Influence of image-defined risk factors on the outcome of patients with localised neuroblastoma. A report from the LNESG1 study of the European International Society of Paediatric Oncology Neuroblastoma Group

BACKGROUND: The European multicenter study LNESG1 was designed to evaluate the safety and efficacy of surgical treatment alone in patients with localised neuroblastoma. In a retrospective, observational study we examined the impact of image-defined risk factors (IDRF) on operative complications and survival (EFS and OS). PROCEDURE: 534 patients with localised, non-MYCN amplified neuroblastoma were recruited between 1995 and 1999. Group 1 consisted of 291 patients without IDRF (Stage L1 in the International Neuroblastoma Risk Group (INRG) staging system), all treated with primary surgery. Group 2: 118 patients with IDRF (INRG Stage L2), also treated with primary surgery. Group 3: 125 patients in whom primary surgery was not attempted, 106 receiving neo-adjuvant chemotherapy. RESULTS: In L1 patients (Group 1) 5-year EFS was 92% and OS 98%. In L2 patients (Group 2 and 3) EFS was 79% and OS 89%. The differences in both EFS and OS were significant. EFS and OS in Group 2 (86% and 95%) were significantly better than 73% and 83% in Group 3. In INSS stage 1, 2 and 3, EFS were respectively 94%, 81% and 76%. Except between stage 2 and 3 the differences were significant. OS were respectively 99%, 93% and 83%, all significantly different. The 17% operative complication rate in L2 patients was significantly higher than 5% in L1 patients. CONCLUSIONS: In localised neuroblastoma, IDRF at diagnosis are associated with worse survival rates and higher rates of operative complications. The impact of IDRF should become an integrated part of therapy planning.