RADIOTHERAPY COMBINED OR NOT WITH CHEMOTHERAPY IN ADULT OR PEDIATRIC PATIENTS WITH BRAINSTEM GLIOMA: A POPULATION-BASED STUDY

Purpose: To assess the treatment outcomes and prognostic factors of brainstem glioma (BCG) treated with radiotherapy (RT) or chemoradiation (CHRT) in the last 20 years using a populational-based study. Methods: Patients diagnosed with BSG from 2000-20 were identified from The Fundação Oncocentro de São Paulo database. BSG patients treated with RT or CHRT were included. Data on age, gender, practice setting, period of treatment, and treatment modality were extracted. The overall survival (OS) was estimated. Uni and multivariate analysis were performed for age, treatment type, period of treatment, gender, and practice setting. Results: A total of 253 patients with BCG were included (197 pediatric and 56 adult). The median follow-up for the entire cohort was 12 months (0233 months). The use of CHRT significantly increased over the years. For the entire cohort, the 1 and 3-year OS was 46% (95%CI: 36-57%), and 23% (95%CI: 16.5-33.4%), with a median OS 11 months (95%CI: 10-13 months). Adults had better survival compared to pediatric patients (p=0.002). The median OS was 33 months (95% CI: 18-55) and 10 months (95% CI: 9-11) for adults and pediatric patients, respectively. No significant difference in OS between RT and CHRT was observed on either the entire, adult, or pediatric population (p>0.05). In the multivariate analysis, being an adult was the only prognostic factor associated with better OS (HR=0.35, 95% CI: 0.21-0.55, p<0.001). Conclusion: BSG had a poor survival with no significant improvement in the treatment outcomes over the last 20 years, despite the addition of chemotherapy. Adult patients were independently associated with better survival.