Evolving Practice and Outcomes in Grade 2 Glioma: Real-World Data from a Multi-Institutional Registry.

Simple Summary: This study explored the current practices in the real world for grade 2 glioma, an uncommon primary brain cancer. Leveraging the prospective BRAIN registry, this study demonstrates that whilst sequential radiotherapy and chemotherapy improve progression-free survival in high-risk grade 2 glioma, the majority of patients are observed following surgery. In high-risk patients who are observed, 61% remain progression-free at 12 months, with 10% being progression-free at 5 years. This clinically meaningful progression-free survival suggests that validated biomarkers beyond the usual definition of high-risk are required to better inform patient management. Factors contributing to decision-making are underway. Background: Grade-2 gliomas (G2-glioma) are uncommon. In 2016, RTOG9802 established the addition of chemotherapy after radiation (CRT) as a new standard of care for patients with high-risk G2-glioma, defined as subtotal resection or age ≥40 yrs. Here, we report current practices using real-world data. Methods: Patients diagnosed with G2-glioma from 1 January 2016 to 31 December 2022 were identified in BRAIN, a prospective clinical registry collecting data on patients with brain tumours. High- and low-risk were defined as per RTOG9802. Two time periods, January 2016–December 2019 (TP1) and January 2020–December 2022 (TP2), were defined. Survival was estimated using the Kaplan–Meier method. Results: 224 patients were identified. Overall, 38 (17%) were low-risk, with 35 (91%) observed without further treatment. A total of 186 (83%) were high-risk, with 96 (52%) observed, 63 (34%) receiving CRT, and 19 (10%) receiving radiation. Over time, CRT use increased (TP1 vs. TP2: 22% vs. 36%, p = 0.004), and the rate of biopsy (TP1 vs. TP2: 35% vs. 20%, p = 0.02) and radiotherapy alone (TP1 vs. TP2: 14% vs. 4%, p = 0.01) decreased. Median progression-free survival (PFS) was significantly longer in high-risk patients who received CRT (NR) over observation (39 months) (HR 0.49, p = 0.007). In high-risk patients who were observed, 59 (61%) were progression-free at 12 months and 10 (10%) at 5 years. OS data remains immature. Conclusion: Congruent with RTOG9802, real-world BRAIN data shows CRT is associated with improved PFS compared to observation in high-risk G2-glioma. Whilst CRT use has increased over time, observation after surgery remains the most common strategy, with some high-risk patients achieving clinically meaningful PFS. Validated biomarkers are urgently required to better inform patient management. [ABSTRACT FROM AUTHOR]