Erker, Craig

Abstract Purpose: Knowledge of prognostic factors and long-term survival in patients with diffuse hemispheric glioma, H3 G34–mutant (DHG, H3 G34), remains limited in this tumor with a poor prognosis. Experimental Design: This retrospective, multi-institutional study investigated prognostic variables for patients with DHG, H3 G34, and their association with progression-free survival (PFS) and overall survival (OS). Uni- and multivariable Cox proportional hazard models were applied with multiple imputed datasets. Results: A total of 153 patients (142 G34R, 9 G34V, 2 via DNA methylation) were included. The median age at diagnosis was 17 years (range, 2–45). Initial gross/near total resection (GTR/NTR) was achieved in 43% of patients. Radiation was given in 91% (85% focal irradiation), and initial chemotherapy was given in 87% [70% temozolomide-based (TMZ), 25% TMZ/lomustine, 5% non-TMZ]. Median OS was 24 months [interquartile range (IQR), 22–28] with a median PFS of 14 months (IQR, 12–19). Twelve patients (8%) were found to be long-term survivors (≥5 years). Exploratory multivariable analysis showed that adjuvant radiotherapy [HR, 0.076; 95% confidence interval (CI), 0.033–0.17] and achieving GTR/NTR compared with < NTR (HR, 0.51; 95% CI, 0.33–0.78) were associated with improved PFS. Multivariable analysis showed improved OS with increasing age at diagnosis (HR, 0.70; 95% CI, 0.57–0.87), initial radiotherapy (HR, 0.38; 95% CI, 0.15–0.96), and initial GTR/NTR compared with < NTR (HR, 0.60; 95% CI, 0.37–0.97). Conclusions: This cohort highlights prognostic factors for patients with DHG, H3 G34, and describes relapse patterns and therapy approaches. Clinical trials and prospective registries are needed to improve outcomes.

Abstract Response Assessment in Pediatric Neuro-Oncology (RAPNO) is an international working group dedicated to developing standardized recommendations for response assessment in children with central nervous system tumors enrolled on clinical trials. This standardization facilitates easier and more reliable comparison of responses across trials. Since the first RAPNO publication in 2013, response guidelines have been issued for medulloblastoma (MB), low-grade glioma (LGG), high-grade glioma (HGG), diffuse intrinsic pontine glioma, ependymoma, and craniopharyngioma. Many of these guidelines have already been incorporated into clinical trials to evaluate their effectiveness and accuracy. RAPNO has always been predicated on the idea that these consensus recommendations will require updates over time as they are applied in practice given technological advancements, evolving treatment approaches, and growing knowledge of disease pathology. A half-day RAPNO symposium sponsored by the Society of Neuro-Oncology was held in San Diego, California, United States, on May 15, 2025. This event coincided with the 8th Biennial Pediatric Society of Neuro-Oncology meeting. The main objectives were to identify ongoing RAPNO challenges, discuss potential updates, and plan future initiatives across 3 specific groups: (1) LGG/Craniopharyngioma, (2) HGG/diffuse midline glioma (DMG)/Ependymoma, and (3) MB and other seeding tumors. This manuscript reviews the symposium proceedings and highlights key topics and challenges discussed, as well as outlining future RAPNO initiatives.