Our understanding of diffuse intrinsic pontine glioma (DIPG) biology has rapidly evolved in recent years. Promising agents such as panobinostat, with demonstrated disease-specific preclinical efficacy, are currently in clinical trials. Determination of clinical benefit by measuring improved progression-free survival (PFS) and overall survival (OS) requires well-defined historical controls. However, many previous studies evaluating these endpoints included small numbers of patients, were single institution studies, and were not limited to DIPG but rather included all brainstem tumors. 1–4The most recent study investigating median post-progression survival (PPS) time (ie, time from initial tumor progression to death) in DIPG patients was published over 20 years ago. 5 We evaluated survival endpoints in patients registered in the International DIPG registry (IDIPGR). Diagnoses of DIPG (defined as tumors with a pontine epicenter and diffuse involvement of at least two thirds of the pons) in patients were made by central radiological review between January 1, 2004 and January 1, 2014. Radiographic progression was determined by central review. PFS was defined as time from date of diagnosis to date of radiographic progression or death from any cause. Time to progression (TTP) was time from date of diagnosis to date of radiographic progression; death was censored. OS was time from date of diagnosis until date of death or censorship. PPS was measured for each patient as OS minus PFS, and for each patient with recorded progression as OS minus TTP. Median and percent survival were estimated using the Kaplan–Meier method.

We identified 372 patients, 235 (63.2%) of whom had documented radiographic progression. Median age at diagnosis was 6.3 years (range 4.6–9.1 y), 55% were female. Caucasian represented the largest portion of racial category (42.7%), followed by other (11.3%), African (9.9%), and Asian (2.4%). Two hundred nineteen patients (58.9%) had symptom duration of less than 6 weeks at diagnosis. Median OS was 11.2 months, consistent with prior reports (Table 1). We found no statistically significant survival differences by age, gender, or racial category. The IDIPGR, launched in 2012, has enrolled 722 patients to date. By gathering data from larger numbers of patients and including international patient data, outcome studies have larger statistical power and may be more representative of patient outcomes. 6