Early Decline of Neuron-Specific Enolase during Neuroblastoma Chemotherapy is a Predictive Factor of Clinical Outcome

High risk neuroblastoma (HR-NB) remains one of the most difficult-to-treat pediatric cancers. However, although current risk-stratification is based on multiple pretreatment criteria, HR-NB remains a significant heterogeneity. We examined 60 patients with HR-NB for a median follow-up time of 28 months. We examined the serum neuronspecific enolase (NSE) levels of each chemo cycle, using the survival receiver operating characteristic (survivalROC) method to assess the prognostic power of NSE levels at variant chemo points. We demonstrated that serum NSE was associated with systemic tumor burden. NSE after the third chemo cycle (C3) (C3NSE) was significantly higher in patients who eventually showed cancer relapse or progression. C3NSE had independent prognostic significance for event-free survival (EFS) but not for overall survival (OS) in multivariate cox analysis. SurvivalROC prompted that the C3NSE is a prognostic marker of HR-NB, which had good discrimination for 2- and 3-year EFS with AUC 0.734 and 0.729, respectively. However, its prognositc value for 2- and 3- year OS declined progressively. C3 is the optimal point to predict EFS. Patients whose C3 serum NSE remain at higher level need to undergo more intensive treatment as early as possible to resist recurrence.