DIPG-69. CHARACTERISTICS OF PATIENTS ≥ 10 YEARS OF AGE WITH DIFFUSE INTRINSIC PONTINE GLIOMA: A REPORT FROM THE INTERNATIONAL DIPG REGISTRY

Patients ≥10 years of age with a DIPG are reported to have a higher rate of long-term survival (≥24 months). The purpose of this study was to compare clinical, radiological, pathological and molecular characteristics between patients ≥10 years old with DIPG who were long-term survivors (LTS) vs short-term survivors (STS) and assess biological differences in this age group compared to patients <10 years old. Data were abstracted from the International DIPG Registry (IDIPGR) for patients ≥10 years old at diagnosis. Imaging was reviewed and those with typical radiographic findings of DIPG were included. The primary outcome was overall survival (OS) categorized as LTS (≥24 months) or STS (<24 months). Among 782 patients with abstracted data in the IDIPGR, 170 were ≥10 years of age (22%). The median age and OS [range] were 12.5 [10.0–26.8] years and 15 [2–82] months, respectively; 12.8% were LTS. Biopsy or autopsy were performed in 38% of patients; 83% of patients were H3 K27M-mutant. LTS were found to have longer symptom duration before presentation, lower WHO grade and larger tumor size compared to STS. WGS and RNA sequencing are being conducted. The rate of LTS in patients ≥10 years of age is approximately 13%. Preliminarily, clinical and imaging parameters associated with LTS in this population are similar to general DIPG cohorts. Biological data will be presented for the approximately 38% of patients with available tissue to delineate potential predictors of outcome.