EPIDEMIOLOGICAL CHARACTERISTICS AND SURVIVAL OF PATIENTS WITH DIFFUSE GLIOMA IN BRAZIL: PRELIMINARY RESULTS OF A MULTICENTRIC RETROSPECTIVE STUDY - LACOG 0619

Abstract INTRODUCTION In Brazil, most of the 9,196 deaths due to brain cancers in 2017 were gliomas. There is a dearth of epidemiological data on diffuse glioma in Brazil. METHODS LACOG 0619 is a multicentric retrospective cohort study, which included patients from nine tertiary oncology centers. Patients aged ≥18 years with histologically proven astrocytoma, oligodendroglioma, oligoastrocytoma or glioblastoma diagnosed from June 2010 to June 2019 were included. The study protocol was approved by each Institutional Review Board. RESULTS 642 patients were included in the analysis. Median age was 51.0 (19-91) years. Most patients were male (n=364, 56.8%), 175 (27.3%) had ECOG 0-1, and 480 (74.8%) had private healthcare insurance. Neurological symptoms were present in 568 (88.5%) patients at diagnosis, and 263 (41.0%) had a history of seizure before surgery. Regarding histology, 361 (56.2%) had glioblastoma, 162 (25.2%) had astrocytoma, 90 (14.0%) had oligodendroglioma, and 23 (3.6%) had glioma NOS. Gross total resection was performed in 168 (26.2%), subtotal resection in 292 (45.5%), biopsy in 108 (16.8%), conventional radiotherapy in 380 (59.2%), and hypofractionation in 44 (6.9%) patients. Concomitant chemoradiotherapy was administered to 370 (57.6%) patients, mostly with temozolamide (n=362, 97.8%). Furthermore, 434 (67.7%) patients received maintenance chemotherapy, 398 with temozolamide (< 6 cycles in 112 [28.4%], 6 cycles in 75 [18.8%], and >6 cycles in 214 [3.8%]). Median follow-up was 29 months (26-33). Median OS according to histology was: 35 months (95%CI 26-46) for glioblastoma, 91 months (95%CI 35-NR) for glioma NOS, and not reached for astrocytoma and oligodendroglioma. Median OS by number of temozolamide maintenance cycles was 18 months (95%CI 15-24) for < 6 cycles and not reached for 6 cycles or more. CONCLUSIONS This is the first multicentric cohort evaluating Brazilian patients with diffuse glioma, providing important data on epidemiology, treatment patterns, and survival in the country.