Neuroblastoma in Infants: Long-Term Survival From INES Protocols A SIOPEN Study

Neuroblastoma is the most common extracranial solid tumor in infants, with a possibility of spontaneous regression even in disseminated disease. Despite an overall good prognosis, relapse can worsen the outcome for some patients. A long-term analysis is crucial to identify subgroups of patients with poorer prognosis, assessing the risks of late relapse, progression or long-term toxicity associated with multimodal treatment in very young children.

Estimation of the 10-year event-free and overall survivals in 750 infants under 12 months with neuroblastoma, enrolled in the prospective INES protocols between 1999 and 2004. Follow-up data from INES patients were updated, and survival analyses were performed in order to determine prognostic factors such as age, stage, genomic profile, or MYCN amplification.

Overall, 10-year overall survival was 91.1% ± 1.0%, and 10-year event-free survival was 82.4% ± 1.4%, with significantly better outcomes in infants under 6 months compared with those aged 6-12 months, even considering the MYCN-amplified tumors only. MYCN amplification was the strongest prognostic factor and was correlated with lower survival in patients with metastatic disease.

Survival in patients less than 12 months remains excellent and stable even at long term, as a 10-year follow-up did not change the number of events. However, survival in MYCN-amplified tumors remained poor. Patients with metastatic tumors require accurate risk stratification. For each treatment group, there was no significant difference in long-term outcomes compared with previous publications from INES. No lethal toxicity affecting long-term survival occurred.