The Role of Time as a Prognostic Factor in Pediatric Brain Tumors: a Multivariate Survival Analysis.

ABSTRACT

There is no evidence that prolonged pre diagnostic symptomatic intervals (PSI) increases the risk of death in pediatric brain tumors. When investigating the role of time previous research had not controlled for confounding variables or measured the pretreatment interval (PTI). We use the term global delay interval (GDI) to describe the sum of PSI and PTI. The aim of this research was to evaluate whether there was a decrease in the probability of survival in children with brain tumors due to a prolonged PSI, PTI and GDI, using a multivariate survival analysis. We retrospective review 127 clinical records labeled with the diagnosis of CNS tumors attended at a specialized pediatric center in Mexico City from January 2008 to December 2012. Patients with PSI and GDI diagnosed between 3 and 6 months showed statistical lower probability of surviving that those with intervals <3 months even when adjusting for age, sex, localization and tumor grade. When stratified for the place of residency and adjusted for sex, age, localization, grade of tumor, type of surgery and coadjuvant therapy, a GDI between 3 and 6 months showed to be a risk factor for the overall survival of brain tumors compared with an interval < 3 months. When analyzing the interaction, high grade tumors are at more risk of dying when GDI was between 3 and 6 months compared to <3 months. Prolonged PSI and GDI showed to be a potential prognostic factor for survival in CNS tumors, especially in high grade tumors. Future prospective research should measure the PSI, PTI and GDI and adjust for covariates in order to properly infer the effect of time in pediatric brain tumors.