Social determinants of health and survival on Brazilian patients with glioblastoma: a retrospective analysis of a large populational database.

Background: The majority of patients diagnosed with glioblastoma develop recurrent disease resulting in poor prognoses. The current study aimed to determine the survival rates of patients diagnosed with glioblastoma in Brazil accounting for the influence of age, treatment modalities, public and private practices, and educational level using a population-based national database. Methods: Patients diagnosed with glioblastoma from 1999-2020 were identified from The Fundação Oncocentro de São Paulo database to create a retrospective cohort. Patients were described according to age, education level treatment modalities and medical practice. In a Cox proportional hazards model, controlled for confounding factors for overall survival, the hazard ratio and 95% CI of overall survival in adults was evaluated. Findings: A total of 4,511 patients were included. The median lengths of survival for patients treated in the public and private settings were 8 and 17 months (p<0.001), respectively. Young patients had longer median overall survival (OS: 18 to 40 years, 41 to 60 years, 61 to 65 years, 66 to 70 years and over than 70 years was 22 months, 10 months, 6 months, 5 months, 4 months, respectively (p<0.001). In general, combined treatments were associated with higher median survival compared to monotherapy. The higher educational level, the higher median survival was observed (4 months for illiterate versus 14 months for university degree). In the multivariable analyses, the significant independent predictors for overall survival were practice setting, educational level, age and treatment modalities. Interpretation: Public practice, older patients, less intensive treatment, and lower educational level were associated with worse survival outcomes in Brazilian glioblastoma patients.