- Group 4 (stage 4 disease): Patients receive alternating courses of OPEC and OJEC for 6 courses as in group 3. Patients who do not achieve metastatic complete response (CR) receive 4 additional courses of alternating OPEC and OJEC chemotherapy. Patients achieving metastatic CR after either 6 or 10 courses of chemotherapy undergo surgery to remove the tumor. Patients with macroscopic residual disease on resected specimen receive 4 additional courses of alternating OPEC and OJEC chemotherapy and then undergo biopsy. Patients with residual disease on biopsy are assessed by regular scans. Patients with disease progression on scans undergo radiotherapy. Patients with ganglioneuroma or total necrosis only after surgery with or without the 4 additional courses of chemotherapy receive no further treatment.