- Group 3 (stage 3 disease): Patients receive OPEC chemotherapy comprising vincristine IV and cyclophosphamide IV on day 1, cisplatin IV continuously over 24 hours on day 1, and etoposide IV over 4 hours on day 3 during courses 1, 3, and 5. Patients receive OJEC chemotherapy comprising vincristine IV, cyclophosphamide IV, etoposide IV over 4 hours, and carboplatin IV over 1 hour on day 1 during courses 2, 4, and 6. Courses repeat every 3 weeks with alternating OPEC and OJEC chemotherapy for 6 courses. Patients with residual disease then receive 4 additional courses of alternating OPEC and OJEC chemotherapy. Patients whose tumor becomes resectable after either 6 or 10 courses of chemotherapy undergo surgery. Patients with residual disease after 10 courses of chemotherapy are assessed by regular scans. Patients with disease progression on scans undergo radiotherapy. Patients with ganglioneuroma or total necrosis only with no evidence of neuroblastoma after either 6 or 10 courses of chemotherapy receive no further treatment.