Influence of segmental chromosome abnormalities on survival in children over the age of 12 months with unresectable localised peripheral neuroblastic tumours without MYCN amplification.

BACKGROUND: The prognostic impact of segmental chromosome alterations (SCAs) in children older than 1 year, diagnosed with localised unresectable neuroblastoma (NB) without MYCN amplification enrolled in the European Unresectable Neuroblastoma (EUNB) protocol is still to be clarified, while, for other group of patients, the presence of SCAs is associated with poor prognosis. METHODS: To understand the role of SCAs we performed multilocus/pangenomic analysis of 98 tumour samples from patients enrolled in the EUNB protocol. RESULTS: Age at diagnosis was categorised into two groups using 18 months as the age cutoff. Significant difference in the presence of SCAs was seen in tumours of patients between 12 and 18 months and over 18 months of age at diagnosis, respectively (P=0.04). A significant correlation (P=0.03) was observed between number of SCAs per tumour and age. Event-free (EFS) and overall survival (OS) were calculated in both age groups, according to both the presence and number of SCAs. In older patients, a poorer survival was associated with the presence of SCAs (EFS=46% vs 75%, P=0.023; OS=66.8% vs 100%, P=0.003). Moreover, OS of older patients inversely correlated with number of SCAs (P=0.002). Finally, SCAs provided additional prognostic information beyond histoprognosis, as their presence was associated with poorer OS in patients over 18 months with unfavourable International Neuroblastoma Pathology Classification (INPC) histopathology (P=0.018). CONCLUSIONS: The presence of SCAs is a negative prognostic marker that impairs outcome of patients over the age of 18 months with localised unresectable NB without MYCN amplification, especially when more than one SCA is present. Moreover, in older patients with unfavourable INPC tumour histoprognosis, the presence of SCAs significantly affects OS.

Treatment of children over the age of one year with unresectable localised neuroblastoma without MYCN amplification: results of the SIOPEN study.

BACKGROUND: In children older than 1 year with localised unresectable neuroblastoma (NB), treatment strategies are heterogeneous according to the national groups. The objective of this phase III non-randomised study was to evaluate the efficacy of conventional chemotherapy followed by surgery. PATIENTS AND METHODS: In the presence of surgical risk factors (SRF), six courses of chemotherapy alternating Carboplatin-Etoposide and Vincristin-Cyclophosphamide-Doxorubicin were given, and surgical resection was attempted after four. Survival analyses were performed using an intention-to-treat approach. The main objective was to achieve a 5-year survival over 80%. RESULTS: Out of 191 registered children, 160 were evaluable. There were 62.5% older than 18 months and 52.5% had unfavourable histology according to International Neuroblastoma Pathology Classification (INPC). Chemotherapy reduced the number of SRFs by one third. Delayed surgery was attempted in 86.3% of patients and was complete or nearly complete in 74%. The 5-year EFS and OS were 76.4% and 87.6% respectively, with significant better results for patients younger than 18 months or with favourable histology. CONCLUSION: This strategy provides encouraging results in children older than 1 year or 12 months with localised unresectable NB without MYCN amplification. However, in children older than 18 months and with unfavourable histology, additional treatment is recommended.