LAUSR

2031Background: Grade II glioma patients with subtotal resection (STR) or age ≥ 40 are considered high risk. RTOG 9802 demonstrated that for these high-risk patients, chemotherapy and radiation therapy improved overall survival (OS) compared to radiation alone. The purpose of this study is to compare the OS of high risk, grade II glioma patients treated with adjuvant chemotherapy alone (CA) to chemotherapy and radiation therapy (CRT). Methods: Using the National Cancer Data Base (NCDB), high risk (age ≥ 40 or STR) grade II glioma patients with oligodendroglioma, astrocytoma, or mixed tumors were identified. Patients receiving CA were compared to patients receiving CRT. Univariate and multivariable analyses (MVA) were performed. Propensity score (PS) matching was utilized to account for difference in patient characteristics. Kaplan Meier statistics were utilized to compare OS. Results: 1054 high risk, grade II glioma patients were identified, 47.1% receiving CA and 52.9% receiving CRT. Median follow up tim...