Pugh, Stephanie

Abstract Meningiomas are the most common primary intracranial tumors and exhibit clinical heterogeneity. Radiotherapy (RT) remains the only adjuvant therapy, but response is variable and biomarkers are limited. RTOG-0539 is the first prospective phase 2 trial to stratify meningioma patients for adjuvant RT based on clinical risk. Here, we apply modern molecular tools to this cohort and uncover correlates of RT response. To do so, tumor tissue from 100 RTOG-0539 patients was profiled using DNA methylation arrays, RNA sequencing, and whole-exome sequencing. Recurrence scores, Molecular Groups, gene expression, and copy number alterations were compared across clinical groups and between RT responders and non-responders. Using this approach, modern grading criteria, including brain invasion, TERT mutation, CDKN2A/B deletion and 1p/1q status, would reclassify 10% of tumors and alter treatment group assignment in 7%. Notably, non-responders to RT had more frequent 1p and 14q loss, and greater copy number burden. In addition, transcriptomic and epigenetic profiling revealed immune-related signatures in RT responders and upregulation of cell cycle–related pathways in RT non-responders, several of which overlapped with targets of vorinostat, a histone deacetylase inhibitor validated in aggressive meningioma models. Of particular importance, the Proliferative Molecular Group was an independent predictor of post-RT recurrence in multivariable analysis, outperforming WHO grade. In conclusion, multi-omic analysis of the RTOG-0539 cohort shows that updated WHO grading criteria, incorporating molecular and cytogenetic features, improve risk stratification. However, molecular classification, particularly the Proliferative group, remains an independent and stronger predictor of RT response. These findings support integrating molecular biomarkers alongside modern grading frameworks to guide treatment and trial design in meningioma.

Abstract BACKGROUND The assessment of BM response to WBRT and its impact on NCF in clinical trials has been limited by lack of standardized imaging protocols. NRG-CC001 is a randomized clinical trial requiring pre-specified MRI protocols at baseline and 6-months, providing a uniform dataset to investigate if RR correlates with NCF changes. METHODS NRG-CC001 randomized patients with BM to hippocampal avoidance WBRT (HA-WBRT) or WBRT. NCF was analyzed using 6-month standardized change scores and deterioration, defined using the reliable change index. Chi-square and t-tests were used for pretreatment characteristic comparisons. Inter-rater reliability between central and institutional assessment of RR was assessed with weighted kappa, κ. Linear regression was used to test trends in NCF change scores across types of response and multivariable logistic regression was used to test the association of RR to NCF deterioration. RESULTS 149 and 135 patients were evaluable for RR and NCF assessment, respectively. Pretreatment characteristics were well-balanced, except for post-high school education (70.6% HA-WBRT vs. 52.5% WBRT, p=0.023). Inter-rater reliability between central and institutional assessment of RR was fair (κ=0.36). There was no difference between arms in RR (p=0.41) with overall rates of 14.1% CR, 42.2% PR, 17% SD, and 26.7% PD. Patients with CR had improved 6-month NCF change as measured by HVLT-R Total Recall (p=0.0005), HVLT-R Delayed Recall (p=0.0003), HVLT-R Delayed Recognition (p=0.011), TMT-B (p=0.033), COWA (p=0.016), and Clinical Trial Battery Composite score (p=0.0011). Multivariable analysis demonstrated less deterioration in HVLT-R Delayed Recall for CR (p=0.019) and PR (p=0.0086) vs. SD/PD and HVLT-R Recognition for PR (p=0.031) vs. SD/PD. CONCLUSIONS HA-WBRT and WBRT result in similar RR at 6-months. CR or PR is associated with better NCF preservation. This suggests investigation into treatment escalation for patients with SD/PD may provide further NCF benefit along with HA-WBRT and memantine.Grant support from NCI-UG1CA189867 and U24CA180803.