Natural history and biology of Stage A neuroblastoma: A Pediatric OncologyGroup study

Purpose: To prospectively analyze the outcome of patients with Stage A neur oblastoma (NB) treated with surgery alone, especially with regard to the pr ognostic significance of age, tumor site. MYCN copy number, tumor cell ploi dy, and histology. Patients and Methods: The clinical course of 329 patients with Stage A dise ase registered on the POC NE Biology Study #9047 between February, 1990 and October, 1997 were evaluated. Age, tumor site, MYCN copy number, tumor cel l ploidy, and histology were analyzed for their impact on event-free surviv al (EFS) and survival (S). Results: The 5-year estimated EFS and S rates for the 329 patients were 91% (+/-3%) and 96% (+/-2%), respectively. The EFS rate was similar for infant s younger than 12 months and children age 12 months or older, but age older than 12 months was predictive of lower S rates (P = 0.044). Patients with adrenal abdominal non-adrenal, thoracic, and cervical tumors had similar S rates. The majority of patients had tumors with favorable biologic features , and only 3% had MYCN amplification. For infants with diploid tumors, the EFS rate was 82% (+/-16%), but effective therapy yielded an S rate. of 100% . Rate of S was 80% (+/-26%) and 64% (+/-27%) for patients with unfavorable tumor histology and MYCN-amplified tumors, respectively. Conclusion: The outcome for patients with Stage A NE treated with surgery a lone is excellent. Although EFS and S rates were significantly worse for pa tients with MYCN-amplified tumours; a subset achieved long-term remission a fter surgery alone. For patients with Stage A and MYCN amplification, addit ional factors are needed to distinguish the patients who will achieve long- term remission with surgery alone from those who will develop recurrent dis ease.