Individualized Prediction of Overall Survival for Primary Intramedullary Spinal Cord Grade II/III Ependymoma

Abstract

The purpose of this study was to develop and validate a nomogram to predict overall survival (OS) for adult patients with primary intramedullary spinal cord grade II/III ependymoma (PISCGE). We also elucidated the effectiveness of postoperative radiotherapy for this disease. Clinical data of patients with PISCGE between 1988 and 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) registry database. The independent prognostic factors were identified using univariate and multivariate Cox analyses. The nomogram was established from the results of the multivariate Cox analysis. We also use some methods to verify the superiority of the prediction model. The effectiveness of postoperative radiotherapy for PISCGE was assessed through coarsened exact matching and survival analyses. Multivariate Cox analysis revealed that sex, age, surgical treatment, tumor grade, and marital status were independent prognostic factors of OS. The nomogram model was established based on these factors and validated internally. Calibration plots based on bootstrap resampling validation showed good consistency between the nomogram prediction and actual observation. This model also exhibited favorable discrimination characteristics. A risk classification system based on a nomogram was established to promote risk stratification of PISCGE and optimize clinical management. Moreover, we found no association between radiation treatment and the OS for these patients (P > 0.05). We built the first nomogram model and risk classification system for PISCGE patients. Our model accurately estimated the individual OS probability of these patients, and proposes different treatment approaches for patients based on the risk classification system. Furthermore, from our findings, radiotherapy confers no survival advantage to these patients.