Purpose: The three-drug combination of melphalan (M), etoposide (E), and carboplatin (C) followed by autologous stem-cell (ASC) rescue has been evaluated prospectively by the French Society of Pediatric Oncology (SFOP) in pediatric high-risk recurrent (HRR) Wilms' tumor (WT) patients with chemotherapy-responsive disease.
Patients and methods: From October 1988 to October 1994, 29 patients with HRR WT were treated in nine SFOP centers. Two additional patients with stage IV anaplastic WT were consolidated in first complete response (CR) with the same regimen and have been studied separately. The regimen consisted of M 180 mg/m2 for 1 day, E 200 mg/m2/d for 5 days, and C at a daily targeted area under the concentration-time curve (AUC) of 4 mg x min/mL for 5 days. ASCs were reinfused 48 hours after M.
Results: Twelve of 28 assessable patients with HRR WT are still in continuous CR at a median of 48.5 months (range, 36 to 96) after consolidation. Disease-free survival (DFS) and overall survival (OS) estimated by the Kaplan-Meier method at 3 years were 50%+/-17% and 60%+/-18%, respectively. Sixteen patients relapsed at a median of 8.5 months (range, 3 to 53) after consolidation. Toxicity data are available in 31 grafted patients. Grade III and IV toxicities included hematologic side effects (n=31), hemorrhage (n=8), mucositis (n=24), diarrhea (n=12), renal disorders (n=8), and pneumonitis (n=3).
Conclusion: The adverse prognostic factors (APF) used to select patients for this dose-intensive chemotherapy define children with very-poor-risk recurrent WT. Despite high treatment-related toxicity, about half of these patients remain disease-free at 3 years. Patient outcome is statistically better when high-dose chemotherapy (HDCT) is performed as early as the second CR or partial response (PR). Novel therapeutic approaches with innovative preparative regimens are warranted for the remaining high-risk patients.