Radiotherapy improves the outlook for patients older than 1 year with pediatric Oncology Group stage C neuroblastoma

Children older than 1 year of age who have neuroblastoma with complete or partial removal of the primary tumor and positive intracavitary lymph nodes (Pediatric Oncology Group [POG] stage C) are a small but higher-risk subset of patients. To further evaluate the importance of identifying patients with POG stage C neuroblastoma and to assess the efficacy and toxicity of adding concurrent radiation therapy (RT) to chemotherapy (CT) in these children, a randomized study was conducted. Eligible patients received cyclophosphamide 150 mg/m² orally days 1 to 7 and Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH) 35 mg/m² intravenously (IV) on day 8 (CYC/ADR) every 3 weeks for five courses with or without RT to primary tumor and regional lymph nodes (24 to 30 Gy/16 to 20 fractions). Second-look surgery was advised to evaluate response and to remove residual disease. Continuation therapy alternated CYC/ADR every 3 weeks with cisplatin 90 mg/m² day 1 followed by teniposide 100 mg/m² day 3 (CDP/VM) for two courses each. Secondary CT with CDP/VM alone was available for patients not achieving complete response (CR) following induc-tion treatment and second-look surgery. Of 29 eligible patients randomized to CT alone, 13 achieved CR, and nine are disease-free (NED) 1 to 52 months (median, 35 months) off therapy. Twenty-two of 33 eligible cases treated with CT/RT attained CR, and 19 are NED 1 to 77 months (median, 23 months) off therapy. Local and metastatic relapses occurred in both arms. Differences in CR, event-free survival, and survival rates were significant, P = .013, .009, and .008, respectively. Surgical compliance was excellent and complications uncommon. Therapy was tolerable in both groups but hematopoietic toxicity was more common in the CT/RT arm. We conclude that POG stage C neuroblastoma in children older than 1 year of age is a higher-risk group that should be identified, that CT/RT provides superior initial and long-term disease control compared with CT alone in this patient subset, and that the occurrence of metastatic failures in both treatment groups suggests a need for more aggressive chemotherapy.