Recursive Partitioning Analysis Identifies Prognostic Groups for Glioblastoma Patients Aged 70 Years or Older (P07.109)

Objective: To develop a prognostic model, based on several clinical and surgical characteristics, for patients ≥70 years of age with newly diagnosed glioblastoma Background Clinicians have struggled with management decisions for elderly glioblastoma patients. Prior studies examining the effects of prognostic factors in the glioblastoma population have excluded patients ≥70 years or have included relatively small numbers of patients in this age range. Recursive partitioning analysis (RPA) enables classification of patients into successively more homogeneous prognostic groups based on multiple input variables. Design/Methods: Four hundred and thirty-seven patients ≥70 years of age with newly diagnosed glioblastoma, pooled from two tertiary academic institutions, were identified for RPA. A resulting prognostic model, based on the final pruned RPA tree, was validated using two hundred and sixty-five glioblastoma patients ≥70 years of age from a dataset independently compiled by a French consortium. Results: RPA produced nine terminal nodes, which were pruned to four prognostic subgroups with markedly different median survivals: I – patients Conclusions: We report a RPA-derived prognostic model specifically tailored to glioblastoma patients ≥70 years of age. This model divides elderly glioblastoma patients into prognostic subgroups that can be easily implemented in both the patient care and the clinical trial settings. This purely clinical prognostic model serves as a template for the future incorporation of the increasing number of potential molecular prognostic markers. Disclosure: Dr. Nayak has nothing to disclose. Dr. Scott has nothing to disclose. Dr. Bauchet has nothing to disclose. Dr. Fraum has nothing to disclose. Dr. Cooper has nothing to disclose. Dr. Chao has nothing to disclose. Dr. Suh has nothing to disclose. Dr. Abrey has received personal compensation for activities with Roche as an employee. Dr. Abrey has has recieved personal compensation in an editorial capacity for Current Neurology and Neuroscience Section Dr. Peereboom has nothing to disclose. Dr. Zouaoui has nothing to disclose. Dr. Fabbro-Peray has nothing to disclose. Dr. Taillandier has nothing to disclose. Dr. Rigao has nothing to disclose. Dr. Vogelbaum has nothing to disclose. Dr. Mathieu-Daude has nothing to disclose. Dr. DeAngelis has received personal compensation for activities with Pharmacokinesis. Dr. Shih has nothing to disclose. Dr. Iwamoto has nothing to disclose.