Radt-59. Analysis of National Treatment Trends After Resection in Low Grade Glioma

BACKGROUND Despite studies demonstrating the benefits of adjuvant chemoradiation in high-risk low-grade glioma patients, the recommendation of adjuvant therapy for high-risk patients remains heterogeneous. Currently, with the introduction of isocitrate dehydrogenase (IDH) inhibitors, it is even more critical to understand adjuvant therapy practice patterns. This study aims to understand the treatment patterns in United States for the past decade. METHODS Using the National Cancer Database (NCDB), patients with a diagnosis of WHO grade II glioma (pre-WHO 2021) were identified between 2010-2021. Patients were stratified into high-risk and low-risk groups (based on RTOG 9802 criteria) and Pignatti risk factors (PRF) and the utilization of adjuvant radiotherapy and chemotherapy were obtained. Adjuvant radiotherapy (RT) was defined as radiation starting within 90 days of diagnosis. Adjuvant chemotherapy was defined as chemotherapy starting within 90 days of diagnosis if no radiation is given, or 180 days of diagnosis if RT was given. RESULTS 9,902 patients were identified on this study of which 7416 (74.9%) were considered high-risk (>=40 years-old or subtotal resection). Patients in the high-risk group or had more PRFs were more likely to receive adjuvant radiation and chemotherapy. In the low-risk group, rates of adjuvant radiation increased from 10% in 2010 to 18% in 2021, and rates of adjuvant chemotherapy increased from 5% in 2010 to 15% in 2021. In the high-risk group, rates of adjuvant radiation steadily increased from 29% in 2010 to 48% in 2021, and rates of adjuvant chemotherapy increased from 20% in 2010 to 42% in 2021. CONCLUSIONS The percentage of patients with WHO grade II gliomas who received adjuvant radiation and/or adjuvant chemotherapy rose from 2010 to 2021. In 2021, the use of adjuvant radiation and chemotherapy remained under 50% even in high-risk patients.