Poor Treatment Outcome of Neuroblastoma and OtherPeripheral Nerve Cell Tumors May be Related to Under Usage of Radiotherapy and Socio-Economic Disparity: A US SEER Data Analysis

Purpose: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiologyand End Results (SEER) neuroblastoma (NB) and other peripheral nerve cell tumors (PNCT) outcome data.This study found under usage of radiotherapy in these patients. Materials and methods: This study analyzedsocio-economic, staging and treatment factors available in the SEER database for NB and other PNCT. For therisk modeling, each factor was fitted by a generalized jinear model to predict the outcome (soft tissue specificdeath, yes/no). The area under the receiver operating characteristic curve (ROC) was computed. Similar stratawere combined to construct the most parsimonious models. A random sampling algorithm was used to estimatethe modeling errors. Risk of neuroendocrine (other endocrine including thymus as coded in SEER) death wascomputed for the predictors.
Results: There were 5261 patients diagnosed from 1973 to 2009 were included inthis study. The mean follow up time (S.D.) was 83.8 (97.6) months. The mean (SD) age was 18 (25) years. About30.45% of patients were un-staged. The SEER staging has high ROC (SD) area of 0.58 (0.01) among the factorstested. We simplified the 4-layered risk levels (local, regional, distant, un-staged/others) to a simpler 3-tieredmodel with comparable ROC area of 0.59 (0.01). Less than 50% of PNCT patients received radiotherapy (RT)including the ones with localized disease. This avoidance of RT use occurred in adults and children.
Conclusion:The high under-staging rate may have prevented patients from selecting definitive radiotherapy (RT) aftersurgery. Using RT for, especially, adult PNCT patients is a potential way to improve outcome.