purpose The purpose of this study was to determine the outcome of children with nephroblastoma and pulmonary metastases (PM) treated according to International Society of Pediatric Oncology (SIOP) 93-01 recommendations using pulmonary radiotherapy (RT) in selected patients. Patients and Methods Patients (6 months to 18 years) were treated with preoperative chemotherapy consisting of 6 weeks of vincristine, dactinomycin, and epirubicin or doxorubicin. If pulmonary complete remission (CR) was not obtained, metastasectomy was considered. Patients in CR received three-drug postoperative chemotherapy, whereas patients not in CR were switched to a high-risk (HR) regimen with an assessment at week 11. If CR was not obtained, pulmonary RT was mandatory. Results Two hundred thirty-four of 1,770 patients had PM. Patients with PM were older (P < .001) and had larger tumor volumes compared with nonmetastatic patients (P < .001). Eighty-four percent of patients were in CR postoperatively, with 17% requiring metastasectomy. Thirty-five patients (16%) had multiple inoperable PM and required the HR protocol. Only 14% of patients received pulmonary RT during first-line treatment. For patients with PM, 5-year event-free survival rate was 73% (95% CI, 68% to 79%), and 5-year overall survival (OS) rate was 82% (95% CI, 77% to 88%). Five-year OS was similar for patients with local stage I and II disease (92% and 90%, respectively) but lower for patients with local stage III disease (68%; P < .001). Patients in CR after chemotherapy only and patients in CR after chemotherapy and metastasectomy had a better outcome than patients with multiple unresectable PM (5-year OS, 88%, 92%, and 48%, respectively; P < .001). Conclusion Following the SIOP protocol, pulmonary RT can be omitted for a majority of patients with PM and results in a relatively good outcome.